BalloonWinds Update --Straight to Launch--

1. BalloonWinds Update--Straight to Launch-- James M. Ryan University of New Hampshire

2. BalloonWindsInstrument Overview • Size: 8’x8’x12’ • Gondola Mass: 6000 lbs • Power Requirements: 1300 W • Power System: • 26 Lithium-Ion Batteries • Thermal Management: • Ice and Electric Heaters • Optical Systems: • Diode-Pumped Nd:YAG • ½-meter Telescope • Direct-Detection Receivers (2)

3. Gondola and Control

4. 2007 TVAC Failure

5. Chamber Reviews Laser Chamber Material 6061-T6 Aluminum Volume (empty) 10 cubic feet Design Pressure 18 psig Test Pressure (Hydrostatic) 28 psig Assembly Test Pressure (Pneumatic) 22.5 psig (1.5 MEOP) Interferometer Chamber Material 304L Stainless Steel Volume 14 cubic feet Design Pressure 16.5 psig Assembly Test Pressure (Pneumatic) 22.5 psig (1.5 MEOP)

6. Chamber Reviews (cont.) Coolant Tank Material 304L Stainless Steel Volume (empty) 18 cubic feet Design Pressure 18.75 psig Test Pressure (Hydrostatic) 28 psig Assembly Test Pressure (Pneumatic) 22.5 psig (1.5 MEOP) Electronics Chamber Material 304L Stainless Steel Volume (empty) 30 cubic feet Design Pressure 18.75 psig Test Pressure (Hydrostatic) 28 psig Assembly Test Pressure (Pneumatic) 22.5 psig (1.5 MEOP)

7. Schedule Delay • AFRL postponed environmental tests • Schedule slip by the preceding instrument • Fixed schedule for the succeeding instrument • Test window closed • 6-month slip in launch schedule with rescheduled test date TBD

8. Rescheduling Process • 2-week window emerged in July-August • New TVAC Facility cleanliness requirements • Assessment began • Flowdown from new requirements • Risk & risk reduction • Impact of risk-mitigation • Environmental test objectives

9. TVAC Facility • Large investment in facility for two optical payloads • Class-100 inside TVAC chamber • Class-100 outside TVAC chamber • Select material list • No particulates • No liquids or volatiles • No silicone-based materials

10. Flowdown from New Requirements • Meticulous cleaning of gondola • Prepare comprehensive material list • Removal or encapsulation of forbidden materials • Vacuum grease • Coolant • Insulation • Wood

11. Risk & Risk Reduction • Facility contamination was primary risk • Risk reduction measures included • Bagging gondola • Reduced altitude simulation • Reduced temperature range (tropopause) • All support equipment located outside facility • No schedule or admittance guarantee after completion of all known requirements

12. Impact of Risk-Mitigation • Gondola’s thermal properties different from flight configuration • T-P profile not representative of flight profile • Consumable state and burn rate not representative of flight • Limited to one cycle. 2nd cycle logistically impractical.

13. Environmental Test Objectives • Verification of thermal system operation • Heating/cooling capacities (duty cycles) • System performance (temperatures vs set points) • Time required to equilibrate at final altitude • Revelation of impacts on opto-mechanical and detector systems • Laser: Power, seeding, frequency tuning… • Telescope: Motor control of focus adjustment… • Interferometer: Alignment, stability, motor control… • Detectors: Chip temperature, Gain, read noise…

14. Environmental Test Objectives (cont.) • Estimation of Mission Duration • Battery power burn rate & “knee” shape • Coolant system capacity & “knee” shape • Pressure chamber leak rates All impacted by risk mitigation efforts Test no longer matched with objectives

15. Straight to Launch • The new facility requirements • Increased resource requirements • Increased associated risk • Decreased benefit of test • Hindered original test objectives • Environmental tests were cancelled • Environmental test objectives rolled into flight objectives

16. Added Flight Objectives Procedures & Impacts • Verification of thermal system operation • Monitor temperatures and heating/cooling duty cycles • Modify temperature set points to counteract temperature and/or duty cycle issues • Raw data will be unusable until thermal stead-state is attained and the interferometer is aligned

17. Added Flight Objectives Procedures & Impacts • Revelation of impacts on opto-mechanical and detector systems • Monitor laser power, spectral widths, optical transmissions, photometric return, etc • Remote adjustments performed to reduce the impact • Raw data black-outs will occur during such adjustments

18. Added Flight Objectives Procedures & Impacts • Estimation of Mission Duration • Capacity for an 8-hour mission will be assumed • Monitor battery bus voltage, coolant temperature and chamber pressures • Cut-down will be initiated if the following value estimates are reached • Bus voltage limit- 25V • Output manifold temperature- 4C • Chamber pressure limit- 0.8 atm

19. Advantages of Not Testing • Schedule contingency • Released resources • Reduced risk of mishandling

20. Revised BalloonWinds Schedule

21. Additional

22. Laser ChamberPre-Failure Cross-supports 2947½-inch lid (0.35-inch eff. thickness)

23. Laser ChamberPost-Failure I Cross-supports Secondary fractures from gondola impact Lid bottom Thermal insulation (yellow)

24. Laser ChamberPost-Failure II Cross-support Secondary fractures from pipe interference Lid bottom Fibertek Laser

25. Laser ChamberPost-Failure III Reverse angle showing the disorder

26. Laser ChamberPost-Failure IV Fragments at the bottom of the thermal-vacuum chamber