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Sounding Rocket Critical Design Review

Rensselaer Rocket Society, Rensselaer Polytechnic Institute, Battle of the Rockets Team 1600

Instructions

  • Slides are a template describing information needed.
  • Each section can be expanded into more slides as needed. Don't try cramming each listed topic on the same slide.
  • Place team/school logo in the top left corner.
  • Put page numbers on the slides.
  • Formatting and background can be customized.
  • Do not include animations or videos as reviewers may not have compatible software.
  • Submit PDR in pdf format for maximum compatibility.PDR should focus on trade studies, CDR should focus on final design.
  • Use consistent units (metric or standard).
  • Do not include this slide in the presentation. Yes, someone will.

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Presentation Outline

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Topic

Speaker

Introduction

Trevor Dankworth

System Overview

Brian Deyo

Rocket Design

Peter Dustin

Recovery

Trevor Dankworth

Payload Design

Henry Rodriguez

Payload Electronics

Kevin Osowski

Software

Alana Barth

Ground Station

Henry Rodriguez

Testing

Brian Deyo

Summary

Alana Barth

Team Organization

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Team Member Name

Role

Trevor Dankworth

Team leader, Vehicle Lead

Alana Barth

Payload/Electronics Lead

Kevin Osowski

Tech Support

Ryan Thibeault

Documentation

Brian Deyo

Safety

Peter Dustin

Construction

Henry Rodriguez

Payload Designer

Acronyms

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Acronyms

Meaning

CAD

Computer-Aided Design

PWM

Pulse Width Modulation

GPS

Global Positioning System

TWR

Thrust to Weight Ratio

FPS

Feet Per Second

System Overview

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Kevin

Mission Summary

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  • Launch a sounding rocket to an altitude above 1100 feet and not to exceed 1800 feet

  • Use a commercial certified G rocket motor

  • Payload must include sensors and a XBEE radio transmitter to send telemetry

  • Telemetry must be sent at a 1 Hertz rate and include current altitude, current speed based on accelerometer, and current speed based on a pitot tube

  • Ground station is required to collect the telemetry and display the data

  • XBEE radio NET/PAN ID must be set to the team number

System Requirement Summary

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Req #

Requirement

1

Total installed impulse shall not exceed 160 Newton-Seconds or a G motor.

2

The rocket must reach at least 1100 feet and not exceed 1800 feet.

3

The rocket must use a motor retainer. Friction fit is not allowed.

4

All common rules must be followed.

5

The rocket must include an independent commercial altimeter to verify the rocket peak altitude.

Rocket Requirements

System Requirement Summary

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Req #

Requirement

1

Telemetry must be transmitted once per second.

2

A pitot tube must be included to measure speed using air pressure

3

Sensors must be included to measure current altitude.

4

Accelerometer must be included to measure speed and acceleration.

5

Telemetry must include a timestamp with sufficient resolution, current altitude, accelerometer derived speed and acceleration, pitot tube derived speed and acceleration.

6

Each telemetry packet must have a packet count that is incremented for each packet.

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XBEE radio can operate at 900 MHz or 2.4 GHz.

8

NET/PAN ID must be set to the team number.

Payload Requirements

Changes Since PDR

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System Level Design

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  • The rocket will be 2.6 inches diameter cardboard tubing flying on a G75 motor.
  • The payload will be located in the nosecone of the rocket.
  • The software we are programming in is Python.
  • For the ground station, we are using a laptop. what is still yellow? we can see.

System Concept of Operations

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Launch

Collect Telemetry & Video

Apogee Event

Main Chute Deployment (500 ft)

Rocket Prep

Ground Station & Telemetry Prep

Sensor Integration into Rocket

Pre-launch Prep

Telemetry & Video Ends

Rocket Lands

Recover Rocket

Return Payload to Ground Station

Download Video

Rocket Design

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Trevor

Changes Since PDR

  • The parachute was changed from a 52” octagon to a 36” circle.
  • Eye bolts were removed to save weight and space; shock cord will be secured with adhesive instead.

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Rocket Airframe (Primary Motor)

Lengths

  • Front Compartment: 9 in.
  • Switchband: 1 in.
  • Booster Airframe: 12.5 in.

Diameter

  • Outer: 2.6 in.
  • Inner: 2.558 in.

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Material

  • LOC Precision Tubing, Cardboard

Nose Cone

  • Length: 9 in.
  • Diameter: 2.6 in.
  • Shape: Tangent Ogive
  • Material: Polystyrene

IMPORTANT: POINT OUT EVERY PART OF ROCKET IN DIAGRAM

SECOND PARACHUTE IS CROSSED OUT BECAUSE WE’RE DOING A DROGUELESS DUAL DEPLOY

Rocket Airframe (Backup Motor)

Lengths

  • Front Compartment: 9 in.
  • Switchband: 1 in.
  • Booster Airframe: 12.5 in.

