Task 1

STAR is always striving to build better and faster rockets in our journey to eventually launch a rocket to space. In order to do that, we need sponsors that would help us raise money :) These sponsors like cool visuals! Design a cool logo or image for our new rocket!

Media Portion:

• Get comfortable navigating through Illustrator/Photoshop

• Become familiar with the design process

Task 2

One of our missions is to get the STAR name out there. Ways to market our club to the public could include stickers, pins, and more.

1. Pick a marketing strategy -- stickers, pins, key chains, etc.

2. Design potential graphics, images, or other necessary files to accompany your product

The Operations intro project will reflect what a member of operations should expect to do. It consists of three sections: documentation, safety, and logistics; and should take under two hours to complete. If any of the project is confusing or ambiguous, please reach out to Rocklin (Ops Lead) on discord.

Documentation

Complete Overleaf’s 30 minute LaTeX tutorial: https://www.overleaf.com/learn/latex/Learn_LaTeX_in_30_minutes

Safety

Fill in a risk assessment matrix for something hazardous that we work with. Examples: fiberglass, power tools, black powder, cryogens. Include the following:

• Risks: hazardous material handling, transportation and storage procedures of propellants, and any other aspects of the design which pose potential hazards to operating personnel.

• Mitigation approach: – by process and/or design – shall be defined for each hazard identified.

Logistics

Plan out a club launch event at a nearby Tripoli/NAR prefecture. Note: This will take place on a single day. Provide times and locations for departing, arriving and returning, important contacts on the team and of those managing the site, and a basic packing list

Introduction

The purpose of this project is to become familiar with the existing outreach events and activities and marketing strategies and develop new ones. For new members, this will also be an opportunity to learn more about basic rocketry and the history of STAR.

Projects must be presented to the whole subteam.

Designing, budgeting, and developing a lesson plan and activity related to aerospace suitable for elementary, middle, or high school level students.

• The activity and lesson plan must span 10 minutes - 2 hours

  • The lesson plan can be in powerpoint form or a worksheet that outlines the scientific principles applicable to the activity and the steps to work through the activity.

• The materials must be easily procurable and safe for students and participants

• The logistics of the activity must be well planned and organized

• Find an event suitable for this activity (ideally an event we did not go to last year)

Intro projects are under continuous revision, but some subteams have opted to make significant changes while still keeping the old project up for reference. Here are those projects.

The PCB you will be working on is a system to detect apogee (peak of arc of rocket) and deploy parachutes. There are 4 parts to the mini-project, you will be able (and are highly encouraged) to ask for help from the mentors at any point!

1. Choose appropriate components for the PCB and create a BOM (Bill of Materials).

2. Create the schematic for the board.

3. Create the layout for the board.

4. Prepare the board to be manufactured. (Please do NOT actually place an order on any site for the boards.)

Board Requirements

• The board will be powered by a 12V/ 500mA power source.* What does this mean? Each component we use will have a minimum voltage needed to operate, and a maximum needed to operate safely. The voltage of our power source is often much higher than this! This means we find a way to deliver a reduced voltage (in our case, 3.3V) to power each component. This is usually done by using a voltage regulator.

• The board will be able to measure and report the altitude of the rocket. What does this mean? To detect altitude, there will need to be a sensor on our board. A sensor that detects altitude is called an altimeter. However, we will also need a way to actually communicate with that sensor, and output its readings. To do this, we will need to use a microcontroller.

• The board will be mechanically secured onto the avionics sled. It will be no larger than 2 by 2 inches. What does this mean? Avionics members will need to work with other subteams to make sure that the boards can be integrated onto a flight vehicle. This includes staying within size constraints, and thinking about how the board will be secured in-flight. For this, we can include mounting holes on our PCB layout.

*Please note that these aren't the specs for the power sources we would actually use. These have just been chosen to make the intro project simpler :)

Component Selection

There are some components that we commonly use on STAR for certain things. You will be expected to use these components when working on projects (unless there is a compelling reason otherwise). You can see more of such components on our Standard Parts List. This PCB will be built around the following components:

• Microcontroller: ESP32-S3-WROOM (datasheet)

• Altimeter: BMP388 (datasheet)

These components will often need additional resistors, capacitors, etc. known as peripherals in order to work. Datasheets often have an 'Application Example' which shows what is needed for the component. In addition to the microcontroller and altimeter, you will also need a voltage regulator for your board.

YOUR TASK... is to find an appropriate voltage regulator and peripherals to make this board. Fill out the BOM template with the components you've found.

(To save time, you don't need to fill out all the details for the peripheral components you're using. Just make sure you list them.)

To Submit: Add the link to your BOM to the 'Notes' column of the Intro Project spreadsheet.

<BOM Template doc here>

Schematic

In this part, you will learn to read datasheets for components and apply the reference schematic designs in the datasheet to complete a schematic in KiCad with a microcontroller, power module, and altimeter. Remember to refer to the KiCad tutorial page in Avionics Tutorials for more complete references for how to use KiCad. Make sure to attend the KiCad workshop!

YOUR TASK... is to make a schematic for the PCB using the components you have listed in your BOM.

Create a new KiCad project titled <Your Name>_IntroProject.Within this folder, create an additional folder titled 'Library'. If you download additional symbols/footprints, place them in this folder.

To Submit: Export your schematic in a .pdf format, and upload to google drive. Add the link to the google drive file to your Intro Project Spreadsheet.

While KiCad has many symbols and footprints included by default, it doesn't have all components. If you can't find a component you need on KiCad, you can look online for a symbol or footprint. Place these files in the 'Library' folder you created. You can get symbols and footprints from SnapEDA or UltraLibrarian (it's free!). Do not use EasyEDA. Always cross check a symbol/ footprint you are using with the information given on the datasheet. When in doubt, trust the datasheet! Ask your mentors for help with this if needed.

Setting up Libraries (if applicable)

Open up intro_proj.pro, the KiCad project. We will now make sure that the calstar schematic symbol library in lib is included.

Hit Preferences > Manage Symbol Libraries as below.

Once the Symbol Libraries window opens, go to the Project Libraries tab and hit the Add existing library to table button in the bottom left row above Path Subsitutions .

Now navigate to lib/ and select calstar.lib . However, we want to replace the calstar library path with ${KIPRJMOD}/../calstar.lib. Relative path is applicable on any machine, while your absolute path (i.e. C:/Users /Cedric/......./lib/calstar.lib) isn't. The window should end up looking like this:

Hit Ok and now go back to the KiCad project window.

Layout

In this part, you will learn to read datasheets for the reference layout designs, and then complete a two-layer board layout of the schematic from the previous step in KiCad. Make sure to attend the KiCad workshop to learn how to use the software.

But first! Follow the following instructions (shout out to the HOPE decal) to set up the design rules for your board. These will prevent you from making a design that isn't actually manufacturable.

Also make sure to review these design guidelines for the layout (once again, shout out to the HOPE decal).

As always, your mentors are always happy to help you and give you feedback!

YOUR TASK... is to arrange the components on your schematic into a suitable layout. You must first assign each component on your schematic a corresponding footprint. Your board should be 2 by 2 inches, and have one mounting hole on each of the four corners.

Much like for the schematic, you may need to download and import additional footprints for your layout.

To Submit: Export your layout as a .pdf and upload to google drive. Add the link to the google drive file to the intro project spreadsheet.

Export for Manufacturing

(in-progress)

Introduction

Welcome to the Recovery specialty's intro/returning project page! Glad you're here.

The recovery specialty is tasked with safely landing the launch vehicle. This responsibility requires working with constraints set in each project, attention to detail, and producing creative and efficient solutions. We work on numerous different components that are essential to the safe landing of the rocket including but not limited to: parachute size and geometry selection, parachute deployment altitude selection, ejection and separation mechanics, and avionics sled design. We require a general understanding of mechanics, electronics, simulations, physics, and more.

For any questions/help please feel free to reach out to Recovery specialty lead Cassidy at office hours or online through Discord or email. We also have mentors you will be assigned to as advisors (and friends) this year so feel free to contact them with any questions. Office Hour times are listed below. OH are highly encouraged if you need help!

• Cassidy Powers | Recovery Specialty Lead

  • OH: Mondays 5-7pm and Wednesdays 5:30-6:30pm or ping me on discord

  • Email: cassidypowers@berkeley.edu

  • Discord: cassidy_powers

New Member Project (18 hrs)

The new member project for the recovery sub-team is intended to:

1. Introduce a strong technical foundation for the critical components of the recovery subsystem to new members

2. Learn to work with constraints, similar to industry

3. Encourage collaboration/asking for help to accomplish these tasks

4. Connect new Recovery members with returning Recovery members.

The deliverables of the project should be presented at the final GM of the onboarding period. Remember! This project is meant to be challenging, but attainable, especially if you ask for help. So please ask questions, come to workshops, and come to office hours!

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Task 1 | Jacob's Trainings (Urgent!) (5 hours)

Due: October 13th

Deliverable: Screenshots of completed training from bCourses: Laser cutting training, electronics lab training, and general workshop training. Upload these into the google drive at this link, under a folder with your name.

The majority of our manufacturing will be done in the Jacob's Hall Maker Space. It is a great place to work on a variety of projects with numerous tools and super helpful staff. We would like you to complete laser cutter training, electronics lab training, water jet training, and metal shop training as these are the tools or sets of tools we use that require in person training. After this introduction to the Jacobs makerspace, you will no doubt use your pass for projects outside of STAR including personal projects and also some classwork. Steps to complete:

1. Apply for a Maker Pass by September 12th at this link. This will not guarantee you a pass. Jacob's will let you know if you get a pass or not by TBD.

2. After applying for a Maker Pass, you need to complete the "General Workshop Safety" (GWS) online module that will be linked when you complete the application.

3. Then you will need to complete tool-specific online trainings (in the same bCourses class as GWS -> under Jacobs Hall -> Equipment) for each piece of equipment you want to use, including

   1. Type A 3D Printers

   2. Laser cutters

   3. Electronics Lab

4. In order to have access to the Electronics Lab and Laser cutters you will need to attend an in person training as well as completing the bcourses training. Trainings should not take more than 2 hours. Coordinate with your teammates to sign up for in person trainings together! Contact Cassidy if you are unable to get a Maker Pass. There are other makerspaces on campus so we can figure something out.

Contact Cassidy if you are unable to get a Maker Pass. There are other makerspaces on campus so we can figure something out.

_______________________________________________________________________________________________________

Task 2 | Stage Separation Flow Chart (2 hrs)

Due: September 29th

Deliverable: Filled out flow chart breaking down each event of stage separation. Cover possibilities of both success and failure at each event and the resulting situation. Remember our main goal is safe recovery of the rocket. Feel free to display this however you would like. One example for how this may look is seen to the left. Upload these into the google drive at this link, under the same folder with your name from task 1.

You can assume all separation occurs due to "pyrogen ignition" regardless of mechanism or type or charge. Don't worry too much about how the separation is actually occurring as the mechanisms vary. I recommend checking out Apogee Rocketry's basic breakdown of events, but please keep in mind this does not cover stage separation.

The basic idea with stage separation is that it is more efficient for the rocket to fly up without the extra weight of a used up motor and the surrounding airframe so the lower part or stage of the rocket is released at a certain altitude once the lower motor has burned out. Apogee has a good explanation of this process as well: How 2-Stage Rockets Work (although they initiated the staging with "headend ignition," which is different from the one implemented by our team but it is still relevant). Openrocket simulations are a good way to visualize the steps of our two stage recovery system. Download Openrocket (directions are in the gitbook under "Tutorials">"Software Setup">"Openrocket Installation") and then download the file linked below containing the most recent stage separation Openrocket file: stage_sep_v2_7_2.ork.

