Critical Design ReviewNASA University Student Launch Initiative

University of Nebraska–Lincoln

2012-2013

Team Overview

• Mission– Build a launch vehicle to reach an 5,280 feet

altitude– Use a dual-deployment recovery system– Deploy a payload at 1,500 feet– Recover all components in a relaunchable

condition

Preliminary Design Discussion

Vehicle Overview

Length: 111”  

Diameter: 5.5”  

Nose cone: 34.6” Von Karman (LD-Haack), 5.5:1

Fin span: 15” (3-fin configuration)

Weight: 32.8 lbs (With motor and payload)

Motor Mount: 98mm 31” long

Stability Characteristics

• OpenRocket Model• Will need to be verified• Mass (with motor): 32.8 lbs• CG: 68.3 inches• CP: 78.7 inches

Launch Characteristics

• Candidate Motors– 75mm diameter– AMW L900RR-P

• Simulation Parameters– 10 foot guide rail

• Rail velocity: 43.32 feet/sec• Thrust-to-weight ratio: 8.33:1

Recovery• Mounting

– Nosecone Tethered to Transition

– Transition Tethered to Booster

– Forged U-Bolts

• Concept of Operations

– Drogue @ Apogee

– Main @ 1,500-Feet

• Main parachute 84” in diameter, 162” long

• Drogue shute 36” in diameter, X-form

• 52” and 30” of shock chord, 1 inch tubular nylon

• Nomex wadding, 24” length

Drift analysis

Kinetic Energy

Test

Structural test•150+ lbs man•No bending

Subscale Launch

Subscale

Actual results•Apogee 1357’•Max Vel. 459 ft/s•Weight 1.873

Final Payload Design

In our mission, the desired direction will be a GPS transmitter on the ground with the receiver in the probe. The goal is to have the GPS guide the probe using the systems on board to “Home base” which will be the launch pad. The scientific significance of this UAV is to introduce a convenience factor into recovery of rocket parts that have implicated the same hardware as this UAV will have.

Assembly

Nosecone

• Characteristics– Von Kármán (LD-

Haack)– 5.5:1 Fineness

• Communications– BRB 900 GPS

Transmitter– Antenna

Transition Assembly

• Components– 2 6-inch bulkheads

– One small step for man

– One 6-inch diameter polycarbonate plate

– One GoPro camera

– Two eyebolts

• Material– Alumium case

• Dimensions– Length – 6”

Avionics• Components

– Perfectflite StrattoLogger

– Featherweight Raven

• Concept of Operation

– Activated by external key switches

– Primary charge fired by both altimeters

– Secondary charge fires 5 seconds later by Raven

Functional RequirementsSystem Subsystem Requirement

Nosecone with payload bay

Primary System • Reduce drag force• Must not deform under flight loading• Mount drogue parachute• Couple with Sustainer

Communications Array • Transmit GPS location to Ground Station

Transition Primary System • House recovery and avionics bays• Must not deform under flight loading• Couple to payload bay• Couple to Booster

Recovery Systems • Tethers the Nosecone and Booster together

Avionics Bay • House Flight Computers• Mount Ejections Charges• Allows space for video camera

Functional RequirementsSystem Subsystem Requirement

Booster Primary System • House motor mount tube• Fin Mounting• Couple to Sustainer• Must not deform under flight loading• Transfer fin moment

Fins • Stabilize vehicle for flight• Must not deform under flight loading

Motor Mount Tube • Transfer axial motor thrust load• Mount Parachute to Engine Block• Retain motor• Allow quick installation of motor

Schedule

Outreach

• Previous Activities– Engineering Week– Astronomy Day– Lockheed Martin Space Day

• Current Collaboration– Water rocketry– Hosting Robotic Competition– Connect a Million minds