Obama's asteroid goal: tougher, riskier than moon

Apr 16, 2010 By SETH BORENSTEIN , AP Science Writer
This Feb. 14, 2000 photo provided by NASA shows the north pole of the asteroid Eros. The crater seen on the surface of Eros measures 4 miles across. President Barack Obama on Thursday, April 15, 2010 said he expected astronauts to land on an asteroid in the next 15 years. (AP Photo/NASA)

(AP) -- Landing a man on the moon was a towering achievement. Now the president has given NASA an even harder job, one with a certain Hollywood quality: sending astronauts to an asteroid, a giant speeding rock, just 15 years from now.

Space experts say such a voyage could take several months longer than a journey to the moon and entail far greater dangers.

"It is really the hardest thing we can do," Charles Bolden said.

Going to an asteroid could provide vital training for an eventual mission to Mars. It might help unlock the secrets of how our solar system formed. And it could give mankind the know-how to do something that has been accomplished only in the movies by a few square-jawed, squinty-eyed heroes: saving the Earth from a collision with a killer asteroid.

"You could be saving humankind. That's worthy, isn't it?" said Bill Nye, TV's Science Guy and vice president of the Planetary Society.

President outlined NASA's new path during a visit to the Kennedy Space Center on Thursday.

"By 2025, we expect new designed for long journeys to allow us to begin the first-ever crewed missions beyond the moon into deep space," he said. "We'll start by sending astronauts to an asteroid for the first time in history."

On the day the president announced the goal, a task force of scientists, engineers and ex-astronauts was meeting in Boston to work on a plan to protect Earth from a cataclysmic collision with an asteroid or a comet.

NASA has tracked nearly 7,000 near-Earth objects that are bigger than several feet across. Of those, 1,111 are "potentially hazardous asteroids." Objects bigger than two-thirds of a mile are major killers and hit Earth every several hundred thousand years. Scientists believe it was a 6-mile-wide asteroid that wiped out the dinosaurs 65 million years ago.

Landing on an asteroid and giving it a well-timed nudge "would demonstrate once and for all that we're smarter than the dinosaurs and can avoid what they didn't," said White House science adviser John Holdren.

Experts don't have a particular asteroid in mind for the deep-space voyage, but there are a few dozen top candidates, most of which pass within about 5 million miles of Earth. That is 20 times more distant than the moon, which is about 239,000 miles from Earth on average.

Most of the top asteroid candidates are less than a quarter-mile across. The moon is about 2,160 miles in diameter.

Going to an asteroid could provide clues about the solar system's formation, because asteroids are essentially fossils from 4.6 billion years ago, when planets first formed, said Don Yeomans, manager of NASA's program at the Jet Propulsion Lab.

And an asteroid mission would be a Mars training ground, given the distance and alien locale.

"If humans can't make it to near-Earth objects, they can't make it to Mars," said MIT astronautics professor Ed Crawley.

Also, asteroids contain such substances as hydrogen, carbon, iron and platinum, which could be used by astronauts to make fuel and equipment - skills that would also be necessary on a visit to Mars.

While Apollo 11 took eight days to go to the moon and back in 1969, a typical round-trip mission to a near-Earth asteroid would last about 200 days, Crawley said. That would demand new propulsion and life-support technology. And it would be riskier. Aborting a mission in an emergency would still leave people stuck in space for several weeks.

The space agency may need to develop special living quarters, radiation shields or other new technology to allow astronauts to live in deep space so long, said NASA chief technology officer Bobby Braun.

Even though an asteroid would be farther than the moon, the voyage would use less fuel and be cheaper because an asteroid has no gravity. The rocket that carries the astronauts home would not have to expend fuel to escape the asteroid's pull.

On the other hand, because of the lack of gravity, a spaceship could not safely land on an asteroid; it would bounce off the surface. Instead, it would have to hover next to the asteroid, and the astronauts would have to spacewalk down to the ground, Yeomans said.

