OPS 3762
Encyclopedia
OPS 3762, also known as FTV-2355, was an American
reconnaissance satellite which was launched in 1964. It was the first radar imaging satellite to be launched, and the only Quill
spacecraft to fly. Its mission was to demonstrate radar imaging techniques for future missions. However, the programme was cancelled before any more satellites were launched.
OPS 3762 was successfully launched aboard a Thrust Augmented Thor SLV-2A Agena-D
carrier rocket, flying from Launch Complex 75-1-1 at the Vandenberg Air Force Base
. The launch, which was the last orbital launch of the year, occurred at 19:08:56 UTC on 21 December 1964, and successfully placed the spacecraft into the low Earth orbit
in which it conducted its mission. Owing to concerns that using radar over the Soviet Union
may have been seen as provocative, OPS 3762 conducted imaging tests over the Northwestern United States
instead.
OPS 3762 was a 1500 kilograms (3,306.9 lb) spacecraft, based around the Agena-D
which also served as the upper stage of its carrier rocket. It operated for four days. Its orbit had a perigee
of 208 kilometres (129.2 mi), an apogee
of 222 kilometres (137.9 mi), 70 degrees of inclination
, and an orbital period
of 88.8 minutes. Its side looking airborne radar
produced images, which were returned in a KH-4
film capsule at the end of the mission. OPS 3762 itself remained in orbit until 11 January 1965, when its orbit decayed
and it reentered
the atmosphere. OPS 3762 completed its mission successfully.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
reconnaissance satellite which was launched in 1964. It was the first radar imaging satellite to be launched, and the only Quill
Quill (satellite)
Quill was an American reconnaissance satellite programme of the 1960s, which employed radar to produce images of the Earth's surface. Only one satellite, OPS 3762, was launched, before the programme was cancelled. Two more spacecraft; a second flight vehicle and an engineering model, were produced...
spacecraft to fly. Its mission was to demonstrate radar imaging techniques for future missions. However, the programme was cancelled before any more satellites were launched.
OPS 3762 was successfully launched aboard a Thrust Augmented Thor SLV-2A Agena-D
Thor-Agena
Thor-Agena was a series of orbital launch vehicles. The rockets used Thor first stages and Agena second stages. They are thus cousins of the more famous Thor-Deltas, which founded the Delta rocket family. The first attempted launch of a Thor-Agena was in January 1959...
carrier rocket, flying from Launch Complex 75-1-1 at the Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
. The launch, which was the last orbital launch of the year, occurred at 19:08:56 UTC on 21 December 1964, and successfully placed the spacecraft into the low Earth orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...
in which it conducted its mission. Owing to concerns that using radar over the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
may have been seen as provocative, OPS 3762 conducted imaging tests over the Northwestern United States
Northwestern United States
The Northwestern United States comprise the northwestern states up to the western Great Plains regions of the United States, and consistently include the states of Oregon, Washington, Idaho, Montana, Wyoming, to which part of southeast Alaska is also sometimes included...
instead.
OPS 3762 was a 1500 kilograms (3,306.9 lb) spacecraft, based around the Agena-D
RM-81 Agena
The RM-81 Agena was an American rocket upper stage and satellite support bus which was developed by Lockheed initially for the canceled WS-117L reconnaissance satellite program...
which also served as the upper stage of its carrier rocket. It operated for four days. Its orbit had a perigee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of 208 kilometres (129.2 mi), an apogee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of 222 kilometres (137.9 mi), 70 degrees of inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
, and an orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
of 88.8 minutes. Its side looking airborne radar
Side looking airborne radar
Side-looking airborne radar is an aircraft- or satellite-mounted imaging radar pointing perpendicular to the direction of flight . A squinted mode is possible also. SLAR can be fitted with a real aperture antenna or an antenna using synthetic aperture .The platform of the radar moves in direction...
produced images, which were returned in a KH-4
Corona (satellite)
The Corona program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency Directorate of Science & Technology with substantial assistance from the U.S. Air Force...
film capsule at the end of the mission. OPS 3762 itself remained in orbit until 11 January 1965, when its orbit decayed
Orbital decay
Orbital decay is the process of prolonged reduction in the altitude of a satellite's orbit.This can be due to drag produced by an atmosphere due to frequent collisions between the satellite and surrounding air molecules. The drag experienced by the object is larger in the case of increased solar...
and it reentered
Atmospheric reentry
Atmospheric entry is the movement of human-made or natural objects as they enter the atmosphere of a celestial body from outer space—in the case of Earth from an altitude above the Kármán Line,...
the atmosphere. OPS 3762 completed its mission successfully.