NASA’s OSIRIS-REx Mission
The recent asteroid study and sample-return mission OSIRIS-REx (an acronym for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer), operated by NASA and manufactured by Lockheed Martin, is now set to depart from the vicinity of the asteroid it was sampling, beginning of next year. It left our planet on the 8th of September 2016 on one of ULA’s Atlas V with the main goal to obtain a carbonaceous target sample of about 60 grams of the surface of a near-Earth asteroid known as 101955 Bennu.
As such, the initial milestone would consist of OSIRIS-REx to rendezvous with the asteroid. This was successfully completed on the 3rd of December 2018. The four candidate sample spots to subsequently collect the particulate were known under the name of Nightingale, Kingfisher, Osprey, and Sandpiper. Two years later, only a few weeks ago, the sample collection played out but did not all go as expected.
The TAGSAM (Touch-And-Go Sample Acquisition Mechanism) instrument was the instrument responsible for sample collection. During this phase, it was crucial to minimize the contact time of the probe with the surface of the asteroid and reduce thruster firings to avoid the contamination of the dust samples. As such, sampling was conducted in a way to reduce contact time to avoid OSIRIS-REx coming into full contact with the asteroid and creating a damaging collision.
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The sampling process worked in the following fashion: the TAGSAM head would release a burst of nitrogen which would blow small particles into the sampler head found in the sampling instrument. It was said that when TAGSAM made contact with the asteroid’s regolith surface, “it flowed away just like fluid”, and that the robotic arms managed to sink 48 centimeters into Bennu’s soft surface.
However, this is when complications arose. After successfully collecting more than the required sample amount, two rocks from the surface jammed the door of the Mylar flap which was meant to enclose the sample in the head. After video feedback of the incident, NASA concluded that material meant to remain in the sample head was slowly leaking into space, and in order to prevent further sample loss, OSIRIS-REx canceled its procedures to evaluate the mass of the sample and decided to conduct the stowing of the sample around a five days earlier than scheduled and then successfully secured it the sample return capsule.
NASA Releases Footage From The Crash
About a day after the sample collection and flap incident, NASA released footage from a camera located on TAGSAM as well as a wide navigation camera on the main body of OSIRIS-REx. Thankfully, it allowed confirmation of sample collection despite the door jamming but showed some sample particles flying away from the spacecraft which prompted NASA’s decision to speed up the recovery process.
The spacecraft is now scheduled to release the return capsule for atmospheric reentry and landing at the Utah Test and Training Range end of Q3 2023. The regolith sample will then be distributed to the various institutions and its study will then hopefully serve to map the properties, chemistry, and mineralogy of such carbonaceous asteroids to determine its geological history as well as provide precise and accurate information about the properties of the sampling site. On a grander scheme, this study has the aims to trace back the origins of the solar system and its evolution.
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