Asteroid Missions May Replace Lunar Base Plans

An anonymous reader alerts us to a story about efforts to modify the United States' space exploration plans to focus on asteroid missions rather than a lunar base. Scientists, astronauts, and former NASA division directors will be meeting next month to develop an alternative to the Bush administration's Vision for Space Exploration. We have previously discussed the possibility of a manned asteroid mission. Quoting: "Numerous planetary managers told Aviation Week & Space Technology they now fear a manned Moon base and even shorter sorties to the Moon will bog down the space program for decades and inhibit, rather than facilitate, manned Mars operations--the ultimate goal of both the Bush and alternative visions. The first lunar sortie would be flown by about 2020 under the Bush plan. If alternative-vision planners have their way, the mission could instead be flown to an asteroid in about 2025."

So...

Just because he was an unpopular president everything he did is wrong, and needs to be reverted, once he leaves... Come on get realistic Presidents are people like you and me they make mistakes sometimes huge ones but they are not wrong all the time... I would like to see more work on the moon vs. asteroids. Asteroids seem much riskier without the benefit yet. The moon on the other hand is fairly stable and we could really work out the kinks in exportation.

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***Come on get realistic Presidents are people like you and me they make mistakes sometimes huge ones but they are not wrong all the time...***

Perfection is difficult. But George W Bush is as close to a perfect fool as I want to see in my lifetime in

Re:So...

George W Bush is many things. But he is not a fool.

I agree with you, I don't think he's a fool, or that he's stupid. I've also defended his verbal gaffs, similar to the way you do -- I don't care about speechmaking, I care about results.

So, speaking as a Republican, what the hell *is* wrong with him? Is it arrogance? Hubris? I really can't defend much of what he's done. He's allowed spending like a drunken sailor. The war has been so totally mismanaged I literally can't believe it ("Wait, you mean we weren't keeping people there after we cleared out the town ALL ALONG?? WTF?") The idiotic waffling on what torture is or isn't. That supreme court nomination that even Rush Limbaugh couldn't stomach. The arrogant dismissals of Europe.

Again, I don't think he's a fool -- that's media created. But based on results, you can't conclude that he's anything but stunningly incompetent, and I don't understand where it all went so wrong. He had such grand opportunities at the start of his presidency, and it was all pissed away.

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You don't think he is a fool, or stupid? I do.

This has nothing to do with intelligence and everything to with knowing about your limits - and caring about them. He has, despite knowing better, done a large number of things that he shouldn't have; I refuse

Re:So...

The Moon is a white elephant.

The Moon will certainly be useful someday - for mining, for energy collection, for tourism, for pure science...but it isn't a useful stop on the way to Mars, nor has it ever been. We've looked at the Moon in recent years for two reasons, both interrelated: first, the big contractors (Lockheed, Boeing, Raytheon, etc.) figure they can bleed us for the Moon and increase their profits before ever beginning the Mars project. Second, the U.S., and humanity in general, suffers from acute myopia and timidity.

We can go to Mars, and we can start NOW. No need for holes on the Moon into which we pour money...and more importantly, time.

Orbit's better for canned monkeys than the moon

The moon has one advantage over building in orbit, which is that you can find some of the materials you need there and not have to haul them up from Earth. But you're probably not going to find all of them, and there's a big honkin' gravity well keeping y

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Asteroids seem much riskier without the benefit yet. The moon on the other hand is fairly stable and we could really work out the kinks in exportation.

Thanks for weighing in with that informed opinion.

A great idea

If true, this is very good news. Asteroids, the smaller and more numerous ones being undifferentiated bodies, have considerably more scientific value than the moon. It's actually much easier to rendezvous with and return from many asteroids than to land softly on the moon and return. The moon is relatively large, with a big gravity well, and without an atmosphere, aerobraking is impossible. Landing from lunar orbit and takeoff to orbit each require delta Vs greater than 2000 m/sec. Entering and leaving lunar orbit takes even more. Asteroids require earth escape, but that is only slightly more than reaching the moon's high altitude (400,000 km). The velocity change required to rendezvous with the asteroid could be minimized by careful choice of asteroid and launch window.

Asteroids would take much more time to reach, and a mission could not be quickly aborted in an emergency. The communications lag would also be significant; real time conversations would be impossible and communications might even be blocked entirely by solar conjunction for a few days at a time. These are challenges for human space flight, but not insurmountable ones.

