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Original Date: 04/26/1999
Revision Date: 01/18/2007
Best Practice : Docking and Berthing
NASA has successfully performed several docking/berthing maneuvers throughout the space program’s history. In the early 1970s, Marshall Space Flight Center (MSFC) created a six-degrees-of-freedom (6DOF) contact-dynamics simulation. This advanced technology process ensures the integrity and reliability of space hardware during a docking/berthing maneuver. Until recently, all 6DOF testing was performed at ambient temperature and atmospheric pressure. The development of the International Space Station (ISS) program, however, created a new dimension for testing. All remote fly-ins and docking/berthing of space hardware must be conducted in a thermally-controlled vacuum environment. In addition, the ISS Common Berthing Mechanism (CBM) requires testing to be performed under operational vacuum and thermal conditions.
To meet these requirements, MSFC adapted its V20 Thermal Vacuum Environmental Test Chamber to perform tests using 6DOF’s operational capabilities:
Positional tolerance of +0.05 inch and +0.10 degrees
Motion range of +5 degrees for roll, pitch, and yaw; +6 inches for translation in the horizontal plane; and 24 inches for vertical travel
Payload weight of 2,500 pounds
This one-of-a-kind test facility also provides visual cues and pilot-in-the-loop studies; analytical contact-dynamics simulations; real-time anomaly resolution for ISS berthing; pilot-in-the-loop proximity operation to dock/berth mechanism hardware; and contact-dynamics testing of 1:1 scale to dock/berth hardware under operational thermal and vacuum conditions.
Since utilizing the V20 facility for docking/berthing simulations, MSFC realized many benefits for the ISS program. These include testing hardware under operational vacuum and thermal conditions; redesigning the alignment guides and latches; identifying mechanical interference problems; setting up functional testing of the CBM; and determining operational constraints of CBM hardware. In addition, NASA pilots gain familiarization with all aspects of docking and berthing. The real-time anomaly resolution for ISS berthing will provide a safety net for missions throughout the ISS’s assembly.
For more information see the
Point of Contact for this survey.
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