NASA formally concluded the OSIRIS-REx mission on September 30, closing a decade of engineering after the spacecraft delivered the largest asteroid sample ever collected to Earth. The mission overcame two initial NASA rejections, unexpected boulder terrains, and a jammed sample lid before returning pristine material from asteroid Bennu.
On September 30, NASA formally ended the OSIRIS-REx mission, bringing a chapter of planetary exploration to a close. Dante Lauretta led the United States’ first mission to sample an asteroid and return it safely to Earth as Principal Investigator. Dante Lauretta pointed out that the effort successfully managed several unforeseen challenges, featuring a rocky terrain that acted more like a liquid than solid ground. The vehicle-sized probe was formally designated Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx). The spacecraft explored and gathered samples from Bennu, an ancient asteroid preserving untouched clues from the birth of our solar system more than 4.5 billion years ago.
The spacecraft launched from Cape Canaveral aboard an Atlas V rocket on September 8, 2016. When its two-year voyage began, Bennu appeared merely as a distant point of light through a telescope. Researchers used its reflected light to correctly forecast a spinning-top geometry alongside a beach-like sandy texture. After a seven-year journey spanning 4 billion miles, the mission delivered its Sample Return Capsule to the Utah desert on September 24, 2023.
OSIRIS-REx Overcomes Rejections and Surprises at Asteroid Bennu
The mission’s path to launch was fraught with hurdles long before the spacecraft ever left the ground.
Telescopic observations had predicted a smooth, sandy sphere. The spacecraft revealed a surface completely covered in jagged boulders and debris.
Our expectations about the asteroid’s surface were completely wrong.
Dante Lauretta, OSIRIS-REx Principal Investigator
When the spacecraft touched down on a small crater named Nightingale, the surface offered almost no structural resistance, reacting more like a fluid than a solid rocky shell. The sampling head sank 20 inches deep before firing its thrusters to pull away with the cargo. A jammed sample lid was one of the hurdles the mission overcame.
Spacecraft Returns Water-Rich Carbon Samples from Bennu
During its extended survey of Bennu, the spacecraft set two Guinness World Records by making the closest orbit of a planetary body and rendering Bennu the smallest planetary object ever orbited by a spacecraft. Remote-sensing observations confirmed that the asteroid is coated in carbon-bearing compounds and the parent body was likely water-rich.
The returned cargo weighed 4.29 ounces on Earth, exceeding mission requirements. That material has already fueled more than 200 research papers, revealing amino acids, sugars, and secondary minerals produced by exposure to liquid water.
| Mission Milestone | Date | Details |
|---|---|---|
| Spacecraft Launch | September 8, 2016 | Lifted off aboard an Atlas V rocket from Cape Canaveral Air Force Station |
| Arrival at Bennu | December 3, 2018 | Began 18-month surface survey and mapping |
| Sample Collection | October 20, 2020 (rehearsal April 2020) | Collected 4.29 ounces of material from crater Nightingale |
| Earth Return | September 24, 2023 | Sample Return Capsule landed in the Utah desert |
| Mission Conclusion | September 30 | NASA formally concluded the OSIRIS-REx mission lifecycle |
OSIRIS-APEX Probe Targets Asteroid Apophis for 2029
Analysis revealed that Bennu carries a risk of impacting Earth.
While the OSIRIS-REx chapter has closed, the hardware itself continues to fly. Now designated as OSIRIS-APEX (short for OSIRIS-APophis EXplorer), the probe is channeling its leftover fuel toward Apophis—a distinct class of near-Earth asteroid compared to Bennu—with an arrival scheduled for 2029. Alongside its new mission identity targeting the near-Earth object Apophis, a significant number of the students and early-career researchers who contributed to OSIRIS-REx are now steering the APEX initiative toward upcoming scientific breakthroughs.
Successful exploration missions are not those that avoid surprises; they are those that are deliberately designed to adapt to them.
Dante Lauretta, OSIRIS-REx Principal Investigator
Most of the Bennu material remains in curation, saved for future scientists equipped with analytical instruments not yet invented.