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There is still plenty we do not know about the moon, seeing as we have sent precisely one real scientist there in all of human history. The moon is also a far more practical setting for a manned base, which is ultimately the point of expanding into space.

Re:A great idea

If true, this is very good news. Asteroids, the smaller and more numerous ones being undifferentiated bodies, have considerably more scientific value than the moon.

I am unqualified to evaluate what you say and so I will not quibble with any of it. However, can I come outright and say that I honestly do not care about scientific value at this point? I want to see a moonbase. I want proof it can be done on a small planetary scale. I want to see new settlements of humans off this planet, even if only to our nearest satellite. I want to see the whole thing shown to be do'able, not for study's sake, but because it should be being done. I want to see a practical application and a first step to living elsewhere. I think a base on the moon provides that in a way that asteroid exploration just doesn't.

Cheers,
Ian

And then what?

Not sure there is any future in putting people on the moon, or down on the bottom of any other gravity well. To prove it can be done? Well, we proved that in 1969, and that didn't get us anywhere.

I'd much rather see us put people (or robots) somewhere th

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how about an asteroid base? they require less fuel to go to and return from and they have plenty of cool stuff that the moon doesn't have... like frozen water, diamonds and precious metals [iridium, platinum, gold etc.] the moon OTOH has relatively strong

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Well I'm not American and therefore not paying for this, but that aside:

I want humans to leave this rock, I think the only way to do it is to make space profitable. As soon as there is profit to be had, good luck stopping people from doing it. Once we're o

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Honestly, if this doesn't sum up the American mentality, I don't know what does

I'm British.

Cheers,
Ian

Re:A great idea

To address your point - for forty years or so people have dithered about what the main point is, so yes I rather feel that the "in my lifetime" bit has been wasted.

Another post sets it out clearly - this one [slashdot.org]. What is the goal? To my mind, the goal is colonisation. If that is the goal, actions which delay this is in favour of a different goal are to be considered counterproductive.
Now, you may well state that your goal doesn't match mine. That's fine, and fully understood. However, unless someone actually states what they want out of the research and what their end goal is then no progress towards it will be made. The thing to do is to define what "it" actually is, and that's what my post was about.

For me, I want to see efforts towards a moon base as it provides definitive proof that it is possible to live off the Earth. I'm aware of dependencies such as provisions and potentially even energy coming in the form of supplies from the Earth, but until we try it we'll never really know. My hope is that some of the solutions to those problems will be found after we're there - I'm a believer in proximity to the problem helping to focus minds, the "necessity is the mother of invention" situation.

And that's that. It's purely a statement of position by myself - I value progress towards an off-Earth settlement as being of greater value than increased understanding of asteroids. That's all the "I want" stuff was - statement of position. Not a waah waah waah give it to me now-type thing (and where's my flying car?), but a statement of what I believe the end goal should actually be.

Cheers,
Ian

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How many times did you say 'I want...' in your post? Honestly, if this doesn't sum up the American mentality, I don't know what does. Me me me me me me me me me... Try opening your mind long enough to realize that A, the world doesn't revolve around you, and B, you should leave the decisions on scientific research to scientists. What makes you think that we need 'proof' of something that man will undoubtedly do well after you're dead? Why spend a huge amount of resources to make you happy, when all we need is scientific progress in the areas that make the most sense today. Namely, sending out robotic explorers in our place. People have to learn to accept the FACT that we will not know everything, discover everything, and conquer everything in their life times.

The only problem I see here is that he seems to be wanting to do this with Other Peoples' Money. We shouldn't leave important decisions to other people whether they be scientists or some other profession. If the science truly is important, they'll be able

Re:A great idea

Flame on.

Dear asshole,

Americans are paying for it, so I'd say what we want matters a fair deal. And in this instance, the original poster was saying that he would prefer that we do the initial work of building a permanent presence on the Moon. In fact, so would I. I am more interested in starting that work now, using the money that *I* am providing, then on the scientific exploration of asteroids, given the choice. Sadly for the scientists, they will have to do a lot of convincing in order for me to prioritize their desires for knowledge over my desire for a permanent settlement on a second Solar body. They can always start their own asteroid-exploring scientific foundation, if they have troubles with the priorities I set for them. Or they can ask for both: I would in fact be quite willing to open my wallet if I could directly support their work. But I can't, they are SOL, and should get back to doing what I'm paying them to do.