Diameter

  • Outer: 2.6 in.
  • Inner: 2.558 in.

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Material

  • LOC Precision Tubing, Cardboard

Nose Cone

  • Length: 9 in.
  • Diameter: 2.6 in.
  • Shape: Tangent Ogive
  • Material: Polystyrene

IMPORTANT: POINT OUT EVERY PART OF ROCKET IN DIAGRAM

SECOND PARACHUTE IS CROSSED OUT BECAUSE WE’RE DOING A DROGUELESS DUAL DEPLOY

Stability

Primary G75:

  • 1.91 Caliber
  • Center of Gravity: 16.5 in.
  • Center of Pressure: 21.5 in.

Backup G65:

  • 2.20 Caliber
  • Center of Gravity: 15.8 in.
  • Center of Pressure: 21.5 in.

Motor retention method

Screw-on motor retention cap

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Rocket Stability and Motor Retention

Fins, Rail, & Avionics Bay

Fins

  • Number of fins: 3
  • Shape: Trapezoidal
  • Tip Cord: 1.5 in.
  • Root Cord: 3 in.
  • Height: 2 in.
  • Mass: about 25.2 grams
  • Material: Plywood

Avionics Bay

  • Payload - nose cone
  • Dual Deploy System - center of fuselage, in coupler

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Total on the pad weight

  • Primary Motor: 1170 g
  • Backup motor: 1110 g

Rail Buttons (2)

  • Diameter 0.25 in.
  • Material: Nylon

Rocket Materials

List of materials used

  • Airframe material - LOC Precision Tubing, Cardboard
  • Fin material - Plywood
  • Nose cone material - Polystyrene plastic
  • Type of adhesives used - Wood glue, JB Weld epoxy
  • Rail button - 2 1-piece nylon buttons for 1010 rail. Each secured with an 8-32 machine screw through the airframe.

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Rocket Recovery System

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Parachute

  • 36 in. Diameter circle
  • Ripstop nylon
  • Drag Coefficient: 0.9
  • In club inventory
  • Parachute will be protected using a nomex blanket
  • We will be using drogueless dual deploy
  • The expected drogue descent rate is 60 FPS
  • The expected main descent rate is 17.9 FPS

Mention main parachute model, drag coeff., and the fact we already have it

Mention drogueless deploy, descent rate

Rocket Recovery System

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Harness

  • Shock cords
    • ⅛ in. kevlar - 1500 lb test - 25 ft.
  • Linkages
    • ¼ in. quick links - 1400 lb test
    • Each main parachute attachment
    • End of harnesses
  • Attachment points, eyebolts, fender washers, etc. and their mounting methods
    • Shock cord will be threaded through holes and epoxied in place
    • Shock cord will be connected to the nose cone and the body tube
    • Main parachute will quick link to recovery harness
      • Glued to hole in Nose Cone aft bulkhead

Mention bulkhead material, thickness, adhesive

Rocket Recovery System

Deployment Method

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  • 1 Stratologger CF Altimeter will be used (scoring)
  • Main parachute release mechanism: black powder charge
  • Motor Ejection
    • G75: 6 seconds
    • G65: 7 seconds

Rocket Recovery Electronics

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Ejection

  • Ejection Charge - Black Powder
    • Main - 0.125 g
    • “Drogue” - 0.125 g
    • Motor - 0.250 g
  • Volumes to pressurize
    • Main - 20.17 cu. in.
    • Drogue - 15.93 cu. in.
  • Pressure port - four 0.025” holes in switch band
  • Each section will be secured via friction fit
  • Charges will be fired with e-matches

Altitude Recording Altimeter

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The Stratologger CF used in the dual-deploy avionics bay will be used for altitude scoring.

  • The payload altimeter was considered, but ultimately decided against when we chose a non-compliant altimeter.

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Altimeter Bay Layout

Stratologger CF

MAIN+

MAIN-

VIN

DRGE+

SW2

GND

SW1

DRGE-

E-Match set 1

IN1

IN2

E-Match set 2

IN1

IN2

-

+

V1

9 V

SLCF Switch

Forward Edge

Aft Edge

2.6”

6.0”

Stratologger CF

9v Battery

Zip-tie slits

Battery Block

Rocket Motor Selection

Primary motor

  • Aerotech G75J-6
  • CG: 16.516 in. from top
  • CP: 21.490 in. from top
  • 6.55:1 TWR

Secondary motor

  • Cesaroni 144-G65-WH_LB-8A-7
  • Modifications: would require a 29mm-to-24mm motor mount adapter
  • CG: 15.778 in. from top
  • CP: 21.490 in. from top
  • 5.99:1 TWR

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Put CoG and CoP here for each

