OSIRIS-REx to Get a Sample of the Asteroid Bennu this Month!

By Dr. Lisa Will, Resident Astronomer at the Fleet Science Center

Launched in 2016, the NASA spacecraft OSIRIS-REx—whose name stands for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer—has been in orbit around Bennu since December 31, 2018. On that day, Bennu, which is only about 0.3 miles long, became the smallest object ever orbited by a spacecraft. The primary goal of this mission is to gather a sample of asteroid material, which will then return to Earth.   

While the spacecraft has been in orbit around Bennu, it mapped the asteroid’s surface to look for a good sampling site. This turned out to be difficult to do, because the surface of the asteroid is really rocky, with lots of sharp rocks and boulders.

The chosen location for the sample collection is called Nightingale, a region only about 50 ft across in the northern hemisphere of the asteroid. This site was chosen because it appears to have an open region of fine-grained material, which can be retrieved by the sampling equipment, although the spacecraft will have to fit in between some large boulders to do so.  

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OSIRIS-REx Match Point Maneuver. Credit: NASA Goddard  

On October 20, OSIRIS-REx will make its first attempt at sample collection with a method called the Touch-and-Go (TAG). The spacecraft will lower to the surface of the asteroid, touching down for mere seconds (seriously, the estimate is less than sixteen seconds!). While it does this, it will release a jet of nitrogen gas, which will kick up asteroid material to be collected by the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) collector head. After that, the spacecraft will return to orbit. The goal is to collect a minimum of two ounces of material to return to Earth. If this attempt fails, OSIRIS-REx has enough nitrogen for two more attempts, possibly at a backup site named Osprey, in early 2021. Later in 2021, the spacecraft will leave Bennu so it can deliver the collected sample of Bennu back to Earth in September 2023. The material from this carbonaceous asteroid, known to have hydrated minerals on its surface, will provide data for amazing science for years to come!  

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TAGSAM Head Collecting Asteroid Sample.     

Wishing the best of luck to everyone involved in this exciting mission.  

Follow the OSIRIS-REx spacecraft on social media for more news!   https://twitter.com/OSIRISREx   https://www.instagram.com/osiris_rex/   Use the hashtag #ToBennuAndBack  

Wishing you clear skies!