OrbitalHub

Wikipedia dicit:

Rehearsals will be performed before the sampling event, during which the solar arrays will be raised into a Y-shaped configuration to minimize the chance of dust accumulation during contact and provide more ground clearance in case the spacecraft tips over (up to 45°) during contact. The descent will be very slow to minimize thruster firings prior to contact in order to reduce the likelihood of asteroid surface contamination by unreacted hydrazine propellant. Contact with the surface of Bennu will be detected using accelerometers, and the impact force will be dissipated by a spring in the TAGSAM arm.

Upon surface contact by the TAGSAM instrument, a burst of nitrogen gas will be released, which will blow regolith particles smaller than 2 centimetres (0.8 in) into the sampler head at the end of the robotic arm. A five-second timer will limit collection time to mitigate the chance of a collision. After the timer expires, the back-away maneuver will initiate a safe departure from the asteroid.

OSIRIS-REx will then halt the drift away from the asteroid in case it is necessary to return for another sampling attempt. The spacecraft will use images and spinning maneuvers to verify the sample has been acquired as well as determine its mass and verify it is in excess of the required 60 grams (2.1 oz). In the event of a failed sampling attempt, the spacecraft will return for another try. There is enough nitrogen gas for three attempts.

In addition to the bulk sampling mechanism, contact pads on the end of the sampling head will passively collect dust grains smaller than 1 mm, upon contact with the asteroid. These pads are made from tiny loops of stainless steel.

After the sampling attempt, the Sample-Return Capsule (SRC) lid will be opened to allow the sampler head to be stowed. The arm will then be retracted into its launch configuration, and the SRC lid will be closed and latched preparing to return to Earth.

Video credit: Lockheed Martin

NASA dicit:

When NASA’s OSIRIS-REx spacecraft arrived at asteroid Bennu in December 2018, its close-up images confirmed what mission planners had predicted nearly two decades before: Bennu is made of loose material weakly clumped together by gravity, and shaped like a spinning top. This major validation, however, was accompanied by a major surprise. Scientists had expected Bennu’s surface to consist of fine-grained material like a sandy beach, but were instead greeted by a rugged world littered with boulders – the size of cars, the size of houses, the size of football fields. Now, thanks to laser altimetry data and high-resolution imagery from OSIRIS-REx, we can take a tour of Bennu’s remarkable terrain.

Video credit: NASA’s Goddard Space Flight Center/NASA/University of Arizona/CSA/York University/MDA/Dan Gallagher (USRA): Producer/Kel Elkins (USRA): Lead Visualizer/Jonathan North (USRA): Animator/Adriana Manrique Gutierrez (USRA): Animator/Dan Gallagher (USRA): Narrator/Erin Morton (The University of Arizona): Support/Aaron E. Lepsch (ADNET): Support/“Timelapse Clouds” by Andy Blythe and Marten Joustra; “The Wilderness” by Benjamin James Parsons; “Maps of Deception” by Idriss-El-Mehdi Bennani, Olivier Louis Perrot, and Philippe Andre Vandenhende

Wikipedia dicit:

Using data collected by NASA’s OSIRIS-REx mission, this animation shows the trajectories of particles after their emission from asteroid Bennu’s surface. The animation emphasizes the four largest particle ejection events detected at Bennu from December 2018 through September 2019. Additional particles, some with lifetimes of several days, that are not related to the ejections are also visible.

Video credit: M. Brozovic/JPL-Caltech/NASA/University of Arizona

NASA dicit:

The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is a NASA asteroid study and sample-return mission. The mission’s main goal is to obtain a sample of at least 60 grams (2.1 oz) from 101955 Bennu, a carbonaceous near-Earth asteroid, and return the sample to Earth for a detailed analysis. The material returned is expected to enable scientists to learn more about the formation and evolution of the Solar System, its initial stages of planet formation, and the source of organic compounds that led to the formation of life on Earth. If successful, OSIRIS-REx will be the first U.S. spacecraft to return samples from an asteroid. The Lidar instrument used aboard the OSIRIS-REx was built by Lockheed Martin, in conjunction with the Canadian Space Agency.

OSIRIS-REx was launched on 8 September 2016, flew past Earth on 22 September 2017, and reached the proximity of Bennu on 3 December 2018, where it began analyzing its surface for a target sample area over the next several months. It is expected to return with its sample to Earth on 24 September 2023.

Video Credit: NASA

NASA dicit:

Since arriving at near-Earth asteroid Bennu in December 2018, NASA’s OSIRIS-REx mission has been studying this small world of boulders, rocks, and loose rubble – and looking for a place to touch down. The goal of OSIRIS-REx is to collect a sample of Bennu in mid-2020, and return it to Earth in late 2023.

Bennu turned out to be rockier than anticipated, but mission planners have now identified four sites on its surface that are smooth enough for OSIRIS-REx to collect a sample. The mission will down-select to the final two sites – a primary and a backup – in December 2019. Like the mythological Bennu bird for which the asteroid is named, all of the candidate sample sites refer to birds that can be found in Egypt.

Video Credit: NASA Goddard

NASA dixit:

“NASA’s OSIRIS-REx asteroid sample return mission launched in 2016 and now (August, 2018) is entering its approach phase. OSIRIS-REx will arrive at asteroid Bennu in December, 2018. OSIRIS-REx will help unveil the mysteries of our solar system’s formation.”

Video Credit: NASA’s Goddard Space Flight Center/Katrina Jackson