USA-50
| Names | Navstar 2-06 GPS II-6 GPS SVN-18 |
|---|---|
| Mission type | Navigation |
| Operator | U.S. Air Force |
| COSPAR ID | 1990-008A |
| SATCATno. | 20452 |
| Mission duration | 7.5 years (planned) 10.5 years (achieved) |
| Spacecraft properties | |
| Spacecraft | GPS II |
| Spacecraft type | GPS Block II[1] |
| Manufacturer | Rockwell International |
| Launch mass | 840 kg (1,850 lb)[2] |
| Dimensions | 5.3 m (17 ft) of long |
| Power | 710 watts |
| Start of mission | |
| Launch date | 24 January 1990, 22:55:01UTC |
| Rocket | Delta II 6925-9.5 (Delta D191)[3] |
| Launch site | Cape Canaveral,LC-17A |
| Contractor | McDonnell Douglas |
| Entered service | February 1990 |
| End of mission | |
| Deactivated | 18 August 2000 |
| Orbital parameters | |
| Reference system | Geocentric orbit[4] |
| Regime | Medium Earth orbit (Semi-synchronous) |
| Slot | ? |
| Perigee altitude | 20,087 km (12,481 mi) |
| Apogee altitude | 20,275 km (12,598 mi) |
| Inclination | 54.6° |
| Period | 717.92 minutes |
USA-50,also known asGPS II-6andGPS SVN-18,was an Americannavigation satellitewhich formed part of theGlobal Positioning System.It was the sixth of nineBlock IIGPS satellites to be launched, which were the first operational GPS satellites to fly.
Background
[edit]It was part of the 21-satellite Global Positioning System (GPS) Block II series that provides precise position data (accurate to within 16 m) to military and civilian users worldwide. Its signals could be received on devices as small as a telephone. The GPS II satellites, built byRockwell Internationalfor the Air Force Space Systems Division, each have a 7.5-year design life. The Air Force intends to launch a GPS II every 2 to 3 months until the constellation of 21 operational satellite and 3 spares is aloft. The GPS Block II join 7 operational Block 1 satellites.[2]
Launch
[edit]USA-50 was launched at 22:55:01 UTC on 24 January 1990, atop aDelta IIlaunch vehicle,flight number D191, flying in the 6925-9.5 configuration.[3]The launch took place fromLaunch Complex 17A(LC-17A) at theCape Canaveral Air Force Station(CCAFS),[5]and placed USA-50 into a transfer orbit. The satellite raised itself intomedium Earth orbitusing aStar-37XFPapogee motor.[1]
Mission
[edit]On 25 February 1990, USA-50 was in an orbit with aperigeeof 20,087 km (12,481 mi), anapogeeof 20,275 km (12,598 mi), aperiodof 717.92 minutes, and 54.6° ofinclinationto theequator.[4]The satellite had a mass of 840 kg (1,850 lb), and generated 710 watts of power.[2]It had a design life of 7.5 years,[1]and was retired from service on 18 August 2000.
References
[edit]
- ^abcKrebs, Gunter."GPS-2 (Navstar-2)".Gunter's Space Page.Retrieved10 July2012.
- ^abc"Display: Navstar 2-06 1990-008A".US National Space Science Data Center.NASA.Retrieved10 July2012.
This article incorporates text from this source, which is in thepublic domain.
- ^abMcDowell, Jonathan."Launch Log".Jonathan's Space Report.Retrieved10 July2012.
- ^abMcDowell, Jonathan."Satellite Catalog".Jonathan's Space Report.Retrieved10 July2012.
- ^McDowell, Jonathan."Launch List".Launch Vehicle Database.Jonathan's Space Report. Archived fromthe originalon 15 August 2020.Retrieved10 July2012.