DANDE - Operations and Implications Tanya Hardon Franklin Hinckley

Transcription

1 DANDE - Operations and Implications Tanya Hardon Franklin Hinckley 7 August 2014 SSC14-XI-8 1

2 DANDE Mission DRAG and ATMOSPHERIC NEUTRAL DENSITY EXPLORER Mission Statement Explore the spatial and temporal variability of the neutral thermosphere at altitudes of km, and investigate how wind and density variability translate to drag forces on satellites. 2

3 How Measurements are Made A atmosphere F D V V W ρ - density C D tracking WTS sensor accelerometers a priori measured solution solution F D 1 C 2 D A 2 V V M a W a priori knowledge a priori knowledge solved a priori knowledge Obtain values for all variables in the drag equation Near-spherical shape creates attitude-independent cross-section and coefficient of drag Near-spherical shape allows post-operational life use as tracking target 3

4 DANDE Satellite Accelerometers WTS Sensor Torque Rod 4

5 Mission Phases Launch: September 29 th, 2013 Separation from the Lightband Adapter Bracket: October 30 th, 2013 (Minimum Mission Success) Brief Re-contact: February 7 th, 2014 Activation ADCS Instrument Checkout Phase Health Checkout Magnetometer Verification Torque Rod Verification Task Launch 9/29/13 Separation 10/30/13 Loss of Contact 1/9/14 5

6 Activation and Separation Activation Identify which object was DANDE 28 objects No GPS position Object C s (DANDE) TLE was not updated for several days Satellite health checkout Separation Timing Targeted separation over Maui Optical Station Lack of GPS required careful timing Possible with minor modifications to existing time-based scheduler 6

7 ADCS Instrument Verification Magnetometer Verification Verify the magnetometer s magnetic field readings Needed independent knowledge of DANDE s orientation Torque Rod Verification Verify that firing the X and Y torque rods produced the correct response Data was difficult to downlink Scope Increase in predicted mission lifetime led to scope creep 7

8 Training Entirely student team Approximately 150 over the course of the mission 9% 3% 22% Experience STK, SolidWorks, MATLAB, Altium, Thermal Desktop, C, Bash Professional quality and complexity Industry Mentorship Lockheed Martin SNC Ball Aerospace L3 Communications 33% 33% 8

9 Experience 9

10 Training Suggestions Each operator should be reasonably proficient at each task Any group of operators can do a good job Integrate the operators with the engineers early Engineers need perspective Talk to past operators Operators need experience Assist DITL debugging Consider the needs of the operators from the beginning Design for an operator-friendly system 10

11 Data Analysis 11

12 Beacons Beacon interval of 15 seconds Useful for tracking 24% of all data downlinked was beacon data Beacon data should be intended for operators Not all fields were useful Some implied by reception Amateur submitted beacons ¾ of total beacon count Thousands more partial beacons First and last contact 12

13 Autonomous Operations Consider how the satellite acts without operator commanding Issues requiring active operator management File generation Controlled power usage System stability Contingency planning What happens if an error occurs Robust and thorough safe mode Handle many errors Prevent exacerbating those errors Can remain in this mode indefinitely 13

14 Ground Station Training does not replace actual experience Operations team had little stick time with the ground station Ground station team separate from operators until launch Operators did not learn quickly Debugging handled by ground station engineers Suggestions Have operations team assist pre-launch testing Take the time to let operators work through issues Let the newer operators run passes even when senior members are present 14

15 Conclusions Entirely student team Professional level project experience Industry-standard tools Career Development Mission successes Met Minimum Mission Success Continued for two months thereafter Lessons learned Integrate operators with satellite and ground engineers Test contingencies Safe mode Monitor scope creep 15

16 Sponsors 16

17 Sponsors 17

18 Questions? Presenters: Tanya Hardon Franklin Hinckley August 7, 2014 DANDE: Operations and Implications Colorado SpaceGrant Consortium Co-Authors: Brenden Hogan Brian Sanders 18