Neil Gehrels Swift Observatory
Neil Gehrels Swift Observatory, previously called the Swift Gamma-Ray Burst Explorer, is a NASA three-telescope space observatory for studying gamma-ray bursts (GRBs) and monitoring the afterglow in X-ray, and UV/Visible light at the location of a burst. It was launched on 20 November 2004, aboard a Delta II launch vehicle. Headed by principal investigator Neil Gehrels until his death in February 2017, the mission was developed in a joint partnership between Goddard Space Flight Center (GSFC) and an international consortium from the United States, United Kingdom, and Italy. The mission is operated by Pennsylvania State University as part of NASA's Medium Explorer program (MIDEX).
Neil Gehrels Swift Observatory | |
| Names | Explorer-84 MIDEX-3 Swift Gamma Ray Burst Explorer |
|---|---|
| Mission type | Gamma-ray astronomy |
| Operator | NASA / Pennsylvania State University |
| COSPAR ID | 2004-047A |
| SATCAT no. | 28485 |
| Website | swift |
| Mission duration | 2 years (planned) 19 years, 2 months, 20 days (in progress) |
| Spacecraft properties | |
| Spacecraft | Explorer LXXXIV |
| Spacecraft type | Swift Gamma Ray Burst Explorer |
| Bus | LEOStar-3 |
| Manufacturer | Spectrum Astro |
| Launch mass | 1,470 kg (3,240 lb) |
| Dry mass | 613 kg (1,351 lb) |
| Payload mass | 843 kg (1,858 lb) |
| Dimensions | 5.6 × 5.4 m (18 × 18 ft) |
| Power | 1040 watts |
| Start of mission | |
| Launch date | 20 November 2004, 17:16:01 UTC |
| Rocket | Delta II 7320-10C (Delta 309) |
| Launch site | Cape Canaveral, SLC-17A |
| Contractor | Boeing Defense, Space & Security |
| Entered service | 1 February 2005 |
| Orbital parameters | |
| Reference system | Geocentric orbit |
| Regime | Low Earth orbit |
| Perigee altitude | 585 km (364 mi) |
| Apogee altitude | 604 km (375 mi) |
| Inclination | 20.60° |
| Period | 96.60 minutes |
| Instruments | |
| Burst Alert Telescope (BAT) UltraViolet Optical Telescope (UVOT) X-Ray Telescope (XRT) | |
Swift Gamma Ray Burst Explorer Explorer program | |
The burst detection rate is 100 per year, with a sensitivity ~3 times fainter than the BATSE detector aboard the Compton Gamma Ray Observatory. The Swift mission was launched with a nominal on-orbit lifetime of two years. Swift is a NASA MIDEX (medium-class Explorer) mission. It was the third to be launched, following IMAGE and WMAP.
While originally designed for the study of gamma-ray bursts, Swift now functions as a general-purpose multi-wavelength observatory, particularly for the rapid followup and characterization of astrophysical transients of all types. As of 2020, Swift received 5.5 Target of Opportunity observing proposals per day, and observes ~70 targets per day, on average.