GPS IIR-1
Encyclopedia
GPS IIR-1 or GPS SVN-42 was the first Block IIR GPS satellite
GPS satellite
A GPS satellite is a satellite used by the NAVSTAR Global Positioning System . The first satellite in the system, Navstar 1, was launched February 22, 1978. The GPS satellite constellation is operated by the 50th Space Wing of the United States Air Force....

 to be launched. It was to have been operated as part of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

 Global Positioning System
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

. It was launched on 17 January 1997, however it was destroyed thirteen seconds into its flight due to a malfunction of the Delta II
Delta II
Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...

 rocket that was carrying it. It was estimated to have cost US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

40 million, with its carrier rocket costing $55 million. The satellite which was used for the IIR-1 mission was the second production IIR satellite, SVN-42.

Launch

GPS IIR-1 was launched on a Delta II
Delta II
Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...

 7925-9.5 rocket, serial number D241, from Launch Complex 17A
Cape Canaveral Air Force Station Launch Complex 17
Cape Canaveral Air Force Station Space Launch Complex 17 , previously designated Launch Complex 17 , was a launch site at Cape Canaveral Air Force Station, Florida used for Thor and Delta rocket launches between 1958 and 2011....

 at the Cape Canaveral Air Force Station
Cape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...

. The launch occurred at 16:28:01 GMT (11:28 local time
Eastern Standard Time
Eastern Standard Time may refer to:*North American Eastern Time Zone, UTC-5*Australian Eastern Standard Time, UTC+10*An album by Hip Hop group Kooley High...

), on 17 January 1997. Thirteen seconds later, the rocket's flight termination system was activated by its onboard computer. This detonated explosive charges aboard the rocket, causing it to explode. At the time of explosion, the rocket was 487 metres (1,597.8 ft) above the launch complex.

An investigation determined that the failure was caused by a crack in the casing of the number 2 GEM-40 solid rocket motor, which propagated around six seconds into the flight. Twelve seconds after launch, this caused a structural failure of the booster, triggering the rocket's onboard self-destruct system
Range safety
In rocketry, range safety is assured by the systems which protect people and assets on the rocket range in cases when a launch vehicle might endanger them. Range safety is usually the responsibility of a Range Safety Officer...

 which destroyed the rocket one second later.

The booster had been damaged by pressure from a support in a new transportation system which had recently been introduced. Following the failure, the system was revised, and ultrasound inspections of boosters on future flights were introduced.

Debris

Debris from the explosion fell into the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

, and on the Cape Canaveral Air Force Station. Some debris landed around the launch pad, and a small fire started. Other debris landed in the parking lot outside the complex blockhouse
Blockhouse
In military science, a blockhouse is a small, isolated fort in the form of a single building. It serves as a defensive strong point against any enemy that does not possess siege equipment or, in modern times, artillery...

, destroying twenty cars that were located there. Two hundred fifty tons of debris fell within 914 metres (2,998.7 ft) of the launch pad. One piece of debris made a hole in a cable track, allowing smoke to enter the blockhouse.

Residents of the area around the launch site were advised to stay indoors, close windows, and turn off air conditioning systems as a precaution, as some vapours from the fuel could be irritant or toxic. The explosion was reported to have been felt 40 kilometres (24.9 mi) away from the launch site, and damage to store windows 16 kilometres (9.9 mi) away was reported.

Impact

A number of Delta II launches were delayed whilst the cause of the failure was investigated and corrective action was taken. It returned to service on 5 May 1997, making the first Delta II launch from Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....

 SLC-2W
Vandenberg AFB Space Launch Complex 2
Space Launch Complex 2 is an active rocket launch site at Vandenberg Air Force Base, in California, USA. It consists of two launch pads. The East pad , which has been demolished, was used for Delta, Thor-Agena and Thorad launches between 1966 and 1972...

. The launch was successful.

As of 2009, it is the only outright failure of a Delta II rocket. The only partial failure of a Delta II was the launch of Koreasat 1, where one of the solid rocket motors failed to separate, however the satellite still reached its correct orbit, using onboard propellant, which left it with a shorter than planned operational life expectancy.

GPS IIR-1 was to have replaced an older satellite, which was still operational at the time of its replacement's launch. This satellite was able to continue operating until another replacement could be launched.

The launch of GPS IIR-1 was the last to use the Complex 17 blockhouse, with future launches being controlled from a Launch Control Center in the 1st Space Launch Squadron Operations Building, 3 kilometres (1.9 mi) south of the pad. This was already under construction at the time of the failure, as the blockhouse was unable to support the Delta III rocket, which was then under development. Following the failure, construction on the new control facilities was accelerated.
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