Mar 23, 2011 15:22 GMT  ·  By

NASA officials announce that the Kepler planet-hunting space telescope has regained full functionality, and is now back online. The observatory remained on safe mode for six days following an attempt to update some of its software.

As experts attempted to do so, a computer malfunctions shut down primary science instrumentation on the space probe, and oriented its solar panels towards the Sun, so as to get the largest amount of sunlight possible under the circumstances.

“This safe mode orientation provides the vehicle with the maximum power and limits the buildup of momentum from solar wind,” Kepler scientists explain, quoted by Space.

The telescope is placed in a Sun-centric orbit, and its primary mission is to discover the existence of alien worlds around very distant stars. As soon as it discovers an exoplanetary candidate, it sends its coordinates back to Earth for verification.

Thus far, the telescope has produced more than 1,200 such results, which are currently in the process of being validated using massive ground-based telescopes. Routine operations went on without a hitch until March 14, when the safe mode event occurred.

After more than 144 hours of inactivity, experts at its control center managed to bring the observatory back online. On Sunday, March 20, is was able to resume its mission. NASA experts supervised it closely for the next few days.

“An anomaly response team will continue to evaluate the spacecraft data to determine the cause of the safe mode event,” mission managers said in a brief statement about Kepler's status.

When the event started, the telescope switched to its backup subsystem interface box (SIB). The SIB is an electronic component in its systems that is in charge of regulating the way electricity is distributed throughout the spacecraft's other systems.

Scientists with the NASA Ames Research Center (ARC), who manage the observatory, say that a command they sent from Earth may have been responsible for the glitch.

During this communications session, experts were trying to implement a firmware update. This required resetting the network interface card (NIC) on Kepler via a code line. The NIC is responsible for supporting SIB operations.

When the reset command was uploaded, the system went offline, and the spacecraft entered safe mode, immediately shutting down its photometer. This is its primary science instrument, used to calculate slight variations in the brightness of distant stars.

After the safe mode event occurred, the team revised the telemetry they got from Kepler, and determined that all primary and secondary systems were healthy and operational. The experts were then able to re initiate power flow to the primary SIB.