February 27, 2009, 8:28 PM — NASA engineers and programmers Friday started repowering the Mars Reconnaissance Orbiter after the spacecraft shut itself down earlier this week.
The restarting process may take almost a week, said Jim Erickson, project manager for the Mars Reconnaissance Orbiter at NASA's Jet Propulsion Laboratory. The scientists will be turning on one system on at a time, and then evaluating that system before firing up the next one, he added.
The NASA flight team is in control of the spacecraft, which still has power and is still orbiting around Mars, Erickson noted. However, the equipment and software have been in the safe mode since the orbiter unexpectedly rebooted itself early Monday morning. NASA reports that the orbiter's batteries are charged and its solar panels are properly generating electricity.
"We are very careful and slowly trying to understand what the vehicle did and what the problems are," Erickson told Computerworld . "It's a case of a treasured asset that's really important to us and to science teams here and across the world. We want to take care of it and get it back into operation so we can get the good science back that we have been getting for the past two years. We are careful but we don't' waste time, either."
The Mars Reconnaissance Orbiter, which has been circling the Red Planet for two and a half years, has been sending back what scientists call key information about Mars.
Last November, for example, NASA announced that the spacecraft had sent back information showing that there are vast glaciers hidden underneath surface rubble. And in late September, the orbiter also sent back information about fractures in the surface of the Red Planet that once directed Martian water flows through underground sandstone.
Between data culled from the Mars Phoenix Lander and the orbiter, NASA reported last summer that its scientists had concluded Mars was once awash in water. The orbiter has sent back information showing that water was on Mars as far back as 4.6 billion years ago.
The Mars orbiter also acts as a communications relay for other Mars spacecraft. Erickson noted that it will play a critical role in helping scientists find landing sites for future Mars missions.
With the orbiter capable of collecting and sending back that much data, NASA is eager to get the spacecraft up and running again.
Erickson explained that it appears this week's problem stems from a brief change in power load in a 3.3-volt power bus onboard the orbiter. The power bus supports various cards in the sub-system and the main processor. However, he also said it's possible that there actually wasn't a power change but that the sensing circuit malfunctioned and erroneously noted a change where there wasn't one.
NASA reported that this is the fifth time since the spacecraft's August 2005 launch that it has entered safe mode. The orbiter is designed to reboot and put itself into safe mode when it senses an onboard problem and decides not to wait for instructions from Earth.
"We've gotten some great data, images, and identification of interesting minerals and future landing areas down [from the orbiter]," said Erickson. "We'd like to get back to normal work and begin providing some of that."