Select "Flight simulations" and "plot" to get a sense of what is happening to each stage throughout the rocket's flight. The "Motors & Configuration" tab is useful for understanding when and where each parachute will deploy. Also in looking at the "Rocket Design" try to picture where in the rocket separation will occur.

In understanding the recovery steps of Stage Separation, you will grasp the recovery steps of our single stage competition (IREC) rocket as well.

_______________________________________________________________________________________________________

Task 3 | Parachute Selection (3 hrs)

Due: October 6th

Deliverable: Filled out the chart below (this is easily done in excel/google sheets) with the proper calculations and information from open rocket. Include a short justification of the formulas used and steps followed. (Use the Arktos OpenRocket file attached at the bottom of this section). Upload these into the google drive at this link, under the same folder with your name from task 1.

Select the best combination of parachutes that satisfies the constraints below:

• Drogue is deployed at apogee (maximum altitude)

• Main is deployed at 800 ft above ground level (AGL)

• Drogue Cd (Coefficient of Drag): 1.5

• Main Cd: 2.2

• Each component must not land with greater than 75 ft*lbs of kinetic energy

• Drift radius must be less than 2500 ft in 20 mph wind

Fill out the chart below with all of the calculations and relevant information obtained from the open rocket.

~ Hint: Fill out the chart and do your calculations in google sheets so you can apply the same drift and kinetic energy equations to each box. Make sure you calculate kinetic energy in ftlbs not J. This link has a quick explanation on how to calculate kinetic energy in ftlbs. ~ Bonus: Play around with OpenRocket and select your own combination of sizes that would be even better than the best option listed above. Or check out the StageSep ork and check out options there!

~ Bonus: Play around with OpenRocket and select your own combination of sizes that would be even better than the best option listed above. Or check out the StageSep ork and check out options there!

_______________________________________________________________________________________________________

Task 4| Lines Diagram (1 hrs)

Due: October 13th

Deliverable: Completed line diagram for dual-side dual-deployment (ie. one line diagram depicting main deployment and one depicting main deployment)

The image below is a line diagram for a single side dual deployment (meaning both the drogue and main are housed in the same part of the rocket). Use this image as a guide to understand the aspects that your line diagram should have. Such as: Shock cord Quick links Parachutes Parachute bags Rocket tubes U-bolt

5

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Task 5| Avionics Bay Assembly (6 hrs)

Due: October 13th

Deliverable: A brief write up presenting your design (include pictures of the full assembly) and explaining your design methodology and decisions. Upload your write up and CAD files into the google drive at this link, under the same folder with your name from task 1. Please note that you must upload all parts contained within your final assembly file in order for me to be able to open your assembly file.

Creating CAD models is a skill every engineer should be knowledgeable about, and recovery is no exception. It is important to model things before manufacturing to avoid wasted materials due to poor design. Recovery designs and manufactures the avionics bays for all the rockets so proper documentation is needed. The avionics bay houses the altimeters and other necessary hardware that enables proper parachute deployment which is often mounted to an accessible sled. A typical avionics bay (av-bay) consists of the following:

• Altimeters: tell the pyrogens for parachute deployment and stage separation when to deploy

• Avionics Sled: secure the batteries and altimeters

• Bulkheads- create sturdy and nearly airtight separations between different sections of the rocket allowing for pressure build up when the explosives ignite. This is critical for parachute deployment

• Alignment Rods: orient the Av-Bay components such that the Avionics Sled can slide in and out

• Access Hatch: the opening through which we can bring the altimeter sled in and out and we can connect wires to the altimeters on the altimeter sled

• Batteries: power the altimeters

You are tasked to create a full CAD model of a usable avionics bay to house 2 altimeters and 2 9V batteries. We have provided the appropriate airframe, batteries and altimeter part models that we frequently use below. Use these part files in your avionics bay assembly. You will have to create and design your own separate model parts for the altimeter sled, bulkheads, and alignment rods. Once you have completed all of the above part models, make an assembly of the entire avionics bay with all the components inside and properly constrained.

• Outer

  • Inner Diameter: 3.900" (9.91 cm)

  • Outer Diameter: 4.014" (10.2 cm)

• Coupler

  • Inner Diameter: 3.786" (9.80 cm)

  • Outer Diameter: 3.900" (9.91 cm)

_______________________________________________________________________________________________________

Task 6| Mentorship (2 hours)

Due: October 13th

Deliverable: Upload a selfie with you and your mentor into the google drive at this link, under the same folder with your name from task 1. Meet for at least an hour with two returning recovery members. Ask for any help you need on your intro projects and get to know each other. This is both to promote the share of knowledge, but also for new members to meet and integrate with returning members.

Once you decide to join Recovery, you will be assigned 2 returning members that you will meet with during the onboarding period. Meet at a coffee shop or somewhere else cool in Berkeley or on campus! If these meetings are not enough for you to get the help you need on your intro projects, you should definitely reach out to your mentors or other returning Recovery members for more help.

New Member Airframe Intro Project

The Airframe meetings at the start of the year - along with the GitBook - will contain all the information required to complete the project. In addition, I will hold office hours, so please stop by and ask any questions you may have. If these scheduled office hours do not work for you, please feel free to reach out to me and schedule a different meeting time.

This intro project is broken up into 4 main sections, spanning 4 weeks

1. Airframe Terminology

2. Airframe Project

3. Technical Project

4. Technical Project Manufacturing

Part 1: Airframe Terminology

There are a lot of different terms and buzzwords we use in STAR day to day as we design and manufacture our rockets. The first step to getting comfortable with the team is learning what all these words mean. For that, we have the Airframe Handbook.

After reading through the Airframe Handbook, take this quiz.

https://forms.gle/j1k29X9hWzCTM9fr7

You must retake this quiz until you have gotten 100%.

After completing the quiz, reach out to your mentor and they will check you off.

The Airframe Terminology quiz is due Monday 9/11 before the meeting!

Part 2: Airframe Project

OpenRocket is a critical tool STAR airframe members use to design the rocket from the ground up. Proficiency in this tool enables us to access a wide range of metrics about the rocket, fine-tune designs to optimize various parameters, and maintain a comprehensive understanding of the entire project and its objectives. After completing this project, you'll have the skills to navigate OpenRocket with confidence. This project also serves as an introduction to the anatomy of a rocket.

Installation:

Use this link to go to the download site for OpenRocket.

https://openrocket.info/

There have been some issues with downloading for Mac users. If you run into trouble, let your mentor know. There are some people on the team that know the workarounds for this.

Once you have it installed, go ahead and open some of the preset rockets. A sample rocket is also provided to look at. Mess around with it to observe how changing different variables changes the performance of the rocket.

If you're feeling a bit lost or scratching your head at what all the buttons do, that's totally okay! The next part is actually learning how to use OpenRocket.

Using OpenRocket:

Now that you have OpenRocket downloaded, it is time to learn how to use the software.

This playlist is a good resource to get situated with the process of using OpenRocket. Some of the videos are redundant, however, they each have their own highlights.

https://www.youtube.com/playlist?list=PLulIhjxR7aZQ4coWt7MRHb4xt9wz0Fz6h

An excellent way to learn from these videos is to follow along and do everything on your own computer

Watch these videos until you are comfortable to move on to the next part of the project.

Airframe Project:

Now that you have a basic understanding on how to use OpenRocket, it is time to put your skills to the test! Your task is to recreate this rocket from scratch.

This document contains details for each component. If you follow all of it, your resulting rocket should have similar characteristics

(Its okay if they are not exact, sometimes OpenRocket values can be slightly different from simulation to simulation)

If you get stuck at any point in this project, try looking up solutions to any issues. Besides STAR and rocketry, it is an important skill for life! That being said, do not hesitate to reach out to your mentor or go to office hours. We are all here for you!

Submission:

Once you are finished, show your mentor your rocket and the simulation. You will get checked off if they match. You can also get checked off at meetings or office hours by any mentor.

Part 3: Technical Project

Now that with a fundamental understanding of the rocket, it is time to move on to meaningful tasks that help us build our rocket. For the 3rd part of the intro project, you will stard getting hands on with designing and manufacturing.

Download Solidworks:

The Projects:

You should have been assigned a specific project. Look at this document to for more information for your specific project:

https://docs.google.com/document/d/1tFv5k92e25U_jdvIXnPqtUpclqbPpx5Qt29PmQItk-0/edit?usp=sharing

Part 4: Technical Project Manufacturing

Coming soon

What is avionics anyway?

Avionics involves working with all the electronics and software we need to launch rockets. Sensors? Power? Communication? GPS Tracking? Remote engine control? That's all avionics!

We welcome members of all majors and all levels of prior technical experience. The goal of this intro project is to go over some fundamental concepts and techniques from the ground up. All we ask is that you're interested in learning about, and eventually contributing to, the work we do at STAR

Introduction

This intro project is separated into modules, each of which is expected to take about a week long to complete. You can complete most of the intro project at your own pace—however, you will need to attend workshops/ events synchronously. (Exceptions on a case-by-case basis, make sure you inform the avionics lead to make other arrangements.)

Navigation

We will use a spreadsheet to give you the instructions for the intro project. A copy of this sheet will be assigned to each prospective member.

Each prospective member should receive a copy of the Intro Project spreadsheet, and be able to edit it. If you did not receive a copy, message the Avionics lead ASAP!!

• Task: The intro project is made up of individual tasks you need to complete. You need to complete all tasks (except the ones marked [OPTIONAL]) to complete the intro project.

• Status: There are 3 options for status: Complete, In-progress, and N/A (not applicable). Use 'N/A' if you decide not to complete an optional task. Use 'In-progress' after you have begun working on a task. Use 'Complete' only once the task is fully completed.

• Check Off By: For tasks marked 'Prospective', you must update the status of that task by yourself. This lets us keep track of how you're doing on the intro project! Some tasks are marked 'Mentor' or 'Lead', you are not allowed to update the status of that task until a mentor or lead approves it.

• Notes: These may include some additional information or resources that might help with the task. Some notes cells will have a border around them, this indicates that there's some information you need to fill in there. (Instructions should be included in the corresponding task.)

Section 1: Orientation and Setup

Section Two: Soldering

Section Three: Coding Basics (C++/ Arduino)

Section Four: Electronics Basics

Section Six: Choosing a Project

Section Seven: PCB Design

Introduction

The intro project is designed with three main parts:

1. A series of workshops given at the beginning of the year to teach basic rocketry and payload knowledge as well as necessary skills (given the first few weeks of the school year)

2. A general rocketry/payload take-home quiz, taken alone (due roughly 1 week after assigned)

3. A glider design project, done with mentor guidance (due roughly 3 weeks after assigned)

The intro project may seem daunting, but don’t worry!

In addition to the existing resources on GitBook, all the returning payload members will be available to help.

We will assign a specific returning member as your mentor, but please reach out to any returning member for any questions. Also, feel free to DM Payload Lead, Tristan Steen, on Discord (chaddusmaximus).

We will also hold a series of intro project work sessions throughout the next weeks, giving an opportunity for hands-on help. Details will be announced on the #payload channel.

Above all, we hope that the intro project will be a fun, educational and rewarding experience.

