NASA space telescope back in business after 2-day shutdown

One of NASA's space telescopes is back in business after a two-day shutdown.

NASA said Monday that the Chandra X-ray Observatory came back online Friday. Chandra's trouble occurred less than a week after the Hubble Space Telescope was sidelined. In both cases, the problem was in the pointing system.

Officials say a glitch in one of Chandra's gyroscopes generated three seconds of bad computer data last Wednesday. That was enough for the 19-year-old telescope to go into so-called safe mode, during which science observations cease. Flight controllers restored Chandra's pointing by switching to a backup gyroscope.

Observations are expected to resume with Chandra by the end of this week. Hubble, meanwhile, remains out of action with a more serious gyroscope issue that cropped up Oct. 5.

Launched by space shuttles in the 1990s, Hubble and Chandra are part of NASA's Great Observatories series. The others are the Compton Gamma Ray Observatory, which was also launched in the 1990s but eventually failed and was destroyed, and the Spitzer Space Telescope, launched in 2003 and still working. Each was intended to observe the cosmos in different wavelengths.