Thursday, April 26, 2001

ACTS

 1993-058B


ACTS, the Advanced Communications Technology Satellite, was a controversial program. NASA's first experimental comsat for almost twenty years was to test out new methods for relaying communications and data. Critics charged that the commercial satellite industry was developing these techniques anyway, and that the program was a waste of taxpayer money and a handout to prime contractor Martin Marietta Astro Space (formerly GE).

ACTS, the Advanced Communications Technology Satellite, was used for Ka band communications. It was operated by NASA's Lewis Research Center (LeRC). Deployed from Orbiter OV-103 Discovery using a Transfer Orbit Stage, it was inserted into geosynchronous orbit by a solid apogee motor burn at 1544 on 1993 Sep 15. Later the same day it began a westward drift in an 0.4 deg inclination orbit.

The Advanced Communications Technology Satellite was a GE (Martin Marietta) Astro Space Series 4000 communications satellite. ACTS was 9.0 m long, 4.3 m diameter, and had a 14 m span set of solar arrays. The 3-axis stabilized satellite had a mass of 2770 kg at launch and 1450 kg on orbit. It was carried into orbit on Shuttle mission STS-51.

ACTS/TOS was deployed from OV-103 Discovery on 1993 Sep 12 at 2113. The Transfer Orbit Stage (TOS), named USS Fred C. Alcorn after an investor in the rocket project, fired 45 minutes later to insert ACTS in geostationary transfer orbit. The apogee motor was fired at 1544 on Sep 15. The scheduled on-station position was 100 deg W.


ACTS 
 

DateTimeEventOrbit  

1993 Sep 12  1145:00  Launch from LC39 
 1147:05  SRB sep 
 1153:31MECO 
 1153:49ET sep, peri 67 km 
 1225  OMS-2 
 1856  ASE unlatch 
 1902  Clamshell open 
 1908  Tilt table raised 
 2113:28  ACTS/TOS deploy 
 2158:35  TOS burn (1:40) 
 2200:15  TOS burnout 
 2210? TOS sep 
   718.71 320 x 40080 x 15.4 
1993 Sep 15  1544  AKM burn at apo 6 
1993 Sep 17    1454.55 35509 x 36784 x 0.3 GEO 77.9W+4.6W 
1993 Sep 24    1437.72 35708 x 35928 x 0.2 GEO 97.2W+0.4W 
1993 Nov 8    1436.10 35773 x 35800 x 0.1 GEO 99.9W 
1994 Jan 3    1436.12 35777 x 35797 x 0.0 GEO 100.1W 
1995 Jan 29    1436.09 35782 x 35790 x 0.0 GEO 100.0W 

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