Cansat 2008: University of New Hampshire Final Presentation

University of New Hampshire

University of New HampshireUniversity of New Hampshire

CANSAT Final PresentationJune 15th 2008



WildCatSat Team



Outline

• Design Overview• Raw Data Plots• Processed/Analyzed Data Plots• Outcome of Flight Ops/Failure Analysis• Comparison of Actual CONOPS to Planned

CONOPS


University of New HampshireUniversity of New HampshireMechanical Design Overview

System Bus:• ABS Plastic• Rapid Prototype using 3-D

Printer

Recovery System:• Octagonal Parachute

– Rip-Stop Nylon– Area: 1.016 m2

• Nylon Cord



Up-righting System:• Hinged side doors • Torsion springs provide force to open doors• Pin connected to servo motor holds doors in

place/releases doorsParachute Release System:• Pin attached to side door• Pin holds parachute to bus while doors closedTotal Measured Mass: 470g

Mechanical Design Overview



Structural Drawings


University of New HampshireUniversity of New HampshireElectrical System Diagram

ProcessorPressure Sensor

Transceiver

Buzzer Servo

Transceiver

Computer


University of New HampshireUniversity of New HampshireElectrical Design Overview

Sensors:• SCP1000 Barometric pressure and temp. sensorMicroprocessor:• Atmel ATMega168Transmitter:• Aerocomm AC4790-1000MBattery• 11.1V 800 mAh Li-Poly• 12.26V Initial, 12.19V After Mission: 0.7V Drop



Ground Station Computer:• HP Pavilion N5425

Ground Station Receiver:• Aerocomm ConnexLink 4790

Ground Station Antenna:• External high gain omni-directional antenna

Ground Station



Raw Data Plots



Processed Data

0 20 40 60 80 100 120 140 160 180 2008.4

8.6

8.8

9

9.2x 10

4

Mission Time (s)

Pre

ssur

e (P

a)

0 20 40 60 80 100 120 140 160 180 200-200

0

200

400

600

800

Mission Time (s)

Alti

tude

(m)

Note: Matlab truncation of LS digit = loss in accuracy



Processed Data (cont.)

(Processed with Matlab’s ‘Diff’ and ‘Filter’ functions and window size of 10)

From VTI Tech: “Assumed constant temp. gradient of dT/dH from 1976 US Standard Atmosphere”

H = 30°C/(6.5°C/km)*(1-(P/101325Pa)^0.19

20 40 60 80 100 120 140 160 180 2000

1

2

3

4

5

6

7

8

9

10

Flight Time (s)

Des

cent

Rat

e (m

/s)

Reference: VTI Technologies



Flight Operations

• Altitude Transmission: Success • Average Descent Rate: 3.3767 m/s• Descent Time: (1340s-1160s)/60 ~3 min


University of New HampshireUniversity of New HampshireFlight Operations (cont.)

• Recovery: Success• Up-righting System: Success • Ground Temperature (bonus): Not Met

From: 34.48.097N 101.35.244WTo: 34.47.88N 101.35.562W

~1.28km Lateral Distance Traveled

Reference: http://www.movable-type.co.uk/scripts/latlong.html



• Pattern Loss ~30%• Ground Absorption• Terrain• Ground Station Antenna height

a) Elev. Pattern b) Azimuth PatternReference: Aerocomm Corp.

Failure Analysis



• Satellite activated• Satellite loaded into rocket• Satellite takes initial pressure reading• Rocket launches• Satellite detects pressure change, starts sending pressure/altitude data • Satellite ejects from rocket• Parachute deploys, slowing descent• Satellite descends at less than 4.6 m/s• Satellite continues to transmit data

• Satellite lands• Doors open up-righting satellite• Parachute released• Buzzer activates• Ground temperature reading and transmission• Data transmission stops

Preparation

Launch

Deployment

Descent

Recovery

CONOPS Comparison


University of New HampshireUniversity of New HampshireWildCatSat Sponsors

– UNH ECE Dept.– UNH ME Dept.

• Jon Arlington at Orbital Sciences Corp.

• The Byrd Family

Todd GrossProfessor and Chair

May-Win TheinAssociate Professor

http://www.unh.edu/

http://www.baesystems.com/

http://www.albint.com/

http://www.dimatix.com/

http://www.nhsgc.sr.unh.edu/index.shtml

http://www.unh.edu/mechanical-engineering/people_m_thein.html

http://www.unh.edu/mechanical-engineering/people_t_gross.html



Questions?

Professor May-Win Thein

Project Advisor

Ph.D Mechanical Engineering

[email protected]

Robert TerryTeam Leader

Electrical Engineer

[email protected]

Cansat 2008: University of New Hampshire Final Presentation

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