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Advanced Communications Technology Satellite


Designation 22796 / 93058B
Launch date 12 Sep 1993
Country of origin United States
Operator NASA
Mission Telecommunications
Geostationary orbit see below
Launch vehicle STS 51

Experimental satellite intended to develop Ka-band services to VSAT's, High Data Rate Terminals, and mobile terminals for broadband personal, institutional, and transportable terminals.

In May 2001, the satellite payload operations were tranferred to the Ohio Consortium for Advanced Communications Technology (OCACT) for educational and research purposes and well as sustaining a Ka-band testbed until commercial Ka-band service is available in the US.


Begin End Position
L: 12 Sep 1993 Jun 2000 100°W
Aug 2000   105°W, inclined

External resources


sat-index articles

Technical data


Prime contractor GE Astro Space
Platform GE-4000 modified
Mass at launch 2545 kg
Mass in orbit 1555 kg
Dimensions 2.03 x 2.13 x 1.92 m
Stabilization 3-axis
DC power BOL: 1770 W (batteries: 2 NiCd of 19 AH each)
EOL: 1418 W (no payload operation during eclipse)
Design lifetime 4 years
Telemetry & Command Ka-band with backup in C-band

Orbit control: Blowdown Hydrazine System with redundant thrusters and 4 tanks
Stationkeeping: +/- 0.05°


Main transponders 4
Backup transponders  
Power 40 W (TWTA)
Bandwidth 900 MHz
Coverage A beam-forming network of 45 horns gives a coverage of about 20% of CONUS providing 3 x 0.3° fixed beams
There is a single 1.0° mechanically steered beam
EIRP max spot beam: 60 dBW
contiguous sectors: 59 dBW
steerable: 53 dBW
Polarization linear H/V

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