Re:A great idea

In contrast, a moderate sized asteroid has almost no gravity, but can be hollowed out, filled with air, and spun to provide the illusion of gravity relatively easily.

Actually, that's a rather poor engineering approach. Few if any asteroids are likely to have the tensile strength to be reliable when spun up to the 1/2 g or so that you'd want. Once you were settled down, suddenly the whole thing would bust up and go flying off in all directions. Actually, you probably wouldn't get a chance to settle down; filling it with air would probably produce a catastrophic failure before you even moved in.

The practical approach would be to mine an asteroid for raw materials, and use them to construct the sort of artificial "habitat" that sci-fi writers have been describing for decades. They'd probably be similar in size and shape to a lot of asteroids, but they'd be structurally sound.

Actually, some writers have suggested a sort of compromise: hollow out an asteroid, construct a structurally-sound habitat in the interior, and leave a few meters of rock as shielding from cosmic rays, incoming meteoroids, etc. But this is really just the same. The asteroid would contribute nothing to the structure except shielding. You could do the same by constructing the habitat, and then bolting on a thick layer of the leftover slag from the mining operation. The result would look like an asteroid, but wouldn't be one in any meaningful sense.

But you don't want to just hollow out an asteroid and start it spinning. You want to live in a habitat with a strong, solid structure. And that won't be found in nature; we'll have to build it.

(Others have suggested that it'd be better to mine comets. They tend to have lots of ice and gases, and those are very useful if you want to grow food. The problem is that the inner solar system has lots of asteroids but not very many comets. And the visiting comets tend to be in orbits that are expensive to get to. The closest asteroids with ice are around Jupiter.)

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Landing from lunar orbit and takeoff to orbit each require delta Vs greater than 2000 m/sec. Entering and leaving lunar orbit takes even more. Asteroids require earth escape, but that is only slightly more than reaching the moon's high altitude (400,000 km

Asteroid misions are important

They provide valuable data on contents and structure of these rocks. Moon doesn't have a chance to fall on Earth anytime, but these
zap through atmosphere everyday.
There are dozens of large asteroids which pass pretty close http://neo.jpl.nasa.gov/ [nasa.gov]

Mining?

Its fairly logical to think that if its so expensive to get stuff into space, just build it there. While manned missions to the moon and on to mars would certainly be amazing, I fail to see the point of a manned mission to an asteroid. Just send a probe and play around with altering a small asteroid's orbit and bring it into a lunar orbit. Creating an automated system that collects small asteroids (small enough that they'd burn up in atmosphere) and bring them to the moon to be processed would be a tremendous step forward in human expansion into space. Unfortunately, I don't think anything like this would happen until commercial space missions start making it further out there.

For anyone that hasn't heard of him, I'd strongly recommend you check out Bill Stone's [ted.com] TED talk. The whole thing is pretty cool, but its the last chapter in the video thats really amazing.

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Just play space billiards and use slingshot orbits to get your energy. Simply kit out your cue ball asteroid with maneuvering jets and precision navigation systems to get a nice accurate hit.

A little sad

Obviously, there's pretty much no scientific value in sending manned missions to the moon anymore, and there is a lot we can gain from meeting up with asteroids.

But it's a little sad, because it really is incredibly cool that we can put a man on the frea

Re:A little sad

Why is there no scientific value in sending people to the moon? Its not like NASA explored the whole thing in the 1960s. We don't know much at all about the levels of water and helium-3 in the surface, both of which are important. Furthermore, seeing as the Earth and Moon seemed to have formed at the same time, investigating the moon can tell us more about the Earth. There is loads more to learn.

Re:A little sad

Because we can send robots there for half the cost, and the space saved in fuel, life support, and whatnot will allow them to carry much more in the way of instrumentation and tools.

Re:A little sad

Don't you think that the far longer distance to the asteroids make the overhead of a human presence on the trip there somewhat bigger, compared to a trip to the moon? A continuous presence on the moon would be realistic before 2030, reusing the same equipment with different crews. I fail to see that on the asteroids. Heck, for the moon it would even be possible to get down to Earth in a somewhat conceivable manner in a medical emergency, not so in the asteroid belt. (Ok, we can choose to land on one that passes nearby, but then it's a very limited time window anyway. It's a series of short excursions, not a permanent project.)

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A robot is not a scientist. The result of each experiment informs scientists how to construct the next experiment. This is easy if they live on the moon, it can take a decade if they don't.

