Mars Reconnaissance Orbiter
An artist's concept of Nasa's Mars Reconnaissance Orbiter NASA/JPL

A Nasa spacecraft orbiting Mars has been put on "precautionary standby" owing to a critical power problem.

Mars Reconnaissance Orbiter aka MRO landed on the Red Planet in 2006 and has been phenomenal in providing Nasa new insights into the planet's climate, weather, atmosphere, and geology. The orbiter's mission has been extended as many as five times, but now it has started showing signs of ageing.

On 15 February, the space agency had to put the orbiter on precautionary standby due to a significant decline in its battery.

Though the MRO mainly uses solar panels to stay up and running, it deploys a pair of nickel-hydrogen batteries to continue the work during shadowy days or when sunlight is blocked by Mars.

"We're in the diagnostic stage, to better understand the behaviour of the batteries and ways to give ourselves more options for managing them in the future," said Nasa's MRO Project Manager Dan Johnston.

Nasa has restored the orbiter's voltage, but the troubleshooting process is still on. The spacecraft has been given a rest, with its ability to make scientific observations and relay data from Martian rovers suspended.

"We will restore the MRO's service as a relay for other missions as soon as we can do so with confidence in spacecraft safety -- likely in about one week," Johnston added. "After that, we will resume science observations."

The MRO is one of Nasa's most successful missions to Mars and its original goal was to study the planet for two years. The spacecraft has sent back more scientific data and imagery than any other mission, approximately around 317 terabits.

Among other things, the MRO has also been mapping the Martian landscape with its high-resolution cameras to help Nasa choose potential landing sites for upcoming Mars missions. We even saw a "Martian tadpole" – a massive impact crater – thanks to the spacecraft's amazing photographic skills.