Drag and Atmospheric Neutral Density Explorer

Transcription

1 Drag and Atmospheric Neutral Density Explorer Winner of University Nanosat V Competition Engineering Challenges of Designing a Spherical Spacecraft Colorado Undergraduate Space Research Symposium April 18,

2 University NanoSat Program 2

3 The University Nanosat Program University Nanosat The National Championships of Spacecraft Design 2 year program now in its sixth iteration 10 out of 30 university proposals selected based on Air Force Relevance $85k initial seed funding for hardware and student support On January 20 th 2009, CU wins the Nanosat 5 competition. Winning an additional $85k, I&T at Kirtland, and flight to Orbit CU Nanosat Entry Has involved a core team of graduate students and expanded to over 60 graduate and undergraduate students Many aspects of the ASEN Graduate Projects but organized as independent research and MS research Has leveraged over $240k from University, Department, DoD, and COSGC Funds DANDE picture courtesy of University of Colorado at Boulder 3

4 The DANDE Mission 4

5 Mission Motivation: Prediction Capability Development Improved Thermospheric Model and First-Ever Measurements Better Prediction and Near Real Time Observations Low cost to deploy Validation and improvement of models HWM (NRL) TIME-GCM (NOAA) HASDM (AFRL/A9A) Improved drag coefficient modeling End goal transfer to small satellite community interested in precise orbit operations in LEO Storm response of CHAMP E/W winds 5

6 DANDE Analogy : as DANDE : The DoD has been interested in neutral density since it has been interested in spacecraft Important to: tracking (NORAD) re-entry formation flying and rendezvous Orbit prediction 6

7 Mission Timeline Day 1 Day 2 Phase 1: LV Separation and commissioning ( km) 1. Launch Mode - time delay Safe Mode 2. Full charge and checkout [18 30 hours] 3. Lightband jettison LV SEPARATION AND COMMISSIONING PHASE Phase 2: Attitude Acquisition 1. Spin Up [24 h] 2. Spin-Axis Alignment [120h] 3. Reserve time [24h] Phase 3: Science [~90 days] 1. Science Mode 2. Standby Mode 3. Comm. Pass 4. Attitude Adjust 5. Repeat Wind Composition Acceleration Tracking DATA ACQUISITION 1 orbit SCIENCE 1 orbit STANDBY DOWNLINK/UPLINK ~2x in 24 hours ATTITUDE ADJUST ~1 orbit per day SCIENCE PHASE Tracking Day 9 Day 100 RE-ENTRY DYNAMICS ~LAST WEEK OF ORBIT 200 km 100 km 7

8 Engineering Challenges of a Spherical Spacecraft 8

9 DANDE_Satellite CC18.JPG Power Generation Air Force Tracking limits the design to Modified Sphere Reduced area for the solar array Cosine loss around the hemisphere Large Arrays cause more drag Solar Panel Trade Study: UN5-SYS121.0 Creation of a hybrid method 9

10 Power Generation Solder Solar Cells Solder Diode & Wiring Epoxy Panels Mount to Hemisphere Total Fabrication time: 2 Weeks 10

11 Power Generation Hybrid Method produces a unique thermal condition Panels insulated from the spacecraft Rise to the thermal extreme and no throughput to conduct heat away 11

12 Attachment to Rocket Body Lightband Planetary Systems Corporation 12

13 Attachment to Rocket Body Flat-mount Rocking V-mount Spinning Rocking Ball-mount Translation Rotation 13

14 Communications and Radiation Pattern CDH PC Spacecraft RS-232 SYMEK TNC31 Ground Station RS-232 SYMEK TNC31 MODEM AUDIO 9,600 TX / RX MODEM 9,600 TX / RX AUDIO SPACEQUEST TX SPLITTER SPACE- QUEST RX YAESU FT847 LOW POWER RF HIGH POWER RF 70cm YAGI HIGH POWER RF 70cm PATCH ANTENNA 70cm PATCH ANTENNA 2m PATCH ANTENNA 2m YAGI Feed point Grounding Antenna 14

15 Communications and Radiation Pattern Anechoic Chamber Testing Antenna Gain Pattern 15

16 Testing Actuator Testing Instrument Calibration Anechoic Chamber Vibration Test Solar Cell Trade Study Mechanism Tests Electronics and Software Thermal Conductivity 16

17 Future of the Colorado Student Satellite Continued Testing (spin table, bakeout, thermal vacuum, communications, calibration) Integration and delivery this year! Launch around 2011 (solar maximum) DANDE picture courtesy of University of Colorado at Boulder 17

18 QUESTIONS? 18

19 Backup Slides 19

20 Technology Development: Accelerometers Measures accelerations with sub-µg precision Status: Calibration Testing through June 2009 TRL 1 TRL 6 End goal low cost drag monitoring method 10-1 Measured Frequency Domain 1/3 Hz drag signal Filter Response Frequency [Hz] 20

21 Technology Development: Mass Spectrometer Measures Wind, Composition, and Temperature Preliminary Testing Complete Status: Calibration testing planned end of May 2009 TRL 3 TRL 6 Important addition to observing the atmosphere Applies to future SWARM missions and DSMP 1.2 PHI = V max = raw data low-pass filter Gaussian fit peak center half-peak width 0.8 dv = SDEA Voltage (V) 21

22 Lessons Learned Having the right mission Choosing the right scope Identify the tall poles : cost/difficulty can we do 90% of the mission with half the cost and risk? REQUIREMENTS: Take your time and do the requirements correctly. Refine the analysis but be careful of paralysis by analysis KEEP IT SIMPLE: BETTER IS THE ENEMY OF GOOD PLAN FOR ITERATIONS TESTING, TESTING, TESTING The biological subsystem, the most important part of the program Respect class schedules and schoolwork. Align research with the program where possible Work around advisors schedules and don t be afraid to ask for help 22