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

The US space agency 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 said 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 a 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 October 5.

(Cover: Illustration of the Chandra X-ray Observatory in Earth orbit. /Photo courtesy of NASA)