8th Navigation Satellite Orbited to Pinpoint U.S. Military Units

A navigation satellite boosted into orbit by a Delta rocket Thursday is the latest in a series of spacecraft capable of pinpointing the location of U.S. military units to within 50 feet.

The unmanned rocket thundered into a clear sky at 1:39 a.m., trailing fire as it headed out over the Atlantic Ocean.

The $65-million Navstar satellite separated from the booster on schedule about 25 minutes into the flight and settled into an orbit 10,898 miles high.

The satellite is the eighth in a series of advanced Global Positioning System spacecraft that guide U.S. and allied warplanes, ships, submarines and troops. In some cases, it is accurate to within 10 feet.

The Air Force plans to send up 16 more satellites by early 1993, three of them spares, under the $8.5-billion program. The first Navstar spacecraft was launched in February, 1989.

The 3,675-pound Navstar satellites, good in any kind of weather, keep track of the speed of military vehicles within a fraction of a mile per hour and the time within a millionth of a second. They contain an atomic clock with an error rate of one second every 300,000 years.

Military personnel tune in the network’s coded radio signals with receivers as small as a hand-held telephone. Boat and private aircraft operators also have access to the system.

McDonnell Douglas of Huntington Beach, Calif., supplied the 128-foot Delta 2 launch rocket.