Mission Overview

Rocket and Subsystems

Payload and Subsystems

Management

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Our Mission:

The MIT Rocket Team aims to develop and test methods of analyzing the causes and effects of fin flutter as it pertains to the flight of high

powered rockets.

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Launch rocket with 6 fins of different thicknesses, geometry, and materials ◦ Analytically demonstrate rocket stability with 6 fins

and additionally only the 3 non-fluttering fins. ◦ Attach strain gauges to fins to measure predicted

versus actual strain ◦ Purposely induce flutter or failure in 3 of 6 fins

Successfully deliver high school outreach payload

Visually identify flutter effects with high speed camera and custom mirror system ◦ Use image post-processing software to accurately

track fin movement

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Requirements: ◦ Launch rocket to 5280 ft

◦ Induce flutter in 3 test fins

◦ Deploy High School Science Payload

Concept ◦ Solid rocket motor

◦ Carbon fiber reinforced airframe

◦ Redundant flight computers

◦ Dual deployment recovery

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Design ◦ 9’0” Tall

◦ 6” Diameter

◦ 42 Pound liftoff weight

Key components ◦ Motor retention

◦ Fin Retention

◦ Avionics package

◦ Recovery package

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Airframe ◦ PML 6” Phenolic ◦ Carbon fiber: Soller Composites Sleeve ◦ Aeropoxy 2032/3660

Bulkheads & Centering Rings ◦ ½” Plywood ◦ Wood glued to motor mount tube

Fins ◦ G10/FR4 ◦ Mechanically attached and removable/replacable

Various ◦ Phenolic tubing: motor mount, avionics package ◦ Nylon: avionics assembly components ◦ Stainless steel: quick links, eye bolts ◦ Nomex: chute protectors, deployment bags

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Center of Pressure ◦ 91” from nose tip

Center of Gravity ◦ 67” from nose tip

Stability Margin ◦ ~3.9 Calibers

◦ ~3.2 without test fins

This is known to be excessive. Effects of liberating fins to be seen during multiple test flights. Lower margin will be used if possible.

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Body tube structural tests

Ejection Charge Tests

Fin drop tests

Avionics Tests ◦ Vacuum Chamber

◦ Electric match actuation

3 Full Scale Flight Tests on full motors

Opportunity for a total of 5 full scale flight tests

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Rocket Motor – Cesaroni L1395 ◦ 4895N-s impulse - more than enough to reach target

altitude given mass estimates

◦ Proven track record and simple assembly

◦ Cheaper and more reliable than Aerotech alternative

Full-scale Test Motor – Cesaroni L1395 ◦ Will provide nearly identical flight profile to test

flutter experiment

Thrust to Weight Ratio: 8.1:1

Rail exit velocity: 55ft/sec (assuming 66” of guidance)

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Subsystem Tests ◦ Ejection Charges ◦ Avionics ◦ Recovery

Fin

Vehicle

3 Full Scale Test Launches ◦ 1/21 at CRMRC ◦ 2/18 at CRMRC ◦ 3/18 at CRMRC or MDRA

2 Additional Flight Options ◦ 2/10 at METRA ◦ 4/2 at METRA

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Motor Retention ◦ Via 3/8” Threaded rod into forward closure

◦ Threaded rod passes through avionics bay to recovery attachment point

Avionics ◦ Beeline 70cm Trackers in each section

◦ Raven2 as primary altimeter

◦ Stratologger as backup

◦ Housed in 12” long coupler tube just above motor

◦ Trackers attached to recovery cords

◦ Avionics bay bulkheads shielded with foil tape

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Fin retention ◦ Custom designed glueless unit ◦ Will allow easy swapping of payload test fins ◦ Will allow reduction in stability margin after first

test flight if seen fit.

