On October 20, 2020, NASA’s Osiris-Rex probe slowly approached the asteroid Bennu, until it was an arm’s length (telescope) at the nightingale site. It then proceeded to perform a “touch-and-go” type of maneuver to collect a few grams of soil sample from the star. A successful operation and although securing the precious pieces gave the engineers a cold sweat on Earth, they are now safe in a sample return capsule (SRC).
Observe the results of the effect
After the samples were collected, the program of investigation predicted that he would return to Earth to drop his capsule. But NASA decided to give him a final tour of the asteroid once and specifically to fly to the Nightingale site to observe changes to the surface due to the sample collection maneuver. This actually involved driving the sampling arm into the ground for about fifty centimeters and pulling a pressure charged nitrogen gas to jointly suspend dust. Spacecraft thrusters also mobilized a large amount of surface material when it was tasked to lift it off the ground quickly. Since Bennu’s gravity is very low, these various actions have a special effect on the star’s surface and in particular the amount of rocks and dust around the site. This final overflight, which will be carried out at an altitude of 3.7 km, will provide an opportunity for the mission team to learn how the contact site between Osiris-Rex and the Benue surface and its surrounding area was altered.
Images of a collection of specimens on the surface of the asteroid Bennu. Sincerely: NASA / Goddard / University of Arizona
Long journey home
The flyby will last up to 5.9 hours, which is slightly more than the duration of the full rotation of the asteroid. During this time, the investigation will take high-resolution images of the northern and southern hemispheres and the equatorial region of the asteroid. The team will then compare these new images with the previous images received in 2019 during reconnaissance overflows made to select the collection site. Once this final round is completed, Osiris-Rex will be in high orbit around Benue until 10 May, time to send its final data to Earth and prepare it for its return journey that will last two years. The probe will not return to our planet: it will drop its sample capsule, which must be received on 24 September 2023 at a shooting range in Utah (United States). If its equipment is still in working order, it may be assigned a possible extended mission. For Benue’s dust, it will be studied by dozens of scientific teams who will try to uncover the secrets of the primitive solar system whose asteroids reflect the composition.