NASA’s pioneering OSIRIS-REx probe has packed its precious asteroid sample back to Earth.
OSIRIS-REx has completed aligning the bits of the carbon-rich asteroid Bennu it captured last Tuesday (October 20), successfully locking the material into the spacecraft’s back cavity, Mission group announced on Thursday (October 29).
And the sample seemed substantial – much heavier than the 2.1 ounces (60 grams) that the task had set as a goal, team members said. Indeed, OSIRIS-REx collected so much documentation on October 20 that its sampling head could not close properly; The top sealing mylar caps are opened in places with protruding Bennu pebbles.
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The OSIRIS-REx team noticed the problem last week when examining the image of the head and collected samples; Material fragments of the escaped asteroid are drifting through the frames. To minimize the amount lost, the team decided to expedite the complicated and precise queuing process, which is expected to take place next week.
So, during the 36 hours on Tuesday and Wednesday (October 27 and October 28), engineers instructed OSIRIS-REx to place the sampling head, located at the end of the probe’s robotic arm, back into the compartment; yank the head to make sure it was fixed properly; severing the connections with the robot arm; and lock the tablet back through the locking of the two pins.
This was all done while OSIRIS-Rex was about 205 million miles (330 million kilometers) from Earth, meaning it took 18.5 minutes per command to reach OSIRIS-Rex, and one 18 minute, 5 for each update from the probe back down to Earth.
OSIRIS-REx mission chief Sandra Freund, of Lockheed Martin Space in Littleton, Colorado, said during a NASA press conference on Thursday: “We just want to try the queue once and we want to make sure that we are successful. “And we certainly did.”
The plan change requires a last-minute reallocation of time on NASA’s Deep Space Network (DSN), the radio telescope system the agency uses to communicate with probes. your distance. Because queuing is so important and highly involved, OSIRIS-REx requires a large amount of continuous DSN time, something NASA’s other missions have sacrificed for the greater good.
It is still unclear exactly how much of the asteroid’s matter lies in the back cavity of OSIRIS-REx, which will hit Earth in September 2023. The team canceled the post-sampling weighing process The planning involves rotating the probe, because this maneuver will result in more sample loss. (For example, moving the arm – to take a sample photo and do a stacking operation – impart the particle release acceleration, explained the mission team members. So they wanted to minimize such movements. )
But there was certainly a lot of asteroid documentation on board, said the University of Arizona mission lead investigator Dante Lauretta.
Lauretta said the sampling on October 20 went extremely well and the head has penetrated deep into the surface of Bennu – perhaps 19 inches (48 cm) or more. The team is confident that OSIRIS-REx pretty much filled its sampling heads that day, meaning it was capable of receding from Bennu at about 4.4 lbs. (2 kilograms) of the material obtained.
The damage over the next few days seems tiny compared to the total – possibly “tens of grams,” Lauretta said. And recent photos of the probe show it’s still packed. Members of the mission team could only see 17% of the head mass in those photos, but they estimate that about 14.1 ounces (400 g) of Bennu material is trapped in that space, Lauretta to speak.
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If that estimate is correct and if the 17% slice is representative of the entire sampling head, then OSIRIS-REx could have held more than 4.4 lbs. (2 kg) sample. Lauretta’s overall prediction was more measured than that, but it was still bullish.
“I believe we still have hundreds of grams of material left in our receiver – maybe more than a kilo, easily,” Lauretta said in today’s press conference.
That would be great news. Such a large amount would allow many groups to study Bennu soil and rock, and perform many experiments with primitive cosmic samples. For example, Lauretta points to organic chemistry – in particular, sugar-related analyzes.
Sugar “is said to have very little [on asteroids like Bennu]”And we thought that wouldn’t be possible with a 15-gram allocation, but something opened up with larger masses available for analysis,” Lauretta said.
(The OSIRIS-REx scientific team can analyze up to 25% of the returned samples. If the total final sample is 60 grams of target, the team will study up to 15 of them.)
If all goes according to plan, such experiments will reveal a lot about the early solar system and the role asteroids like Bennu could have contributed to helping life. continues to take place on Earth, by supplying more water and carbon-containing organic chemicals. Unraveling such big questions is the primary goal of the $ 800 million OSIRIS-REx mission, which kicks off in September 2016 and arrives in Bennu in December 2018.
The next important step in the mission involves preparing for the return trip (although engineers are also trying to find out if they can somehow get an estimate of the raw mass of the existing sample. pre-arranged). The orbital dynamics dictate that OSIRIS-REx must start going home from early March to May and the current plan is to target the earliest part of that window, team members said today.
OSIRIS-REx was NASA’s first asteroid sampling mission, but it is not the first in history. Japan’s Hayabusa mission moved small pieces of the stone asteroid Itokawa to Earth in 2010, and that probe’s successor, Hayabusa2, is expected to return a sample of the asteroid. Ryugu carbon-rich next December.
Mike Wall is the author of “Out There” (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.