Neutral Buoyancy Test Evaluation of Hardware and Extravehicular Activity Procedures for On-Orbit Assembly of a 14 Meter Precision Reflector

Neutral Buoyancy Test Evaluation of Hardware and Extravehicular Activity Procedures for On-Orbit Assembly of a 14 Meter Precision Reflector
Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
Total Pages: 38
Release: 2018-12-31
Genre:
ISBN: 9781792938283

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A procedure that enables astronauts in extravehicular activity (EVA) to perform efficient on-orbit assembly of large paraboloidal precision reflectors is presented. The procedure and associated hardware are verified in simulated Og (neutral buoyancy) assembly tests of a 14 m diameter precision reflector mockup. The test article represents a precision reflector having a reflective surface which is segmented into 37 individual panels. The panels are supported on a doubly curved tetrahedral truss consisting of 315 struts. The entire truss and seven reflector panels were assembled in three hours and seven minutes by two pressure-suited test subjects. The average time to attach a panel was two minutes and three seconds. These efficient assembly times were achieved because all hardware and assembly procedures were designed to be compatible with EVA assembly capabilities. Heard, Walter L., Jr. and Lake, Mark S. Langley Research Center NASA-TM-107735, NAS 1.15:107735 RTOP 506-43-41-02...

Extravehicular Activity Compatibility Evaluation of Developmental Hardware for Assembly and Repair of Precision Reflectors

Extravehicular Activity Compatibility Evaluation of Developmental Hardware for Assembly and Repair of Precision Reflectors
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 64
Release: 2018-07-08
Genre:
ISBN: 9781722391324

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This report presents results of tests performed in neutral buoyancy by two pressure-suited test subjects to simulate Extravehicular Activity (EVA) tasks associated with the on-orbit construction and repair of a precision reflector spacecraft. Two complete neutral buoyancy assemblies of the test article (tetrahedral truss with three attached reflector panels) were performed. Truss joint hardware, two different panel attachment hardware concepts, and a panel replacement tool were evaluated. The test subjects found the operation and size of the truss joint hardware to be acceptable. Both panel attachment concepts were found to be EVA compatible, although one concept was judged by the test subjects to be considerably easier to operate. The average time to install a panel from a position within arm's reach of the test subjects was 1 min 14 sec. The panel replacement tool was used successfully to demonstrate the removal and replacement of a damaged reflector panel in 10 min 25 sec. Heard, Walter L., Jr. and Lake, Mark S. and Bush, Harold G. and Jensen, J. Kermit and Phelps, James E. and Wallsom, Richard E. Langley Research Center...

Evaluation of Hardware and Procedures for Astronaut Assembly and Repair of Large Precision Reflectors

Evaluation of Hardware and Procedures for Astronaut Assembly and Repair of Large Precision Reflectors
Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
Total Pages: 72
Release: 2018-09-19
Genre: Science
ISBN: 9781723834172

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A detailed procedure is presented that enables astronauts in extravehicular activity (EVA) to efficiently assemble and repair large (i.e., greater than 10m-diameter) segmented reflectors, supported by a truss, for space-based optical or radio-frequency science instruments. The procedure, estimated timelines, and reflector hardware performance are verified in simulated 0-g (neutral buoyancy) assembly tests of a 14m-diameter, offset-focus, reflector test article. The test article includes a near-flight-quality, 315-member, doubly curved support truss and 7 mockup reflector panels (roughly 2m in diameter) representing a portion of the 37 total panels needed to fully populate the reflector. Data from the tests indicate that a flight version of the design (including all reflector panels) could be assembled in less than 5 hours - less than the 6 hours normally permitted for a single EVA. This assembly rate essentially matches pre-test predictions that were based on a vast amount of historical data on EVA assembly of structures produced by NASA Langley Research Center. Furthermore, procedures and a tool for the removal and replacement of a damaged reflector panel were evaluated, and it was shown that EVA repair of this type of reflector is feasible with the use of appropriate EVA crew aids.Lake, Mark S. and Heard, Walter L., Jr. and Watson, Judith J. and Collins, Timothy J.Langley Research CenterORBITAL ASSEMBLY; EXTRAVEHICULAR ACTIVITY; REFLECTORS; TRUSSES; ORBITAL WORKERS; SPACE MAINTENANCE; ASTRONAUT TRAINING; AEROSPACE ENVIRONMENTS; SPACE TOOLS; PANELS; WEIGHTLESSNESS; SIMULATION; SPACE ERECTABLE STRUCTURES

Government Reports Annual Index

Government Reports Annual Index
Author:
Publisher:
Total Pages: 1448
Release: 1993
Genre: Government reports announcements & index
ISBN:

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