A NASA spacecraft stuffed with a lot of asteroid debris Grab this week Scientists said Friday that it is jammed and that precious particles are being washed away into space.

Scientists announced the news three days after the Osiris Rex spacecraft briefly touched the asteroid Bennu, 200 meters away.

The mission’s chief scientist, Dante Loretta, said Tuesday’s operation collected much more material than expected to bring it back to Earth – in hundreds of grams. The sample container at the end of the robot’s arm penetrated very deep into the asteroid with this force, however, the rocks absorbed and became sticky around the edge of the cap.

The team was scrambling to put the sample container in the return capsule early Tuesday – much sooner than originally planned – for the long journey home. The particles keep escaping, and the scientists want to reduce the loss.

“Time is of the essence,” said Thomas Zurbuchen, head of science missions for NASA.

A cloud of asteroid particles can be seen orbiting the spacecraft as it moves away from Bennu – at least half an ounce (5 to 10 grams) at any time. The situation appears to stabilize, according to Loretta, once the robot arm stops moving and is held in place.

The requirements for Orisis-Rex – NASA’s first mission to return the asteroid sample, totaling more than $ 800 million – were at least 2 ounces (60 grams) of samples to return. The carbon-rich material contains the building blocks preserved in our solar system and could help scientists better understand how planets formed and how life on Earth arose.

The spacecraft was launched in 2016, and arrived at Bennu in 2018. Regardless of what’s on board, it will still leave the asteroid’s vicinity in March. The samples will not return to Earth until 2023.

Japan is awaiting the second batch of samples taken from a different asteroid, which is scheduled to return in December.