Evolution of GPS: From Desert Storm to today's users

  • Published
  • By Space and Missile Systems Center and SMC History Office
In a desert, it's easy to get lost. There are no roads, no signposts, nor vegetation to give locational clues.

That was the grim situation facing U.S. and coalition forces during the 1990-1991 crisis in the Persian Gulf, known as Operation Desert Shield/Desert Storm.

Sometimes called "the first space war" by historians due to the extensive use of space-based satellites and other technological assets to command and control military forces on a battlefield, Desert Storm marked a major test of GPS in an actual combat environment.

Despite some shortcomings at the time, the use of GPS during its infancy revolutionized combat operations on the ground and in the air during the first Gulf War.

Among the many uses of GPS in Desert Storm, navigation proved to be a crucial capability for desert warfare. GPS signals enabled coalition forces to navigate and out-maneuver the enemy, and they could also fire with unprecedented accuracy in the vast desert terrain almost 24 hours a day despite difficult conditions. GPS provided coalition forces a distinct advantage over the enemy; they were actually able to navigate regions in Iraq that the Iraqis themselves refused to enter.

However, during Desert Storm, the GPS constellation was still several years from full operational capability. In 1991, there were only 19 GPS satellites in orbit, spanning across three generations of GPS satellite -- GPS I, II, and IIA -- which provided up to 20 hours of 3-D coverage. While 24 operational satellites are needed to provide 100 percent global, 3-D coverage with acceptable performance, GPS usefulness was proven before the constellation reached initial operational capability in 1993.

Meanwhile, for deployed forces in the desert, it became extremely critical to procure small lightweight GPS receivers often pronounced "sluggers" by the troops. By today's standards, these GPS ground units are considered primitive. The handheld version of GPS back then weighed several pounds. Most units had a backpack-sized device called "manpacks" to interpret the signals.

The SLGR program had already begun in 1987 with a competitive non-development item acquisition process by the Space and Missile Systems Center, which awarded a contract in 1989 for more than 1,000 sets. By the time Desert Storm began one year later, it quickly became apparent there would be an immediate need for additional navigation equipment because, as one troop wrote to a manufacturer, "As you are no doubt aware, navigation in this desert is an absolute nightmare, and for this reason I find it absolutely necessary that I obtain a satellite navigation system by whatever means possible."

Although each U.S. Army unit had at least one GPS receiver for maneuvering, the demand for receivers was so great that special approval from the Pentagon was obtained for the Army to acquire commercial units. Once a waiver was approved, the GPS Joint Program Office at SMC, managed by Col. Marty Runkle with Lt. Loralee Ryan as GPS user equipment project manager, awarded contracts for over 8,000 more receivers from commercial providers.

Inside an office building at what is now Schriever Air Force Base, Colorado, Airmen and civilian workers with the 2nd Space Operations Squadron helped turn the partially functional GPS constellation into a battlefield asset in 1991, making the Persian Gulf War the first conflict where space-based navigation was used. Operators from the 2nd Space Control Squadron maneuvered satellites so that more GPS spacecraft would be overhead for troops using the sluggers and manpacks.

Other operations enabled or enhanced by GPS included precision bombing, artillery fire support, the precise positioning of maneuvering troop formations, and certain special forces operations such as combat search and rescue missions. In addition to being carried by ground troops, GPS receivers were attached -- in some cases with tape -- to vehicles and helicopter instrument panels and were also used in F-16 Fighting Falcons, KC-135 Stratotankers and B-52 Stratofortresses.

After the Gulf War, the U.S. Army announced it would install GPS receivers in all armored vehicles to help minimize fratricide, which became a major source of casualties in Desert Storm, most often caused by armored unit commanders lost in the featureless Iraqi desert or out of position during ground attacks.

Since the Gulf War, the United States has employed GPS in several peacekeeping and military operations. During Operation Restore Hope in 1993, GPS enabled the airdrop of food and supplies to remote areas of Somalia that lacked accurate maps and ground-based navigation facilities. U.S. forces entering Haiti in 1994 also relied on GPS. During the Balkan crisis, GPS assisted delivery of aid to the Bosnians by guiding U.S. Air Force transport planes at night to drop food and medicine in designated drop zones.

It was actually the military's success in the Persian Gulf conflict that gave the commercial GPS market its biggest boost, sparking a surge in a growing multi-million-dollar market that had barely existed just a few years prior to the war. Desert Storm provided the stage to display the military uses of GPS, from helping Soldiers navigate across a featureless desert to enabling artillery and bomber units to target the enemy with unprecedented accuracy.

GPS was always a dual-use military and civil system, but a policy directive announced by President Bill Clinton in 1996 reiterated this and established an Interagency GPS Executive Board to manage it as a national asset. Plans to upgrade GPS with two new civilian signals for enhanced user accuracy and reliability, particularly with respect to aviation safety, were officially announced in 1998.

In May 2000, the discontinuance of the selective availability function, which formerly added error to the signal so non-military users got less accuracy on GPS, made the GPS signals in space a "global utility" more responsive to civil and commercial users worldwide.

The capabilities of GPS systems are used worldwide by billions of people in their consumer, professional and military devices. Whether paying at the gas pump, withdrawing money from an ATM, precision farming, international banking or international shipping, GPS enables our modern way of life. It is also a critical component of delivering precise combat power in support of joint and coalition warfighter objectives, as proven on the desert battlefields of Southwest Asia a quarter of a century ago.