Spacecraft nº:

USA satellite nº:

Also called TDRS I

Launch data:

Designation27389 / 02011A
Launch date 08 Mar 2002 - 22:59 UT
Launch site CC, SLC-36A
Launch vehicle  Atlas 2A (AC-143 / #137)
MissionCommunications, Data relay
Geostationary orbit on:
Perigee / Apogee  km
Inclination  deg
Period  min

To be tested from 151°W.

Four days after launch, an anomaly occured with one of the 4 fuel tanks, pressure has dropped: a faulty valve prevented helium to pressurize a tank. Once a neighboring tank was empty, helium could be transfered to the faulty tank and little burns were possible. The satellite finally arrived in GEO in early Oct 2002 after months of effort! Enough fuel is available for the 15-year lifetime.


Prime contractor Hughes
Platform HS-601 modified
Mass at launch 3180 kg
Mass in orbit 1670 kg
Dry mass 1500 kg
Dimension stowed: 2.7 x 3.4 x 8.4 m (8 meters with the antenna folding)
Solar array 21 m span
Stabilization 3-axis
DC power 2300 W
Design lifetime 11 years

The 2 main (east-west) antennas are steerable single-access antennas that can simultaneously transmit and receive at S-band and either Ku- or Ka-band, supporting dual independent two-way communication. The selection of Ku- or Ka-band communications is done on the ground. Receive data rates are 300 megabits/second at Ku- and Ka-band, and 6 Mbps at S-band. The spacecraft carries additional capability for Ka-band receive rates of up to 800 Mbps. Transmit data rates are 25 Mbps for Ku- and Ka-band, and 300 kilobits/second for S-band. In addition, an S-band phased array antenna can receive signals from five spacecraft at once, while transmitting to one. There is no C-band on these satellites.

Telemetry: 2211.5 MHz (0.5, 1 or 4 kbps)
Telemetry: 2206.5 MHz (0.5, 1 or 4 kbps)
Telemetry: 13731 MHz
Command: 2035.96 or 2031.81 MHz (2 kbps)
Command: 14786 MHz (+ 15150 MHz)

Ref: #7, #15, #78a - update: 06.04.09