Microgravity Environment Program on the International Space Station

1. Microgravity Environment Programon the International Space Station NASA Glenn Research Center (GRC)Principal Investigator Microgravity Services (PIMS)October 21, 2002

2. Components of Microgravity Environment

3. PIMS analyzes acceleration data from a number of acceleration measurement systems, such as: • Space Acceleration Measurement System (SAMS-RTS): [0.01-400 Hz] • Space Acceleration Measurement System (SAMS-TSH): [0.01-200 Hz] • Orbital Acceleration Research Experiment (OARE): [ 0.01 Hz] • Microgravity Acceleration Measurement System (MAMS): • • MAMS-OSS: [  0.01 Hz] • • MAMS-HiRAP: [ up to 100 Hz] Acceleration Measurement Systems localized vibratory measurements rigid-body quasi-steady measurements MAMS-OSS/HiRAP SAMS-RTS SAMS-TSH OARE

4. Science Supported • Biotechnology • Combustion • Fluid Physics • Materials • Fundamental Physics • Vehicle Dynamics Microgravity Support • Platforms SupportedMeasurement SystemsWhen • ISS ................................. SAMS, MAMS ................................ May 2001 - present • Shuttle ........................... SAMS, OARE, SAMS-FF ............... Jun 1991 - Jan 2003? • KC-135 .......................... SAMS, SAMS-FF ........................... 1997 - present • Sounding Rockets ......... SAMS-FF ........................................ 1997 • Mir .................................. SAMS ............................................. Aug 1994 - deorbit

5. PIMS Functions During Experiment Life Cycle

6. Space Acceleration Measurement System (SAMS) Microgravity Acceleration Measurement System (MAMS) packetGrabber packetGrabber packetGrabber packetGrabber REAL-TIME DISPLAYS REAL-TIME DISPLAYS REAL-TIME DISPLAYS REAL-TIME DISPLAYS listener/talker packet MONITOR CONTROL web data base archive packetWriter off-line analysis 01010101 Microgravity Analysis Software System

7. ISS Acceleration Data Archived by GRC

8. Impacts on Microgravity Science (Real-Time) pedaling shoulder sway MASS Provides Real Time Capabilities to Microgravity Investigations Problem: MASS knowledge base shared with TEMPUS experiment team revealed TEMPUS experiment would be adversely affected by crew exercise MASS Efforts: Monitored real time data stream and informed TEMPUS when exercise was started and completed Results: TEMPUS experiment able to safe experiment operations until MASS indicated exercise was complete

9. Impacts on Microgravity Science (Near Real-Time) MASS Provides Near Real Time Capabilities to Microgravity Investigations Problem: SOFBALL experiment sensitive to impulsive disturbances during execution of test points MASS Efforts: MASS provided near real time OARE data to the SOFBALL science team, revealing strong correlation between STS thrusters and SOFBALL science data Results: SOFBALL experiment able to request periods of STS free drift to eliminate the highly undesirable effects of the STS thruster activity

10. Impacts on Microgravity Science (Off-Line/Detail) 1 2 12 hours MASS Provides Off-Line Analysis of the Microgravity Environment in a Detailed Fashion Problem: Detailed analysis of acceleration data from specific time periods is needed to extract information about the microgravity environment MASS Efforts: MASS developed specialized analysis techniques Results: MASS data analysis techniques

11. Impacts on Microgravity Science (Off-Line/Summary) LSLE refrigerator compressors Antenna dither 2 Vehicle structural modes 1 WAKE SLEEP Centrifuge Exercise MASS Provides Off-Line Analysis of the Microgravity Environment in Summary Fashion Problem: Volume of acceleration data available needs to be processed into manageable, understandable formats MASS Efforts:MASS developed analysis techniques that consider extended periods of data Results:PCSA data plots “A recent analysis by us has shown a mean 58% success rate (success defined as an improvement) for microgravity missions compared to 30% where a microgravity environment was not a mission requirement. The microgravity environment is another variable that has to be considered for a successful experiment.” Dr. Edward Snell, USRA span > 15 days

12. Sensor - SAMS - F06 • SAMS 121f06 (on EXPPCS test section) • ~1½ ft. from mixer in EXPRESS Rack 2 • PEAK: 237 mg • 50%, 30-second duty cycle Rack-to-rack transmission of disturbance due to an experiment operation SAMS F05 ARIS-ICE POP ARIS-ICE Controller MAMS “Disturber” EXPPCS sample mixer SAMS F02 ER2 ER1 SAMS - F03 (Z-panel, ER2), PEAK: 22 mg SAMS - F04 (Z-panel, ER1), PEAK: 10 mg Impacts on Microgravity Science (Transmissibility)

13. Impacts on Microgravity Science (Transmissibility) • SENSOR: • MAMS HiRAP • in EXPRESS Rack 1 • SOURCE: • Shuttle: Atlantis STS-104, Flight 7A • docked at forward end of US Lab with Pressurized Mating Adapter (PMA-2) • EFFECT: • broadband (impulsive) especially at softmate • narrowband, 17 Hz (with harmonics) from nearly continuous dither of Shuttle’s Ku-band antenna …after hardmate hardmate STS-104 PEAK: 6 mg STS-105 PEAK: 14 mg softmate STS-104 PEAK: 10 mg STS-105 PEAK: 29 mg Ku: ~200 ugRMS (Shuttle) vs. ~40 ugRMS (ISS)

14. Impacts on Microgravity Science (Evolution) • DESCRIPTION: • STS-108 docked to the ISS in support of UF-1 mission • Difference in quasi-steady vector magnitude due to large shift in the center of mass (~35 ft) and new attitude for combined vehicles ISS + Shuttle mean = 3.11 g. ISS mean = 1.46 g.

15. Summary of Recent Events

16. PIMS Questions • How would you compare jolt from Progress docking to Shuttle? • Household awareness -- at home we might, on occasion, be cognizant that R/F compressor just kicked on (hear it, and if close enough maybe feel it). Were you ever aware of ISS equipment cycling on/off either hearing it and/or feeling it [particularly for vehicle systems, but experiment too]? • US Lab specific equipment on/off?