NASA's Probe Sampled Too Much From Asteroid Bennu and Now It's Leaking (opb.org) 45
A reader shares some space news from OPB:
A NASA spacecraft sent out to collect a sample of rock and dust from an asteroid has nabbed so much that it's created an unexpected problem. Rocks are jammed in the device in a way that's keeping a Mylar flap open, creating a gap that's letting some of the collected pebbles and dust drift out into space.
"We had a successful sample collection attempt — almost too successful. Material is escaping," says Dante Lauretta of the University of Arizona, the principal investigator for the OSIRIS-REx mission. "We think we're losing a small fraction of material, but it's more than I'm comfortable with. I was pretty concerned when I saw these images coming in." To prevent any further loss, the team is now preparing to stow the sample collection device quickly into its return capsule, possibly starting the stowing process as soon as Tuesday. The capsule is expected to return to Earth in 2023...
It's now looking like the collection device must have penetrated farther down into the asteroid's surface than expected — perhaps as deep as 48 centimeters, or about a foot and a half.
Maybe that's because new findings from mission "suggest that the interior of the asteroid Bennu could be weaker and less dense than its outer layers — like a crème-filled chocolate egg flying though space..." according to an article earlier this month in the news digest of the University of Colorado Boulder: The results appear in a study published in the journal Science Advances and led by the University of Colorado Boulder's OSIRIS-REx team, including professors Daniel Scheeres and Jay McMahon... Using OSIRIS-REx's own navigational instruments and other tools, the group spent nearly two years mapping out the ebbs and flows of Bennu's gravity field. Think of it like taking an X-ray of a chunk of space debris with an average width about the height of the Empire State Building. "If you can measure the gravity field with enough precision, that places hard constraints on where the mass is located, even if you can't see it directly," said Andrew French, a coauthor of the new study and a former graduate student at CU Boulder, now at NASA's Jet Propulsion Laboratory.
What the team has found may also spell trouble for Bennu. The asteroid's core appears to be weaker than its exterior, a fact that could put its survival at risk in the not-too-distant future. "You could imagine maybe in a million years or less the whole thing flying apart," said Scheeres, a distinguished professor in the Ann and H.J. Smead Department of Aerospace Engineering Sciences.
"We had a successful sample collection attempt — almost too successful. Material is escaping," says Dante Lauretta of the University of Arizona, the principal investigator for the OSIRIS-REx mission. "We think we're losing a small fraction of material, but it's more than I'm comfortable with. I was pretty concerned when I saw these images coming in." To prevent any further loss, the team is now preparing to stow the sample collection device quickly into its return capsule, possibly starting the stowing process as soon as Tuesday. The capsule is expected to return to Earth in 2023...
It's now looking like the collection device must have penetrated farther down into the asteroid's surface than expected — perhaps as deep as 48 centimeters, or about a foot and a half.
Maybe that's because new findings from mission "suggest that the interior of the asteroid Bennu could be weaker and less dense than its outer layers — like a crème-filled chocolate egg flying though space..." according to an article earlier this month in the news digest of the University of Colorado Boulder: The results appear in a study published in the journal Science Advances and led by the University of Colorado Boulder's OSIRIS-REx team, including professors Daniel Scheeres and Jay McMahon... Using OSIRIS-REx's own navigational instruments and other tools, the group spent nearly two years mapping out the ebbs and flows of Bennu's gravity field. Think of it like taking an X-ray of a chunk of space debris with an average width about the height of the Empire State Building. "If you can measure the gravity field with enough precision, that places hard constraints on where the mass is located, even if you can't see it directly," said Andrew French, a coauthor of the new study and a former graduate student at CU Boulder, now at NASA's Jet Propulsion Laboratory.
What the team has found may also spell trouble for Bennu. The asteroid's core appears to be weaker than its exterior, a fact that could put its survival at risk in the not-too-distant future. "You could imagine maybe in a million years or less the whole thing flying apart," said Scheeres, a distinguished professor in the Ann and H.J. Smead Department of Aerospace Engineering Sciences.
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"By the way, the headline is misleading. Is the asteroid leaking, or is the probe?"
Some debris has been stuck between the container and its lid and now smaller pebbles float out.
I read it yesterday in my local newspaper (sic) not that anybody thinks I might have RTFA.
The universe is beautiful (Score:4, Funny)
Re:The universe is beautiful (Score:4, Funny)
Next time an asteroid is to strike Earth should we just stand outside with our mouths wide open.
