critical design...

Illinois Space Society 1

Critical Design ReviewUniversity of Illinois at Urbana-Champaign

NASA Student Launch 2017-2018


Overview


Launch Vehicle Summary

Javier Brown


Flight Profile


Current Launch Vehicle Design

1) Ejection charge at apogee

2) Drogue deployment at apogee

4) Main parachute deployment at 800 feet

3) Nose cone separation and parachute deployment at 1000 feet

Nose cone

Upper body tube

Coupler

Booster tube


Vehicle Major Dimensions

Total Length: 130’’

Total Mass: 43.5 lb.

Nosecone: 30’’

Upper Airframe: 48’’

Payload Bay: 14’’

Avionics Coupler: 16’’

Booster Frame: 48’’

Outer Diameter: 6’’

Root Chord (Fins): 12’’


Launch Vehicle Materials

Upper Airframe and Booster Frame: Blue Tube

– High Strength

– Proven benefits based on past usage

Bulkheads: Aircraft Plywood

– Adequate structure support

– 0.25” thick

Centering Rings: Aircraft Plywood– Desired additional support due to thrust considerations

Fins and Nosecone: Fiberglass

– High Strength

– Proven benefits based on past usage


Static Stability Margin

Stability @ liftoff: 2.42 calibers

Current CP location: 97.064’’

Static CG location: 82.331’’


Motor Selection

Motor: L1420R-P

Diameter: 2.95’’

Max thrust: 374 lbf･s

Total impulse: 1038 lbf

Burn time: 3.18s

T/W ratio: 8.48

Off-rail speed: 60.1 ft/s


Motor Subsystem

RMS 75/5120 Motor Casing

– Constructed from high strength aluminum

Motor Mount Tube

– 24’’ Blue tube (Vulcanized, high density)

– Center rings permanently fixed

Plywood centering rings

– Utilized 3 rings for assurance

Aero pack 75 mm Retainer


Booster Subsystem

Housing for the Motor Subsystem

3 16′′

fiberglass fins

– Slotted between centering rings and filleted for absolute support

Integrated 1515 rail buttons (x2)

Houses drogue parachute and tubular Kevlar shock cord

– deploys at apogee

Rail button


Avionics Coupler Section

Parachute connections via U-bolts

1 4’’ threaded rods to support sled

Contains recovery electronics and ejection charges

3’’ Switch Band

– Rotary Switches (x2)


Avionics Bay Recovery Hardware

Parachutes

– Main: Iris Ultra 96’’

– Drogue: Fruity Chutes Elliptical 18’’

– Nosecone: SkyAngle 36’’

Black powder ejection charges

– Ignited by e-matches

1 2’’ tubular Kevlar shock cord

Redundant altimeters

– 1 Telemetrum altimeter for altitude and tracking

– 1 Stratologger altimeter for altitude

• Will be official competition altimeter


Upper Airframe

Houses Payload

– Hardware and Electronics

Contains main parachute

– Shock cord


Nosecone

6’’ Ogive 5:1 shape

Material: Fiberglass

Houses nosecone electronics and hardware

– Parachute and shock cord

– Redundant Altimeters (x2)

• Telemetrum

• Stratelogger


Custom MATLAB Flight Simulator User Interface

OpenRocket simulation tools were also utilized and verified with MATLAB.


Flight Simulations


CFD Analysis

Pressure analysis conducted on the launch vehicle

Determine the reliability and safety of avionics in the nosecone

Pressure variations subside very quickly as curvature decreases


Simulation Results

Apogee:

– OpenRocket – 5438 ft

– MATLAB – 5010 ft

Offrail Velocity:

– OpenRocket – 60.1 ft/s

– MATLAB – 63.7 ft/s

Maximum velocity:

– OpenRocket – 678 ft/s

– MATLAB – 701 ft/s

– Vertical Velocity (Avg) – 643 ft/s

Future work will be conducted to narrow the discrepancies between the custom MATLAB simulator and OpenRocket, using higher fidelity models.


Drift Predictions

Predictions determined using OpenRocket. Will be verified by MATLAB in future work.

All predictions are well within the stipulated threshold of 2640 ft.