Once there, they would need some combination of jet packs, spikes or nets to enable them to walk without skittering off the asteroid and floating away, he said.

"You would need some way to hold yourself down," Yeomans said. "You'd launch yourself into space every time you took a step."

Just being there could be extremely disorienting, said planetary scientist Tom Jones, co-chairman of the NASA task force on protecting Earth from dangerous objects. The rock would be so small that the sun would spin across the sky and the horizon would only be a few yards long. At 5 million miles away, the Earth would look like a mere BB in the sky.

"It's going to be a strange alien environment being on an ," Jones said.

But Jones, a former astronaut, said that wouldn't stop astronauts from angling to be a part of such a mission: "You'll have plenty of people excited about exploring an ancient and alien world."

Explore further: Astronauts to get 'ISSpresso' coffee machine

More information:
NASA's Near Earth Object program: http://neo.jpl.nasa.gov/index.html
Association of Space Explorers' report on threat of asteroids: http://tinyurl.com/asterthreat

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trekgeek1
3.4 / 5 (9) Apr 16, 2010
Wow, I'm glad they decided to perform such a challenging task. This will really give new technologies an audience to play for. I hope a lot of ideas on paper start to be considered seriously now. I hope they remember to account for the asteroids attraction to them as well. It would be a shame to unintentionally nudge an asteroid to earth 100 years from now.
HaveYouConsidered
3.3 / 5 (7) Apr 16, 2010
No, sorry, but spacecraft don't "bounce off" non-elastic surfaces like the rocky ices of these objects. I'm sure that engineers can invent a landing strut able to penetrate into and hold onto the surface of an asteroid--think snowshoes and ice picks and you get the general idea. Plus, the craft has substantial mass of its own and isn't likely to be shoved aside merely by a relatively low-mass astronaut descending a ladder, etc.
RobotB9
1.7 / 5 (15) Apr 16, 2010
This leads me to the conclusion that Obama is ignorant of space technology. He will certainly be remembered for the damage he did to NASA.
pauljpease
4.8 / 5 (13) Apr 16, 2010
This leads me to the conclusion that Obama is ignorant of space technology. He will certainly be remembered for the damage he did to NASA.


Yeah, you're right. Obama's over there in the Oval Office making all of this up, and we all have to obey his orders. That's how it works, right? He doesn't have teams of knowledgeable advisors who work in the space industry suggesting promising missions.

In case you can't connect the dots, Obama is working very hard at making space exploration profitable. He wants a larger role for private companies in space exploration. And the subtle comment in the article about platinum on the asteroid is not just a footnote. We're quickly using up scarce elements on Earth, where will we get them from 100 years from now? Mining asteroids might be big business in the future, wouldn't it be nice for the US to "stake our claim"? Or, we could go back to the moon, which is very easy and expensive in comparison with little chance of returning anything useful.
dtseng123
2.3 / 5 (7) Apr 16, 2010
He's taking a note from JFK, but politics and science are two different things. I agree with you RobotB9 that this is the most dangerous thing ever. I think Mars is a great idea, but an asteroid is near suicidal. Its a giant rock spinning without any gravity. I'm not saying its impossible. I'm just saying its going to be really difficult and dangerous. Good luck to the astronauts who go.
deatopmg
1.8 / 5 (9) Apr 16, 2010
OMW! This is more silly political posturing. Like orbiting Mars, why would one want to spend the money to land a person on an asteroid when the same information will have already been collected by robots? They want to mine the trace iridium?
I've been around long enough to know that this is a fools mission.
Well at least the mission can be canceled in 2013.
Hungry4info2
5 / 5 (8) Apr 16, 2010
Its a giant rock spinning without any gravity.


In case you had forgotten from High School, all matter has gravity.

In case you had forgotten from spaceflight history, NEAR landed on Eros.