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So build a robotic moon base. It would be a good first step, and if it became self-sufficient, it would let us skip the hugely expensive "escape earth's gravitational field" part of lunar exploration, ultimately bringing costs down.

Further, I think advanc

Re: Scientific value

Why is it "so hard" to duplicate a known result 50 years later? The kudos go out to the first designers who did it with 1960's tech. Our computers are gloriously more powerful now, and their target deadline is another 8-ish years out anyway. (Past Windows

Sounds fine to me

Practical, cheaper, potentially immediate benefits.

* Learning how to manage NEOs in case of the ultimate nightmare scenario
* Applying and extending our experience in microgravity
* Potential to access resources far easier than on the moon (metals, water, ox

Both missions has their merits

The difference is that a manned moon-base is relatively resource-demanding while asteroid missions not necessarily has to be manned. It can be more of a problem doing a manned asteroid mission than a robotic one.

The only problem with an unmanned asteroid mission is that it may require some human decision from time to time - but normally there is no problem with time delays there. Not much that's in a hurry on an asteroid unless it's heading for Earth. Just put the robot to sleep for a while and recharge the batteries. Keep in mind that there may have to be different robots there compared to the robots we have on Mars.

The thing that's more interesting with a permanent moon-base is that there is a possibility that a lot of the material found on the moon can be used as construction material. It will require a processing plant - and it can't be used for everything, but it's there. Much of the soil is composed from oxides - which means that you can extract oxygen. Allocation of area for growth is no big problem either. The catch is that all this may have a high cost. But what is the cost when the Chinese decides that it's their turn to go to the moon?

Infrastructure Development....

This is a situation where we need a concrete reason to develop the heavy lift infrastructure needed.

And a moonbase makes as much sense as the "International Space Station".

The REAL driver for developing the infrastructure remains Space Based Solar.

http://w [nss.org]

Good!

Good, I hope that they succeed in changing that strategy. For any colony to actually be useful and self-sustaining, there has to be some hope of an economic return on investment. The driest deserts and coldest tundras here on Earth are like tropical paradises compared with anything outside our planet, whether that's the moon, Mars, or a space station floating around the asteroid belts. Any space colony would be heavily dependent upon imports for survival (e.g., food, clothing, natural resources, manufactured goods, etc.). That will require a roughly equal amount of exports to balance trade, probably in the forms of valuable minerals and manufactured goods that are best made in microgravity environments. That becomes rather difficult to accomplish if you're stuck in a gravity well like a planet or relatively large moon, because lifting those items back out would be prohibitively expensive. We need to stop obsessing over planets and moons, just because we happen to be bipedal and live on a planet now. Asteroids are the way to go.

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With the risk of resurrecting a /. fad of old, a space elevator on the moon is much more realistic than the Earth counterpart right now. No atmosphere, a much lower gravity well (less public opinion with more or less irrational fears). With that kind of ap

The Moon has some advantages

The Moon actually has more sunlight than anywhere on earth, especially any tundras. You can use that both for energy and farming. Greenhouses could be pretty simple to get operating there. What plants can handle month long days I don't know, but there's go

Short term vs. longer termed solution

I really can't help wonder if some people try to keep us from going to the moon (again) and this time actually see for ourselves what has been going on there in the past. Or they simply are incapable of looking at the big picture. A moonbase would be a muc

What's the Goal?

All these people seem to think that getting to Mars is the ultimate goal, that gathering scientific data is the point, and we've been to the moon already. This is starry eyed gee-whiz thinking. The quote at the end of TFA explains the REAL goal - we need a permanent colony somewhere other than here. Yes the Moon is a harsher environment, but the cost in time and money to put a colony on Mars is so much higher than putting one on the Moon that it just doesn't make sense. Sure, while we're there we should do some science, but getting people to live there will produce more sustained value than dozens of brief scientific visits to places with only scientific interest. Look at how they consider the Moon now - if a place is only worth visiting a couple of times at most, we're going to run out of places to go pretty quick. A colony would provide LOTS of incentive for private company participation. Building an Earth/Moon ferry service is feasible in 50 years - no private company is going to invest in one to Mars anytime soon.
I want a Moonbase!

How about both?

