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Studying NASA's Transition to Ka-Band Communications for Low Earth OrbitAs the S-band spectrum becomes crowded, future space missions will need to consider moving command and telemetry services to Ka-band. NASA's Space Communications and Navigation (SCaN) Testbed provides a software-defined radio (SDR) platform that is capable of supporting investigation of this service transition. The testbed contains two S-band SDRs and one Ka-band SDR. Over the past year, SCaN Testbed has demonstrated Ka-band communications capabilities with NASAs Tracking and Data Relay Satellite System (TDRSS) using both open- and closed-loop antenna tracking profiles. A number of technical areas need to be addressed for successful transition to Ka-band. The smaller antenna beamwidth at Ka-band increases the criticality of antenna pointing, necessitating closed loop tracking algorithms and new techniques for received power estimation. Additionally, the antenna pointing routines require enhanced knowledge of spacecraft position and attitude for initial acquisition, versus an S-band antenna. Ka-band provides a number of technical advantages for bulk data transfer. Unlike at S-band, a larger bandwidth may be available for space missions, allowing increased data rates. The potential for high rate data transfer can also be extended for direct-to-ground links through use of variable or adaptive coding and modulation. Specific examples of Ka-band research from SCaN Testbeds first year of operation will be cited, such as communications link performance with TDRSS, and the effects of truss flexure on antenna pointing.
Document ID
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Chelmins, David T.
(NASA Glenn Research Center Cleveland, OH United States)
Reinhart, Richard C.
(NASA Glenn Research Center Cleveland, OH United States)
Mortensen, Dale
(NASA Glenn Research Center Cleveland, OH United States)
Welch, Bryan
(NASA Glenn Research Center Cleveland, OH United States)
Downey, Joseph
(NASA Glenn Research Center Cleveland, OH United States)
Evans, Michael
(NASA Glenn Research Center Cleveland, OH United States)
Date Acquired
December 4, 2014
Publication Date
September 29, 2014
Subject Category
Communications And Radar
Report/Patent Number
Funding Number(s)
WBS: WBS 553323.
Distribution Limits
Work of the US Gov. Public Use Permitted.
space communications
International Space Station
TDR satellites
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