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Payload Design

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Henry

Changes Since PDR

  • The battery loaders were replaced with rectangular holes for zip ties
  • Modified the HOLEders for the base.
  • Modified the payload base
  • New CAD software
  • Small diameter change
  • Widened the payload sled

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Payload Design Overview

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Components

  • HOLEder
  • Holes

Dimensions

  • 2.4” base diameter
  • 1.4 in. top diameter
  • 7.75 in. height

Talk how the bottom of the nose cone is going to be taken off and that the payload is going to be stuck in

Mechanical Layout

  • Battery Side
    • Battery
    • Accelerometer
  • Hardware Side
    • Camera
    • Radio
    • Microcontroller
    • Altimeter
    • Buck Converter
    • GPS

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Battery Side

Hardware Side

  • Show mass of all components of the selected design
    • Mass of each structural element in grams
    • Sources/uncertainties – whether the masses are estimates, from data sheets, measured values, etc.
    • Total mass of all components and structural elements
    • Margin : The amount of mass (in grams) in which the mass budget meets, exceeds, or falls short of the mass requirement

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Mass of components:

  • Accelerometer - 1.27 g ±.001 g
  • Camera - 3 g ±.1 g
  • Radio - 15 g ±.1 g
  • Microcontroller - 25 g ±.1 g
  • Altimeter - 1.2 g ±.01 g
  • Buck Converter - 2.2 g ±.01 g
  • Battery - 240.4 g ± .01 g
  • GPS - 3 g ± .1 g
  • Zip Ties (3): .054 g ±.0001 g
  • Base HOLEder (2): 2.08 ±.001 g
  • HOLEder (2): 1.4 g ±.01 g
  • #4-40 x ½” Pan Head screws (20): 9.07 g ± .001 g

Total: 303.674g ± .4431g

Payload Mass Budget

Payload Electronics

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Kevin

Changes Since PDR

  • Switched from an arduino nano to a raspberry pi zero w
  • Switch from BGNing Pitot Tube to Hobbypower airspeed sensor

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Payload Electronics

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GPS

Pitot tube

Radio

Accelerometer

Raspberry Pi Zero

Battery

Buck Converter

Camera

Altimeter

Processor and Memory Selection

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Ultimate Choice: Raspberry Pi Zero

  • Spec: 1 GHz single-core ARM Cortex-A7 CPU
  • 500 mA power consumption
  • 1 GHz
  • Interfaces:
    • Mini HDMI port
    • Micro USB OTG port
    • Micro USB power
    • HAT-compatible 40-pin header
    • Composite video and reset headers

Payload Altitude Sensor Description

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Ultimate Choice: Mini Alt/WD Perfectflite

  • Specs:
    • Manufacture: Perfectflite direct
    • Performance specs:
      • Stores 5 minutes of flight data at 20 samples per second
      • Plus/minus .5% altitude accuracy
    • Power: 9V operating voltage, 8 mA operating current
  • Interfaces:
    • I2C 7-bit addresses

Payload Pitot Tube Sensor Description

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Ultimate Choice: Hobbypower Airspeed Sensor

Specs:

    • Manufacture: Hobbypower
    • Performance specs: measures up to 100m/s, sends data at 14 bits
    • Power: 5V DC
  • Interfaces:
    • I2C 7-bit addresses

Payload Accelerometer Sensor Description

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Ultimate Choice: Adafruit 9 DOF

  • Specs:
    • Manufacture: Adafruit
    • Performance specs: plus or minus 8g
    • Power: 5V DC
  • Interfaces:
    • I2C 7-bit addresses

Bonus Sensors

  • GPS receiver: Ultimate GPS Breakout v3
    • Manufacturer - adafruit
    • Specs -165 dBm sensitivity, 10 Hz updates, 66 channels
    • Power consumption - 20 mA
  • Camera: TTL Serial JPEG Camera
    • Spec: It can take pictures
      • Frame speed: 640*480 30fps
      • Current draw: 75mA
      • Operating voltage: DC +5V
      • Communication: 3.3V TTL
    • We will controlling it using the raspberry pi

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Payload Radio

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Ultimate Choice: XBee Pro 60mW PCB Antenna - Series 1 (802.15.4)

  • Manufacturer: Digi
  • Frequency: 2.4 GHz
  • Power Consumption: 215 mA

Payload Radio Antenna

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According to the specifications given by the website for the radio, an antenna will not be required. The radio comes with an antenna that should give us the required signal strength, but testing is needed to confirm this.

