The First Space Operations Squadron (1SOPS) of the 50SPW, located at Falcon AFB in

Colorado Springs, Colorado, provides launch and early orbit support for the GPS satellites.  The

early orbit support includes control of the Navstar satellites to deploy solar arrays, perform

stabilization maneuvers, and complete other procedures to make the satellites ready for service. 

The 1SOPS can also provide backup capability for critical day to day commanding procedures if

necessary.  When a satellite is ready for service, command is transferred to the Second Space

Operations Squadron (2SOPS) of the 50SPW for payload turn on and continued operations.  The

2SOPS has responsibility for day to day operations and overall constellation management.  The

2SOPS is also located at Falcon AFB.

The Forty Fifth Space Wing (45SPW) of the AFSPC is responsible for management of Navstar

pre launch operations, including receiving of the satellites, storage on the ground if necessary,

mating to the launch vehicle, and integration and compatibility testing.  The 45SPW is located at

Cape Canaveral Air Force Station, Florida, which is the launch site for the GPS satellites.

1.6  GPS PROGRAM HISTORY

1.6.1  Pre Concept Validation (1960s 1972)

Since the early 1960s various U.S. agencies have had navigation satellite programs.  The John

Hopkins  Applied Research Laboratory sponsored the TRANSIT program and the U.S. Navy

(USN) sponsored the TIMATION (TIMe navigATION) program.  TIMATION was a program to

advance the state of the art for two dimensional (latitude and longitude) navigation.  TRANSIT

became operational in 1964 and is currently providing navigation service to low dynamic vehicles

such as ships.  It is scheduled to be phased out in 1996.  The USAF conducted concept studies to

assess a three dimensional (latitude, longitude, and altitude) navigation sy

stem called 621B.

1.6.2  Phase I   Concept Validation (1973 1979)

A memorandum issued by the US Deputy Secretary of Defense on 17 April 2024 designated the

USAF as the executive service to consolidate the TIMATION and 621B concepts into a compre 

hensive all weather navigation system named Navstar GPS.  The Navstar GPS JPO was

established on 1 July 1973.

Two experimental Navigation Technology Satellites (NTS) were built and launched to support

concept validation of the GPS.  The first true GPS signals from space came from NTS 2.  NTS 2

was launched on an Atlas booster from Vandenberg AFB in June 1977 but malfunctioned after

only 8 months.  The first Navstar GPS Block I (research and development) satellite was launched

in February 1978.  A total of 11 Block I satellites were launched between 1978 and 1985.  All of

the Block I satellites were launched from Vandenberg AFB using the Atlas booster.  Block I

satellites did not incorporate SA or A S features.  As of June 1995 only one Block I satellite

remained operational.  Table 1 1 contains the launch dates and status (as of June 1995) of the

NTS and Block I satellites.

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