WASHINGTON — NASA’s OSIRIS-REx spacecraft will make one last shut method to the asteroid it collected samples from subsequent week earlier than heading again to Earth.
On April 7, the spacecraft will go 3.7 kilometers above the situation on the asteroid Bennu known as Nightingale the place, in October, the spacecraft briefly touched down and picked up as a lot as a number of hundred grams of fabric, now saved within the spacecraft.
Instantly after that pattern assortment maneuver, the mission had no plans to return to the neighborhood of Bennu. Nevertheless, NASA determined to make a last go over the landing website to see what modifications the sampling made to the Nightingale area, just like the creation of a crater.
“We sat down and did a danger evaluation, and we determined it was very low danger and the science return was essential. So, we’re going again to take a look at the positioning and see if we are able to decide the crater,” Dante Lauretta, principal investigator for OSIRIS-REx on the College of Arizona, mentioned throughout a March 17 presentation in regards to the mission on the 52nd Lunar and Planetary Sciences Convention on-line.
He predicted that the positioning ought to haven’t only a single crater however as many as 5: one created by the sampling mechanism and 4 from thrusters on the spacecraft that fired to brake the spacecraft’s descent and pull it away from the floor. “There needs to be 5, or some type of cloverleaf sample from all of that interplay with the floor,” he mentioned.
Evaluation of information collected throughout that Oct. 20 sampling mechanism, on the finish of a robotic arm prolonged from the underside of the spacecraft, went deeper into the floor than predicted. The sampling head went 48.eight centimeters beneath the floor earlier than the spacecraft stopped its descent and beginning transferring again up.
“The floor was not slowing us down in any respect,” he mentioned. “If we hadn’t fired the back-away thrusters, we most likely would have sunk in meters into the floor of this asteroid, which is fascinating to consider.”
Shortly after the pattern assortment maneuver, photographs confirmed some materials leaking out of the sampling head. That brought on the mission to speed up efforts to stow the pattern assortment unit in a capsule that can retailer it in the course of the journey again to Earth.
“We undoubtedly misplaced tens of grams of pattern from the time we collected it till the time we stowed,” Lauretta mentioned. “We’re nonetheless assured that there’s substantial quantities of fabric in that return capsule prepared to return residence.”
Due to the accelerated effort to stow the sampling head, the mission didn’t try and measure precisely how a lot materials was stowed by spinning the spacecraft and measuring the distinction in its second of inertia from earlier than the sampling maneuver. Nevertheless, visible estimates of the sampling head recommend it accommodates a minimum of a number of hundred grams of fabric. “We really feel like we collected considerably greater than our 60-gram requirement,” he mentioned.
The flyby of the Nightingale website would be the final time OSIRIS-REx approaches Bennu. The spacecraft will start its journey again to Earth Could 10, arriving on Sept. 24, 2023. The capsule containing the samples will land within the Utah desert. “We’re very excited to get these samples into our labs and unravel the historical past of Bennu and the photo voltaic system,” he mentioned.