As space missions go, it was almost too successful.
This week NASA managed to briefly land its OSIRIS-REx spacecraft on Bennu , a skyscraper-sized asteroid some 200 million miles from Earth, allowing the probe to collect samples that scientists one day hope to study.
But during its 16-second space forage, the OSIRIS-REx gathered so much material that its container door became wedged open, allowing the rocks to spill back into space.
Thomas Zurbuchen, NASA’s associate administrator for science, told reporters that time was "of the essence" as they struggled to stop more valuable evidence spewing out of the ship.
He said mission teams will skip their chance to measure how much material they collected, as originally planned.
Instead they will, proceed to the stow phase, a fragile process of tucking the sample collection container in a safe position within the spacecraft without jostling out more valuable material.
NASA said a planned second sweep of the asteroid had been cancelled and they would instead plan for its return to Earth in 2023.
OSIRIS-REx principle investigator Dante Lauretta the experiment could not have gone better, adding: "we're almost the victim of our own success here,"
The $800 million, minivan-sized OSIRIS-REx spacecraft, built by Lockheed Martin, launched in 2016 to grab and return the first U.S. sample of pristine asteroid materials. Japan is the only other country to have accomplished such a feat.
Asteroids are among the leftover debris from the solar system’s formation some 4.5 billion years ago and scientists says a sample could hold clues to the origins of life on Earth.