The National Aeronautics and Space Administration (NASA) said on Friday its robotic spacecraft Osiris-Rex had succeeded in collecting a large sample from asteroid Benu — but so much that it’s leaking, AFP reported.

The probe is thought to have collected some 400 grams of the sample, much more than the 60 grams needed, AFP quoted mission chief Dante Lauretta.

“A substantial fraction of the required collected mass is seen escaping,” Lauretta said.  

The lid for the collector at the end of the probe’s arm where the fragments are being stored has been slightly wedged open by larger rocks, creating a leak, the scientists suspect. The exact amount of the leak isn’t precisely known. 

The team in charge of the probe is now working to quickly stow the remaining samples. 

“My big concern now is that the particles are escaping because we were almost a victim of our own success here,” Lauretta said.

Also read: NASA selects Nokia to build 4G Mobile network on moon

As a result, a plan to carry out a mass measurement on Saturday has been cancelled since it could risk scattering further samples.

The task at hand is to reduce the probe’s activity as much as possible and prepare to stow the material in a capsule, as quickly as possible.

Osiris-Rex is set to come home in September 2023 which will help unravel the origins of our solar system.

Also read: US astronaut votes from space

“Bennu continues to surprise us with great science and also throwing a few curveballs,” Thomas Zurbuchen, a NASA associate administrator, said in a statement.

“And although we may have to move more quickly to stow the sample, it’s not a bad problem to have. We are so excited to see what appears to be an abundant sample that will inspire science for decades beyond this historic moment,” he added, AFP reported.