Checkpoints Schedule:

• By 2023-9-14 - Quiz Complete

• By 2023-10-5 - Design Project Complete

Part 1: General STAR & Rocketry Quiz Questions

1. Name all of the Specialty Subteams on STAR.

2. List all of STAR's previous rockets.

   1. What are their diameters?

   2. What Material(s) are they made out of?

3. Explain the difference between the chord line and the camber line.

4. Indicate which axes of rotation is controlled by each part of the aircraft:

   1. Horizontal Stabilizer

   2. Vertical Stabilizer

   3. Ailerons

5. What is the maximum length of a payload cube that could theoretically fit in a 20cm diameter rocket?

6. A G-class motor is roughly how many times more powerful than a D-class motor?

7. With roughly what speed will a 10kg rocket hit the ground if in free fall from 1280m? (You may use g=10 m/s/s)

   1. Is this a realistic speed to assume? Why or why not?

8. Give two pros and two cons of a dual-deployment (two parachute) recovery system.

9. How do altimeters measure altitude?

10. Is it possible to directly measure the velocity of a rocket during flight? Why or why not?

    1. Describe two ways you might calculate the velocity of a rocket with the following sensors: GPS tracker, altimeter, accelerometer, gyroscope. What are the potential advantages and drawbacks of each method given?

11. Explain what each number means in the following UTS designation: #6-32x1

12. Explain what each number means in the following Metric screw designation: M6-1.0x20

Quiz Submission

Please fill out your quiz on the Google Form here: https://forms.gle/dgfJjoa6jdXKbwXN8 (Due 9/14)

Part 2: Design

Design Objective Outline

Our goal is to build a mini glider that fits inside a 4” inner diameter, 12" long payload tube. Your task is to design and prototype a glider that can be ejected from the rocket for an unpowered flight to deliver a payload to the ground. Your glider does not have to fold like DAVE, but design the dimensions of your wing spars and stabilizers to fit in the payload tube as if it did. You will be responsible for designing your glider’s fuselage, wings, wing spars, and stabilizers. After that, you will build your design.

Requirements

Engineering is defined by requirements!

Tolerances are important, so consult the Tolerancing Page on the GitBook when designing to account for manufacturing differences.

Listed below are all the parts you will need to integrate into your design. It is easiest to make the vertical stabilizer a part of the fuselage

Components to Integrate:

• Fuselage (Balsa Wood 1/8 inch thick)

• Wing Spars (Balsa Wood)

• Wings (Choice of Tissue Paper or Mylar)

• Horizontal Stabilizer (Balsa Wood)

  • If you want to try a tissue paper or Mylar horizontal stabilizer, design balsa wood stabilizer spars

• Vertical Stabilizer (Balsa Wood)

Materials Available:

• Balsa Wood

• Tissue Paper

• Mylar

• Tape

• Sewing Pins

• Super Glue

• Elmer's Glue

Detailed Design Requirements:

1. All components when hypothetically folded must fit within the space of a cylinder, 4" in inner diameter and 12" in length.

2. All components must be mounted securely to your fuselage. Glue, tape, and sewing thread will be used to attach components to the fuselage, but it is required that indents or cutouts be designed into the fuselage to allow components to be securely placed.

3. The wings and stabilizers may be arranged in any reasonable format (keep in mind the principles of aerodynamics when designing your glider and keep in mind the CG and the CoP).

4. Your glider itself will not carry an official payload, but a place to hold a payload must be included in your design. This space must be able to fit two quarters side-by-side (a 1.91x0.955" rectangle). In your final build, quarters can be added or removed non-permanently depending on the stability of your finished glider to aid in its flight.

Your glider may be as elaborate or simple as you'd like, but it should adhere to the above requirements, and should be able to be manufactured given the resources and parts that Jacobs and STAR are providing.

Designing in SolidWorks

We will use CAD (Computer-Aided Design) software in order to model our glider. STAR has standardized using SolidWorks as our preferred CAD software. If you have used CAD software other than SolidWorks, such as Fusion 360, Inventor, or Creo, then SolidWorks should not be too difficult to pick up.

If you have never used CAD software before, don’t worry! We will hold a CAD workshop during GM (date TBD). If you are not able to attend, there are also great online resources:

Step 1: Installing SolidWorks

You all already did this, so don't download it again, but all of the information for downloading SolidWorks 2023 is in the #info channel on the Discord.

The first challenge of this stage is installing SolidWorks. The GitBook has a very helpful “SolidWorks Installation” page to help you with this.

Step 2: Working with the tube

The most challenging (and annoying) constraint placed on many payload projects is the size of the payload tube (the part of the rocket that the payload is stored in). Learning to work with the size limits of a cylinder is essential.

In this project, your tube space is limited to 4" inner diameter and 12" length, a common size for a smaller-scale rocket. It is often convenient to work with space envelopes limited by a rectangle, so the foremost important fact to understand is that a 4" diameter circle will not fit a 4x4" square. Your usable space is limited to what you can fit (or inscribe) within a circle.

Step 3: Start designing!

That's all the essentials to get you started on your design. Remember, you can come up with anything as long as it meets the detailed design requirements. Be sure to have your wing and stabilizer materials decided on before starting your design as they can influence your glider's weight and stability. Remember, if you need help be sure to reach out to your mentor or other payload members.

Step 4: CAD Submission

When finished with your design, please upload your SolidWorks/other CAD files here: https://forms.gle/h4Y89PrVZWnDM4Dr9 (Due 10/5)

Manufacturing

Now you start actually building your glider!

Your fuselage, wing spars, and stabilizers will need to be laser cut out of balsa wood. To do this, your CAD files will need to be put into Adobe Illustrator in order to upload the files to the laser cutter. This will be done during the specialty meeting following the 10/5 GM. Your finished Illustrator files will be sent to a payload member with a Makerpass and they will get the parts laser cut for you.

The GM of 10/12 will be your manufacturing day! Tissue paper and mylar will be provided for your wings (and possibly stabilizers) and glues, tape, and sewing pins will be provided to attach your components. Quarters will also be provided to add ballast weigh if necessary. After assembling your gliders we will go to the ramp behind Etcheverry and test them!

Congratulations on completing your intro project!

Introduction

The purpose of this project is to ensure that new and returning members research various parts of a rocket propulsion system from both theoretical and practical engineering points of view.

Your project should be completed with your intro project group.

Returning Members

All returning members are expected to act as mentors for Fall 2023.

Contact

If you have any questions about any part of the question at any time, do not hesitate to reach out to the propulsion lead (Eduardo) or the propulsion deputy (Brian). Discord is preferred, but if you are having difficulty getting started with Discord, email is fine.

• Eduardo

  • Discord: eduardawg

  • email: eduardogodinez@berkeley.edu

• Brian

  • Discord: slavgeeko776

  • email: brian_mechgeeko@berkeley.edu

• For access to the STAR general discord, please message us!

  • If you have access, find us in the #propulsion #alula channels!

Week 1: Introduction to Propulsion

Our first meeting with be at the STAR general meeting on Thursday, where we will give new members a run down of what you can expect with prop as well as a run-through of our current projects! Recruits can also come to our propulsion meetings on Monday night.

If you are not able to make it in person, please feel free to reach out to us so we can answer any question you may have, as well as set you up with an educational group mentor!

The way the propulsion intro project will be broken down is listed below:

1. Week 1: Propulsion Intro (9/11 - 9/15)

   1. Spark Session 1 - Intro to propulsion, solids vs liquids, feed systems

   2. Assigned intro mentor

2. Week 2: Propulsion System Components + Prop System Overview (9/18 - 9/22)

   1. Spark Session 2 - Propulsion system components (valves, injectors, cooling methods, etc.)

   2. More in depth readings for each component

   3. Spark Session 3 - Overview of our propulsion system

   4. Select technical project by the end of Thursday meeting

   5. Sunday trip to the Richmond Field Station (RFS)

3. Week 3: Technical Projects Begin (9/25 - 9/29)

   1. Focus on work for intro project, meeting with technical mentor for support

   2. Additional spark sessions based on your interest/feedback.

   3. Attend propulsion meeting and RFS workday. *Mandatory at least one RFS trip in w2-w5*

4. Week 4: Technical Projects + Hotfire (10/2 - 10/6)

   1. Work with mentor and team to finish intro project (Most mentors will be extra busy working towards hotfire but will still attempt to hold meetings)

   2. Attend propulsion meeting and RFS trip

   3. Come to propulsion spark sessions as well as other specialty workshops

5. Intro Project Presentations: End of Week 5

   1. Deliverables Listed in Intro Project

   2. Hotfire review

   3. Write some slides to present final product or design for CDR style meeting

You can view our week 1 slides here. This week will focus on establishing a point of contact between you and your group, as well as establishing a meeting time. You are welcome to get started on the readings for week 2 and 3.

Initial Readings:

• General Rocket Propulsion Understanding:

  • How Rocket Engines Work

  • Section 1.2 on page 4: Rocket Propulsion Elements

  • pg 12, section 1.5.1.2: Fundamentals of Rocket Propulsion

• Videos:

  • Video: Liquid Propellant Rocket Engine

• BONUS:

  • Liquid Propellant Feed Systems

  • Scott Manley: Rocket Fuels at Home

Week 2: Propulsion System Components

Now that you have met the team and been assigned a mentor, it's time to get learning! You will be expected to go through the assigned material(below) on your own time throughout the course of this week. If you have any questions, please feel free to attend Office Hours with returning members, or to reach out on discord.

There will be an in person workshop on the ALULA feed system during Prop Meeting on Thursday, Sept 21st! We encourage you to attend, but if that is not possible, it will be recorded.

Educational Material:

• Solid Rocket

  • Video of NASA’s solid rocket booster

  • Fundamentals of Rocket Propulsion

    • Read pg 9, section 1.5.1.1

    • Pay special attention to the fig 1.5a. What are the six parts of a solid rocket listed? Excluding “payload,” can you say what each part does?

  • BONUS: Solid Rocket Grain Design

• Liquid Rocket

  • Rocket & Space Technology - Solid Propellants

    • Read Liquid Propellants

  • Fundamentals of Rocket Propulsion

    • Read pg 12, section 1.5.1.2

• Feed Systems

  • Video: Propellant Feed Systems

  • Fundamentals of Rocket Propulsion

    • Read pg 357, 10.8.1 Liquid-Propellant Feed System

    • Reach pg 360, 10.8.1.1 Gas Pressure Feed System

  • How Does a Pressure Regulator Work

  • Rocket Propulsion Elements

    • Read section 6.3-6.4 (up to table 6-5) on page 203

  • Cryogenic Propulsion Systems

• Bonus Material:

  • Rocket Propellants Detailed Survey

Week 2: Propulsion System Components

The information covered in this week's material is a very general overview on some advanced topics in propulsion. If you don't understand something or want to learn more, our main resources folder is located here in Propulsion(feel free to add resources you find online!)

Workshops:

• ALULA Feed Systems Workshop

Educational Material

• Injectors

  • Bi-Liquid Injectors

  • Rocket Propulsion Elements

    • Read section 8.1 on page 276, up to injector flow characteristics

  • Pintle Injectors

  • Impinging Injectors Video

• Valves

  • design fundamentals

  • Valve Design Textbook

  • Example of a Liquid Oxygen Valve

  • Poppet Valves

• Thrust Chambers

  • Cooling in Liquid Rockets

    • Ablative Cooling

    • Film Cooling

    • Regenerative Cooling

      • Very Technical but good to skim the introduction at least. Good heat transfer explanations

  • Rocket Propulsion Elements

    • Read intro to chapter 8 on page 271

    • Read section 8.2 on page 285 up to “Film Cooling” on page 2

  • STAR Gitbook RPA instructions

• Bonus Material:

  • Everyday Astronaut: Rocket Engine Cooling

  • Famous/Exciting Rocket Stuff!!

