NASA’s Mars Curiosity rover is back in action on the surface of the Red Planet, but authorities are still investigating the cause of a recent short-circuit issue and what it could mean for the program.

The rover is expected to resume movements of its robotic arm this week after the rover was shut down following an error with its drilling arm late last month, according to an Economic Times report.

The short circuit was first detected on February 27, and it triggered a fault-protection response that stopped the rover’s operations. The team has avoided driving the rover or using its arm ever since then as it looked into the problem via diagnostic tests, according to the report.

The team is cautiously putting the Curiosity rover back to work, but there is more tests to be done before NASA fully has a handle on the problem.

Curiosity Project Manager Jim Erickson of NASA’s Jet Propulsion Laboratory in California was quoted in the report as saying that diagnostic testing had narrowed the possible sources of the short circuit, which they now believe was the result of an intermittent short in the percussion mechanism of the drill — although further analysis will be needed to confirm that diagnosis.

Scientists discovered the problem while the rover was sifting through rock-powder drilled from the Martian surface. If the short proves to be a serious problem, the team won’t be able to drill into hard rock.

The short happened on the 911th Martian day of the mission, also known as a sol. It happened on the third up-and-down movement of 180, and it lasted less than one one-hundredth of a second. Although that might not sound like much, it is enough to trigger the fault protection.

Further testing will take place to find out more about the short before the team changes the position of the arm again.

In the meantime, the team will finish processing the rock sample that was in the possession of the arm, and examine it with onboard instruments.