The Surveillance Calibration (or SURCAL) satellites were a series of

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. Example ...

s for the Naval Space Surveillance radar system. They were launched in the 1960s.

Background

The SURCAL series of satellites were produced by the

Naval Research Laboratory The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. Located in Washington, DC, it was founded in 1923 and conducts basic scientific research, appl ...

to act as test and calibration targets for the Naval Space Surveillance radar. The first SURCAL satellite was intended to remain attached to the launch vehicle and was a 5.5 inch long, 5.5 inch diameter cylinder. The other four SURCAL satellites were box-shaped with solar panels, a transponder, and antennas. They transmitted a 216

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...

signal on command.

Launches

Other vehicles

Astronautix The ''Encyclopedia Astronautica'' is a reference web site on space travel. The encyclopedia includes 79,433 articles with 13,741 illustrations, a comprehensive catalog of missiles, spacecraft, space technology, astronauts, and spaceflight from ...

includes passive satellites such as the SURCAL 150B and SURCAL 160 target objects as part of the SURCAL program.

References

{{Portal bar, Spaceflight Satellites of the United States Spacecraft launched in 1962 Spacecraft launched in 1963 Spacecraft launched in 1965 Spacecraft launched by Thor rockets Radar calibration satellites