    • RIP Robert Goddard

    • RD-180: Absolute Legend

    • Copenhagen Suborbitals Project

  • Propulsion Systems Lectures (Heavy duty shit)

  • Workshop Recordings, Feed System Presentations

  • STAR Gitbook Resources

Instrumentation and Control, Technical Project

Education:

• Instrumentation:

  • Pressure Transducers

  • Force Detectors

  • Temperature Detectors

  • Level Sensors

• Control:

  • Basics of State Machines and Procedural Flow

Workshops:

• Rocket Propulsion Analysis (RPA) Setup and Basic Execution

• LE2 Control System: Procedural Flow, State Machine

• Systems Workshop

Presentation end of week 4 / beginning of week 5

PROPULSION TECHNICAL INTRO PROJECT

You will select / be assigned a technical mentor(but can attend anyone's OH for help). Depending on what you would like to learn, you can choose who to work with, or jump across people's Office Hours to find the knowledge you might need to complete specific aspects of your project.

Weekly office hours and meetings will be provided by your new mentor!. Also, never be afraid to reach out for help - ask anyone you feel comfortable with. It is better to ask for clarification on something that might seem obvious than to spend hours confused.

After week 4, new members will host a design review for their education and technical project and then move forward integrated ALULA/LE3 member work.

We will also be hosting several workshops during weeks 3-5! To complete your intro project and develop knowledge in propulsion specialties, please attend at least one workshop(really as many as you can) over these weeks.

Technical Project Options / Further Research Launching Points:

New members will completely own a small project on Propulsion, working to integrate your research/design/testing into the full-scale ALULA and LE3/Flight propulsion projects.

(referenced are specific technical mentors that will provide direct project guidance)

We will cover each project idea in detail after the second week of introductory material.

Don't feel overwhelmed - You'll learn how to break down your goal into small, manageable portions that will integrate smoothly into a full project.

INTRO PROJECTS (More details coming soon!)

• Modular Test Stand for Feed System - Sophya

  • Goal: Design and construct new test stand for feed system testing

• Cryogenic Insulation - Ricardo, Eduardo

  • Goal: Improve current method for insulating flight components exposed to cryogenic environments. Gain familiarity with extreme-condition mechanical systems.

• Ball Valve - Rotary Actuator Coupling Assembly - Andrew

  • Goal: Design system which effectively connects and constrains our main lox valve and actuator. Should allow easy access to surrounding fittings while minimizing weight

• LOX and Ethanol Fill and Vent valve key - Andrew

  • Goal: Design and machine a slotted tool/key that couples the manual valve shaft and can effectively actuates manual valves through airframe utility ports. Should minimize port size required and easy to use.

• Pyro Valve Simulation - Sara

  • Goal: Create simulation for fluid flow through ethanol main valve as well as perform FEA for pyro valve under pressure

• Feed System Tank Mounting - Brian, Austin

  • Goal: Improve system for mounting tanks onto feed system stand. Ideally easy to disassemble for prop system movement between flight and ground system while remaining sturdy.

• Ablative Thermal Conductivity Approximation - Eduardo, Liam

  • Goal: Approximate a thermal conductivity for our ablative sleeve based on data from hotfire on October 7th. Will be used to improve simulations

• Needle Valve Calibration - Liam

  • Goal: Calibrate needle valve for eventual integration with motor. Work towards flow control.

Additional Links:

• Combustion Chamber Resources

Valves

• Ball Valves

• Bang-Bang Valve

• Needle Valve

• Solenoid Valves

• https://en.wikipedia.org/wiki/Pyrotechnic_valves

• Pneumatic Actuator: Pressure-operated actuation, most commonly linear piston.

Tanks

• Airframe Tank Design Considerations

• https://www.hi-tempfab.com/news/evaluating-structural-insulation-materials

• https://drive.google.com/drive/folders/1_mXhe1RK5ao4N8UiF0Dvd5v7Afx3xgfC?usp=sharing

• Cryogenic Insulation Basics

• https://dura-foam.com/resources/foam-roofing/nasa-shuttle-fuel-tank/

QDs (Quick Disconnects)

• Quick Disconnect Coupling Mechanism

Ignition

• How the F1 Engine Starts

• https://www.liquisearch.com/liquid-propellant_rocket/ignition

Sims

• Simulink Modeling - Feed Systems

• Intro to Optimization

Introduction:

Welcome to the safety team! Since the safety team doesn’t construct any part of the rocket as part of its duties, the intro project is mostly about understanding some core safety concepts and resources. The project is formatted as a quiz: you should read each question, do any relevant research into safety documents, legal regulations and wording, and hazard analyses, and write down an answer to the question. Being exactly correct is not important; the point of answering the questions is to determine how to answer these questions by researching safety information, and to be able to provide analysis of safety-related operations that our club personnel, and hopefully you as well, will be performing throughout the year.

Resources:

• @Grant Posner will hold STAR office hours to answer any questions you have about the project itself, or about safety-related information.

• Some examples of Material Safety Data Sheets (MSDS):

Project:

Write down answers to the following tasks and questions, and send them to the safety subteam lead for review. Remember, it’s not pass/fail -- the purpose is to think about safety hazards in a useful way.

1. Examine at least the two example MSDS provided, and answer the following for each:

   1. How should the material be stored?

   2. What hazards are associated with its storage?

   3. How can we mitigate the material’s storage hazards?

   4. What hazards are associated with use?

   5. How can we mitigate the material’s use hazards?

2. Look at the NAR High Power Rocket Safety Code:

   1. What is the minimum amount of time before approaching a rocket after a misfire?

   2. Why would we want to wait before approaching the rocket after a misfire?

   3. Suppose we’re constructing a rocket with an L motor. How far should personnel be from the pad during launch?

3. Look at the California Code of Regulations. Which division of the code most applies to the safety team?

   1. Find the laws regarding fireworks in CA. Do high powered rockets count as fireworks? Why/why not?

   2. Find the laws regarding experimental high powered rockets in CA. Does this apply to us? What limits are there regarding motor impulse?

4. What is the purpose of, and when should we use, each component of PPE/safety equipment that we have?

   1. Safety glasses

   2. Closed-toe shoes

   3. Latex gloves

   4. Welding gloves

   5. Face shields

   6. Flammables cabinet

   7. Wall mounts with chains/straps (hint: GN2 cylinders)

5. What hazards are associated with constructing a rocket? Think about what each subteam works on, and what specific risks each subteam’s personnel may face (and feel free to talk to me or to any of the other subteam leads about what all the subteams work on!):

   1. Airframe

   2. Electrical

   3. Payload

   4. Propulsion

   5. Recovery

6. What hazards are associated with launching a rocket? You can use the NAR HPR SC for insight.

7. What does a Risk Assessment Code describe?

8. [For returning members] Describe a safe aspect of the design of last year’s SL rocket, and an unsafe aspect of the design. How could we have mitigated the unsafe design aspect?

9. Examine . Describe a couple failure modes of the system, along with a way to mitigate each. Please ask me or the propulsion leads if you have any questions about the propulsion design!

Introduction

The purpose of this intro project is to familiarize members with basic principals of aerodynamics, data analysis, and amateur rocket construction.

The Project will consist of two parts. The first is the optimization of an airframe built in OpenRocket, and the second is focused around analysis of flight data from the most recent 4/20/19 SubArktos flight.

It is impossible to stress enough that this is not a trivial project, it is strongly recommend that you ask for help whenever you run into any problems from either Aled Cuda or Rebecca Bennett, or simply in the #simulations channel, it is more than likely that we made mistakes writing this. I have no doubt that you will be able to complete the project

Task 1: Rocketry and Open Rocket fundamentals

For this part of the project we will be using OpenRocket to test out our designs.

Linked here is the open rocket design file (download the whole thing, not the contained rocket.ork [ork files are secretly zips of ork files that are secretly xml files]), your goal is to optimize this for your choice of either altitude or velocity using the given motor (the F32-5, with 32N of average thrust and a 5 second charge delay is a midpower motor). In order to complete this part of the project your design must reach either 2250 ft of altitude, or 750 ft/s. Any parts you use in your design must either be available from , , or laser cuttable from plywood in the Jacobs Maker Space (this is what I would recommend for your fins to give you a little bit of freedom). If you would like to do something more fancy contact Aled Cuda on discord to get approval before using it. Additionally your rocket must carry a 0.37 oz 1.9x0.7" cylinder, aka a Jolly Logic Altimeter 3. Finally the stability of the vehicle must be between 1.2 cal and 1.8 cal (you should aim for about 1.4).

Your submission should take the form of your optimized open rocket file which you should DM to Aled Cuda on Discord with the filename YOURNAME-rocket.ork.

Once all intro projects have been completed we will build the original rocket and a rocket based on the best ideas from all intro projects and drag race them at the next STAR launch.

Task 2: Basic data analysis

• Maximum velocity obtained during flight (ft/s)

• Parachute decent rate (ft/s)

• Parachute deployment time (time from liftoff) (s)

• Total flight time (s)

• Total motor burn time (s)

And for extra brownie points:

• Maximum acceleration reached during liftoff (this ones more difficult than it may seem) (ft/s/s)

Present your findings in a DM to the lead (Aled Cuda)

Introduction

The intro project is designed with two main parts:

1. A general rocketry take-home quiz, taken alone (due roughly 1 week after assigned)

2. A design project, also done alone (due roughly 3 weeks after assigned)

The intro project may seem daunting, but don’t worry! In addition to the existing resources on GitBook, all the returning payload members will available to help. To encourage intra-team communication, new members are encouraged to ask for help from a designated returning member, as part of our mentorship program. Furthermore, do not hesitate to ask questions on the #payload Discord channel or PM Jared Farley or other payload members.

We will also hold a series of intro project workshops throughout the next weeks, giving an opportunity for hands-on help. Details will be announced here and on the #payload channel.

Above all, we hope that the intro project will be a fun and rewarding experience.

Checkpoints Schedule:

• By week of 2020-09-21 - Quiz Complete

• By week of 2020-10-05 - Design Project Complete

Part 1: General STAR & Rocketry Quiz Questions

1. What are the subteams of STAR?

2. What are the names of STAR's rockets?

   1. What are their diameters?

   2. What are they made out of?

3. What is the maximum side length payload cube that could theoretically fit in a 20cm diameter rocket?

4. A G-class motor is roughly how many times more powerful than a D-class motor?

5. With roughly what speed will a 10kg rocket hit the ground if in free fall from 1280m? (You may use g=10 m/s/s)

   1. Is this a realistic speed to assume? Why or why not?

6. Give two pros and two cons of a dual-deployment (two parachute) recovery system.

   1. How do altimeters measure altitude?

7. Is it possible to directly measure the velocity of a rocket during flight? Why or why not?

   1. Describe two ways you might calculate the velocity of a rocket with the following sensors: GPS tracker, altimeter, accelerometer, gyroscope.

   2. What are the potential advantages and drawbacks of each method given?

8. Explain what each number means in the following UTS designation: #6-32x1

   1. What is the smallest screw gauge in the UTS system?

   2. What are the standard and fine TPI of a #4 screw?

9. Explain what each number means in the following Metric screw designation: M6-1.0x20

   1. How is the designation of threading different in the UTS system than the Metric system? Subtle but important.

   2. Why is the Metric system superior to the US Customary system?

Quiz Submission

Please upload your quiz as a PDF here:

Part 2: Design

Design Objective Outline

Requirements

Engineering is defined by requirements!

