OSIRIS-REx Attempts to Collect Sample of Near-Earth Asteroid Bennu

On October 20, 2020, NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) spacecraft briefly touched an asteroid to collect regolith (rocks and dust) from the surface of the near-Earth asteroid (101955) Bennu. All spacecraft telemetry data indicates the sample collection event, known as ‘Touch-And-Go’ (TAG), executed as expected. Now, the OSIRIS-REx team will begin to assess whether the spacecraft grabbed any material, and, if so, how much; the goal is at least 60 grams. If the TAG event provided enough of a sample, the team will command the spacecraft to begin stowing the precious primordial cargo to begin its journey back to Earth in March 2021. Otherwise, they will prepare for another attempt in January 2021. OSIRIS-REx launched from Cape Canaveral Air Force Station in Florida on September 8, 2016. The spacecraft arrived at Bennu on December 3, 2018, and began orbiting the asteroid for the first time on December 31, 2018. OSIRIS-REx is scheduled to return to Earth on September 24, 2023, when it will parachute its Sample Return Capsule (SRC) into Utah’s west desert where scientists will be waiting to collect it. “This amazing first for NASA demonstrates how an incredible team from across the country came together and persevered through incredible challenges to expand the boundaries of knowledge,” said NASA Administrator Jim Bridenstine. “Our industry, academic, and international partners have made it possible to hold a piece of the most ancient Solar System in our hands.” On October 20 at 1:50 p.m. EDT, OSIRIS-REx fired its thrusters to nudge itself out of orbit around Bennu. It extended the shoulder, then elbow, then wrist of its 3.35-m (11-foot-) sampling arm, known as the Touch-And-Go Sample Acquisition Mechanism (TAGSAM), and transited across the asteroid while descending about 805 m (2,641 feet) toward the surface. After a four-hour descent, at an altitude of approximately 125 m (410 feet), OSIRIS-REx executed the ‘Checkpoint’ burn, the first of two maneuvers to allow it to precisely target the sample collection site, known as “Nightingale.” Ten minutes later, the spacecraft fired its thrusters for the second ‘Matchpoint’ burn to slow its descent and match the asteroid’s rotation at the time of contact. It then continued a treacherous, 11-min coast past a boulder the size of a two-story building, nicknamed ‘Mount Doom,’ to touch down in a clear spot in a crater on Bennu’s northern hemisphere. The size of a small parking lot, the Nightingale site is one of the few relatively clear spots on this unexpectedly boulder-covered space rock.   “This was an incredible feat — and today we’ve advanced both science and engineering and our prospects for future missions to study these mysterious ancient storytellers of the Solar System,” said Dr. Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate. “A piece of primordial rock that has witnessed our Solar System’s entire history may now be ready to come home for generations of scientific discovery, and we can’t wait to see what comes next.” “After over a decade of planning, the team is overjoyed at the success of today’s sampling attempt,” said OSIRIS-REx principal investigator Dr. Dante Lauretta, a researcher at the University of Arizona. “Even though we have some work ahead of us to determine the outcome of the event — the successful contact, the TAGSAM gas firing, and back-away from Bennu are major accomplishments for the team. I look forward to analyzing the data to determine the mass of sample collected.” Real-time data indicates the TAGSAM successfully contacted the surface and fired a burst of nitrogen gas. The gas should have stirred up dust and pebbles on Bennu’s surface, some of which should have been captured in the TAGSAM sample collection head.   “Today’s TAG maneuver was historic,” said Dr. Lori Glaze, Planetary Science Division director at NASA Headquarters. “The fact that we safely and successfully touched the surface of Bennu, in addition to all the other milestones this mission has already achieved, is a testament to the living spirit of exploration that continues to uncover the secrets of the Solar System.” “It’s hard to put into words how exciting it was to receive confirmation that the spacecraft successfully touched the surface and fired one of the gas bottles,” said OSIRIS-REx deputy project manager Dr. Michael Moreau, a researcher at NASA’s Goddard Space Flight Center. “The team can’t wait to receive the imagery from the TAG event late tonight and see how the surface of Bennu responded to the TAG event.” _____ This article is based on a press-release provided by the National Aeronautics and Space Administration.