RADCAL (short for RADar CALibration Satellite) was a
radar calibration satellite
Radar calibration satellites are orbital satellites used to calibrate ground-based space surveillance radars. There are two types: active and passive.
Passive satellites
Passive calibration satellites are objects of known shape and size. Examples ...
launched and operated by the
United States Air Force. It was active from June 1993 until it stopped communicating in May 2013.
Design
Construction
RADCAL was built by Defense Systems Inc. as
United States Air Force Space Test Program payload P92-1.
It was built under a one-year contract-to-launch
and cost $10 million.
Components
Payload included two
C Band transponders (operating at the same frequency as space-detection radars
), a Doppler beacon that transmitted at 150 and 400
MHz, and a pair of modified
Trimble Inc.
Trimble Inc. is an American software, hardware, and services technology company. Trimble supports global industries in building & construction, agriculture, geospatial, natural resources and utilities, governments, transportation and others. Trim ...
TANS Quadrex
Global Positioning System
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...
receivers.
The receivers were used to determine the satellite's orbit as a reference for calibrating space detection radars.
It also carried the Small Satellite Power System Regulator, an experiment testing improved battery charging on solar panel-equipped vehicles.
Mission
Launch
RADCAL launched into
polar orbit at 23:30:00 UTC on 25 June 1993
from
Vandenberg Air Force Base's
Space Launch Complex 5. The launch vehicle was
Scout
Scout may refer to:
Youth movement
*Scout (Scouting), a child, usually 10–18 years of age, participating in the worldwide Scouting movement
**Scouts (The Scout Association), section for 10-14 year olds in the United Kingdom
**Scouts BSA, sectio ...
S217C.
Operation
RADCAL was used to calibrate ground-based space tracking radars: they would track it and compare their estimated position to its true position.
By the end of its operational lifetime, it was one of only two functional radar performance monitoring satellites (along with
DMSP F-15) and was actively used by a number of civilian and military organizations. Its GPS receivers were used in experiments to determine its
attitude
Attitude may refer to:
Philosophy and psychology
* Attitude (psychology), an individual's predisposed state of mind regarding a value
* Metaphysics of presence
* Propositional attitude, a relational mental state connecting a person to a pro ...
in space. It was the first satellite to use a GPS to determine its attitude. RADCAL was designed to last for three years, but remained operational until May 2013.
References
{{Orbital launches in 1993
Spacecraft launched in 1993
Space radars
USA satellites
Radar calibration satellites