Curiosity Rover Faces Second Glitch this Month, Activity Put on Hold

NASA announced Wednesday that it has paused all operations by the Mars Curiosity rover for a few days while engineers investigate a voltage change detected Nov. 17.

"The vehicle is safe and stable, fully capable of operating in its present condition, but we are taking the precaution of investigating what may be a soft short," Mars Science Laboratory Project Manager Jim Erickson at NASA's Jet Propulsion Laboratory said in a statement.

The term "soft short" refers to a leak through something that's partially conductive of electricity, and can result in a voltage change. The last time Curiosity experienced a soft short was the day it landed back in August 2012. According to NASA, it was related to explosive-release devices used for deployments just before and after the landing and lowered the bus-to-chassis voltage from 16 volts to about 11 volts, though rover operations were not affected.

Officials detected the latest voltage change between the chassis and 32-volt power bus responsible for distributing electricity throughout the rover. Data showed that levels had dropped from 11 volts to just 4 volts, though the rover is designed to work properly through this and an even broader range.

However, soft shorts decrease the rover's ability to tolerate any future shorts that may occur, and can be indicative of a bigger problem at the site of the short. For this reason, engineers are anxious to identify what cause the voltage change, with analysis so far uncovering that the change appeared three times in the hours before it became persistent.

The rover went into safe mode earlier this month when an unanticipated software reboot known as a warm reset occurred during a communications pass with the Mars Reconnaissance Orbiter. The problem was traced back to an error in existing onboard software and three days later the rover was back into a fully operational state. Officials say the two events do not appear to be related.