This story is part of Welcome to Mars, our series exploring the red planet.

When Mars gives you pebbles, you give them back.

NASA’s Perseverance spacecraft ran into a sampling problem late last year when some The gravel got in the way of the conveying tube Filled with rocks in the internal handling system. This means that the rover team has to get creative in clearing the blockage.

The problem occurred along the rover’s bit circuit, which passes sample tubes inside for processing. As a test, NASA ordered the rover to rotate the carousel. It worked. The upper two pebbles were kicked. “This is great news, as these small pieces of debris are believed to be the cause of the unsuccessful transfer of the drill bit and sample tube to the carousel again on December 29,” Deputy Project Director Rick Welch wrote in a mission update on Friday.

NASA Tweeted a Stylish GIF Shows before and after bit circuit views. You can see how the largest gravel has now been removed.

There is still a small amount of debris left, but it may not cause any problems in the sampling process and these small pieces may fall off when the rover is moving.

Getting rid of the gravel was just one task the rover had to accomplish. The team also decided it would be smart Empty any remaining rock from the sample tube So it can be reused for a new sample if needed. This experiment took some effort as the team experimented with different methods of cleaning the tube, including directing it toward the ground. “With the open end of the tube continuing toward the surface, we rocked the back of it for 208 seconds — via the tap function of the drill,” Welch said.

The rover checked its manual labor and saw some rocks on the ground. Follow-up photos show that the tube can be reused, possibly to re-sample the original rock that led to the gravel problem.

Collecting rock samples is an essential part of the perseverance business. NASA plans for the future Follow-up task to collect samples and return them to Earth for study.

Pebbles saga is a good example of the flexibility and creativity required for a robot to operate successfully on Mars. The unexpected can happen, such as when the helicopter escorting the rover is Ingenuity was recently grounded due to bad weather. With some rotation and a few flashes, it looks like Perseverance will be back to building its rock group fairly soon.