DSCS 3-F11

USA

Spacecraft n°:

USA satellite n°:

Defense Satellite Communications System
Also called USA 148 and DSCS-3B 8 (code B8)

Launch data:

Designation	26052 / 00001A
Launch date	21 Jan 2000 - 01:03 UT
Launch site	CC, LC-36A
Launch vehicle	Atlas 2A (AC-138)
Mission	Military: Communications
Geostationary orbit:
Perigee / Apogee	35706 x 35868 km
Eccentricity	1.92E-03
Inclination	0.01 deg
Period	1436.13 min

A cable problem was detected before launch and caused several months delay.

It is the first of four remaining super high-frequency communications satellites to feature the SLEP (Service Life Enhancement program) upgrades. This upgrade includes increased downlink power (50 W TWTA), improved connectivity to its antennas and upgraded transponder channels.

Specifications

Prime contractor	Lockheed Martin Missiles and Space
Platform - Bus	DSCS III
Operator	US Air Force
Mass at launch	1156 kg
Dry mass	884 kg
Basic shape	Box + 2 panels
Dimension	1.93 x 1.96 x 2.06
Solar array	11.62 span
Stabilization	3-axis
DC power	1240 W
Design lifetime	10 yrs - still active

Other specifications might be similar to these of the earlier satellites

Location:

Date	Position	Remarks
April 2010	135.11° W

Features fixed (multiple-beam) antennas and a steerable high power antenna.

X-band:

Main transponders	6
Backup	two 40 W and two 10 W amplifiers
Power	channels 1 & 2: 40 W (TWTA) channels 3 to 6: 10 W (SSPA)
Coverage and EIRP max	2 Global beams: 29 dBW 2 Spot beams: 34 dBW Gimballed dish: 44 dBW

Transponder frequency chart (GHz)

Channel	Bandwidth (MHz)	Frequency
1	50	?
2	75	?
3	85	?
4	85	?
5	60	?
6	50	?

Frequencies are probably in 250 MHz, S-band and X-band range. In X-band, uplink in the 7.9-8.025 GHz, 8.025-8.400 GHz, downlink in 7.250-7.750 GHz

Mission details:

Super High Frequency (SHF) for U.S. government and military; sophisticated survivability enhancement; worldwide, longhaul coverage; X-band.
The Atlas IIA rocket took off from Cape Canaveral and placed a Lockheed Martin/Valley Forge DSCS III satellite in geostationary transfer orbit, attached to an IABS upper stage. The DSCS III, serial number B-8, is part of the US Air Force's Defense Satellite Communications System and will be parked over the Pacific.
AC-138 entered a 148 x 899 km x 29.3 deg parking orbit at 0113 UTC on Jan 21. At 0125 UTC the Centaur reignited for its second burn and delivered the payload to a 240 x 35253 km x 26.1 deg geostationary transfer orbit. On Jan 22 the IABS was scheduled to make its apogee burn. The IABS carries two Marquardt R-4D engines to place the DSCS in geostationary orbit.

Ref: #7(JR419), #15, #84a, #206, #226 - update: 19.05.10