Osiris-Rex Asteroid Sample Collection Date Slips

Artist's concept of NASA’s Osiris-Rex spacecraft descending toward Bennu to collect a sample of the asteroid’s surface.
Credit: NASA/Goddard/University of Arizona

HOUSTON—NASA’s Osiris-Rex asteroid sample return mission team is relaxing previous plans to descend to the surface of its target, called Bennu, to gather surface pebbles and soil for return to Earth, in part due to work constraints imposed by the coronavirus pandemic.

But the planned date for Osiris-Rex to return to Earth and drop off a sample container for a parachute descent onto the U.S. Army’s Test and Training Range still remains Sept. 24, 2023.

However, the planning date on which the spacecraft is to briefly tap the surface at the Nightingale crater near Bennu’s north pole to gather up to 2.2 kg (4.4 lb.) of material has moved from Aug. 25 to Oct. 20. Plans for a second rehearsal of the sample collection maneuvers have also moved from June 23 to Aug. 11.

The departure from Bennu of Osiris-Rex has moved from March 2021 to mid-2021. Its asteroid sample bounty could help to inform scientists about the Solar System’s 4 1/2 billion-year-old planet forming process, including the distribution on Earth of water ice and organics, the chemical building blocks for life.

“Spacecraft activities require significant lead time for the development and testing of operations, and given the current requirements that limit in-person participation at the mission support area, the mission would benefit from giving the team additional time to complete these preparations in the new environment,” according to a May 20 statement from NASA’s Goddard Space Flight Center, which is managing the Osiris-Rex mission. “As a result, both the second rehearsal and first sample collection attempt will have two extra months for planning.”

The $1 billion mission launched on Sept. 8, 2016, and reached Bennu, a rocky, carbon-rich relic from the early Solar System, in early December 2018 to begin a lengthy reconnaissance and sample selection site process.

On April 14, the mission team successfully rehearsed the early stages of the sample acquisition process. The spacecraft autonomously departed its 1-km-high altitude orbit and marched through the initial stages of a descent to an altitude of 65 m (213 ft.) before returning to orbit. The second rehearsal, now rescheduled for Aug. 11, is to take the spacecraft to an altitude of 40 m (131 ft.), before rising to its “safe orbit.”

The initial rehearsal included a test extension of the Osiris-Rex’s 3.5-m (11-ft.)-long Touch-and-Go-Sample-Acquisition-Mechanism (TAGSAM), the device that is to release a burst of nitrogen gas toward the surface of Bennu to dislodge and throw up pebbles and soil into the spacecraft’s sample container.

Meanwhile, the Japan Aerospace Exploration Agency’s (JAXA) Haybasua-2 asteroid sample return mission spacecraft is continuing its return to Earth, which is targeted for November/December, to drop off a sample container into remote Australia with surface and subsurface material gathered from the larger asteroid Ryugu during two surface encounters in 2019.

Hayabusa-2 was launched on Dec. 3, 2014.

Scientists from the Osiris-Rex and Hayabusa-2 missions plan to exchange samples to support research activities.

Mark Carreau

Mark is based in Houston, where he has written on aerospace for more than 25 years. While at the Houston Chronicle, he was recognized by the Rotary National Award for Space Achievement Foundation in 2006 for his professional contributions to the public understanding of America's space program through news reporting.