Payload Power

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Ultimate Choice: Dynamite Speedpack NiMH 1800mAh 6C Battery DYN1050EC

  • Battery Configuration: 6-Cell Flat
  • Power Capacity: 1800 mAH
  • Mounting: Battery will have two end caps that will be screwed onto the payload sled.
  • Protection circuits: buck transformer

zip ties not end caps

Payload Power Distribution

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Electrical Power System Design

  • Regulators: Buck Converter to convert from 7V to 5V
  • Power Distribution: parallel circuit
  • Power Management: buck converter

Payload Power Budget

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  • Battery
    • 12.96 watt-hours
    • 1800 milliamp output
    • 7.2 volts

  • Electronics
    • Camera - 75 milliamp consumption
    • Radio - 215 milliamp consumption
    • Raspberry Pi Zero - 500 milliamp consumption

Maybe add all the small stuff??

Software

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Alana

Changes Since PDR

  • Since we are now using a raspberry pi zero W, we will be using python instead of c++ for the software.

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Software Flow Chart

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Payload Software Design

  • Identify software states and how software transitions to each state
    • Power up - The Raspberry Pi Zero W doesn’t have a power switch: as soon as we connect it to a power outlet, it will turn on. It needs an SD card to put the code in the raspberry pi.
    • Integration- Vertical integration
    • Launch- when the rocket starts, the pi will turn on and start to record the data.
    • Transmission - The code operates by taking the data from the rocket and records it to the SD card.
    • Landing - when the rocket lands, the pi will turn off.

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vertical Integration -the process of integrating subsystems according to their functionality

Software Development Plan

  • Prototyping tool- Figma
  • Software subsystem development sequence -
    • First, we used Figma for prototyping (which we have completed). Then we have started programming the raspberry pi zero W. Then we are going to do the testing.
  • Development team - Alana Barth and Kevin Osowski
  • Test methodology - Spiral Model because it is more flexible with the requirements, allows more time for exploring options, and leaves room for possible error.

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Ground Station

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Henry

Changes Since PDR

  • No changes were made to the design of our ground station

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Ground Station Design

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Radio

Laptop

Rocket

Ground Station Antenna

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  • We do not plan on needing an additional antenna at this time, as the radio we ordered has one installed.
  • The radio has a listed range of 1 mile, but testing is needed to verify.
  • Our ground station is hand held.

Ground Station Software

The use of a pre existing

software packet is still in discussion but one has not been chosen.

This is a prediction of our telemetry display:

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Package

Ground Station Portability

The ground station is always portable due to it simply being a laptop with a radio attached. The battery life will be around 16 hours

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Testing

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Alana

Payload Testing

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  • Testing will begin by making sure each component works individually. i.e plugging the altimeter into an old circuit setup to make sure it works

  • Once we know every subsystem works, we will integrate everything into the current system and test for strains on the arduino

  • Short of launching the rocket, testing can be done by moving the payload and testing for a change in altitude and any accelerations

Rocket Testing

  • Parachute deployment testing will be done by detonating the charges with the rocket still on the ground, allowing us to check that everything works.
  • We have a test launch planned for mid February which will be our flight test.

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Flight Operations

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  • Insert payload into the rocket and secure

  • Screw nose cone on

  • Flip power switch

  • Check to make sure every subsystem receives power

  • Launch

Program Schedule

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  • November 30th - finish PDR
  • December 3rd - begin construction of payload bay
  • December 10th - begin construction of rocket
  • January 31st - finish CDR and submit it
  • February 21th - finish rocket
  • February 28st - finish payload bay
  • March 7th - begin integration of rocket and payload
  • March 14th - finish initial integration and begin troubleshooting
  • March 20th - finish troubleshooting and have integration complete
  • March 20th - March 28th - conduct all testing and make necessary modifications
  • March 30th/31st - competition

Program Budget: Rocket

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Part Description

Quantity

Unit

Price

Total Price

2.56" Nose Cone

1

ea

$17.25

$17.25

2.56" Body Tube

2

30"

$8.37

$16.74

38 mm MMT

1

34"

$6.88

$6.88

Coupler

1

6"

$3.35

$3.35

G-75 Motor

6

ea

$23.39

$140.34

Motor Casing

1

ea

$105.00

$105.00

Cost of rocket:

$289.56

Program Budget: Payload

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Part Description

Quantity

Unit

Price

Total Price

Video Camera

1

ea

$39.95

$39.95

Pitot Tube

1

ea

$23.29

$23.29

Arduino Nano

1

ea

$22.00

$22.00

Battery

1

ea

$17.29

$17.29

Buck Converter

1

ea

$9.95

$9.95

Cost of Payload:

$112.48

Mention that everything not shown here is already available in club inventory

Program Budget: Travel

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Food

3

ea

$50.00

$150.00

Tolls

2

ea

$26.00

$52.00

Rental Car

1

ea

$273.57

$273.57

Gas

25

gal

$2.80

$70.00

Hotel

2

rm

$170.00

$340.00

Cost

$885.57

Total cost (rocket, payload, and travel): $1,287.61

Summary

  • Some of our parts have arrived, and we are waiting for the last few parts to come in
  • Initial construction of the rocket has begun, and construction of the payload will begin once the rest of the parts come in

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