At the moment, NASA’s OSIRIS-REx workforce is readying to carry out an early stow of a pattern from asteroid Bennu, a course of initially scheduled for November 2.
“The abundance of fabric we collected from Bennu made it attainable to expedite our choice to stow,” OSIRIS-REx mission lead and College of Arizona planetary scientist Dante Lauretta mentioned in a NASA press launch on Monday. “The workforce is now working across the clock to speed up the stowage timeline, in order that we will defend as a lot of this materials as attainable for return to Earth.”
On Tuesday, Oct. 20, NASA’s OSIRIS-REx spacecraft prolonged its 11-foot arm and touched Bennu, an asteroid in regards to the dimension of the Empire State Constructing. From it, OSIRIS-REx autonomously collected a pattern of rocks, mud, and particles.
Although assortment didn’t require human oversight and enter, stowing the pattern is completed in levels and would require support from the workforce again on Earth. Scientists will ship instructions to the spacecraft to start the method, and with every step of stowing, OSIRIS-REx will ship the workforce information and pictures, ready for a command to proceed.
Why stow early?
“We spent years getting ready for this, analyzing each state of affairs,” Coralie Adams, the OSIRIS-REx TAG navigation supervisor, informed NOVA in regards to the sampling mission.
However final week’s state of affairs could also be shocking even to the OSIRIS-REx workforce: The spacecraft could have collected an excessive amount of of asteroid Bennu, inflicting the spacecraft’s assortment container to jam. On Thursday, OSIRIS-REx scientists obtained pictures that confirmed a few of the pattern had leaked into outer house from the gathering head, which wasn’t in a position to absolutely shut.
“A considerable quantity of pattern is seen floating away,” Lauretta mentioned on Friday.
The OSIRIS-REx workforce aimed to gather no less than 60 grams (2.1 ounces) of rock, dust, and dirt from Bennu, an asteroid about 200 million miles away from Earth. Regardless of the gap, Bennu is taken into account a near-Earth object (NEO) with a 1 in 2,700 probability of putting our planet within the late 2100s. (Andrea Riley, NASA’s DART mission program govt, says “there’s no concern to be fearful” on condition that probability.) By amassing the pattern and analyzing it again on Earth, scientists hope to higher perceive the menace different NEOs could pose—and whether or not asteroids can reveal the historical past of planetary formation in our photo voltaic system.
Gathering a giant pattern from Bennu was key, Hal Levinson of the Southwest Analysis Institute in Boulder, Colo., mentioned in a NASA press convention on Monday, Oct. 19. “Once I received into this a very long time in the past, we used to assume the planets fashioned the place we see them. What actually occurred is like somebody picked up the photo voltaic system and shook it actual laborious. To actually put the story collectively requires having a giant pattern” from Bennu and ultimately different asteroids in our photo voltaic system, he explains.
To gather a pattern from Bennu, a workforce at Lockheed Martin Area in Littleton, Colo., spent years creating OSIRIS-REx’s arm and its asteroid sampling technique, collectively referred to as the Contact-and-Go Pattern Acquisition Mechanism (TAGSAM). Fairly than having all the spacecraft contact down on Bennu, whose radius is a mere 861 ft, the workforce employed TAGSAM to succeed in out, contact, and in the end accumulate materials from the asteroid’s Nightingale Crater.
“The final 10 minutes, because the spacecraft was descending in the direction of the floor of Bennu, was unreal,” Lauretta mentioned. “It was this slow-motion thrill trip,” Beau Bierhaus, an OSIRIS-REx TAGSAM scientist added.
At TAGSAM’s finish is a foot-wide assortment head like an “air filter,” Lauretta explains. This blew high-pressure nitrogen gasoline because it settled down on Bennu on Tuesday, disturbing the gathering website and sucking up as a lot rock, dust, and dirt because it presumably may in simply 6 seconds on the floor.
The cameras reveal that OSIRIS-REx is carrying as much as 2 kilograms (2.2 kilos) of pattern, which is at its higher restrict. “About 400 grams appears seen from the cameras. The gathering lid has failed to shut correctly and stays wedged open by items which can be as much as three centimeters in dimension, making a centimeter-wide hole for materials to flee,” Neel V. Patel writes for MIT Expertise Evaluate. “It appears when OSIRIS-REx touched down on Bennu’s floor, the gathering head went 24 to 48 centimeters deep, which might clarify the way it recovered a lot materials.”
A lot of the escaped materials—as a lot as 10 grams, Lauretta believes—received out due to actions of OSIRIS-REx’s arm on Thursday. Luckily, the arm is now in a locked place, which ought to remove extra losses. Given the scale of the pattern, even with a few of it having drifted into house, the workforce is not going to pursue a second sampling try. Nor will it proceed with its Pattern Mass Measurement exercise, wherein the spacecraft was going to pirouette in a lot of spin maneuvers, permitting scientists to estimate the mass of the pattern. Realizing that such motion may lead to extra pattern loss, the workforce determined to cancel the process.
OSIRIS-REx has been orbiting Bennu since December 2018. In March, the spacecraft will depart and make its manner again to Earth. Greater than two years later, because it passes over the Utah desert, OSIRIS-REx will drop off a small capsule containing its bounty of rocks and dust, which is able to parachute to a touchdown—and a workforce of keen scientists—on Sept. 24, 2023.