Components to Integrate

Detailed Design Requirements:

1. All components must fit within the space of a cylinder, 4" in diameter and 8" in length.

2. All components must be mounted by non-permanent means. For example, you may not glue the Arduino to the frame. One method could be to use zip ties/Velcro; if you choose this option, be sure to include slots/holes for the ties/velcro. For parts with mounting holes, screws and nuts are preferred.

3. The distance sensor must be mounted to the front of the rover, facing forward.

4. The wheels may be arranged in any reasonable format. (Tricycle-like approach recommended).

5. You do not have to worry about wiring the electronics or mounting the rover to the tube.

Your frame may be as elaborate or simple as you'd like, but it should adhere to the above requirements.

Designing in Solidworks

If you have never used CAD software before, don’t worry! We will hold an intro project training class during Workshop 1, most likely on the week of 9/21. If you are not able to attend, there are also great online resources:

Step 1: Installing SolidWorks

The first challenge of this stage is installing SolidWorks. The GitBook has a very helpful “SolidWorks Installation” page to help you with this.

Step 2: Working with given hardware

Assume another team has already picked out the motors and electronics necessary for a rover. As a design engineer, your task is to cohesively incorporate all the given components into a (hopefully) functioning rover.

A good place to start is by looking at the physical dimensions of each component. Attached are 2D dimensioned engineering drawings of all the parts.

Step 3: Working with the tube

The most challenging (and annoying) constraint placed on many payload projects is the size of the payload tube (the part of the rocket that the payload is stored in). Learning to work with the size limits of a cylinder is essential.

Keep this in mind when designing your chassis!

Step 4: Start designing!

That's all the essentials to get you started on your design. Remember, you can come up with anything as long as it meets the detailed design requirements. The rest of this sub-section lists a few tips.

Step 5: Additional resources

A detailed step-by-step design guide will be released later in the semester (Although I heavily encourage you to try it out yourself first & ask any Payload member for help before consulting the guide).

Project Submission

Please upload your SolidWorks/other CAD files here:

Introduction

Welcome to the Recovery team's intro/returning project page! Glad you're here.

The recovery team is tasked with safely landing the launch vehicle. This responsibility entails understanding the constraints provided by others/the specifications of the launch vehicle itself and producing creative and efficient solutions. Tasks include but are not limited to: parachute size/material/geometry selection, parachute deployment altitude selection, ejection/separation mechanisms, and a general understanding of mechanics, electronics, simulations, physics, and more.

For any questions/help, feel free to reach out to the recovery team lead, Allen, and deputy, Evan at office hours or online through Discord/email. Office Hour times/locations for both are listed below. OH are highly encouraged if you need help!

• Allen Ruan | Recovery Team Lead

  • OH: Thurs 3-5PM, Kresge Engineering Library or Etcheverry CAD Lab(check discord for exact location)

  • Email: allenruan@berkeley.edu

• Evan Borzilleri | Recovery Team Deputy

  • OH: Monday 10AM-12PM, Kresge Engineering Library (check discord for exact location)

  • Email: evanjborzilleri@berkeley.edu

New Member Project (8 hrs)

The new member project for the recovery subteam is intended to:

1. Introduce a strong technical foundation for the critical components of the recovery subsystem to new members

2. Learn to work with constraints, similar to industry

3. Encourage collaboration/asking for help to accomplish these tasks

The deliverables of the project should be presented at the recovery subteam meeting (Sept. 27th) in the form of a .ppt slide deck containing snapshots of the various projects. Remember! This project is meant to be challenging, but attainable, especially if you ask for help. So please ask questions, come to workshops, and come to office hours!

Task 1 | Knot Tying (0.5 hrs)

Workshops | [Recovery]

Objective | Become familiar with and learn to tie all the knots necessary for parachute deployment systems (All knots will be demoed in the workshop). The following knots must be perfected:

• Eight knot

• Square knot

• Bowline knot

• Alpine Butterfly knot

• Double hitch

Deliverable | The student must demonstrate tying all the knots above to either Evan or Allen

Task 2 | Recovery Sequence (0.5 hrs)

Workshops | [Recovery]

Objective | Create a flowchart detailing the sequence of recovery events starting from when the launch vehicle is at apogee to when it is fully recovered. Images/Drawings are encouraged.

Deliverable | Flowchart (can use draw.io or any other diagram sites)

Task 3 | Parachute Selection (3 hrs)

Workshops | [Recovery] [OpenRocket]

Objective | Select the best combination of parachutes that satisfies the constraints below:

Constraints:

• Drogue is deployed at apogee (maximum altitude)

• Main is deployed at 600ft above ground level (AGL)

• Drogue Cd (Coefficient of Drag): 1.5

• Main Cd: 2.2

• Each component must not land with greater than 75 ftlb-f

• Drift radius must be less than 2500ft in 20mph wind

Deliverable | Modified table with filled out fields in .ppt and correct option with explanation of why this is the best option out of the three. .ppt must show work/calculations. Cheating is not tolerated.

Task 4 | Bulkhead Design (4 hrs)

Workshops | [PDM] [Recovery] [Solidworks]

Objective | Create a CAD assembly of a rocket bulkhead using Solidworks. Once complete, check-in to CalSTAR’s Solidworks Workgroup PDM. The CAD Assembly shall consist of the following parts/components:

• Outer Bulkhead

• Inner Bulkhead

• U-Bolt

  • 1/4" Bolt

  • 1/4" Flat Washers (x4)

  • 1/4" - 20 Nuts (x4)

Drawings of the necessary parts are provided below:

For bonus points:

• Include material properties for each component

• Etch text on both sides of the combined bulkhead

Deliverable | Snapshots of the full assembly (two different views), and screenshot of assembly uploaded to the PDM

Task 5 | Creative Section (X hrs)

Workshops | [Recovery] [Solidworks]

Objective | CAD and mockup a functional electronics sled for the avionics bay. The sled must meet the following requirements:

• Designed in 3D modeling software (preferably Solidworks)

• Must be able to mount Stratologger CF altimeters and 9V Duracell batteries

• Fit within a 4in diameter tube

Deliverable | Manufactured sled and its assembly file uploaded to the PDM. Add photos to the .ppt and describe the design

Returning Member Project (10.5 hrs)

Similar to the new member project, the returning member project is intended on refreshing everyone’s mind on performing the pertinent tasks for the recovery team, in addition to educating members on a deeper level focused on manufacturing and big-picture understanding. It is due on 09/20.

Task 0 | Intro Project (7.5 hrs)

Workshops | [OpenRocket] [PDM] [Recovery] [Solidworks]

Objective | Complete tasks 1, 3, and 4 the intro project

Deliverable | Document all work on a .ppt as outlined above

Task 6 | Wiring Diagram (1 hr)

Workshops | [Recovery]

Objective | Create a wiring diagram of all the electronics/wiring included in the avionics system for a dual deployment recovery system using a flowchart software (eg. draw.io). Include + and -. This might require looking into an altimeter datasheet (look up perfectflite stratologger CF). Components that shall be included:

• 1 Altimeter

• 1 9V Battery

• 1 External Switch

• 1 Main Charge

• 1 Drogue Charge

Below is a snapshot of a diagram with the altimeter and batter to get you started.

Deliverable | Snapshot of wiring diagram in .ppt

Task 7 | Launch Day Checklist Quiz (0.5 hrs)

Workshops | None

Objective | Complete the following quiz about the sequence of events that we, as a recovery team, complete during a launch day. Unlimited attempts, but must get a perfect score.

Link: https://goo.gl/forms/MhCX3EOcK8SDAHts1

Deliverable | Screenshot of perfect score

Task 8 | Technical Writing (1.5 hr)

Workshops | None

Objective | Given the importance of technical reports/documentation in what we do, write a paragraph detailing the specs and function of the bulkhead you have just created. Include an image of the CAD and the actual manufactured bulkhead. Include a reference for the figure and a caption. Format is up to you, but please check for typos and grammatical errors. If you have any questions, there exists a lot of good documentation on LaTeX online, and/or come to OH.

Deliverable | .pdf of the LaTeX document

"One bad year of competition is really annoying, but one bad year of education leads to three bad years of competition." --Sam

Welcome to avionics!

If you're reading this, you're probably a new member who's looking to get involved with our avionics projects at STAR. This document--our new intro project--will teach you everything you need to know to be a filly contributing member on the team, even if you have no experience. For your own reference, here's a concise list of all the different websites and resources that you'll be interacting with as an avionics member:

• Our gitbooks page, which you're reading right now! In addition to the intro project, there are also helful tutorials written by previous avionics members linked here: https://app.gitbook.com/@rocketry/s/public/~/drafts/-MjLyQKJMVHvQ78dHKoB/tutorials/avionics. Try to read through them since they might help a lot with doing your intro project.

• The STAR google drive, linked here: https://drive.google.com/drive/folders/0B1_9aZj6iTHlanFqejNER29MdGs?resourcekey=0-brHPjsPqJYx5BjBnSWMupQ&usp=sharing

• Quire, which is a sort of mega to-do list so we can keep track of what to do when. It's similar to trello, if you've ever used it.

• The STAR calendar: https://calendar.google.com/calendar/b/1?cid=dGJzbDNzZ290MXUyYW5wMm90M3NhNzAxOTBAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ

• Our github, which is where avionics projects live (including your intro projects): https://github.com/calstar

• Cadlab, which is sort of like a mirror for github. It lets you look at the schematics for our projects without needing to download them and open kicad. Link: https://cadlab.io/star

• And, of course, the club discord!

Overview

This intro project serves as an introduction to the Kicad software suite, which is used by the avionics team to design circuit boards for STAR projects. The projects is split up into two paths--one path is for students who are more interested in schematic design, and the other path is for students more interested in PCB layout. Schematic design and PCB layout are both fundamental parts of using Kicad. The primary goal of both intro projects is for students to learn how board design is done on the avionics subteam, and gain experience on a project that is very similar to "real" avionics projects.

The schematic-focused path of the intro project is called "cas-rpi-hw" and it consists of adding two new parts (a raspberry pi compute module, and an FPGA) to our current CAS-Core board. The layout-focused path of the intro project is called "cas-radio-revised-hw" and it consists of adding one new part (a dual radio transmitter-reciever) to our current CAS-Radio board. Both CAS-Core and CAS-Radio will be explained in more detail later on.

Here are the links to the github repositories where our intro projects live. These repositories contain the starter files for the project, and they tell you the specifications that you'll be trying to fulfill. https://github.com/calstar/cas-rpi-hw https://github.com/calstar/cas-radio-revised-hw

What is Kicad?

The circuit design process in Kicad follows a relatively predictable structure, which is separated into two main phases: schematic design, and PCB layout. Schematic design involves deciding which components and pins are connected to which, and PCB layout involves actually drawing the physical wires that will connect the components together. Each component on a circuit board has one symbol (a diagram showing which pins it has, and what their names are) and one footprint (a diagram showing the exact size and shape of its pins). Symbols are used in the schematic design stage, and footprints are used in the PCB layout stage.

Kicad has tools that you can use to create your own symbols and footprints for any circuit element, but we will not be using those tools in the intro project (all symbols and footprints are pre-made for you). Even outside the intro project, these tools are not always necessary because Kicad has thousands of well-known circuit elements pre-loaded with symbols and footprints. Even if it is not included in Kicad, there are also symbols and footprints publicly available on the web for many different circuit elements (for example, at snapeda.com). You will probably only need to use the footprint/symbol editor if you need to add a very rare or obscure component to your circuit.

