A Mars lander’s digger is burrowing into the red planet again after hitting a snag seven months ago.

NASA said Thursday the mechanical mole has penetrated three-quarters of an inch (2 centimeters) over the past week. While just a baby step, scientists are thrilled with the progress.

“We’re rooting for our mole to keep going,” said the experiment’s lead scientist, Tilman Spohn of the German Aerospace Center, in a statement.

The German device is meant to penetrate 16 feet (5 meters) into Mars to measure internal temperatures. It barely got a foot down (30 centimeters) before stalling in March, soon after starting to hammer. Over the weeks and months, engineers devised a backup plan: To help, the robot arm on the InSight lander is pressing against the drill to create enough friction for it to keep digging.

Since Oct. 8, the mole has hammered 220 times on three occasions, making slow but steady progress.

Scientists said it will take time — and lots more hammering — to see how deep it goes.

“When we first encountered this problem, it was crushing,” said the Jet Propulsion Laboratory’s Troy Hudson, who is leading the recovery effort.

“But I thought, ‘Maybe there’s a chance; let’s keep pressing on.’ And right now, I’m feeling giddy,” he said in a statement.

InSight arrived at Mars last November.

(AP)