Critical Design Review Agenda 1) OverallVehicle Design 2) Motor - - PowerPoint PPT Presentation

Critical Design Review

1) OverallVehicle Design 2) Motor Selection 3) Flight Stability Margin 4) Thrust toWeight Ratio 5) Flight Stability Margin 6) Sub-scale Model 7) Kinetic Energy 8) Drift Calculations 9) Recovery Subsystem 10)Payload Subsystem 11)Education 12)Requirement Compliance 13)Next Steps 14)Timeline

Agenda

Vehicle Sub Section Length (Inches) Nose Cone 20 Payload Bay 18 Main Parachute 18 Electronics Bay 9* Drogue Chute Bay 15 Lower Body Assembly 30

Vehicle Dimensions

• Overall length is 86.97 inches
• Weighs 25.1 pounds
• Universal Outer Diameter: 5 inches
• Universal Inner Diameter: 5 inches
• Wall Thickness: 0.079 inches

Payload Ejection Bay

• 4:1 Ogive style nosecone
• Material of Construction: G12 Fiber glass with aluminum tip
• Base Diameter: 5”
• Length: 20”

Vehicle Design - Nosecone

• Material of Construction: G12 Wound Fiberglass tubing
• Single Diameter Airframe
• Length: 67 inches
• Outer Diameter: 5 inches
• Wall Thickness: 0.079 inches

Vehicle Design - Airframe

• Design
• G12 Filament Wound Fiberglass
• 5“ diameter
• 18” length
• Connected to nosecone via 4 shear pins
• Attached to coupler that houses the CO2

deployment system

• 2 rail system and T frame holds payload stationary

Vehicle Design – Payload Bay

Vehicle Design – Main Parachute Bay

• SkyAngle Cert 3 Large 80” parachute
• Attach to ¼" welded eyebolt by self-tightening knot
• After tied will epoxy knot
• ½” tubular nylon shock cord
• Length 25’
• Ejected at 700’

• G12 Filament Wound Fiberglass
• 5" tube coupler
• 5" coupler bulkheads
• 2 threaded steel rods
• Used to retain coupler
• Outer 1” ring
• Allows easy access to the arming switches
• Eye bolt on bulkhead
• Will have parachute and shock cord attached

Vehicle Design – Electronics Bay

• 5” diameter
• Length 30”
• Motor Mount supported by 3 centering rings
• 75” diameter
• 16” length
• Motor retainer that uses screw compression
• Fins mounted by Through-the-Wall Construction
• Contains the drogue chute bay

Vehicle Design – Lower Body Assembly

• 32” SkyAngle parachute
• Built in lower body Assembly
• Connected to aft section of the electronics bay by ¼” wield eye bolt
• Attach to eye bolt with tightening knot and epoxy
• 4 mil-spec tubular nylon shroud lines

Vehicle Design – Drogue Chute Bay

• Motor Mount
• Material of Construction: 75mm G12 Fiberglass tubing
• Length: 16”
• Supported in place by fiberglass centering rings
• Each ring is filleted on both inner and outer sides of mating edge
• Motor Retainer
• AeroPack
• Material of Construction: Aluminum
• Secured to body utilizing epoxy and screws

Vehicle Design – Motor Mount & Retainer

• Material of Construction: G12 Fiberglass
• Thickness: 0.1875”
• Method of Attachment
• Through-the-wall mounting method
• Secured to motor tube with epoxied fin tabs
• 3/8" ≤ fillet desired
• 4 symmetrical trapezoidal fins
• 11” root cord
• 3” tip cord
• 6” sweep length
• 4.5” height

Vehicle Design - Fins

• Fiberglass
• G12 body tube, couplers, nosecone, and fins
• Balance of weight and strength
• Readily available and easy to work with
• Steel
• Threaded rods, washers, bolts, and eyebolts
• Cheap, easy to find, and durable
• Plywood
• Sled of electronics bay
• Light weight
• Easy to work with

Material Overview

• Kevlar
• Blast shield and shock chord
• Strength and fire resistant
• Nylon
• Parachute, shear pins, gears, and gear tracks
• High tensile strength
• Quick to deploy
• Readily available

Material Overview

• Motor: Aerotech K1000T-P
• Motor Diameter: 75 mm
• Weight: 90.8 oz
• Thrust to Weight Ratio: 9:1
• Rail Exit Velocity: 70.7 ft/s on 8’ 1515 rail
• Max Thrust: 1,140 N
• Average Thrust: 1,012 N
• Impulse: 2,497 N*s
• Max Velocity: 645 ft/s
• Mach Equivalent: 0.575 Mach
• Burn Time: 2.47 seconds

Final Motor Selection

Flight Stability Margin

• Static Stability: 2.15
• Dynamic Stability: 2.75
• Center of Pressure: 65.91”
• Center of gravity: 55.15”

• Was made with a LOC IRIS 3.10" Kit and an AeroTech DMS H100 motor
• Similar shape fins
• Flight was recorded using an AltusMetrumTeleGPS
• Max altitude 1325’
• Max velocity 301 ft/sec