Another core feature of Kicad is Libraries, which are used to store symbols and footprints. Every symbol or footprint must be in a library. You can create your own libraries to store symbols and footprints in, and these libraries can either be global or project-specific. Creating project-specific libraries is generally simpler and easier to manage. Annoyingly, the symbol libraries and footprint libraries are stored in two different ways. Symbol libraries are stored in a .lib file, but footprint libraries are stored in a .pretty folder. The .pretty folder contains multiple .kicad_mod files, and these files are the individual footprints.

A typical Kicad project proceeds as follows: 1: Decide on the main components you are planning to use on your circuit board. 2: Create schematic symbols for these components, unless they already exist in Kicad. 3: Create footprints for these components, unless they already exist in Kicad. 4: Create connections between pins in the schematic design stage 5: Associate symbols with footprints (tell Kicad which symbol corresponds to which footprint) 6: Draw the physical traces between footprints in the PCB layout stage 7: Generate gerber files Here is a convenient cheatsheet that explains this process in full:

You can get started with Kicad by downloading and installing it here: https://www.kicad.org/download/

If you have no prior experience with Kicad, then I highly recommend watching this tutorial video series by Digikey. It is useful both as a first look to get familiar with Kicad, and as a refresher to brush up on the details. Following along with their practice project is completely optional--the tutorial is still very helpful even when just passively watching.

Basics: https://www.youtube.com/watch?v=vaCVh2SAZY4 Schematic symbol editor: https://www.youtube.com/watch?v=c2niS9ZRBHo Schematic design: https://www.youtube.com/watch?v=4Gtd7xY6zS4 Footprint editor: https://www.youtube.com/watch?v=ZHH4G_EWhm0 Associate footprints with symbols: https://www.youtube.com/watch?v=Ghv0bGiZFL8 PCB Layout 1: https://www.youtube.com/watch?v=Ghv0bGiZFL8 PCB Layout 2: https://www.youtube.com/watch?v=jaQPr7PgImk Generate gerber files: https://www.youtube.com/watch?v=ENmDnoKs2hM Generate BOM & Order parts (optional): https://www.youtube.com/watch?v=I7GUiGoD1w8&t=642s Solder components to board (optional): https://www.youtube.com/watch?v=Zkn_Au5aeLA

CAS

CAS stands for Common Avionics Stack and it is one of our most recent avionics projects. The fundamental idea behind CAS is that the entire system is organized into modular boards, each of which are about 3 inches by 3 inches in area. Each board has one general purpose, and the boards are all connected together in a 'stack.' The boards can exchange data because each board has an identical 80-pin header.

The CAS board that already exist are: Core (main function: performing computations and gathering data), Pyro (main function: igniting fuses), Radio (main function: sending and recieving radio). The CAS boards that are currently in development are your two intro project boards, as well as the CAS-Prop board (main function: interfacing with the propulsion system). The files for the boards can be found on cadlab (https://cadlab.io/star) and github (https://github.com/calstar).

The Cas-Stacking component (located in hardware-sch-blocks here: https://cadlab.io/project/22829/master/circuit/Q0FTX2J1cy9DQVNfYnVzLnNjaA%3D%3D) is the most important part of CAS because it is used to connect all the CAS modules together. Each CAS module contains one copy of the CAS-Stacking board. Each pin X on one CAS-Stacking board is shorted to its corresponding pin X on every other copy of the CAS-Stacking board. One Cas-Stacking board has 80 pins in total: 40 on the left (A1-A40) and 40 on the right (B1-B40). Pins B15-B40 are currently unused.

The following is a description of the pins used by Cas-Stacking. Except for the power and miscellaneous pins, most of the pins should be used to interface with the board's microcontroller.

• Power

  • +3.3V

  • +5V

  • +BATTERY

  • GND

• I2C #1

  • SCL

  • SDA

• I2C #2

  • SCL

  • SDA

• SPI High-Speed

  • SCK

  • MISO

  • MOSI

  • SS1, SS2

• SPI Low-Speed

  • SCK

  • MISO

  • MOSI

  • SS1, SS2, SS3, SS4, SS5, SS6, SS7, SS8

• Other

  • INT1, INT2, INT3, INT4, INT5, INT6, INT7, INT8

Included below is the schematic footprint for a Cas-Stacking board. The pins A1-A40 are on the left, and the pins B1-B40 are on the right. The 4 circles on the corners are larger protrusions that are used to stabilize the board and keep it from falling out.

One thing to note about CAS is that, unlike most circuit boards, CAS boards have 4 layers instead of 2. This is not a significant change to the design process, but it is something to keep in mind. The plan for the 4 layers is to designate the outer two as front copper pour and back copper pour, while making the middle two boards a ground plane and a power plane. A 'plane' is basically a copper pour that fills the entire layer.

Using git

Git and github are a system to manage and keep track of files in large programming projects. Each individual project is stored in a 'repository.' STAR maintains a github account here with several repositories: https://github.com/calstar.

If you have never used git before, or you need a refresher, here are a few guides you can follow: https://inst.eecs.berkeley.edu/~cs61b/fa21/docs/using-git.html https://product.hubspot.com/blog/git-and-github-tutorial-for-beginners https://rogerdudler.github.io/git-guide/ https://guides.github.com/introduction/git-handbook/ In general, your workflow using git will look something like this: 1: Do some work inside your project directory. 2: Enter the command git add * to add your files to the staging area. 3: Enter the command git commit -m "your message here" to create a commit for your files. 4: Enter the command git push to push your files to the remote repository. The first time you use git, though, you will have to initialize your repository and also specify what remote repository you want to be connected to. Here are the main steps to doing this: 1: Create a directory that you want your project to be in. 2: Enter the command git init. 3: Enter the command git clone <remote repository url here>. 4: The files from the remote repository should now be in your project directory. From there, you can follow the workflow mentioned above. One of the most useful commands is git status, which can help you out if you are confused or stuck. It will tell you what is the status of your local repository and what has been changed, staged, deleted, etc.

Managing submodules

NOTE: This section isn't needed for completing your intro project, but it could be a good reference for the future when you want to make your own kicad projects.

Kicad has a large number of preloaded libraries (for symbols & footprints), but it is also possible to import your own libraries. There are a lot of these libraries publicly available on github. In fact, even the kicad default libraries are available on github (https://github.com/KiCad/kicad-symbols, https://github.com/KiCad/kicad-footprints). At avionics, we have created our own library to hold some of our symbols and footprints. This library is located at the the 'hardware-sch-blocks' repository on our github (https://github.com/calstar/hardware-sch-blocks) and cadlab (https://cadlab.io/project/22829/master/files).

When we create new avionics projects, we will want to include hardware-sch-blocks as a kicad submodule. Here are the steps for creating a new project and importing our hardware-sch-blocks submodule into the symbol editor: 1: Open kicad and create an empty project. In your terminal, navigate inside the project directory. 2: Type the command git init to start a git repository. 3: Type the command git submodule add https://github.com/calstar/hardware-sch-blocks 4: Open the schematic editor in your kicad project, and click 'manage symbol libraries.' 5: Go to the 'project-specific libraries' tab and add a new library. 6: Set the library's nickname to 'star-common-lib' and set the library path to ${KIPRJMOD}/hardware-sch-blocks/star-common-lib.lib 7: Click 'ok' and save the project. 8: If you click on 'place symbol' and scroll down in the dialog box, you should see a section labeled 'star-common-lib' The steps for importing our submodule into the footprint editor are similar, though it assumes you have already followed the above steps for importing our submodule into the symbol editor. 1: Open the layout editor in your kicad project, and click 'manage footprint libraries.' 2: Go to the 'project-specific libraries' tab and add a new library. 3: Set the library's nickname to 'star-common-lib' and set the library path to ${KIPRJMOD}/hardware-sch-blocks/star-common-lib.pretty 4: Click 'ok' and save the project. Here is another useful reference for learning about kicad submodules: https://www.youtube.com/watch?v=oXzJFrLo77Y

Be aware that if you are trying to pull or clone a github repository with submodules in it, you will need to use the --recursive tag when entering the command.

Intro Project A: CAS-RPI-HW

Step 0: Getting started

• First, create a new directory to hold this kicad project. On the command line, cd into this directory.

• Enter the command git init to create a git repository in this directory.

• Enter the command git clone https://github.com/calstar/cas-rpi-hw --recursive to download the starter files for the project. Your project will be located inside the core directory. If you look inside it, this is what you should find:

--core.pro: Click on this to open the kicad main window. --core.sch: Click on this to open the schematic editor. --core.kicad_pcb: Click on this op open the PCB layout editor. --hardware-sch-blocks: This contains the symbol and footprint libraries for star-common-lib. The schematic library is located at star-common-lib.lib, and the footprint library is located at star-common-lib.pretty. --RPi-CM4-Kicad: This contains the symbol and footprint libraries for the RPi compute module. The schematic library is located at Raspberry-Pi-Compute-Module-4.lib, and the footprint library is located at Raspberry-Pi-Compute-Module-4.pretty.

• To get started with the project, open the schematic file core.sch which will pull up the kicad schematic editor. The project should be blank except for two symbols for the Cas-Stacking board, which is inherited from the star-common-lib library. (It's true that Cas-Stacking is just one part and not two, but sometimes we will split very large kicad components into multiple symbols so they are more convenient to work with in the schematic editor.)

• Here is what you should see at the beginning.

Before proceeding to the next steps, look at the readme on the intro project github page: https://github.com/calstar/cas-rpi-hw. This tells you what the main projects specs are, and has some advice to help you plan the circuit schematic. You will probably want to refer to this readme frequently.

Step 1: Create Schematic

• The first thing to add is the raspberry pi compute module. You can find it by using the 'place symbol' tool and then going to the RPi-CM4-Kicad-library. The component has 200 pins in total, and it's split up into multiple sub-blocks, either by structure or by function. You could put the component directly on the schematic, but since it's so big, we're going to create a hierarchical sheet to hold it. Click on 'create hierarchical sheet' and place a hierarchical sheet down on the schematic. Go inside the sheet and add your RPi-CM4 component. Then, wire up the power and ground pins using global flags, and connect everything else to hierarchical pins. Then, exit the hierarchical sheet, and place the hierarchical pins on the sheet so that they can connect to the rest of the schematic.

• You can also put the Cas-Stacking connector in its own hierarchical sheet. Luckily, this has already been done, since a hierarchical sheet exists in hardware-sch-blocks. To add it to your schematic, create a new hierarchical sheet, and specify the path as hardware-sch-blocks/CAS_bus/Cas_bus.sch. This should cause Kicad to load in the existing CAS_bus hiararchical sheet to the schematic. Then, all you have to do is place down the hierarchical pins on the schematic.

• Hierarchical sheets are a great way to simplift your kicad projects and make them more modular. You can place other components into hierarchical sheets at your discretion if you think it would make the circuit neater. Feel free to review the existing cas-core schematic on cadlab; you will see that some components are nested in hierarchical sheets, but others are not. Generally, hierarchical sheets are best for very big components, or related groups of components that all accomplish one task. Here's a quick tutorial where you can learn about hierarchical sheets: https://www.youtube.com/watch?v=PEoVUlZz9lw

• The next thing to add is the ice40 fpga. Luckily, kicad already has this component in its default libraries. If you click the 'place symbol' tool and then search for 'ice40', you should see symbols pop up that you can use for the ice40 fpga. Click on the one (or ones) you want, then click 'ok' and you should be able to place them on the schematic.

• Afer that, try adding the BMP388. This should be very similar to adding the fpga, except you will find it under the 'star-common-lib' section. Place it down in the same way you placed down the fpga.

