NASA's OSIRIS-REx Spacecraft Heads For Earth With Asteroid Sample (nasa.gov) 24
A user shares a press release from NASA: After nearly five years in space, NASA's Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft is on its way back to Earth with an abundance of rocks and dust from the near-Earth asteroid Bennu. On Monday, May 10, at 4:23 p.m. EDT the spacecraft fired its main engines full throttle for seven minutes -- its most significant maneuver since it arrived at Bennu in 2018. This burn thrust the spacecraft away from the asteroid at 600 miles per hour (nearly 1,000 kilometers per hour), setting it on a 2.5-year cruise towards Earth. After releasing the sample capsule, OSIRIS-REx will have completed its primary mission. It will fire its engines to fly by Earth safely, putting it on a trajectory to circle the sun inside of Venus' orbit. After orbiting the Sun twice, the OSIRIS-REx spacecraft is due to reach Earth Sept. 24, 2023. Upon return, the capsule containing pieces of Bennu will separate from the rest of the spacecraft and enter Earth's atmosphere. The capsule will parachute to the Utah Test and Training Range in Utah's West Desert, where scientists will be waiting to retrieve it.
"OSIRIS-REx's many accomplishments demonstrated the daring and innovate way in which exploration unfolds in real time," said Thomas Zurbuchen, associate administrator for science at NASA Headquarters. "The team rose to the challenge, and now we have a primordial piece of our solar system headed back to Earth where many generations of researchers can unlock its secrets." To realize the mission's multi-year plan, a dozen navigation engineers made calculations and wrote computer code to instruct the spacecraft when and how to push itself away from Bennu. After departing from Bennu, getting the sample to Earth safely is the team's next critical goal. This includes planning future maneuvers to keep the spacecraft on course throughout its journey.
"OSIRIS-REx's many accomplishments demonstrated the daring and innovate way in which exploration unfolds in real time," said Thomas Zurbuchen, associate administrator for science at NASA Headquarters. "The team rose to the challenge, and now we have a primordial piece of our solar system headed back to Earth where many generations of researchers can unlock its secrets." To realize the mission's multi-year plan, a dozen navigation engineers made calculations and wrote computer code to instruct the spacecraft when and how to push itself away from Bennu. After departing from Bennu, getting the sample to Earth safely is the team's next critical goal. This includes planning future maneuvers to keep the spacecraft on course throughout its journey.
Abundance? (Score:3)
While navigating to, landing on, retrieving and returning content from an asteroid is incredibly difficult and very rewarding (as the content is from the exterior of the asteroid, and existing samples are basically burned husks or molten cores), 60 grams (or two ounces) is hardly an abundance.
Yet, the (hopefully) successful delivery in a couple of years will mark the third successful asteroid mining mission (the Japanese being the first to bring 1500, 10 micrometer sized asteroid material in mission Hayabusa, and the second to bring some 100 milligrams of asteroid material in mission Hayabusa 2).
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curious.
i s s is closer and cheaper to arrive at.
and what happens if descent to earth becomes problematic
Re:Abundance? (Score:5, Informative)
The Utah Test and Training Range is a target of 6,930 sq.km, whereas the ISS covers an area of less than 0.01 sq.km. Also the goal is for the capsule to end up stationary, and braking is carried out using the Earth's atmosphere.
Descent to Earth was problematic for the Genesis [wikipedia.org] sample return, where a parachute failed. In that case some of the samples were still usable.
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Descent to Earth was problematic for the Genesis [wikipedia.org] sample return, where a parachute failed.
No, the Genesis parachutes were never triggered because the atmospheric entry sensors had been installed backwards.
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No, it's not. When you reenter Earth's atmosphere, braking is free (friction with the atmosphere). When you have to rendezvous with the ISS, you have to enter a stable orbit (which takes a lot of fuel to slow down to the correct orbital speed), then maneuver slowly to the ISS.
The extra fuel would have made the mission a lot heavier which has a knock-on effect in all phases of the mission (maneuvering a heavier spacecraft takes more fuel, and more power if you use an ion drive, which means heavier solar pane
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You can point your craft at the earth and let the atmosphere handle slowing it down.
If you point it at the ISS, the stakes are considerably higher.
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The mission goal was 60 grams, but although they don't know exactly how much they got until it comes home, speculation was that it was around a kilogram [scientificamerican.com]. That's quite an abundance relative to expectation.
Re:Abundance? (Score:5, Informative)
On October 22, personnel at Lockheed Martin Space in Littleton, Colorado, home of OSIRIS-REx mission support, received images from the spacecraft that revealed an estimated several dozen grams of the Bennu sample had drifted off.
...
Thankfully, this leak doesn’t appear to have jeopardized the mission. As of October 27, images of TAGSAM’s head confirmed that the device is holding at least 400 grams of material, and maybe much more, Lauretta said. In lab experiments with a replica of the TAGSAM device, scenarios that most closely resembled the October 20 event trapped at least 1,200 grams of debris. “There’s a high probability that the TAGSAM head was as full as it possibly could have been,” Lauretta said.
and the spacecraft? (Score:2)
I assume the main spacecraft will enter the atmosphere and burn up completely? Or is it going to enter orbit for awhile? Or return to space?
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Based on the article ( ;) ) it will visit another asteroid - it still has quite a bit of fuel. Hopefully they'll be able to reach another asteroid and slow down into its orbit. Even without the capability to return samples, they could photograph it, or maybe even land there.
Ideally, an asteroid type that wasn't studied much would be reachable.
The summary is confusing (Score:5, Informative)
The summary is confusing.
The spacecraft heads home on an orbit toward Earth, and releases the sample return capsule into a ballistic trajectory that enters the atmosphere. The capsule enters and lands (with a parachute), while the carrier spacecraft executes a divert maneuver so that it does not follow the capsule into the atmosphere.
The divert maneuver swings the spacecraft past the Earth, which puts the spacecraft into an orbit that has a perihelion of about 0.5 AU (nearly Mercury distance), and an aphelion of about 1 AU. Two years later, the Earth has orbited around twice, back to where the spacecraft's orbit brings it around to fly past Earth again. If for some reason the capsule release had failed the first time, the back-up plan is to drop it on that second pass. If everything worked correctly, however, the spacecraft is free to use the Earth as a gravity slingshot and head back out to the asteroid belt, and possibly find another asteroid to explore (although this time, not to sample, since the sample return capsule is gone).
An exhaustive discussion of trajectory can be found here: https://spaceflight101.com/osi... [spaceflight101.com]
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thank you for the good article!
(though I see on the timeline the sample return is scheduled for 9/24/13, lol)
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(though I see on the timeline the sample return is scheduled for 9/24/13, lol)
well, only if they get that flux capacitor working.
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Very pointy and ground-rooted analysis of reality - but I question its place in an article about space exploration
returning part of an asteroid to earth (Score:5, Funny)
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Or Michael Crichton's Andromeda Strain
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More of this please (Score:3)
It'd be awesome to develop a swarm of these type of missions to various asteroids. For instance, build smaller (~500kg ?) spacecraft, stick 10 of them on a Falcon, send the up and point them to different asteroids. Make sending out robotic probes more like Starlink deploys than one-off missions.
Yes, greatly understating the complexity of space travel, particularly of doing things outside of LEO. But I think there are a lot of lessons SpaceX can give us about standardizing, with incremental changes, to get a lot of stuff into space at less cost
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That sounds like a good predecessor to the Starshot proposal, throw things around in our solar system before tossing them at Alpha Centauri.
https://en.wikipedia.org/wiki/... [wikipedia.org]