may 21-25, 2007phase ii fsr1 iss hardware magnetic susceptibility testing and analysis trent martin...
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May 21-25, 2007 Phase II FSR 1
ISS Hardware Magnetic Susceptibility Testing and Analysis
Trent Martin
NASA AMS Project Manager281-483-3296
May 21-25, 2007 Phase II FSR 2
History
• To minimize operations constraints, the AMS project worked with Hamilton Sundstrand, Boeing, and MacDonald Dettwiler Robotics to ascertain realistic limits for ISS hardware
• Testing/analysis was performed specifically on EVA equipment and nearby ORU’s
• Without substantial additional funding MDR was unable to raise the level of certification of the SSRMS above a 10 gauss limit
• SSRMS limitations may require a reduction in the magnetic field during nearby SSRMS usage
May 21-25, 2007 Phase II FSR 3
35G
100G
200G
300G
600G
1000G
Geometric center of AMS-02 Cryomagnet
Y(OUT OF PAGE)
Z
X
Y
Z
X-RAM(INTO PAGE)
ORBITER
ISS(PAS)
May 21-25, 2007 Phase II FSR 4
XZ
Y
Y Z(into page)
X-RAM
ISS(PAS)
ORBITER
35G
100G
200G
300G
600G
Geometric center of AMS-02 Cryomagnet
1000G
May 21-25, 2007 Phase II FSR 5
Solar Array Rotary Joint
AMS
S3 Truss
ISS Outboard
35G
100G
200G
300G
600G
1000G
Adjacent Attached Payload Envelope
May 21-25, 2007 Phase II FSR 7
EVA Tool Testing• Testing performed June 5-9, 2000 in Advanced Space
Propulsion Lab (ASPL), at the Sonny Carter Facility and at the Hamilton Sundstrand Space Systems EMC Facility
• The purpose was to evaluate the Extravehicular Mobility Unit (EMU) System level, Flight Accessory, SAFER and PGT equipment operation for exposure to magnetic B field exposure during EVA
• Equipment was suspended in various orientations and moved through field to determine susceptibility up to a maximum field of 600 gauss
• Results were documented in Report: FEM-0032 and EMU 1- 13-054
• Results were used to raise certification level of this hardware from 63 gauss, to 300 gauss.
May 21-25, 2007 Phase II FSR 12
Testing of ISS ORU’s near AMS
• The Boeing Company analyzed and tested nearby ORU’s on the S3 Truss to ensure no susceptibility based on the magnetic field that would be present at their locations
• No issues were identified
May 21-25, 2007 Phase II FSR 13
SSRMS
• No testing has been performed on the Space Station Remote Manipulator Systems (SSRMS)
• Without other funded analysis MacDonald Dettwiler Robotics (MDR) has certified that the SSRMS can sustain up to 10X the earths magnetic field; roughly 10 gauss (total)
• Therefore, AMS magnet must either be deactivated while attached to the SSRMS or have a reduced field when SSRMS is operating in close proximity (adjacent attached payload site)
• While this is not ideal for mission success, AMS accepts this provisional operation for ISS Safety
May 21-25, 2007 Phase II FSR 14
Magnetic Field
• Certification Testing– Magnetic Field Mapping of the AMS-02 Cryomagnet– Magnetic Field Testing
• US EMU – Wireless Video System (WVS)/EMU RF Camera Assembly (ERCA)
transmits video but cannot switch lenses when exposed to fields in excess of 350 Gauss. Corrects itself when removed from field.
– Magnetic attraction of the EMU flight system equipment may exert a force of 8 lbs 4 oz when exposed at 600 Gauss. At this same level, the SAFER could not provide a means to rescue the crewmember.
– 300 Gauss set as new limit (factor of safety = 2)• Russian Orlan Suit – 175 Gauss set as new limit• Pistol Grip Tool (PGT)
– Stopped functioning at 250 Gauss, but recovered once removed from field.
– No damage at all up to 1000 Gauss.• Simplified Aid For EVA Rescue (SAFER)
– Experienced no failure at 1000 Gauss
May 21-25, 2007 Phase II FSR 15
Magnetic Field
• Certification Analysis– ISS Electromagnetic Effects Panel has reviewed
the following items which fall are on the S3 truss – all are acceptable with various caveats
• Umbilical Mechanism Assembly (UMA) • Capture Latch Assembly (CLA) • External TV Camera • Video Luminaire Assembly• Space Station Remote Manipulator System (SSRMS)• Special Purpose Dexterous Manipulator (SPDM)• RPCM• MDM
Component Design Magnetic
Field Level
Expected Worst Case AMS
Magnetic Field Level
Keep Out Zone Level
or Rational for no Keep Out Zone
EMU (Space Suit) 300 G 1000 G 300 G
Orlan (Russian Suit) 175 G 175 G 175 G
PGT >1000 G 1000 G 300 G (operates up to 250 G)
SAFER > 1000 G 1000 G 300 G
UMA None Established
(NE)
<6 G Fixed hardware that only operates in a field less than 6 G if an
adjacent payload is installed – currently not planned
External TV Camera NE <6 G Fixed Component
Video Luminaire Assembly
NE <6 G Fixed Component
SSRMS NE 8.4 G 10 G
SPDM NE 8.4 G 10 G
RPCM NE <6 G Fixed Component
MDM NE <6 G Fixed Component