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but the creme sounds disgusting, I want to be one of the ones dead from overstuffing with chocolate, preferably dark.
Re:The universe is beautiful (Score:5, Funny)
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Little Shop of Chocolate
The [Delivery] Arrival
The Day the Earth Stood Outside (with mouths open)
Earth Girls eat Chocolate
They Eat
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just stand outside with our mouths wide open
Or, with a huge sheet of paper (science says that paper beats rock).
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I _told_ those big lizards that scissors would be useless!
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That little interlude actually killed off a few brain cells when I read it. I could hear the synapses cry out in pain, and then they were gone.
Re: The universe is beautiful (Score:2)
Apologism... (Score:2)
They killed Bennu and want to hide their murder behind fancy words!
Easy to say, but has to be said: (Score:4, Insightful)
Hindsight is easy, but STILL.
Surely if you are designing a device to pick up rocks, you consider the possibility that rocks will get jammed in that device ?
Re:Easy to say, but has to be said: (Score:5, Interesting)
Based on this article [opb.org], their testing never showed this problem.
Nothing like this problem was ever seen in simulations of the mission that the team did on Earth, he says. It's now looking like the collection device must have penetrated farther down into the asteroid's surface than expected — perhaps as deep as 48 centimeters, or about a foot and a half.
In other words, they were more successful than they planned. They had hoped to gain several grams of material. It now appears they may have hundreds of grams.
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I don't see how the depth of penetration or amount of rocks affects the problem of one somehow jamming in the device.
Did they simply assume that, based on their tests, it was impossible for a rock to get jammed and then make no plans for that possibility ?
Whatever they do (Score:3)
don't let it crash land in Arizona.
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I guess that the satellite's body will be warmer than the asteroid (electrical devices shed heat) so they will lose some volatiles. Which in itself will be an interesting measurement.
Mining (Score:5, Funny)
Many of the flying rocks in the solar system aren't actually rocks, as it turns out. This mission as well as the Japanese Hayabusa missions are revealing that assumptions that date back to the beginning of last century about the nature of many asteroids are extremely Earth-biased. Without a lot of flowing water and planet-sized gravity ever touching them, many asteroids and most comets are nothing more than gravel piles. Some are just muddy dust piles. There's been this image of asteroid miners dating all the way back to the 1930s that they will be hard rock miners, wrestling valuable minerals from incredibly dense, tough flying mountains. As it turns out, they'll just be janitors with vacuum cleaners who have to bring their own nitrogen to mobilize the material conveniently, sucking up tons of loose material and feeding it into the furnaces with hoses, not drills and giant lasers and explosives.
It's a severe blow to the fictional image of asteroid miners everywhere. Space Engineers is built on a misconception.
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Iron meteorites (Score:3)
There are some large solid-metal nickel-iron meteorites known on the Earth -- isn't there according to Wikipedia a really big one in Namibia?
So there are hypothesized to be nickel-iron parent bodies in the Asteroid Belt, presumable core fragments of one or more dwarf planets, large enough to form a metallic core, that got smashed up?
Someone I know suggests that mining those riches of not only nickel but the trace amounts of rarer platinum-group metals (PGMs) won't be as easy as it seems. The usual way
Re:Iron meteorites (Score:5, Informative)
That is an appropriate use of the important distinction between "hard" and "tough".
Hmmm, that's a new story to me (and as a geologist, I've heard and paid critical attention to more mining tales than the average man on the Clapham Omnibus). It doesn't strike me as hanging together.
So ... you're blasting along a vein/ seam/ bed, chucking the rubble onto the conveyor (into the cart-on-wheels, whatever) to take to the crushing plant so you can separate the interesting stuff ("ore") from the uninteresting stuff ("gangue").
And you encounter a body of metal. Wow. Paydirt!
But, explosives bend it, not shatter it.
So, you use the drills you use to drill the holes for the explosives ... to drill holes into the metal (tool-steel wins over copper, or do you have to go up to sand-slurry pipe drills? Meh.) which intersect at depth. Then you thread steel rope through the intersecting holes (tricky ; not impossible ; hint - don't start with steel wire) and use the rope as a saw to cut through the copper until you have a big lump of copper. Remove; drill better-angled holes; repeat.
Sorry, that story doesn't add up to me, and I've only a distant acquaintance with practical mining. Using (wire) rope and sand to cut metre-plus blocks of anything is a technique that goes back at least as far as the Renaissance, if not further. Your miners would have been confounded for a couple of days while they figured out how to profit from this unexpected (and valuable!) ore body.
