NASA closes the book on epic OSIRIS-REx asteroid-sampling mission: 'I am immensely proud of what we did'

On Sept.

30, NASA formally concluded OSIRIS-REx, the historic first U.S. mission to pluck a pristine piece of an asteroid and deliver it safely back to Earth.

The van-sized OSIRIS-REx spacecraft — whose name is short for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer — visited and sampled Bennu , an ancient space rock holding pristine remnants from the dawn of our solar system more than 4.5 billion years ago.

Among those cosmic relics are raw organic building blocks , the kind that may have seeded life on Earth.

"I have known this day was coming for a long time, but it is still difficult to see it arrive," OSIRIS-REx Principal Investigator Dante Lauretta, who's based at the University of Arizona, said in a post on LinkedIn .

"I feel enormous pride in what we accomplished together, and real sadness that this journey has come to an end." For the mission team, the farewell capped a decade of high-stakes engineering, on-the-fly troubleshooting and nail-biting close calls that ultimately delivered to Earth the largest asteroid sample ever collected in space, one that held secrets from the early solar system .

Long before launch, the team faced obstacles that nearly thwarted the endeavor — chiefly, two rejections from NASA — before finally securing the green light for the $1 billion project under the New Frontiers Program in 2011.

When OSIRIS-REx launched on Sept.

8, 2016, on a two-year journey across the inner solar system, Bennu was little more than a point of light in telescopes.

Scientists expected the asteroid’s surface to be a smooth, sandy sphere where OSIRIS-REx could seamlessly touch down.

Much to their surprise, however, when the probe arrived at the asteroid in late 2018, it revealed Bennu to be a treacherous, loosely bound amalgamation of jagged boulders.

"Our expectations about the asteroid's surface were completely wrong," Lauretta said in an Oct.

7 statement from the University of Arizona.

"There was no obvious place to collect a sample anywhere." When OSIRIS-REx touched down on a small crater named Nightingale , Bennu offered so little structural resistance that scientists said its surface reacted more like fluid than a hard, rocky shell.