SectionDrift in 0 mph

winds (ft)

Drift in 5 mph

winds (ft)

Drift in 10 mph

winds (ft)

Drift in 15 mph

winds (ft)

Drift in 20 mph

winds (ft)

Booster and

Upper Airframe9.3 590 1041.4 1614.3 2335.32

Nosecone 9.3 349.1 791.1 1430 2117


Kinetic Energy

Predictions determined using OpenRocket.

Terminal Velocities

– Nosecone – 20.67 ft/s

– Upper Airframe and Booster Frame 1st separation:

• Drogue – 36.27 ft/s

• Main – 11.95 ft/s

Kinetic Energies

– Booster Frame – 26.25 ft ･lbf

– Avionics Coupler – 14.74 ft ･lbf

– Upper Airframe – 21.55 ft ･lbf

– Nosecone – 29.85 ft ･lbf

All kinetic energies are with specified threshold of 75 ft ･lbf


Vehicle Verification Plan

Detailed verification plan can be found in CDR report

Focus on quantitative comparison

– Scrutinize and catalog launch vehicle components as they arrive

Paramount milestones

– Incremental testing of all components during the build process

– Aerodynamics have been verified by subscale launch but other performance issues were observed and addressed as they occured.

– Full-scale model will be verified during test launch


Subscale Vehicle

~ 1/2 scale model of full-scale launch vehicle

– Material - Exact to that of the full-scale vehicle

– Stability margin – 2.27 calibers

Data from test launch was used to address the possible performance issues that may arise in the full scale model


Subscale Launch Vehicle

Test flight occurred on January 8th, 2018 in Wisconsin Team members were able to practice proper launch preparation techniques


Subscale Flight Results

Off rail launch procedure was precise and typical of any launch. All recovery systems worked without problems.

There was some deviation from the flight profile,

which may have been the result of stability

issues manifesting in the vehicle.

It is suspected that the fins were not

suitable.


Comparison between Flight Data and Simulation


Deployable Rover Payload

Destiny Fawley and Ryan Noe


Payload Requirements

Design a remotely activated custom rover that deploys from the internal structure of the launch vehicle.

- Must remain inside rocket until landed

- On-board communication system

- Correct orientation to exit after landing

The rover will autonomously move at least 5 ft. (in any direction) from the launch vehicle.

- On-board program facilitates movement

- Traverse field terrain

Once the rover has reached its final destination, it will deploy a set of foldable solar cells.

- Solar panel deployment mechanism on rover

Internal Requirements

- 5 lb. or less

- 6” or smaller diameter rocket


Payload Overview

Lazy Susan Orientation Mechanism

Deployable Rover

Two systems:

- Lazy Susan Orientation Mechanism

- Deployable Rover



Screw bulkhead into body tube

Axle gear bolted to bulkhead

Servomotor rotates platform

Rover secured with servo latches



Lazy Susan controlled by Arduino Micro

Redundant Rotation Trigger

– Detect launch/landing with accelerometer/gyro

– Receive signal from Ground Station

Rotate platform with gyroscope input


Wheel Orientation and Rover Mobility

MORRTE Wheel Configuration

Segmented body provides mobility

– Similar to RHex robot

– Bio-inspired

– Six wheels provide redundancy

– Will be updated with grip pads

Path of Travel

Rhex Robot

Image from makezine.com


Rover Sensors and Power Systems

Redundant Drive Trigger

– Time delay from ground station signal

– Lazy Susan ‘Green’ signal

Drive forward

Deploy solar panel

– Record solar power data

Middle Segment


Latching Mechanism

Locking Mechanism

– Controlled by Lazy Susan Arduino

– Thicker hooks for strength

– 0.2” hook clearance

– 0.1” servo clearance


Solar Panel Deployment

3D printed non-spring loaded hinges

– Shape to fit solar cells

– Facilitate solar panel deployment

– Hold cells together

Servo controls movement

– Actively holds closed during launch

– Opens hinge when commanded by Arduino

Servo 3D Printed HingeSolar Cells


System Dimensions/Mass

Rover

– 12.77 x 3.94 x 4.35”

Platform

– 14.12 x 4.5 x 4.25”

Total Mass: 3.75 lbm


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