To get back to point,
Yes. A couple of percent of the reflection spectra of asteroids are indeed metal rich. The rest are silicates, with various amounts of water and other "volatiles". But ...
That doesn't necessarily follow - and particualrly not in "planet" sizes.
You see, while the Solar system was assembling, there were a number of radioactive systems which were operating, that are now "extinct [wikipedia.org]" because all the "parent" nuclei have decayed and we can only see the (inactive) daughter nuclei. Some are mostly of interest to geologists/ planetary scientists, but the Al-26-to-Mg-26 system produces a lot of energy (there is a lot more Al than there is, say, Th ot U), and that means that early-formed bodies in the solar system can differentiate and internally melt at far smaller masses than can today.
There is moderate evidence that a handful of the asteroids (the couple of percent I mentioned earlier is somewhat optimistic ; it probably includes bodies that have a dusting of metals on the surface) are metallic. Meteorites suggest a higher figure - until you account for the ease of identifying metallic meteorites compared to stony ones. Most asteroid miners will extract (in approximate sequence) "volatiles"; oxygen, aluminium (I assume vacuum electrochemistry), iron, trace elements. And they'll be robots - chewing up the asteroid to separate "volatiles" from everything else, and using the "volatiles" to form polymers for building the rest of everything (except where "refractories" are needed). Most likely, the non-volatiles will be "bagged" for later re-processing.
One of these days I'm going to work out what proportion of the asteroid belt (by volume, and number) we'll need to land on Mars to give Wossname something to stop his tears boiling. It's a lot.
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So there are hypothesized to be nickel-iron parent bodies in the Asteroid Belt, presumable core fragments of one or more dwarf planets, large enough to form a metallic core, that got smashed up?
There is asteroid 16 Psyche [wikipedia.org] which is 95% metal. NASA [youtu.be] is launching a probe to explore it in August 2022.
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Nitrogen is a consumable resource - one would really want something more like a street sweeper*. Staying anchored will obviously be a big challenge, although there's a number of projects that have been working on that. Honestly, I think the best solution for anchoring will be to initially drive a number of fixed anchor towers (whether to large boulders or rocket-driven pilings into loose material), guyed to each other, and then do all mining with drag lines or similar off of them. Gravity is extremely we
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[...] throw a rope around the asteroid. Send a second rope-laying device after the first, crawling along the first rope. Pull through on the ropes to deploy a fabric - somewhat stronger than "solar sail" fabric, but not by a huge amount. Tighten to "snug".
Repeat at 90deg.
Slowly tighten the bag, and when bits start to break off (or shortly before), send out intermediate sheets. These can be retrieved later - they're a re-usable material. Use
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Honestly, I think the best solution for anchoring will be to [...]
[...] throw a rope around the asteroid. Send a second rope-laying device after the first, crawling along the first rope. Pull through on the ropes to deploy a fabric - somewhat stronger than "solar sail" fabric, but not by a huge amount. Tighten to "snug". Repeat at 90deg. Slowly tighten the bag, and when bits start to break off (or shortly before), send out intermediate sheets. These can be retrieved later - they're a re-usable material. Use the tightening bag to feed the asteroid into the maw of the processing plant.
I agree Rei's notion of driving anything into these asteroids isn't viable. OSIRIS-REx has demonstrated that the surfaces are so friable that there's going to be very little stability to be had by trying to hammer something into them. Quite aside from the material loss caused by all that hammering.
I suspect the fabric will have to be much much tougher than any notional solar sail fabric though. Lunar regolith is famously sharp-edged and we have every reason to believe that asteroid regolith will be just
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I said "somewhat stronger than solar sail fabric", I didn't say "related to". Though in practice it would be (at some degree) related to solar sail fabric, since it would be a carbon-based polymer fabric.
I see the refinery process as being multi-stage :
separate the volatiles components and pipe off for separation by well-known chemistry. that's going to give you water, CO2, maybe some ammonia, formaldehyde, traces of alcoh
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Geologists (meat-bag or robotic) are going to be essential workers in space - even NASA recognised that and included a geologist in their Apollo crews, along with the otherwise useless military test pilots.
To be fair, the Apollo missions were publicity stunts with only the thinnest of thin veneers of science around the edges. The military test pilots were the correct personnel to send to plant flags, make footprints and tire tracks, and take photos and video of flags and footprints and tire tracks. The few hundred pounds of random rock they scrounged along the way was an afterthought.
