1 ARMADILLO – SHOT II The University of Texas at Austin Post-flight Analysis Travis Imken Shaina Johl Christopher McBryde Travis Sanders July 1 st, 2012 Boulder, CO

Mission Overview The ARMADILLO SHOT II payload will verify the systems-level functionality of multiple subsystems on ARMADILLO 1.CDH computer boots and interfaces with subsystems 2.Flight software executes and stores data to SD card 3.COM uplinks and downlinks 4.EPS provides constant and steady power 5.GPS collects data and calculates position 6.NVS (camera) collects pictures of the flight 7.Magnetometer measures Earth’s magnetic field 8.Pressure/temperature sensor collects flight data 2

Expected Results 3 From the mission objectives: 1.CDH computer boots in 120 seconds with automatic interface to subsystems 2.Flight software executes all code and data is recorded 3.COM internally indicates downlink *(ground radio deaf) 4.EPS provides power for whole flight 5.GPS has a position fix and records all visible satellites 6.Camera takes pretty pictures 7.Plausible magnetic field measurements 8.Relevant pressure and temperature measurements

Quick Recap 4 ARMADILLO systems integration flight was a mixed success: Four complete successes (and the pressure sensor too) Two partial successes and one failure, all with understanding Many ARMADILLO lessons learned… and we’re still smiling!

Results: Success and Failure – 1 1. CDH Computer and Kraken First log file created after 90 seconds (Linux boot complete) and no hardware restarts –Matches flatsat and SDL results Log files created for all interfaced subsystems. Software logs indicate interfaces with COM, NVS, GPS, and magnetometer were established with no errors 2. Flight Software and SD Card Flight software automatically executed on boot launching four separate executables Data streams established with all data collecting subsystems and recorded to SD card SD card data parsed after flight on ground station computer with no errors 5

Results: Success and Failure – 2 3. COM Downlink and Uplink COM software enabled radio and transmitted packets as shown by collected log file No packets were received or transmitted by ground station handheld radio due to handheld hardware failure before SHOT –Tests prior to SHOT departure showed GS radio deaf at 20 feet –UT Austin ground station antenna (200 feet away through building) received packets perfectly. Results as expected, but unable to independently verify success. 4. EPS Power Distribution Power provided for flight and field-sitting – 2.4 hours! Components used a peak of 15 watts (COM transmit) and averaged 10 watts on 3.3 and 5V Voltage drop from 8.04V to 7.33V (~65% power capacity used) and is much better than expected 5V current limit may have been reached (next slide) by EPS protection design EPS heaters were not activated 6

Results: Success and Failure – 3 5. GPS Data and Analysis GPS powered on, interfaced by CDH, and created log files Log files were not populated with data indicating no satellites seen All antenna connections good and GPS still operational Lab tests (on power supply) indicated all hardware functional Failure Analysis – Most Likely Scenario: GPS assembly nominally draws 5V 1.5A but occasionally spikes to 1.7A EPS limits 5V to 2.5A. Sum of other components and GPS likely caused limit to be hit, resetting the GPS and preventing fix from being established ARMADILLO Impact and Lessons Learned Balloon GPS assembly had additional interface boards to process data and communicate with the old CDH interface board. This board consumes an additional 2.5W (0.5A) and is not for flight. ARMADILLO power budgets cycle GPS modes and power to prevent this (Power-current budgets established pre-PDR and kept up-to-date) 7

Results: Success and Failure – 4 6. Camera taking pictures for the presentation NVS operated as expected on in-house software and took 264 pictures, but… Flight pictures looked like this:And should have looked like this: Contrast settings in software made everything white due to sunlight Camera software configured from SDL star tests (lots of black pictures) ARMADILLO Impact and Lessons Learned Easy in-house software fix to make aperture/contrast controllable for using flight camera for star tracking, visual navigation, and pretty images 8 Saturday room picture

Results: Success and Failure – 5 7. Magnetometer Measurements 110 minutes of magnetometer data collected at 10 Hz. Magnetic field magnitude within 3% of expected values from National Geophysical Data Center 9

Results: Success and Failure – 6 7. Magnetometer Measurements Continued Three axis measurements are plausible but will require analysis Appears to have little interference from other electronics. ARMADILLO flight is more isolated and includes shielding. 10

Results: Success and Failure – 7 8. Pressure Measurements Ground pressure measured to be 14.4 psia – very plausible! Max altitude pressure measured to be 0.35 psia – very plausible! Temperatures varied inside: –26C at launch –10.4C minimum inside –Up to 50C in the field – toasty ! Would have been nice to correlate with GPS altitude data from ARMADILLO or EOSS Altitude correlation could be compared to atmospheric pressure and temperature models of the atmosphere ARMADILLO Impact and Lessons Learned Interior was warm with ~50% of the flight hardware in the box CubeSat thermal control is important and iterates the need for analysis (already part of the UNP deliverables!) 11

Results: Success and Failure – 8 12 LAUNCH POWER ON BURST? TOUCHDOWN TEMPERATURE PRESSURE GROUND COOKING

Conclusions 13 The ARMADILLO SHOT II payload was an overall success. All subsystems were operational with mixed data success EPS provided power longer than expected Flight-like software and flight-like CDH hardware configuration performed exactly as planned with no errors All hardware recovered in working order for continued EDU development and PQR preparations Plenty of things to go back to Austin and work on after catching up on sleep!

Actions for ARMADILLO 14 Action Items: Diagnose GPS unit health and performance upon return to UT Perform similar Flatsat test with EPS and monitor current and validate against current budgets Incorporate various software tweaks for camera and flight software Diagnose our handheld ground radio for future testing Continue work on thermal analysis to look at internal heating Impact to UNP-7 ARMADILLO: GPS Investigation – the unit will still fly! –GPS unit flew successfully on sounding rocket earlier in 2012 –No interface boards used in flight; Kraken v2 has SPI interface –Different and better antenna (L1 + L2 frequencies) is used in flight

15 Happy Canada Day