Minnesat SHOTII Presentation, June 16th, 2006 11

Minnesat

University of Minnesota

Jason Mintz

Jim Pogemiller

Abdul Azeem Khan

Vincent Jusuf

SHOT II Presentation

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Mission Overview

• Collect GPS sensor data in an atypical environment• Compute payload attitude from GPS sensor data • Compare GPS attitude to attitude from MIDG INS

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SHOT II / UN-4 Connection

• Minnesat Mission Statement: The purpose of Minnesat is to design, construct, and validate an ultra-short baseline GPS attitude determination system in Earth orbit.

• SHOT II experiment will verify ultra-short baseline design approach of GPS attitude determination system

• SHOT II experiment will test algorithms used to compute attitude from GPS receivers

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SHOT II Design and Test Details

• SHOT II payload structural design:– Aluminum GPS housing– Foam-core housing– Polyethylene wrap insulation– Composite antenna mounting arm

• SHOT II payload electrical design:– 4 A hr, 2 cell (7.4 V) Li-Poly battery– Step down DC regulator to power GPS receivers & Computers (7.4 V 5 V)– 9 Volt Battery to power MIDG unit

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SHOT II Design and Test Details

• SHOT II experiment design:– 4 GPS antennas 4 GPS receivers ( 1 per antenna)– Antennas mounted to replicate baselines between GPS antennas on Minnesat– MIDG IMU truth system– 5 GUMSTIX Computers

• Data logger: one for each receiver & MIDG

• Test program: 2 hour functional test– Verify operation in extreme temperature cases: – Hot case on hot rooftop– Cold case in dry ice cooler

• User Guide Compliance– Mass– Payload Interface: Polyethylene tubing, Washers & Pins (Similar to SHOT I)– Electrical grounding: GPS box– Battery powered: Li-Poly GPS, GUMSTIX & 9 Volt MIDG

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Expected results

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Expected Results

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Demonstration