In case you had forgotten from spaceflight history, all spaceflight is difficult and dangerous.
Megadeth312
1.8 / 5 (8) Apr 16, 2010
Hungry4info2,

In case you are a moron, the gravity from even a large asteroid would be negligible in relation to any propulsion system, on the scale of small fractions of that of the moon, which already proved troublesome, mainly due to the charged dust particles kicked about.
Bob_Kob
3.5 / 5 (6) Apr 16, 2010
@Megadeth312

I watched Armageddon so I know for a FACT asteroids have gravity.
nuge
2.3 / 5 (3) Apr 16, 2010
Stop being stupid, they DO have gravity, there just is so little of it you'd barely notice. I think that is the point he was trying to make - everyone was saying they have NO gravity, which is wrong. Anyway if they land in the middle rather than on the end there will be more gravity.

The asteroid would contain lots of iron, right? Maybe they could have a magnetic ship? At any rate I don't think it would be entirely impossible to land on it, it just may be easier to hover.
gopher65
4 / 5 (3) Apr 16, 2010
You could indeed "bounce" off an asteroid that was fairly small, if you were traveling slowly enough that you failed to collapse your spacecraft (and travelling that slowly would be the whole idea if you were trying to land:P).

Landing on an asteroid is challenging. If fact this entire mission is challenging in the extreme. It's so challenging that I'm not sure that NASA can accomplish it by 2025. But even if they don't, there is no harm in trying. The absolute worst that happens is what happened to Constellation: project cancelled due to missed deadlines and general overbudgetness, but the money spent on interesting research isn't wasted because that research can be repurposed toward other missions (as is happening right now with the research done for Constellation).
Jameson_Jenna
Apr 17, 2010
This comment has been removed by a moderator.
dsl5000
1.7 / 5 (3) Apr 17, 2010
We've already gone to Mars with rovers Spirit and Opportunity. The mission is difficult because conventional rockets will not be effective. Most of the rocket fuel is spent from exiting earth. Unless the astronauts are to stay and build an outpost on Mars. Otherwise the return trip is axed because 'no' there is no rocket fuel station there to gas up.

In all honesty I feel we have the technology already to go to mars if we utilized our Nuclear submarine technology. After all they are underwater and out of sight for years. (though I'd say that is our(American) treasure box of advanced tech.)

ISS can recycle water. We just need a new propulsion system since nuclear propulsion due to some crazy ban.

Yeehaw then we can start the Wild Wild Space age :P
Skepticus
1.7 / 5 (3) Apr 17, 2010
Landing a full-fledged manned spacecraft on an asteroid is not impossible, just too damn unrealistic. Aside from collecting samples, doing some good science, then what? We haven't any experience of constructing semi-permanent occupancy, minerals and water extraction even on the not-too-low gravity on the Moon. Can we expect the asteroid pioneers to do all in one giant leap, if we intend to exploit the resources in the feeble gravity on asteroids? Consider all the specialist equipments that will require, and the training (but from what knowledge base? Mining on Earth?), it may well be turned to another flashy NASA's riding-a-horse-to-tour-the garden, when the obstacles are too much for the financial and technological resources. And where is the base of operation? Again, carting everything from old Earth, with all that gravity drag. Every major tactical or strategic moves requires staging areas. You don't see the US fight the Af-Pak wars direct from US soil due to costs and logistics.
Skepticus
1.7 / 5 (3) Apr 17, 2010
Out in deep space, if things goes up sh*t creek, you are screwed. Help will just be prayers and comes from millions of miles away, with no deep-space-rated ships already built and ready to go far out (and more schools and hospitals and blah blah blah named after you the hapless explorers). Even if no permanent Moon base(s) are involved, materiel from Earth can be launched leisurely as schedules and other considerations permit, then assembled in orbit of the Moon, to give a capability head-start until they are ready or needed. With the Moon as the staging area, any problems with the equipments due to prolonged exposures to the harsh environment of open space beyond the relative radiation safety of LEO will be solved with the near help from Earth if needed be. And plenty of experience along the way in building all sorts of ships that can routinely (eventually, more efficiently and much less costly)to venture far out of LEO.
Skepticus
1.7 / 5 (3) Apr 17, 2010
In case of future Moon base(s), regarding the Moon treaty,they are not insurmountable legal blocks. Frankly,IMHO, as long as anybody does not install (atomic) missiles, (lasers) weapons, nor mess up the natural environment of the Moon so badly, nor claim land ownership, then it will be (albeit with tortuous legal arguments) that all activities fall under the umbrella of exploration and research. It was done all the time in international politics, and this will be no different, whether the US or China or whoever will be on the Moon. Face the naked fact: Unless the objecting parties have the deep-space capability for offensive moves, all they can do is protest. Terrestrial war footing as pressure will not likely to happen, as the globe is so interconnected these days, and a major war over technical and legal grounds will badly damage the economy of the aggressor as much as the defender, and the whole world.
Shootist
1.2 / 5 (5) Apr 17, 2010
"nor mess up the natural environment of the Moon so badly"