Airframe ◦ PML Phenolic reinforced with carbon sleeve ◦ Removable

Screwed into fin can centering rings

Force transferred from aft centering ring through airframe

◦ Phenolic coupler reinforced with carbon

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Nose cone ◦ PML 6” Fiberglass nose cone

◦ Houses drogue parachute

High School Science Payload ◦ 6” x 24” cylinder with outreach experiment from

local school

◦ Mass of no more than 8 pounds

◦ Between drogue and main. Extracted by drogue when main deploys

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5 ft drogue parachute Deployment at apogee

Shear 2x 2-56 screws

4.5 g black power charge

14 ft main parachute Deployment at 700

feet

Pulled out by high school payload

High school payload released by Tender Descender

Deployment Bag used

Final Descent Rate & Energy

System Under

Drogue 55 ft/s

1670ft-lbf

Nose/Payload Final

Descent Rate 19.1 ft/s

72ft-lbf

Rocket Body Under

Main 13 ft/s

60ft-lbf

Liberated Fin

<40 ft/s

<25 ft-lbf

Barometric testing

Deployment sensing

Altitude verification

Nose cone release

Shear pin failure force

Black powder charge

Separation distance

Charge release locking mechanism

Black powder charge

Operational verification

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• Tube-Stores payload during flight

• Charge released locking mechanism - releases sabot at 300 ft

• Chute Bag – ensures clean main parachute opening

• Separation of rocket and nose cone prevents parachute entanglement

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Main Chute Deployment Bag HS Payload

Drogue Chute

Broken Charge Released Locking Mechanism

Strain Gauges ◦ 8 on each fin ◦ Saved to SD card via Arduino

High-speed Cameras ◦ A Cassio Exilim camera for each fin ◦ Recording at 480 frames per second ◦ Securely mounted in avionics bay

Mirrors ◦ Mounted on the outside of rocket ◦ Enables head-on view of each fin

Software and simulations ◦ Rockety Online Fin Flutter Simulator ◦ Rocket Team Matlab Fin Flutter Simulator ◦ OpenCV image processing script ◦ Matlab strains to deflections converter

Data (Predicted vs Experimental) ◦ Time and velocity at which fins experience flutter ◦ Fin deflections versus time and velocity

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Fin flutter measurement system to quantitatively analyze the fin flutter induced modes in the three test fins

Software debugging

Mirror mount placement and rigidity

Camera placement and stability

Operational testing ◦ Strain gauges

◦ Radio relay circuits

◦ Data logging

◦ Electrical components

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2 Fins will be liberated during flight

Limiting velocity of 40ft/sec

Limiting energy of 25ft-lb

Each fin will have a tracker for location

Each fin will be painted in a contrasting color for visibility against the sky

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Tracker in tip of fin, no streamer ◦ Only acceptable if energy and

velocity are low enough, as shown through extensive drop tests

◦ Fins must be painted vibrant colors

Fin tethered to rocket body ◦ Tethered by a Kevlar cord

from the tip of the fin to the base of the rocket

◦ Likely not possible due to motor burning

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Tracker

Kevlar Cord tied to tip of fin, taped to bottom of fin and attached to base of rocket

Streamer attached to fin, tracker attached to streamer ◦ Streamer stored in small tube in base of

rocket ◦ Attached by a Kevlar cord tied to the tip of

the fin ◦ Kevlar cord taped to bottom of fin for

aerodynamic reasons

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Streamer with attached tracker

Kevlar cord between streamer and tip of fin

Streamer stored in tube in base of rocket. Tape is used to hold it in. It deploys when fin liberates and pulls it out

Attached Fin

Liberated Fin

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Month Date Task

September 10 Project initiation

November 28 PDR materials due

December 3 Construct Scale rocket

17 Scaled test launch

19 Initiate materials acquisition for full scale rocket

January 6 Return from winter break

6 Test MATLAB and openCV software

6 Initiate construction of fin unit

7 Initiate construction of test body tubes

7 Begin machining mirror mounts

7 Initiate construction of payload circuits

9 Perform tests on body tubes (crush, bending, etc).

9 Perform ejection charge tests

9 Perform tests on camera placement and mirror positions

10 Cut out fins

11 Perform fin unit tests

13 Initiate construction of flight body tubes

13 Initiate construction of avionics bay

15 Initiate construction of mirror system and avionics mounting system

15 Perform tests on electrical subsystems

16 Start integrating vehicle components

19 Prepare for full scale launch (pack parachutes, build motor, etc)

21 First full-scale test launch

23 CDR materials due

February 18 Second full-scale test launch

March 10 Optional full-scale test launch

17 Third full-scale test launch

26 FRR materials due

April 2 Optional full scale test launch

21 Competition launch

Boston Museum of Science Mid-January

MIT Museum: Mid-January

MIT Splash Weekend: 20 November

MIT Spark Weekend: Mid-March

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