As far as I'm concerned the crew of NASA's return to the Moon should be 30% geologists for at least the two decades after the
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Hmm, drilling is my game. But I don't see a lot of benefit to that. If you find a vein complex (by surface mapping) which you suspect (surface mapping, structural interpretation) is going deep, then you might benefit from a rig that can drill to X hundreds of metres. But that's a couple of wheels, a 10m mast and racks of 10m lengths of pipe. (Even if you don't pump a
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Hmm, drilling is my game. But I don't see a lot of benefit to that. If you find a vein complex (by surface mapping) which you suspect (surface mapping, structural interpretation) is going deep, then you might benefit from a rig that can drill to X hundreds of metres. Unless there is a wonderful deposit of some sort that goes deep, there's nothing half a km below the surface of the Moon different to what you can get by going sideways a half a kilometre.
Perhaps. Perhaps not.
Unfortunately, being small (1/4 of the Earth's diameter translates to to 1/64 the volume, so around 1/64 of the cooling time) the Moon is pretty dead now, and has been for a long time. It died a long time ago, and didn't have time to modify it's layer-cake structure much while it was still active.
That's the thing. Because of its size and evident lack of fissionables in the core, its geology is considerably un-Earthlike. The processes which created vein complexes on Earth either didn't exist at all or existed for a relatively short period of time. Instead, other processes happened, with unknown effects. We need a major sampling program because our current models are Earth-centric and may not apply to the Moon. We need enough data to build new models, which will come in hand
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True. And irrelevant. We'll engineer ourselves habitats in space which provide an Earth-like gravity long before we even have a gene-engineering plan for microgravity that is concrete eno
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I'm all for collecting more information on the Moon, on general curiosity principles. But for prioritising the spread of humans to a second (or more) environment, you're going to need a better reason than curiosity.
Dr. Tyson does make a compelling case. Fortunately we have another reason. Elon Musk is On A Mission From Rod (Smallwood). The religious motivation should hold at least through his lifetime.
True. And irrelevant. We'll engineer ourselves habitats in space which provide an Earth-like gravity long before we even have a gene-engineering plan for microgravity that is concrete enough to send to the Ethics Committee.
Plenty relevant for the next century, and probably more. Building a giant Lunar rover is something we have a good idea how to do right now, combining previous Lunar rover experience with ISS experience and mining vehicle experience. Admittedly most of the Lunar rover designers and engineers are dead, but we at least
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A lot of your notions appear to be based around a scenario where we're much better at building things in space than we actually are. We're great at building things on Earth. We struggle to even fit together Earth-built structures designed to fit into each other in space. The other huge challenge is that it's bad enough to have to fill dependency chains for keeping mining operational , but manufacturing involves extremely long and complicated dependency chains. And to make matters worse, asteroids have on
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If the human species doesn't get good at it, the species is dead. Which elicits a big [shrug] from me - I've no genetic interest in the species.
If it weren't for two problems - the depth of the gravitational hole you have to get things out of (worth about 11km/s), and the atmosphere surrounding it (worth another several km/s - comparable to the Moon's
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Meh, it just shows how much we've been lacking in imagination.
Since you're already in a vacuum, "all you need to do" is throw some coal at the asteroid, heat it up with a huge fat laser beam and scoop up the reduced metal.
Hmmm, maybe I'm showing my own lack of imagination by assuming that the asteroid rock is oxidized in the first place? Maybe all the miners need to do is hawl the rocks home or even process it on the spot into useful products. Maybe you can take the pile of ruble, which just happens to be m
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Engineers will re-invent themselves, don't worry!
I was referring to the PC/XBox game Space Engineers. There doesn't seem to be much unobtanium out there, so converting an asteroid into a spaceship on the spot might be tough. Who knows though. We're literally just scraping the surface so far.
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Sand or gravel piles don't make for good scifi images, but back when I was a boy, some astronomers claimed that comets (not asteroids) were the equivalent of piles of sand. There's a paper you can find on the web by Paul R. Weissman, Erik Asphaug and Stephen C. Lowry "Structure and Density of Cometary Nuclei" that gives some of the history of that.
Units (Score:1)
"average width about the height of the Empire State Building"
This has no meaning to me, can someone translate this into libraries of congress please?
Over probing (Score:2)
wait a minute, hasn't over-probing by aliens be a staple of bad sci-fi movies, tinfoil hatters, and conspiracy theorists for more than half a century now?