The Naval Research Laboratory's (NRL's) Naval Center for
Space Technology (NCST) conceived the TIMATION (TIMe/navigATION) program
in 1964 and launched the TIMATION I satellite in 1967 and the TIMATION
II satellite in 1969. TIMATION proved that a system using a passive ranging
technique, combined with highly accurate clocks, could provide the basis
for a new and revolutionary navigation system with three-dimensional coverage
(longitude, latitude, and altitude) throughout the world. NCST's TIMATION
program paved the way for what eventually became the Global
Positioning System (GPS).
In 1973 the TIMATION program was merged with the Air Force's
621B program, with the Air Force being named as the Executive Service,
to form the NAVSTAR GPS program. NRL'S TIMATION III satellite was redesignated
the Navigation Technology Satellite 1 (NTS-1) and was launched in the
summer of 1974 in connection with the NAVSTAR effort. NTS-1 had two rubidium-vapor
frequency standards (clocks), while the earlier TIMATION satellites had
carried selected high-performance crystal oscillator clocks to test the
The successful launch of NTS-2 marked the beginning of a
new era in navigation and timekeeping history. NTS-2 was launched on 23
June 1977 as the first NAVSTAR GPS Phase I satellite. NTS-2 technological
features included cesium frequency standards, a nickel-hydrogen battery,
three-axis gravity-gradient stabilization with momentum-wheel unloading,
control of the spacecraft orbit, laser retroreflectors, solar-cell experiments,
radiation dosimeters, and a worldwide network for data acquisition. The
satellite experiment has verified Einstein's relativistic clock shift.
All of the NTS and TIMATION satellites were designed, built, and tested
by the SED at NRL'S Payload Processing Facility
in Washington, D.C.
Collier trophy was presented to NRL in 1993 in recognition
of NRL'S pioneering contributions to GPS.