bwwwhahahahahah. What a maroon.
Skepticus
2.5 / 5 (2) Apr 17, 2010
In this regard concerning the Moon treaty, all the protesting parties can do is to compete for a presence on the Moon, for national prestige, national internal and external security. If the US don't move, the Chinese will, for example. They have the cheap labor force, the political system to tell people to do (or get paid) whatsoever the government says with no protests, a huge financial reserve, and a growing technological base of space-related technological knowledge acquired and acquiring by many means. You can extrapolate the rest what the Chinese will do with their bases ~384,000 km away from earth, and not much you can do about it. I wonder, with all the smart-arses abound in NASA, CIA, Pentagon, NSA,...they certainly have figured it out more comprehensively than stupid me. Too much financial and political in-fighting between different parties of narrow-minded-but with-big-political-clout-vested interests? One can only (feebly)hope it is not the case.
rproulx45
5 / 5 (1) Apr 17, 2010
why don't we put a fuel depot in orbit. Fill it up over time, then use the fuel as missions warrant.
Skepticus
2.3 / 5 (3) Apr 17, 2010
"nor mess up the natural environment of the Moon so badly"

bwwwhahahahahah. What a maroon.


Would you be so kindly as to expanse on your comment as to why I was a [sic]maroon in voicing my thoughts for this serious matter, in a comprehensive missive? I paraphrased the sentence that you quoted from the "Moon Treaty on Wiki : "...Bans altering the environment of celestial bodies and requires that states must take measures to prevent accidental contamination...". Thanks.
Shootist
1.8 / 5 (5) Apr 17, 2010
sending astronauts to an asteroid, a giant speeding rock

as if the moon weren't a giant speeding rock . . .

""It is really the hardest thing we can do," NASA Administrator Charles Bolden said.":

Somebody needs to fire this clown.

Somebody needs to disband NASA and give Space Travel to the Navy.

GDM
4.5 / 5 (2) Apr 17, 2010
Landing on an asteroid (unmanned robot) is cheaper, easier and more efficient than landing on the moon. Robots can mine, refine, and build using the resources (oxygen, iron, etc). What to build? Fuel tanks, solar power cells, and eventually, habitats/vehicles that are far beeter than can be lifted from the Earth. Check it out on NSAS's own websites. It's all been there for decades. By the time a manned craft lands on one of the 1,000's of near-earth asteroids in 2025, they will need reservations at the local Bigelow Hotel chain.
rgw
3 / 5 (2) Apr 17, 2010
You could indeed "bounce" off an asteroid that was fairly small...
Funny I don't remember any of the ISS supply vehicles, Shuttle, Soyuz et al. 'bouncing' off the Space station. Do you think that 1000's of scientists, 2500 years of mathematics and 200 generations of computers might be able to figure this out?
Rynox77
3.4 / 5 (5) Apr 17, 2010
sending astronauts to an asteroid, a giant speeding rock

as if the moon weren't a giant speeding rock . . .