• Add more components according to the spec on the github readme, such as the accelerometer and rpi cam connectors. Use the resources linked in the readme to figure out how everything should be wired together. You will probably want to review: the datasheets for all relevant components, the downloadable rpi schematics from the CM4IO-KICAD folder, the previous cas-core board schematics on cadlab, and the list of pins for the cas-stacking connector. This step will probably take the longest as you read through all the resources and figure out where everything should go.

• Kicad has the following useful hotkeys. Use E to edit a components properties, R to rotate a component, M to move a component, and W to start drawing a wire (use esc to cancel a wire drawing).

Step 2: Associate Components With Footprints

• When you are satisfied with the state of the schematic, you can associate the components with footprints before proceeding to the layout stage.

• Select the 'annotate schematic symbols' tool and click 'annotate' to give a number to every symbol on the board.

• Open the CVPCB tool from the toolbar.

• Search for each board component and associate it with a footprint.

• Generate the netlist.

• Open PCBNew and read in the net-list.

Step 3: Layout PCB

• You'll see each footprint generate on top of each other in one big clump. Move them out of the way so they aren't all on top of each other. Make sure that all the footprints can fit inside the boundaries of the cas-stacking board.

• All the components have little white 'air wires' showing what needs to be connected where. Your next step is to move the components around (with the M hotkey) and rotate them (with the R hotkey) so that most of the air wires aren't crossing over each other. You probably will still have some air wires crossing over, but try to move the footprints out of the way so you can minimize it as much as possible.

• You can calculate proper trace width using an online trace width calculator, and set the trace widths in KiCad (go to the track width tab on the toolbar, click on ‘edit pre-defined sizes’ in the dropdown menu, and input the new sizes). You will have to set both trace width and drill size. Remember that power traces generally need bigger trace sizes than other types of traces.

• Route the traces according to the connections provided by the air wires, until all of the air wires are gone. You will probably need to use vias to go through the board in order to fit all the traces in.

• When routing power traces, try not to make them go through any vias (though its not an absolute necessity). The power traces should have "priority" over other types of traces.

• Remember keep your layout relatively neat and not too clumped up--if you tried to solder the components onto the board then you would need a little bit of room to do so correctly!

• If you're confused about something, you refer to the old cas-core and cas-radio projects that already exist to see what the settings were like (trace width, drill size, board layer settings, etc). Just clone the repository into a new directory and open the project in kicad, then you can navigate around the project and see what a finished kicad project is supposed to look like.

• Try using Kicad's 3d viewer to see what your board is going to look like once it's been fabricated. You can do this at any stage in the layout process!

• When you're done drawing traces, create a ground pour on the second layer (creating a ground plane), and then create a power-supply-voltage pour on the third layer (creating a power plane).

• Generate gerber files once the layout is finished. Generating gerbers is always the last step in a Kicad project.

Intro Project B:CAS-Radio-Revised-HW

Step 0: Getting started

• First, create a new directory to hold this kicad project. On the command line, cd into this directory.

• Enter the command git init to create a git repository in this directory.

• Enter the command git clone https://github.com/calstar/cas-radio-revised-hw --recursive to download the starter files for the project. Your project will be located inside the radio directory. If you look inside it, this is what you should find:

--radio.pro: Click on this to open the kicad main window. --radio.sch: Click on this to open the schematic editor. --radio.kicad_pcb: Click on this op open the PCB layout editor. --hardware-sch-blocks: This contains the symbol and footprint libraries for star-common-lib. The schematic library is located at star-common-lib.lib, and the footprint library is located at star-common-lib.pretty.

• To get started with the project, open the schematic file radio.sch which will pull up the kicad schematic editor. The project should be blank except for two symbols for the Cas-Stacking board, which is inherited from the star-common-lib library. (It's true that Cas-Stacking is just one part and not two, but sometimes we will split very large kicad components into multiple symbols so they are more convenient to work with in the schematic editor.)

• Here is what you should see at the beginning.

Before proceeding to the next steps, look at the readme on the intro project github page: https://github.com/calstar/cas-radio-revised-hw. This tells you what the main projects specs are, and has some advice to help you plan the circuit schematic. You will probably want to refer to this readme frequently.

Step 1: Create Schematic

• The AT86RF215 transciever is probably the most important part of this project, since it's the component that actually does the radio communication. It is an IC radio module with two separate radios included (a 0.9 GHz one, and a 2.4 GHz one). The two radios are independent of each other. They also have both transmission (data in) and recieving (data out) capabilities. The AT86RF215 has 48 pins on it, with the following functions. It's not necessary to understand what every single pin is used for, but it's provided here to help make the wiring diagram easier to comprehend.

• 0.9 GHz Radio

  • RFP09: Differential RF Input (positive)

  • RFN09: Differential RF Input (negative)

  • FEA09: Digital Output A

  • FEB09: Digital Output B

  • RXDP09: I/Q Interface Output (positive)

  • RXDN09: I/Q Interface Ouput (negative)

• 2.4 GHz Radio

  • RFP24: Differential RF Input (positive)

  • RFN24: Differential RF Input (negative)

  • FEA24: Digital Output A

  • FEB24: Digital Output B

  • RXDP24: I/Q Interface Output (positive)

  • RXDN24: I/Q Interface Ouput (negative)

• Power

  • DVDD: Internally Regulated Digital Supply Voltage

  • AVDD0: Internally Regulated Analog Supply Voltage 0

  • AVDD1: Internally Regulated Analog Supply Voltage 1

  • EVDD: External Analog Supply Voltage

  • DEVDD: External Digital Supply Voltage

  • AVSS: Analog Ground

  • DVSS: Digital Ground

• Communication

  • MISO: SPI MOSI Connection

  • MOSI: SPI MISO Connection

  • SCLK: SPI SCLK Connection

  • SELN: SPI SELN Connection

  • RXCLKP: RX I/Q Interface Clock Output (positive)

  • RXCLKN: RX I/Q Interface Clock Output (negative)

  • TXCLKP: TX I/Q Interface Clock Input (positive)

  • TXCLKN: TX I/Q Interface Clock Input (negative)

  • TXDP: TX I/Q Interface Data Input (positive)

  • TXDN: TX I/Q Interface Data Input (negative)

• Miscellaneous

  • IRQ: Interrupt Signal

  • RSTN: Reset Pin (active low)

  • TXCO: Crystal Oscillator Input

  • XTAL2: Crystal Oscillator Output

  • CLKO: Clock Output

• Let's add the transciever to the schematic. You can find it by using the 'place symbol' tool and then going to the star-common-lib library. The component has 48 pins in total, and while you could put the component directly on the schematic, it's so big that we're going to create a hierarchical sheet to hold it. Click on 'create hierarchical sheet' and place a hierarchical sheet down on the schematic. Go inside the sheet and add your AT86RF215 component. Then, wire up the power and ground pins using global flags, and connect everything else to hierarchical pins. Then, exit the hierarchical sheet, and place the hierarchical pins on the sheet so that they can connect to the rest of the schematic.

• You can also put the Cas-Stacking connector in its own hierarchical sheet. Luckily, this has already been done, since a hierarchical sheet exists in hardware-sch-blocks. To add it to your schematic, create a new hierarchical sheet, and specify the path as hardware-sch-blocks/CAS_bus/Cas_bus.sch. This should cause Kicad to load in the existing CAS_bus hiararchical sheet to the schematic. Then, all you have to do is place down the hiararchical pins on the schematic.

• Hierarchical sheets are a great way to simplify your kicad projects and make them more modular. You can place other components into hierarchical sheets at your discretion if you think it would make the circuit neater. Feel free to review the existing cas-core schematic on cadlab; you will see that some components are nested in hierarchical sheets, but others are not. Generally, hierarchical sheets are best for very big components, or related groups of components that all accomplish one task. Here's a quick tutorial where you can learn about hierarchical sheets: https://www.youtube.com/watch?v=PEoVUlZz9lw

• Refer to the resources included in the github readme to figure out how the AT86RF215 should be wired up. You will probably want to review: the AT86RF215 datasheet, the cariboulite schematic, the hackrf github page, the previous cas-core and cas-radio board schematics on cadlab, and the list of pins for the cas-stacking connector. This step will probably take the longest as you read through all the resources and figure out where everything should go.

• Kicad has the following useful hotkeys. Use E to edit a components properties, R to rotate a component, M to move a component, and W to start drawing a wire (use esc to cancel a wire drawing).

Step 2: Associate Components With Footprints

• When you are satisfied with the state of the schematic, you can associate the components with footprints before proceeding to the layout stage.

• Select the 'annotate schematic symbols' tool and click 'annotate' to give a number to every symbol on the board.

• Open the CVPCB tool from the toolbar.

• Search for each board component and associate it with a footprint.

• Generate the netlist.

• Open PCBNew and read in the net-list.

Step 3: Layout PCB

• You'll see each footprint generate on top of each other in one big clump. Move them out of the way so they aren't all on top of each other. Make sure that all the footprints can fit inside the boundaries of the cas-stacking board.

• All the components have little white 'air wires' showing what needs to be connected where. Your next step is to move the components around (with the M hotkey) and rotate them (with the R hotkey) so that most of the air wires aren't crossing over each other. You probably will still have some air wires crossing over, but try to move the footprints out of the way so you can minimize it as much as possible.

• You can calculate proper trace width using an online trace width calculator, and set the trace widths in KiCad (go to the track width tab on the toolbar, click on ‘edit pre-defined sizes’ in the dropdown menu, and input the new sizes). You will have to set both trace width and drill size. Remember that power traces generally need bigger trace sizes than other types of traces.

• Route the traces according to the connections provided by the air wires, until all of the air wires are gone. You will probably need to use vias to go through the board in order to fit all the traces in.

• When routing power traces, try not to make them go through any vias (though its not an absolute necessity). The power traces should have "priority" over other types of traces.

• Remember keep your layout relatively neat and not too clumped up--if you tried to solder the components onto the board then you would need a little bit of room to do so correctly!

• If you're confused about something, you refer to the old cas-core and cas-radio projects that already exist to see what the settings were like (trace width, drill size, board layer settings, etc). Just clone the repository into a new directory and open the project in kicad, then you can navigate around the project and see what a finished kicad project is supposed to look like.

• Try using Kicad's 3d viewer to see what your board is going to look like once it's been fabricated. You can do this at any stage in the layout process!

• When you're done drawing traces, create a ground pour on the second layer (creating a ground plane), and then create a power-supply-voltage pour on the third layer (creating a power plane).

• Generate gerber files once the layout is finished. Generating gerbers is always the last step in a Kicad project.

Introduction

The purpose of this project is to ensure that new and returning members research various parts of a rocket propulsion system from both theoretical and practical engineering points of view.

The project consists of two parts: an in-person component and a project component.

Returning Members

If you are a returning member for the 2019-2020 academic year, you are not required to complete the project component, but you are required to satisfy the in-person requirement by participating in any of the offered workshops. Leading or helping plan a workshop will be considered as participation.

If you are interested in contributing to a workshop (highly encouraged), please contact Michael via Discord.

Contact

If you have any questions about any part of the question at any time (even if it's 4AM on a weekend), do not hesitate to reach out to the propulsion lead (Michael) or the propulsion deputy (Trevor). Discord is preferred, but if you are having difficulty getting started with Discord, Email is fine.

