NASA Scientific and Technical Aerospace Reports - The University ...

20100017226 NASA Johnson Space Center, Houston, TX, USA
Orbital Debris: Quarterly News, Volume 14, Issue 2
Liou, J. C.; April 2010; 12 pp.; In English; Original contains color illustrations
Report No.(s): JSC-CN-20368; No Copyright; Avail.: CASI: A03, Hardcopy
ONLINE: http://hdl.handle.net/2060/20100017226
This bulletin contains articles from the Orbital Debris Program office. This issue’s articles are: ‘Orbital Debris Success
Story --A Decade in the Making’, ‘Old and New Satellite Breakups Identified,’ ‘Update on Three Major Debris Clouds,’ and
‘MMOD Inspection of the HST Bay 5 Multi-Layer Insulation Panel’ about micrometeoroid and orbital debris (MMOD)
inspection of the Hubble Space Telescope (HST) insulation panel. A project review is also included (i.e., ‘Small Debris
Observations from the Iridium 33/Cosmos 2251 Collision.’) There are also abstracts of conference papers from the staff of the
program office.
CASI
Micrometeoroids; Space Debris; NASA Programs
20100017776 Jacobs Technologies Engineering Science Contract Group, Houston, TX, USA
Results and Analysis from Space Suit Joint Torque Testing
Matty, Jennifer; [2010]; 8 pp.; In English; International Conference on Environmental Systems, 11-15 Jul. 2010, Barcelona,
Spain; Original contains color illustrations
Contract(s)/Grant(s): 731384
Report No.(s): JSC-CN-20467; Copyright; Avail.: CASI: A02, Hardcopy
ONLINE: http://hdl.handle.net/2060/20100017776
A space suit’s mobility is critical to an astronaut’s ability to perform work efficiently. As mobility increases, the astronaut
can perform tasks for longer durations with less fatigue. Mobility can be broken down into two parts: range of motion (ROM)
and torque. These two measurements describe how the suit moves and how much force it takes to move. Two methods were
chosen to define mobility requirements for the Constellation Space Suit Element (CSSE). One method focuses on range of
motion and the second method centers on joint torque. A joint torque test was conducted to determine a baseline for current
advanced space suit joint torques. This test utilized the following space suits: Extravehicular Mobility Unit (EMU), Advanced
Crew Escape Suit (ACES), I-Suit, D-Suit, Enhanced Mobility (EM)- ACES, and Mark III (MK-III). Data was collected data
from 16 different joint movements of each suit. The results were then reviewed and CSSE joint torque requirement values were
selected. The focus of this paper is to discuss trends observed during data analysis.
Author
Space Suits; Mobility; Torque; Astronauts; Extravehicular Mobility Units
20100017827 NASA Johnson Space Center, Houston, TX, USA
Observed Coupling Between the International Space Station PCU Plasma and a FPMU Langmuir Probe Facilitated
by the Geomagnetic Field
Hartman, William; Koontz, Steven L.; [2010]; 1 pp.; In English; Spacecraft Charging Technology Conference, 20-24 Sep.
2010, Albuquerque, NM, USA
Report No.(s): JSC-CN-20624; Copyright; Avail.: Other Sources; Abstract Only
Electrical charging of the International Space Station (ISS) is a matter of serious concern resulting from the possibility
of vehicle arcing and electrical shock hazard to crew during extravehicular activity (EVA). A Plasma Contactor Unit (PCU)
was developed and integrated into ISS in order to control the ISS floating potential, thereby, minimize vehicle charging and
associated hazards. One of the principle factors affecting ISS electrical charging is the ionosphere plasma state (i.e., electron
temperature and density). To support ISS electrical charging studies a Floating Potential Monitoring Unit (FPMU) is also
integrated into ISS in order to measure the ionosphere properties using Langmuir probes (LP). The FPMU was located on the
Starboard side of ISS. The PCU is located near the center of ISS with its plasma exhaust pointed to port. From its integration
on ISS in 2006 through November of 2009, the FPMU data exhibited nominal characteristics during PCU operation. On
November 21, 2009 the FPMU was relocated from the Starboard location to a new Port location. After relocation significant
enhanced noise was observed in both the LP current-voltage sweeps and the derived electron temperature data. The enhanced
noise only occurred when the PCU was in discharge and at unique and repeatable locations of the ISS orbit. The cause of this
enhanced noise was investigated. It was found that there is coupling occurring between the PCU plasma and the FPMU LP.
In this paper we shall 1) present the on-orbit data and the presence of enhanced noise, 2) demonstrate that the coupling of the
PCU plasma and the FPMU measurements is geomagnetically organized, 3) show that coupling of the PCU plasma and the
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