""It is really the hardest thing we can do," NASA Administrator Charles Bolden said.":

Somebody needs to fire this clown.

Somebody needs to disband NASA and give Space Travel to the Navy.


Ok, Physorg, I write perfectly relevant and logical comments and they get removed. Yet something inane like this makes the 'cut'. Brilliant, guys. Just remove my f'ing account.
GDM
not rated yet Apr 17, 2010
to Rynox77: I agree, why were they removed?
to Physorg editors: Why were my comments edited and some deleted? They were completely relevant, material, based on fact, and non-offensive. Why the censorship?
GDM
5 / 5 (3) Apr 17, 2010
What was censored from my remarks above was a mention that asteroid regolith can also be used to make concrete, which is a better radiation shield than what we can currently make, since we have to lift everything from the bottom of Earth's gravity well. And aside from my poor spelling (due to rapid typing and no proofreading), asteroids and comets are also a good source of water, which costs about $10,000 a pound shipped up from Earth, versus about $10 coming from an asteroid. Finally, what was cut was that asteroids are a prime source of platinum group metals, which are going to be is short supply on Earth in a very short time. Pretty racy stuff, huh?
powerup1
1 / 5 (1) Apr 17, 2010
@RobotB9, you sound like you've been drinking to much tea ;-)
Ensa
4 / 5 (1) Apr 18, 2010
Getting to the moon is something that with a budget and some commitment can be achieved by a few nations already, soon corporations will be able to do it. Getting to NEO's is technology and capability development that will put whoever can do it ahead.
Soon space will be overtly militarized, no matter what the Americans do and there will be conflict over the most cheaply available resources and so-on. The direction Obama and his advisers are taking will put America ahead technologically and militarily, regardless of the actual success of the first manned NEO missions.
billyswong
5 / 5 (3) Apr 18, 2010
It wonders me that there are people above who suspected the feasibility and meaningfulness of manned mission to asteroid. At least it is easier than Mars! For Mars, we have: 1) another gravity well to jump out of; 2) a sandstorm weather which may damage the lander interior; 3) a far longer round-trip time than a near-earth asteroid. If one think visiting asteroids is too hard, then forget Mars. Mars is definitely a harder target for manned missions, not easier.
VOR
2 / 5 (1) Apr 18, 2010
I dont have anything against this new mission. But I dont see how its much better than creating a moonbase. Both require innovation, etc, and would bring certain rewards. Did they not find enough water on the moon for fuel?
Skeptic_Heretic
5 / 5 (1) Apr 18, 2010
Hungry4info2,

In case you are a moron, the gravity from even a large asteroid would be negligible in relation to any propulsion system, on the scale of small fractions of that of the moon, which already proved troublesome, mainly due to the charged dust particles kicked about.

There won't be too many charged dust particles clinging on as the gravity wouldn't be strong enough to overcome the electrostatic and velocity forces making the dust fly off for the most part. Solar wind would be buffeting the object clean in some cases.

Should be quite interesting to see what we find.
Skepticus
1 / 5 (1) Apr 18, 2010
...concrete, which is a better radiation shield than what we can currently make, since we have to lift everything from the bottom of Earth's gravity well. And aside from my poor spelling (due to rapid typing and no proofreading), asteroids and comets are also a good source of water, which costs about $10,000 a pound shipped up from Earth, versus about $10 coming from an asteroid. Finally, what was cut was that asteroids are a prime source of platinum group metals, which are going to be is short supply on Earth in a very short time. Pretty racy stuff, huh?

