NASA's Perseverance Mars rover got some rocks stuck in its throat.
Late last month, Perseverance collected its sixth Red Planet rock sample, but it hasn't been able to seal up the titanium tube.
"I recently captured my sixth rock core and have encountered a new challenge. Seems some pebble-sized debris is obstructing my robotic arm from handing off the tube for sealing/storage. More images and data to come. #SamplingMars takes perseverance," mission team members said on Perseverance's Twitter account.
Perseverance landed in February 2021 inside the 45km wide Jezero Crater, which once housed a lake and river delta. The rover has two main missions: find ancient Martian life and collect several dozen samples. NASA/ESA plan to bring back pristine material from Mars by 2031, maybe even earlier.
Perseverance has already saved five samples of the Red Planet's rock. Using a percussive drill at the end of its 2.1-metre robotic arm, the six-wheeled robot collected sample number six from a rock called Issole on Dec. 29.
There was no problem until Perseverance transferred the sample, which was already inside the titanium tube, into the "bit carousel," a rotating structure on the rover's chassis. Sensors detected resistance early in this step, which suggests a blockage.
Last week, Perseverance was told to remove the sample-filled tube from the carousel and take pictures of it. Pictures showed that the bit carousel had pebbles in it.
Right now, the Perseverance team's working on it.
"The designers of the bit carousel did take into consideration the ability to continue to successfully operate with debris," Louise Jandura, chief engineer for sampling and caching at NASA's Jet Propulsion Laboratory in Southern California, which manages Perseverance's mission, wrote in a blog post.
"However, this is the first time we are doing a debris removal, and we want to take whatever time is necessary to ensure these pebbles exit in a controlled and orderly fashion," Jandura added.
Apparently, this isn't Perseverance's first sampling challenge on Mars. In August, the rover failed to collect any samples during its first sampling effort. It turned out the target rock was too soft and crumbled into bits, so it didn't make it into the tube.
"One thing we've found is that when the engineering challenge is hundreds of millions of miles away (Mars is currently 215 million miles [346 million kilometres] from Earth), it pays to take your time and be thorough," Jandura wrote. "We are going to do that here. So that when we do hit the unpaved Martian road again, Perseverance sample collection is also ready to roll."