• Michael's Discord: mvronsky (accessible through CalSTAR discord)

• Trevor's Discord: zat15 (accessible through CalSTAR discord)

• Discord: in the #propulsion channel

• Michael's Email: michaelvronsky@obvious.edu

• Trevor's Email: tzinky@obvious.edu

• Office Hours:

  • Michael's OH: Tuesdays 14:10-15:30 in Kresge Engineering Library

    (exact location may vary, will be announced on Discord)

  • Trevor's OH: Wednesdays 16:30-18:00 in Kresge Engineering Library

    (exact location may vary, will be announced on Discord)

1. In-Person Component

To satisfy the in-person component, you must attend one of the following events:

• Safety Workshop (First one on Friday, Sept. 20 at 19:00)

• Michael or Trevor's Office Hours, to review safety (See above for OH)

In addition to attending a safety session, you are required to attend one of the following events. If you have time to attend more than one, you are encouraged to do so.

• A trip to the Richmond Field Station (RFS) (See #propulsion for updates)

  • This is more time consuming, but highly recommended, as it is where we do most of our work

• Injectors and cooling workshop (Thursday Sept. 26, 7PM-8PM)

• Mechanical design workshop (Time TBD)

• CAD workshop (Sunday Sept. 22 9AM-11AM)

• Solid propellant workshop (Thursday Sept. 26 6PM-7PM)

• Pipes and Fittings workshop (Wednesday Oct. 2nd, 8PM-9PM)

Lastly, once you believe you have finished your intro project, you should schedule a time with Michael during office hours to go over your submission. If you are super busy and can't find a time, then talk to me and we can sort something out.

2. Project Component

You may choose any of the three project components to complete. All are intended to be of about the same difficulty, and should give you insight about the various engineering tasks that we undertake.

2.1 Fluids

This task involves assorted tasks related to fluids design in propulsion systems.

2.1.1 - Injectors

Injectors serve to mix and atomize the propellants flowing into the thrust chamber. Injectors also help regulate the flow of propellants and ensure efficient combustion.

• Describe 4 types of injectors, and explain their pros and cons

• Design an injection system for the given engine.

  • Your design should consist of the following:

    • The selected injector type, and a justification for its selection

      • Factors to consider here are manufacturability/machinability and efficiency of mixing, among others

    • If there are multiple injection elements, describe their layout on the injection plate

    • The orifice area for each injection element. This can be calculated using an equation found in chapter 8 of Sutton (9th ed.)

  • The engine parameters are:

    • 1000psi chamber pressure

    • Mass flow rates are 0.17 kg/s for LOX, 0.08 kg/s for RP-1

    • 250 psi pressure drop across the injector

    • Injection plate diameter is 2”

2.1.2 - Feed System Analysis

The following Piping and Instrumentation Diagram (P&ID) is for a simplified gas-fed system. For each component labelled, describe its function, and what would happen if that component were not included in the system. Note that this is not the entire feed system, just one side of it. There are 2 fluids in the system, N2 and RP-1.

In the diagram, all ball valves are "L-port".

The following page will be very useful in interpreting this diagram:

2.1.3 - Flow coefficient

The flow coefficient of a component, often denoted Cv, is a very useful measure of its behaviour in the feed system.

Describe what the flow coefficient is, and explain why it is important to look at the flow coefficient of components when selecting them.

Then, showing your work, derive the pressure drop across this swagelok check valve (https://www.swagelok.com/en/catalog/Product/Detail?part=SS-4C-1/3) when carrying RP-1 at a mass flow rate of 0.08 kg/s. Discuss your answer, particularly whether this pressure drop is significant in the context of the feed system (which operates at 1250-1800 psi).

Deliverables

• Your injector design and area calculations

• Your interpretation of the P&ID diagram

• Your solution to the question in part 2.1.3

2.2 Thrust Chamber Design

A thrust chamber is to be designed for a 1000lbf engine using Kerosene and Liquid Oxygen.

• Design constraints:

  • O/F ratio = 2.5

  • The feed system can supply up to 1200psi feed pressure, and an injection pressure drop of 250psi will be used.

    • Based on these parameters, decide on a reasonable chamber pressure.

  • The thrust chamber must fit in a 7.5” diameter airframe.

  • Ambient pressure will be 1atm

Deliverables:

• Chamber geometry: Using the Rocket Propulsion Analysis (RPA) software, determine the thrust chamber size and shape.

• Tank analysis: A total impulse of 30,000 N*s is desired. Using the mass flow rates derived in RPA, determine the mass of each propellant required, as well as the associated volume.

• Material analysis: Pick three materials that are commonly used as thrust chamber materials and describe the pros and cons of each material in this application

  • A good analysis should include comparisons between quantitative material properties such as yield strength, thermal conductivity, and thermal expansion as well as qualitative material properties such as brittleness, machinability, cost, and corrosion resistance

  • If a metal is one of the materials chosen, it must be a specific grade i.e. 1018 steel vs just steel, or 316 stainless steel vs just stainless steel

2.3 Test Stand Mechanical Design/CAD

Just like any other subteam, our work requires the design and construction of many mechanical systems, often for a very specialized task. In the past, these have included structures to house the propulsion system in the rocket or on the test stands, testing jigs for various components, mounting brackets, and more.

In this task, you will design a test stand for testing small solid motors. Test stands are used to fire the motor while it is static on the ground. Test stands help verify motor design and test key features of any propulsion systems. Common features of test stands include thrust measuring devices, safety features, and, obviously, motor systems. In this project, you will design a small test stand intended to test fire solid model rocket motors up to a “G” class. Your design of this should ideally maximize safety and measurement accuracy, while minimizing costs and complexity.

Design Constraints

• Must be able to safely test fire up to a “G” class solid motor

• Must be able to handle various motor diameters up to 29mm

• Must be able to measure the thrust produced by the motor

Deliverables:

• A completed Solidworks assembly file of your test stand

• A bill of materials including all part names, order links (www.mcmaster.com is a great website for ordering pretty much any part you can think of, plus they have CAD’s on the website which is pretty great), and prices. A template is provided here.

• A justification of your design. Factor of Safety calculations, while optional, would be nice. This can be just a quick paragraph or two explaining your thinking, possibly improvements, possible failure modes, etc.

Resources

Introduction

You have been given a design for a very simple rocket flight computer that consists of six components: a battery, a voltage regulator, an ATMega328P microprocessor, an MPL3115A2 altimeter, and two black powder ports. You will be describing the system in more detail and writing firmware to control the rocket’s recovery system (parachutes) via the two black powder ports.

Details and Specifications

• The details of the battery and voltage regulator do not matter, but they must both be included in the final system diagram that you create.

• You have been provided with an interface for a HAL (Hardware Abstraction Layer). You will use its functions to write the firmware for the ATMega328P. The file is below, in the Files section.

  • The pinMode, digitalRead, and digitalWrite functions act as they would in Arduino.

  • The i2c_*** functions act as they would in the Arduino Wire library.

  • The millis function returns time, in milliseconds, from program start.

  • Arduino reference materials and the HAL are listed below, in the Resources section.

• When configured correctly, the MPL3115A2 provides integer altitude data, in feet, via the I2C protocol.

  • Registers implemented in the simulator are:

    • Pressure Data Out MSB/CSB/LSB (OUT_P_XSB)

    • System Mode (SYSMOD)

    • Control Register 1 (CTRL_REG1)

    • Control Register 2 (CTRL_REG2)

    • Who Am I (WHOAMI)

    • Data Ready Status (DR_STATUS)

    • Pressure/Temperature Data Config (PT_DATA_CFG)

  • Depending on how you use the altimeter, you may not need all of these registers.

• The simulation runs at 100 times real time, i.e. millis() returns 100 * (milliseconds elapsed since start of program). Be careful if using sleeps and while debugging.

• The two black powder ports are activated by two specific GPIO pins on the ATMega328P. To activate each one, turn on the pin for at least 50 milliseconds.

  • The drogue chute ignition pin is PB3.

  • The main chute ignition pin is PD7.

• The firmware must be written in C.

• The initial altitude reported by the MPL3115A2 will be somewhere within [-100, +100] feet in altitude (inclusive)

• The altitude will remain within [-5, +5] feet of an unspecified constant altitude between [-100, +100] feet -- the ground altitude -- for at least 30 seconds after flight computer startup and before launch. All altitudes following are in reference to this ground altitude. It is expected that there will be some inaccuracy in the timing of the ejections in your firmware due to the fluctuation of altitude readings while the rocket is on the ground.

• The black powder ignitions must happen at apogee, +/- 2 seconds, and at 600 feet of altitude during descent, +/- 2 seconds.

• Neither black powder ignition should happen unless the rocket has passed 200 feet in altitude.

• Determine and implement a proper strategy for the case in which the flight computer passes 200 feet in altitude, but does not reach an apogee of 600 feet in altitude.

• Describe at least three failure modes and how they are being mitigated or avoided.

• Describe test procedures you would use to verify correct functionality in the lab (i.e. not at a launch) and at a launch.

• Show how the microprocessor should be hooked up to the MPL3115A2 and any additional hardware added in order to mitigate failure modes and run test cases (such as status LEDs or buttons). This must be in the form of a wiring diagram or schematic.

• Add at least one feature to the code and/or schematic that is used for safety, such as beeping when black powder is connected. Describe the feature and explain any changes made to accommodate it. You are encouraged to look at how COTS (Commercial Off-the-Shelf) altimeters work for inspiration. Some examples are the Stratologger CF and the MissileWorks RRC3.

Compiling and Testing

• The HAL you are provided is in fc.h. You are expected to write an fc.c file that defines fc_setup and fc_loop.

  • fc_setup is called once, followed by fc_loop called repeatedly until the simulation is complete.

  • All of the other functions declared in fc.h are defined by the simulation runner, in fc_sim.mac.o or fc_sim.win.o.

  • Download the appropriate fc_sim.***.o file from the Files section and rename it to fc_sim.o (if you want).

• You are provided with a compiled, but not linked, simulation runner, called fc_sim. You will compile your flight computer code and link it with fc_sim to create an executable that, when run, will tell you how the launch went!

• To compile your flight computer:

  • Copy

    gcc -g fc_sim.o fc.c -o fc_sim

    The -g is to compile with debug symbols.

  • Note: On linux you may have to add a "-lm" flag to link the math library.

• To test your flight computer, simply run fc_sim.

• To debug your flight computer, use your favorite C debugging tool, such as gdb. You are not provided the code for the flight computer simulator, but you can debug your own code.

  • Tip: VSCode makes it very easy to write, build, run, and debug code once you have it set up!

Resources

• MPL3115A2 Datasheet

• ATMega328P Datasheet

• Arduino Function Reference

• Arduino I2C Reference

• ATMega328P-Arduino Pin Mapping

Additional Questions

1. One simple electrical system consists of a battery and a microcontroller with a single button connected with a pullup resistor and a single LED with current-limiting resistor, as shown below. Determine how long it will last on battery power. Explain your answer.

   • Vbatt = 15V, and its capacity is 1A-hr. For safety, only 80% of its full capacity should be used.

   • U1 outputs 5V, and is 90% efficient.

   • The microcontroller draws a constant 20mA.

   • R1= 10kΩ, and S1 is pressed 5% of the time.

   • R2 = 200Ω, D1's Vf = 2.1V, and D1 is on 50% of the time.

2. Write a short snippet of C code that, given an 8-bit register r and a bit index b:

1. Sets bit b.

2. Clears bit b.

3. Toggles bit b.

4. Assigns bit b to a boolean value v.

Files

Submission

Please PM Jacob, the Avionics Lead (Jashaszun#9329) a ZIP of the following files via Discord:

• Any C files you wrote that are required to compile and run your flight computer.

• A text file or PDF containing your answers to all other parts of the project.