Hi GDM,
I am curious about the interesting idea of using concrete to make deep space ships. From what I know, concrete setting requires considerable time for the exothermic reactions between ingredients to set and harden. How would you do it it the cold deep space? Modifying the pre-cast technique with suitable insulations, and then assemble the pieces?
dirk_bruere
4 / 5 (1) Apr 18, 2010
If things go true to form the next US president will cancel these plans and set new "tough goals". Just as long as they don't cost money.
HaveYouConsidered
5 / 5 (1) Apr 18, 2010
The older I get (I'm 53) the harder it is to see the value of sending humans to places that have not first been explored extensively by robotics, which are increasingly sophisticated in their abilities and could be made even more so.

Without the need for food, water, air, heavy radiation shielding etc. needed by humans we can explore the solar system 10x faster and cheaper the way we're doing it now, with robotics, then only go someplace in person once a darn good reason has turned up.

While I've always enjoyed watching maned spaceflight it gets harder each year not to see it as a grossly inefficient industry living off national pride and bravado, trying to justify its own existence. We spent decades building the ISS, for example, with little scientific justification for its huge price tag, and did so with the (original) plan to scuttle it into the Pacific only a few years after its completion. It is hard not to see that as a sci-tech/aerospace industry welfare program.
ormondotvos
1 / 5 (2) Apr 18, 2010
Clever of Obama to come up with a possible asteroid deflecting mission while the skies of Europe are full of ash that might be from an asteroid hitting the Earth...
otto1923
not rated yet Apr 18, 2010
Somebody needs to disband NASA and give Space Travel to the Navy.
And the military would know better than anyone else the value of taking the High Ground... militarily, we ultimately want to shoot for the asteroid belt. Thats where the resources are.
What was censored from my remarks above was a mention that asteroid regolith can also be used to make concrete
What kind of concrete are you talking about? Cement is made from baked limestone, calcium carbonate, which is created by lifeforms on earth. You also need water to get it to set.
HaveYouConsidered
2 / 5 (3) Apr 18, 2010
Headline for the 22nd century. "Terrorists stymied in their use of computer-printed viruses, now developing asteroid deflection on-the-cheap, financed by conflict platinum sales and dug deep in their concrete bunkers."
El_Nose
5 / 5 (1) Apr 19, 2010
When I read of this on other news sites I got the impression NASA felt this was in fact a little easier than getting back to the moon.

And as for comets and asteroids haveing gravity THEY DO NOT HAVE GRAVITY- at least nothing of value. lets use some of the current news stories- the new classifcation of a planetoid , only objects of a diameter of 300km have enough gravity to force it into a spherical ball. So if it isn't 180 miles around it is a big peanut- and earth is the most dense object in the solar system @ 5.52 g/cm^3 so if it was just as dense as earth (not likely) and the size of Ceres 950 km in diameter gives the equation :

(6.67300 * 10^-20 (km^3) (kg^(-1)) (s^(-2)))*((3 537 952 kg/151.197196 km^2) for surface gravity = 1.0327 * 10^-14 m / s2

which is 0.00000000000000105% of the surface grivty on earth- remember this is if we landed on the biggest planetoid which is on average 100 times larger than a meteor

escape velocity needed 5.58829932 * 10^-5 m / s
El_Nose
5 / 5 (1) Apr 19, 2010
Now consider this:

If we were in the movie Armageddon -- and we had to land on a big freaking monster metoer the size of texas - 1,270 KM in diameter - 5.77902379 * 10^-15 m / s^2 surface gravity and an escape velocity of : 4.83333485 * 10^-5 m / s

if we had used a thruster to jump a canyon we would have gone past going into orbit and flown off into space -- heck even before that part if we didn't match the velocity of the metoer perfectly when trying to land the shuttle on it and did not GRAB it we would bounce off into space

if we were really unlucky and had issues firing our rockets someone could go outside the shuttle and pickit up like Superman - jump using leg muscles and achieve escape velocity. because 5 million lbs would feel like 2.3 micrograms
baudrunner
1.5 / 5 (2) Apr 19, 2010
If I were Obama, I would cease entertaining any thoughts of a manned landing on an asteroid. WOT! (Waste Of Time)

Mars is far more important.

