NASA's Swift satellite has regained its bearings following a glitch that prevented it from taking observations. But it will likely be several more weeks before it can resume studying cosmic explosions called gamma-ray bursts.
NASA's Swift space telescope has stopped taking observations following a glitch that left it disoriented. Mission officials are confident the problem can be fixed, but in the meantime, the spacecraft may miss several of the fleeting cosmic explosions it was designed to watch. Launched in November 2004, Swift studies brief bursts of gamma rays caused by the deaths of massive stars or collisions between dense stellar corpses. Since overcoming some communication delays early in the mission, the spacecraft has been functioning well. A key to Swift's success is that it is able to rapidly swivel to train its instruments on the source of each transitory burst. But on 10 August, Swift lost its bearings while turning to observe a new target. It could no longer tell which direction it was pointing in the sky, a crippling problem for an astronomical satellite. In its disorientation, the satellite misinterpreted a known double star system called Scorpius X-1 as a gamma-ray burst.
The Swift satellite, is pinpointing the location of distant enigmatic flashes, called gamma-ray bursts, that appear to signal the births of black holes. The Swift satellite is named after the nimble bird, because it can swiftly turn and point its instruments to catch a burst in progress and study both the burst and its afterglow. It is part of the 'RoboNet-1.0' global network
The probe was launched from pad 17A at Cape Canaveral Air Force Station, Florida. Launch was at 1716 GMT November 20, 2004 , six minutes later than planned when launch preparations fell slightly behind schedule. The Swift space telescope saw its first gamma-ray bursts (GRBs) - the massive cosmic explosions it was built to study, on 17 December 2004, only a few days after its instruments were switched on. On 19 December, the US space agency satellite caught three more. GRBs are the most powerful explosions in the Universe, releasing more than one hundred billion times the energy our Sun emits in a year.
The Swift space probe has measured the distance to two gamma-ray bursts, GRB 050318 and GRB 050319 , on March 18 and 19, 2005, from opposite parts of the sky, The redshifts are 1.44 and 3.24, respectively, which corresponds to distances of about 9.2 billion and 11.6 billion light years. Gamma-ray bursts are the most powerful explosions known in the Universe and are thought to signal the birth of a black hole --either through a massive star explosion or through a merger smaller black holes or neutron stars. Several appear each day.