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Exploiting orbital effects for short-range extravehicular transfersThe problem studied in this paper is that of using Simplified Aid for Extravehicular Activity (EVA) Rescue (SAFER) to carry out efficient short-range transfers from the payload bay of the Space Shuttle Orbiter to the vicinity of the underside of the vehicle, for instance for inspection and repair of thermal tiles or umbilical doors. Trajectories are shown to exist, for the shuttle flying noise forward and belly down, that take the astronaut to the vicinity of the underside with no thrusting after the initial push-off. However, these trajectories are too slow to be of practical interest, as they take roughly an hour to execute. Additionally, they are quite sensitive to errors in the initial push-off rates. To overcome both of these difficulties, trajectories are then studied which include a single in-flight impulse of small magnitude ( in the range 0.1 - 0.4 fps). For operational simplicity, this impulse is applied towards the Orbiter at the moment when the line-of -sight of the EVA crewmember is tangential to the underside of the vehicle. These trajectories are considerably faster than the non-impulsive ones: transit times of less than 10 minutes are achievable. Furthermore, the man-in-the-loop feedback scheme used for impulse timing greatly reduces the sensitivity to initial velocity errors. Finally, similar one-impulse trajectories are also shown to exist for the Orbiter in a gravity-gradient attitiude.
Document ID
19950049820
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Williams, Trevor
(Cincinnati Univ. Cincinnati, OH, US, United States)
Baughman, David
(Cincinnati Univ. Cincinnati, OH, US, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1993
Publication Information
Publication: In: Spaceflight mechanics, 1993; AAS(AIAA Spaceflight Mechanics Meeting, 3rd, Pasadena, CA, Feb. 22-24, 1993, Parts 1 & 2 . A95-81344
Publisher: American Astronautical Society (Advances in the Astronautical Sciences, Vol. 82, Pts. 1 & 2)
ISSN: 0065-3438
Subject Category
Space Transportation
Accession Number
95A81419
Distribution Limits
Public
Copyright
Other

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