1. 1 Formation Flying Shunsuke Hirayama Tsutomu Hasegawa Aziatun Burhan Masao Shimada Tomo Sugano Rachel Winters Matt Whitten Kyle Tholen Matt Mueller Shelby Sullivan Eric Weber

2. 2 Design A satellite that will fly escort to the space shuttle Satellite provides visual inspection of shuttle exterior for 24 hour period of time Satellite will be transported into space on shuttle Satellite must meet University Nanosat requirements Rachel Winters (2/30)

3. 3 Previous Work AERCam “Sprint” –Successfully tested on STS-87 for 1.25 hours around Orbiter –Live video feed –Remote controlled Mini AERCam –Successful ground tests –Live video feed, including orthogonal view –Remote and supervised autonomous control options http://aercam.jsc.nasa.gov/ http://spaceflight.nasa.gov/station /assembly/sprint/index.html Rachel Winters (3/30)

4. 4 Improvements Our design is... –Completely autonomous –Powered sufficient to operate for 24 hours –Supervision is only necessary for launch and retrieval Rachel Winters (4/30)

5. 5 Systems Integration & Management Rachel Winters, Matt Whitten Major Tasks: Expendable vs Recoverable spacecraft Recovery method design Determine shuttle-interface requirements Determine picture order Rachel Winters (5/30)

6. 6 Relative Orbit Control & Navigation Kyle Tholen, Matt Mueller Major Tasks: Determine relative orbit to meet mission requirements Determine major disturbances from orbit and counteract them Single vs Multiple spacecraft trade study Determine thruster equipment Find Tank size Determine navigation method Rachel Winters (6/30)

7. 7 Configuration & Structural Design Shelby Sullivan, Eric Weber Major Tasks: Find camera and lens Camera field of view analysis Design structure (material, shape) Configure component positioning Mass budget Solidwork components Rachel Winters (7/30)

8. 8 Attitude Determination & Control Shunsuke Hirayama, Tsutomu Hasegawa Major Tasks: Determine method of attitude control Single vs Multiple cameras Determine pointing accuracy necessary Determine torque disturbances Rachel Winters (8/30)

9. 9 Power, Thermal & Communications Aziatun Burhan, Masao Shimada, Tomo Sugano Major Tasks: Determine power needed by satellite Battery only vs Solar Cell + Battery Define thermal environment (outside and inside sources) Determine method of heating Determine transmission method Determine differential drag Integration for CPU Rachel Winters (9/30)

10. 10 Trade Studies Expendable vs Recoverable Satellite –less expensive to reuse –viable method of recovery –reasonable amounts of extra fuel needed Single vs Multiple Satellite(s) –amount of extra fuel needed for plane transfers –ability to “see” entire shuttle with only 1 satellite Rachel Winters (10/30)

11. 11 Solar cells + Battery vs Battery only –Amount of power solar cells can provide in 24 hr period –Amount of power needed by satellite components –Size of battery needed to compliment solar cells vs size of battery needed with no recharge Single vs Multiple camera(s) –Ability to control attitude –Camera size Trade Studies continued Rachel Winters (11/30)

12. 12 Design Walkthrough Assumptions and Requirements –Mass restricted to 50 kg –Volume restricted to 60x60x50 cm 3 –Necessary to operate for 24 hours, power source must last this long –Assumed an earth-relative orbit that was the same as the ISS orbit –Assumed our shuttle-relative orbit was within safety standards (r p = 118 m, r a = 237 m) Rachel Winters (12/30)

13. 13 Orbit Design –Accuracy of known location/velocity was important –Maintain a “safe” distance away from the shuttle –Remain within camera range Created a general orbit Rachel Winters (13/30)

14. 14 Orbit Design continued Determined orbital disturbances –J2 disturbances –Drag differences in Low Earth Orbit –This determined the amount of thrust needed to maintain desired orbit Rachel Winters (14/30)

15. 15 Orbit Design continued Plane change decided –Used a plane change to keep the number of satellites to 1 (Trade Study) –Affects the amount of cold gas needed Rachel Winters (15/30)

16. 16 We determined the type of attitude control we wanted: zero-momentum –It allows us to control all three axes of rotation –We needed to be able to point at the shuttle at all times –This determined the mode of control: Reaction Wheels We already needed control to counteract torque disturbances –Aerodynamic torque –Gravity-Gradient torque –Solar radiation pressure torque Satellite Design Rachel Winters (16/30)

17. 17 To simplify the process of calculating torque, we chose to design the center of mass to be in the center of the satellite We chose to make the satellite a 50x50x50 cm 3 cube to simplify the thermal analysis Satellite Design continued Rachel Winters (17/30)

18. 18 Satellite Design continued We modeled the components and satellite in Solidworks to map out what we wanted it to look like Rachel Winters (18/30)

19. 19 Thermal control designed –Found the temperature range of the environment –Found the temperature tolerance of hardware –Used the mass-based layout to determine necessary thermal control within satellite Satellite Design continued Rachel Winters (19/30)

20. 20 Satellite Design continued Power subsystem –Approximated power drain with major components –Made early approximation on battery/solar requirements –Determined number of solar cells we can support –Found power demand including all components –Determined back-up battery requirements Rachel Winters (20/30)

21. 21 Hardware determination Camera –Small mass, weight; operable in space conditions –This determined an orbit range to stay within Rachel Winters (21/30)

22. 22 Hardware continued Star tracker –For accurate attitude control, 2 sensors needed –Very accurate (within.001 degree) –Must not be exposed to sunlight Rachel Winters (22/30)

23. 23 Hardware continued Gyro –Adds accuracy to attitude determination –Included in Reaction Wheel System Rachel Winters (23/30)

24. 24 Hardware continued Reaction wheel –Used to keep shuttle in field of view –Able to induce up to 50 mNm of Torque Rachel Winters (24/30)

25. 25 Hardware continued GPS –Differential GPS used for location/velocity information –Light weight –Includes two antennas, two receivers Receiver Antenna Rachel Winters (25/30)

26. 26 Hardware continued CPU –Provides computer processing for hardware components –Includes several USB ports Rachel Winters (26/30)

27. 27 Hardware continued Transmitter (wifi) –Able to transmit large amounts of data over orbit range –Connects with USB port –Orbiter must also be connected to wireless network http://www.amazon.com/802-11G-Wireless-Adapt-FROM100- Meters/dp/B000MN8MV4 Rachel Winters (27/30)

28. 28 Hardware continued Thrusters –Needed to make orbital changes –Cold gas thruster system Nitrogen Tank Thruster Rachel Winters (28/30)

29. 29 Hardware continued Battery –Satellite needs power to operate for 24 hours –Use solar cells  minimize battery demand Rachel Winters (29/30)

30. 30 Hardware continued Heater –Some devices are temperature sensitive –Maintains temperature of satellite within allowable range Rachel Winters (30/30)

31. 31 Demonstration

32. 32 Recommendations for Future Work

33. 33 FMEA

34. 34 Thank you! For all your time and assistance. Mr. Surka Joe

35. 35 Questions? Comments? Formation Flying