The US government wastes billions every year. By waste I don't even mean programs that I might disagree with. I mean money that just goes missing. How about we fix that, get rid of earmarks, and put that money towards deficit reduction *and* space explo

Sounds Good

I've been watching a lot of the old Twilight Zone episodes lately, and based on the examples they show, asteroids look like a better destination than the moon anyway. Asteroids seem much more habitable to humans. It looks like they have breathable atmosphe

hitch a ride on an asteroid

just hope the orbital path of the asteroid does not bring it to a location in space where it can collide with other asteroids...

Case For Mars

In the book, "The Case for Mars" the author, also the creator of the Mars Direct Plan, argues skipping the moon all-together and go straight to Mars. This is because Mars is full of resources that could be used to make a self sustaining colony, whereas a Lunar base requires everything to come from Earth. Differences between a Lunar Base and the ISS? The Lunar base is on the Moon, and on the Moon you can do geology and astronomy particularly well; on ISS, there's not much useful science.

I'm not sure cruising to asteroids is the answer, but at least there are probably lots of interesting and diverse resources, and the missions could be made lightweight(no lander required). The geology of Asteroids is probably alot different than the Moon's because there was no volcanic past or differentiation. But my opinion is, cut to the chase, go to Mars, its the most interesting thing out there.

DOD will push back

It is not just NASA that wants the moon.

They should go to the asteroids,

I have felt this for a long time.

A number of Earth-crossing asteroids are easier to get to, energetically, than the Moon. (Apollo could certainly have
reached some asteroids, which was pointed out at the time, and a lot more Earth-crossing asteroids are known now.) The trip times tend to be long,
so you need to be prepared for long duration flights (which is not that different from being prepared for long duration lunar visits, and is also
true of any trip to Mars). And, you don't need anything like a lunar module. (With most asteroids, and certainly all of the Earth crossing ones, you will "dock" with
them more than "land" on them, the gravity is that week.) The weight saved from the lunar module can be used for provisions instead.

There is plenty of science to do, and if we are ever going to economically exploit the materials in space, we are much more likely to
do it with asteroids than with either the Moon or Mars.

doable; cold war

One big advantage of a crewed mission to a near-earth asteroid over a crewed mission to Mars is that we simply don't have the technology to get to Mars. A transfer orbit to Mars takes 1.4 years (total round-trip time). (This is simply the period of a body in a Keplerian orbit that's tangent to the Earth's orbit at perihelion and tangent to Mars's orbit at aphelion. A spaceship isn't like a car, which takes less time to get there if you drive faster. A spaceship only thrusts with its engines in order to change its orbit.) The big unsolved scientific and engineering problem is how to keep a crew of human beings from getting exposed to unacceptable doses of radiation when they're in Earth-Mars orbital space for that long. The radiation intensity from galactic cosmic rays [wikipedia.org] is much, much higher out there than it is in Earth orbit. Feasible amounts of shielding actually make the problem worse rather than better, because of secondary radiation. According to this article [space.com], the duration of a mission to a near-earth asteroid could be 60-90 days, so it avoids this very tough, unsolved problem. There are many other aspects of a near-earth asteroid mission that are also a heck of a lot easier than a Mars mission. You don't have to land in a deep gravity well and then take off again, for one thing. If you look at the history of uncrewed Mars missions, it's pretty damn scary -- the success rate is very low, and that's for missions that don't have to take off and return to Earth, and don't have to provide life support.

The big question in my mind is what is the rational justification for government-funded crewed spaceflight at this point. There's no scientific justification; uncrewed probes give more bang for the buck. The shuttle's only mission is to go to the ISS, and the ISS's only mission is to give the shuttle somewhere to go. Thirty or forty years ago, this was all basically cold war propaganda stuff. It seems to me that the U.S. is having a hard time dealing with an unanticipated outbreak of peace. The rational thing to do would have been to continue harvesting the peace dividend, start ramping down our foreign military commitments, and let both crewed and uncrewed space exploration make the transition to the private sector. Instead we've been blundering around like idiots with our ridiculously large military, and in terms of space exploration we've been choking the scientifically productive uncrewed program by diverting the available money into extremely expensive projects like the ISS that have no rational justification.

The End of Spirit

I can't believe what I am reading. First of all. This was a setup from the get go. There never was any intention by Bush to put a base on the moon. This was a rouge to divert funding from NASA. The same tactic has been used before. So this isn't really news, it's been in the cards all along. After awhile they'll cut the Astroid missions back too.

