![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2022\/06\/osiris-rex-the-mission-infographic-id-6230.jpg\")
<\/p>\nThe OSIRIS-REx spacecraft is on its way back to Earth after a multi-year, successful mission to the Near-Earth Asteroid (NEA) Bennu. The spacecraft is now bringing a sample of Bennu\u2019s surface back for a drop-off at Earth before continuing with an extended mission.<\/p>\n
The prolonged mission is called OSIRIS-APEX and will see the craft intercept the asteroid Apophis shortly after that space body makes a very close approach to Earth, coming inside the geostationary orbital belt which resides at 35,786 km above sea level.<\/p>\n<\/p>\n
OSIRS-REx, the story thus far<\/p>\n
OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) launched on September 8, 2016, on an Atlas V rocket from Florida and intercepted and entered proximity operations with Bennu on December 3, 2018.<\/p>\n
\u201cFrom a technical, by the book, standpoint, it all worked,\u201d related Beau Bierhaus, lead scientist for the TAGSAM (Touch-And-Go Sample Acquisition Mechanism) system on OSIRIS-Rex.<\/p>\n
\u201cThe other way of thinking about it is that we did not know in advance what the surface was going to be like. And after literal years \u2014 we got there in late 2018 and then we didn\u2019t sample until October of 2020. And so we were there for almost two years before we sampled \u2014 we had mapped the object globally in exquisite detail.\u201d<\/p>\n
<\/p>\n
Overview of the OSIRIS-REx mission. (Credit: Canadian Space Agency)<\/p>\n
\u201cWe had done TAG rehearsals to get very close to the surface. But the very last thing after all of that time, and after all of that data had been collected, the very last thing that had not been done yet was the actual contact between the spacecraft and the asteroid.\u201d<\/p>\n
Because of this missing element, and no way to gather that data until the TAG event, Lockheed Martin had to prepare for two very different surface scenarios: the surface could either react like a gravel path\/driveway or like freshly fallen, powdery snow.<\/p>\n
In the gravel scenario, TAGSAM would not penetrate deep into the surface \u2014 just as a person walking on a gravel path will not sink beneath the surface even when the surface gives and changes under their weight.<\/p>\n
But that same person walking on newly fallen snow will sink into the snow.<\/p>\n
\u201cSo we had to account for those two different end-member scenarios,\u201d related Bierhaus. \u201cAnd because we had planned for both \u2014 and the reality actually turned out to be more like the snow where we just sunk into the surface \u2014 we were successful.\u201d<\/p>\n
Part of what allowed for this versatility in design were tests conducted with NASA\u2019s Zero-G plane, affectionately known as the vomit comet.<\/p>\n
The plane flies parabolic arcs to allow teams to simulate microgravity.<\/p>\n<\/p>\n