USA-4

USA-4

Operator	U.S. Air Force
COSPAR ID	1984-091A
Spacecraft properties
Manufacturer	Lockheed Martin
Launch mass	700 kg (1,500 lb)
Power	980 W
Start of mission
Launch date	18:03 GMT, 28 August 1984
Rocket	Titan III(34)B
Launch site	Vandenberg, SLC-4W
Orbital parameters
Periapsis altitude	287 kilometres (178 mi)
Apoapsis altitude	38,156 kilometres (23,709 mi)
Inclination	63.60º
Period	702.80 min
←  USA-3 USA-5  →

USA-4 (BYEMAN codename QUASAR 5) was an American communication relay satellite carrying a Satellite Data System (SDS 5) payload operated by the National Reconnaissance Office and U.S. Air Force. The fifth of seven Quasar missions, it was launched on a Titan IIIB rocket from Vandenberg, SLC-4W in California on August 28, 1984. ^[1]

Overview

The QUASAR 5 satellite launched from what was then called the Air Force Western Test Range (AFWTR), ^[2] now SLC-4W at Vandenberg SFB, for a launch cost of $25.8 million. ^[3] The satellite was inserted into a highly elliptical 287 × 38,156 km orbit at an inclination of 63.3° (near-Molniya orbit). The apogee was set in the northern hemisphere.

The satellite was equipped with a Satellite Data System (SDS) payload developed by the US Air Force Space and Missile Systems Organization (SAMSO) and acted as a communication relay for transmitting real-time data from US reconnaissance satellites such as KH-9 Hexagon. ^[4] It was also used for communications to US Air Force aircraft on polar routes. In 1984, the Permanent Representative of the US to the United Nations stated in a report that the spacecraft was engaged with "practical applications and uses of space technology such as weather or communications". ^[5]

Titan-3(34)B Agena-D rocket launching from Vandenberg AFB

See also

• List of USA satellites

References

1. "Titan". www.astronautix.com. Astronautix. Retrieved 8 November 2025.
2. "Technical details for satellite USA 4". N2YO.com - Real Time Satellite Tracking and Predictions. Retrieved 8 November 2025.
3. "Titan 34B - Quasar 5". Space Launch Schedule. Retrieved 7 November 2025.
4. "Quasar 1, 2, 3, 4, 5, 6, 7 (SDS 1, 2, 3, 4, 5, 6, 7)". Gunter's Space Page. Retrieved 8 November 2025.
5. "Information Furnished in Conformity with the Convention on Registration of Objects Launched into Outer Space" (PDF). United Nations Committee on the Peaceful Uses of Outer Space: 2. 21 November 1984. Retrieved 8 November 2025.