Sub Scale

• Total mass 10.202 kg
• Zero Separation Scenario
• Terminal velocity 55.94 ft/sec
• Kinetic energy of section one 679.898 Lbf
• Single separation Scenario
• Terminal velocity 55.94 ft/sec
• Kinetic energy of section one 679.898 Lbf
• Kinetic energy of section two 413.814 Lbf
• Dual separation Scenario
• Terminal velocity 19.4 ft/sec
• Kinetic energy of section one 70.181 Lbf
• Kinetic energy of section two 11.592 Lbf
• Kinetic energy of section three 49.771 Lbf

Kinetic Energy at Landing Single Separation Scenario

Drift Calculations

Tail wind velocity Nominal Drift Distance 0 mph 0.00 5 mph 582.30 10 mph 1164.60 15 mph 1746.90 20 mph 2329.20

• Two StratologgerCF altimeter
• Two new 9V batteries
• Two initial blast caps each with 2g of black powder
• Two backup blast caps each with 3g of black powder
• Two bulkheads connected with two threaded rods
• Lower half contains 32” drogue parachute
• Upper half contains 80” main parachute
• Sections are tethered by tubular nylon shock chord

Recovery Subsystem

• On launch rail altimeters are keyed on
• At apogee, the main altimeter ignites the first lower ejection charge, that

ejects the drogue parachute

• One second after apogee, the backup altimeter ignites the second lower

charge as a backup

• At 700’ above the ground the main altimeter ignites a upper ejection charge,

ejecting the main parachute

• At 650’ above the ground the backup altimeter ignites the second upper

ejection charge as a backup

Recovery Subsystem

• CO2 nosecone deployment
• Autonomous deployment of rover and

solar panels

• Radio transceiver
• 433 MHz
• ~40mW output power
• Electric coupling from rover to CO2

deployment circuit

• GPS/IMU positioning system
• Local and remote data logging

Payload Subsystem

• Geared wheel deployment
• Four wheel drive
• Sliding solar panel system
• GPS/IMU distance tracking
• Operates independent of orientation
• Can drive upside down or right side up
• IMU to detect orientation of rover

Rover Design

• Gear Wheel Design
• Rests easily on the rack and pinion in the

payload bay

• Determined to have sufficient traction on the

terrain of the launch field.

• Allows use of one system for driving and

deployment

Rover Wheel Design

• Six 1.378" x 1.654" x 0.079" panels
• Output 223 mW at 6.3 V
• Produced by IXYS Solar as a part of

their IXOLAR series

• Deployed with a HiTec Ultra-Nano

Servo

• Total deployed surface area of 6.838
• sq. In.

Solar Panel Design

• Peregrine CO2 ejection system to deploy

nosecone

• Nosecone attached to payload bay with

shear pins

• Rover deploys itself after nosecone has

been ejected

• Alleviates risk of nose mass or binding

preventing deployment of the rover

Payload Deployment System

• Battery and control electronics

all mounted on the rover

• GPS
• IMU
• 5 Servos
• 2S LiPo Battery
• Transceiver
• Electrical coupling to CO2 e-match

triggering system

• Spring-loaded pogo pins
• Simply drive away rover to 'release' from

system

Payload Electronics

• Rover Board
• ATMega32U2
• 8MHz, 3.3 V Operation
• GPS chip and antenna all in one
• Inertial moment unit
• AX5043 Radio Transceiver
• 433MHz ¼ monopole antenna
• Ground Station
• ATMega32U2
• AX5043 Radio Transceiver

Payload Electronics

Rover board Ground station board

• Servos control
• Each servo driven by a PWM pin from the microcontroller
• Will handle turning by slowing one side
• CO2 ejection system
• Main activation is controlled by key switch
• Secondary control is continuity check between the rover and e-match control circuit
• Setting off the E-match will require the rover to verify that it is not moving and the

radio signal to go has been received

Payload Electronics

• GPS
• Low update rate
• Positional accuracy only 2.5m
• Can safely overshoot minimum required

distance

• IMU
• High update rate
• Use accelerometer and gyroscope to

evaluate distance

• Error builds up over time
• Combine
• Reduce total error
• Kalman Filter Approach

Distance Evaluation System

• Boy Scouts Rocket Camp
• 317 Youth (K-6th)
• Assisted kids in the construction and launching of kits
• Helped adult educators
• Hallow-engineering
• 35 Youth (K-8th)
• Helped local kids launch balloon rockets

Education

• Engineering Design Challange
• 160Youth (10th-12th)
• Designed and carried out rules of competition
• Winter Banquet
• 210 Youth (5th-12th)
• 20 Adult
• Assisted in the construction and launching of rockets with A-B engines

Education Cont.

• Future Events
• Clay High School
• 9th-12th grade
• Present to upper level physics classes
• Launch a rocket with F motor
• Boy Scout Troop in Akron, Ohio
• 5th-12th grade
• Space Exploration merit badge

Education Cont.

• Test: Rover communication range
• 0’ to 2329’
• Test: Rover is able to leave airframe
• Test: CO2 ejection charges
• Test: Rover is able to move a minimum distance of 5’
• Test: Solar panels deploy from rover
• Test: Parachute deployment

Test plans and Procedures

• Building will begin in late January
• Launch location is TBA
• Planning to fly in mid-February
• tentatively on the 24th
• Parts have been ordered and are on their way

Next Steps: Full-Scale Test Flight