NASA blasted the InSight lander to Mars with the aim of drilling some 16 feet into the Martian ground.

But the drill, also called the "mole" or "self-hammering heat probe," only burrowed 14 inches into the soil before getting stuck. The space agency hasn't been able to move the heat-detecting probe since February.

But NASA has a plan. And the people behind that plan appear confident.

"This is a very, very challenging problem," said Ashitey Trebi-Ollennu, the lead arm engineer at NASA's Jet Propulsion Laboratory. "Sometimes it appears intractable. But we engineers love solving challenging problems."

The strategy is relatively simple in theory, but of profound difficulty to deploy from tens of millions of miles away.

The InSight lander's instruments. Image: nasa

NASA engineers plan to use a robotic scoop to scrape red soil into the 14-inch hole and fill it up. Then, they'll plant the flat bottom of the metal scoop into the soil next to mole, thus pinning the drill against the scoop.

This way, the drill won't bounce around as much in the hole. Instead, the drill's hammering motion will be forced down into what NASA believes is highly compact or clumped soil. (Though, it may also be a rock, which could doom this part of InSight's mission.)

"This might increase friction enough to keep it moving forward when mole hammering resumes," Sue Smrekar," the InSight Deputy Principal Investigator, said in a statement.

Replicating the plan in NASA's lab. Image: nasa jpl

Previously, NASA used the scoop to push on the soil around the hole, hoping to collapse the hole so the drill wouldn't wobble around. But NASA failed to collapse the shallow pit.

Ultimately, the goal is to drill 16 feet into the Martian ground where the probe can measure the heat inside Mars' interior. How geologically active is the planet, and what exactly is going on below the desert surface, are two weighty questions.

"We're cautiously optimistic that one day we'll get the mole working again," Trebi-Ollennu said.