Now that fact that so many posters think this is a good idea, is terribly disheartening. If these posts are for real (and not more b.s. from the propaganda machines that now dominate our media), then it means America has lost it's Spirit. We no longer have a can-do attitude. We no longer care about going beyond ourself and pushing frontiers. We no longer see our ourselves as capable of achieving great things. In short we no longer Dream. And that...more than anything else will be our doom.

Re:The End of Spirit

Oh, we still dream. It's just that we've replaced aspirations with fantasies.

As an Apollo-era teenager I share my age group's frustrations that I don't have my jet car on Mars yet. Heck, we quit following the last few missions. Been there, done that. But all this smacks of back seat desperation. _IF_ by now we had created a huge space station that had learned to be self-sustaining with zero resupply/repair ferries for years, then it _might_ be reasonable to talk about multi-year manned missions around the inner solar system. But as it is, it's more than a little ugly. Sure, you'd get enough volunteers. But watching them die 30 million miles from earth because something and its backup broke is PR that would set your gamble back many years.

Been to the moon so why bother to go back? Why do we have a permanent presence in antarctica -- the favorable corn-growing season?

And, sadly, I also wonder whether this is likely to be some weird propaganda that costs nothing during any particular year of a presidency but keeps the Star Trek voter happy.

The moon? Why we can't supply ISS!

The problems with going to the moon are not technical. They are political and managerial. We cannot adequately supply a spacestation that is a few hundred miles away with enough material to conduct meaningful science. NASA strangled any option for going there besides shuttle and that leaves us with Progress (1.5 tons cargo/launch) and maybe the ATV which costs nearly half a billion dollars a flight to deliver a few tons per year. NASA did this deliberately and consistently has hamstrung commercial space access. How in the world are they going to deliver a practical amount of cargo to support any real science or habitation on the moon? The answer is they can't. The present ESAS moon architecture is completely incapable of doing anything remotely like a moon base or real exploration. It is a dead end levied on NASA by a couple of ego-maniacs with not a lick of real-world experience between them. The sooner ARES is cancelled the better.

There are numerous alternative architectures that can deliver the hundreds of tons of supplies you need on the lunar surface within practical budgets. But they involve direct commercial and industry involvement. Until these players are fully engaged we will not be going back to the moon in a meaningful way. Most importantly these architectures provide the foundations for going to Mars in a meaningful way. Anyone who thinks you are gonna do anything meaningful on Mars with a handful of crew is simply wrong. It requires a bare-bones crew of at least 90 to support three science teams of 6 each. If you want confirmation look at Antarctic operations to get yourself calibrated. Furthermore on any real Mars mission at least part of the crew that goes does not come back on the first return opportunity. They are there for at least two cycles and transfer tasks and responsibilities to the second cycle crew etc etc. It is getting used to not coming back for 5 years that is perhaps one of the most important psychological barriers we must cross. The moon is a good place to start this- staying there permanently creates an enormous improvement in efficiency. You can finally forget about the retreat to Earth as the only safe option. Worth nearly 3000 m/sec delta V.

So the moon is worthy goal- but it is the practice of developing self-sustaining colonies that is the real barrier.

V is for Vision

The Moon-Mars plan is referred to as the "Vision for Space Exploration."

What exactly is the vision? The founding document [nasa.gov] [large PDF warning] for the "VSE" lists goals and strategies, but no vision of what the goals and strategies are meant to accomplish. A vision involving the Moon could be "create a new civilization on the Moon that might do for the U.S. what the New World colonies did for the Old World." (you can snicker but that is an example).

"Go to the Moon and Mars" is not a vision. It's an strategy.
"Build launchers and spacecraft based on current infrastructure & technology" is an implementation of that strategy.

Again... what is the vision?

Re:Bush Screws Up Everything He Touches

Manned asteroid missions have little if anything to do with asteroid deflection strategies. If you want to keep the Earth safe from big nasty dinosaur-killers, you spend money on tracking every Earth crossing Asteroid in the sky, not on sending people to 1 or 2 of them. Early detection of potential dangers makes any deflection strategy (almost certainly unmanned, despite what your favourite movies might tell you) more plausible

The purpose of visiting asteroids is looking for something to mine or doing science to investigate the origins of the solar system.

Re:So it begins

Given how there was no funding to begin with, it is hard to see how it can be cut back. However, the resulting confusion is indeed highly likely to get rid of both missions at the same time.