USA-38, also known as GPS II-2 and GPS SVN-13, was an American

navigation satellite A satellite navigation or satnav system is a system that uses satellites to provide autonomous geopositioning. A satellite navigation system with global coverage is termed global navigation satellite system (GNSS). , four global systems are op ...

which formed part of the

Global Positioning System The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide ge ...

. It was the second of nine Block II GPS satellites to be launched, which were the first operational GPS satellites to be launched.

Background

It was part of the 21-satellite Global Positioning System (GPS) Block II series that provides precise position data (accurate to within 16 m) to military and civilian users worldwide. Its signals could be received on devices as small as a telephone. The GPS II satellites, built by

Rockwell International Rockwell International was a major American manufacturing conglomerate (company), conglomerate. It was involved in aircraft, the space industry, defense and commercial electronics, components in the automotive industry, printing presses, avioni ...

for the Air Force Space Systems Division, each have a 7.5-year design life. The Air Force intends to launch a GPS II every two to three months until the constellation of 21 operational satellites and three spares is aloft. The GPS Block II joins seven operational Block 1 satellites.

Launch

USA-38 was launched at 22:19 UTC on 10 June 1989, atop a

Delta II Delta II was an expendable launch system, originally designed and built by McDonnell Douglas, and sometimes known as the Thorad Delta 1. Delta II was part of the Delta rocket family, derived directly from the Delta 3000, and entered service in ...

launch vehicle A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistage ...

, flight number D185, flying in the 6925-9.5 configuration. The launch took place from Launch Complex 17A (LC-17A) at the

Cape Canaveral Air Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the sta ...

(CCAFS), and placed USA-38 into a transfer orbit. The satellite raised itself into

medium Earth orbit A medium Earth orbit (MEO) is an geocentric orbit, Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.

using a Star-37XFP

apogee motor An apogee kick motor (AKM) is a rocket motor that is regularly employed on artificial satellites to provide the final impulse to change the trajectory from the transfer orbit into its final orbit (most commonly circular orbit, circular). For a ...

Mission

On 11 July 1989, USA-38 was in an orbit with a

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

of , an

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

of , a period of 717.92 minutes, and 54.5° of

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

to the

equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

. It operated in slot 3 of plane B of the GPS constellation. The satellite had a mass of , and generated 710 watts of power. It had a design life of 7.5 years, and was deactivated on 12 February 2004.

References

{{Orbital launches in 1989 GPS satellites USA satellites Spacecraft launched in 1989