The Mars rover Perseverance has pebbles stuck in its drill. NASA has a plan to fix it.

This image of pebble-size debris in the bit carousel on NASA’s Perseverance Mars rover was acquired on Jan. 7, 2022, by the rover's WATSON camera. The image was taken to assist the Perseverance team in diagnosing an anomaly that occurred during a rock sampling on Dec. 29, 2021.
This image of pebble-size debris in the bit carousel on NASA’s Perseverance Mars rover was acquired on Jan. 7, 2022, by the rover's WATSON camera. The image was taken to assist the Perseverance team in diagnosing an anomaly that occurred during a rock sampling on Dec. 29, 2021. (Image credit: NASA/JPL-Caltech/MSSS)

NASA's Perseverance rover will dump its latest Mars sample to unclog pebbles from its drill. 

Perseverance mission managers made the unexpected announcement that they had to dump out Percy's latest sample via a blog post on Friday (Jan. 14). The team even shared in the post that they never thought they would have to do that as one of Perseverance's main goals is to pick up Mars samples for future analysis.

"I never imagined we would perform [this maneuver] – ever," wrote Jennifer Trosper, project manager at NASA's Jet Propulsion Laboratory, in the blog. "Simply put, we are returning the remaining contents of Sample Tube 261, our latest cored-rock sample, back to its planet of origin."

Related: Where to find the latest Mars photos from NASA's Perseverance rover

The car-sized rover reported the stuck debris publicly during its sixth rock core seizure on Jan. 7, via the mission's Twitter account and a previous blog post. Engineers have continued to work on the issue to clear the problem without causing any damage to the craft. This fix will likely require that Percy sit in place for another week or so.

Trosper outlined the steps JPL has taken so far to figure out a solution. Perseverance took pictures of the ground below on Jan. 12 so "we would have a good idea what rocks and pebbles already exist down there," she said. There has also been some "terrestrial experimentation," though Trosper did not elaborate on what exactly this entails.

Pre-launch rover testing on Earth revealed that evacuating the drill's collection tube is fairly easy to do, she reported, although this hasn't been tested yet on windy, dusty Mars where the gravity is a quarter that of our own planet's. 

"We sent commands up yesterday, and later on today the rover’s robotic arm will simply point the open end of the sample tube toward the surface of Mars and let gravity do the rest," Trosper said, meaning the procedure was likely finished over this past weekend. Results are expected to be reported on Tuesday (Jan. 18).

The commands will ask the rover to do rotation tests of its bit carousel to assess pebble movement, and more information will come from new pictures taken underneath Perseverance to see if more "pebbles happen to pop free," she said.

The team is not sure how much of the cored rock is still in the tube, but if the evacuation goes well they may attempt to redo the coring procedure. Perseverance is caching samples like this one for a planned sample-return mission to pick up.

Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook.  

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.

Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for Space.com for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, "Why Am I Taller?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: https://qoto.org/@howellspace