My priorities would be:

1. Continued development of viable plasma VASIMR type rocket engine. (possible moon mission to mine H-3 to fuel it would be a great project)

2. Mars colonization.

3. Unmanned return surveillance mission to binary star system Centauri using plasma rockets.
CouchP
5 / 5 (1) Apr 19, 2010
In case you can't connect the dots, Obama is working very hard at making space exploration profitable.

I agree whole heartedly. Could you imagine taming these near earths to put them in stable orbits allowing them to be mined? This is a strategic step towards colonization of the solar system and has been outlined by many science fiction and non-fiction writers.
El_Nose
5 / 5 (3) Apr 19, 2010
@baudrunner and everyone else

-- It could also be the fact that over the next 30 years asteriods capable of destroying life on earth will come as close as high earth orbit. there are at least three times in the next thrity years earth will have real potential to be hit --

object name / date of miss / LD of miss / speed
LD=lunar distance ~ 384,000 km
------------------------------------------
(2004 QA22) / 2130-Aug-24 / 0.0003 / 3.74
(2009 WM1) /2059-Nov-23 / 0.08 / 14.25
(2007 UD6) / 2048-Oct-18 / 0.09 / 7.56
99942 Apophis / 2029-Apr-13 / 0.10 / 7.42
(2009 WQ6) / 2189-Nov-18 / 0.1 / 12.42

NASA website : http://neo.jpl.na...p;show=1

LD is a comparison of the distance to the moon to how close the object will possibly miss the earth

example:Apophis will come as close as one tenth the distance to the moon
GDM
5 / 5 (1) Apr 19, 2010
to otto1923 and skepticus: I'm still reviewing around 350+ white papers on asteroid mining and refining, but the type of cement I'm thinking of is called Magnesium Oxy-Sulfate (MOS) Sorel Cement which requires calcium sulfate instead of limestone. Also, Magnesa (MgO) is also used for creating refactory bricks for steel making. However, I am not an expert in these areas. I do recall reading that the curing of cement is not greatly affected by heat or cold, but mostly by the chemical reactions, but I'm trying to find out where I read that. Another option is to make glass. There is plenty of silica, and in the micro-gravity environment of an asteroid, the glass can be make much stronger than on Earth, and even "foamed" to create greater strength. Bottom line, there are resources available, and we need to learn how to use them. More later...
HaveYouConsidered
5 / 5 (1) Apr 20, 2010
Whether the next step is to an asteroid, the moons of Mars, or Mars itself, all require we proceed on space qualification tests and final development of VASIMR engines, yes? To cut the flight time and ship mass, and shielding requirements. Shouldn't this be the R&D priority? Are there viable competing engine designs?
GDM
not rated yet Apr 20, 2010
VASIMIR - yes! The first space test of the VASIMIR engine is supposed to take place soon on the ISS, to hopefully provide station-keeping and reaction control instead of using their current methods. I think we will see a lot more from Chang-Diaz and a long future in VASIMIR engines.
Shootist
1 / 5 (5) Apr 24, 2010
This leads me to the conclusion that Obama is ignorant of space technology. He will certainly be remembered for the damage he did to NASA.


Just what would a "Community Organizer" know about anything other than graft and protection rackets?
Bloodoflamb
5 / 5 (3) Apr 24, 2010
So if it isn't 180 miles around it is a big peanut- and earth is the most dense object in the solar system @ 5.52 g/cm^3 so if it was just as dense as earth (not likely) and the size of Ceres 950 km in diameter gives the equation :

(6.67300 * 10^-20 (km^3) (kg^(-1)) (s^(-2)))*((3 537 952 kg/151.197196 km^2) for surface gravity = 1.0327 * 10^-14 m / s2

For a spherical object, the acceleration at its surface is given by:

g=G*M/r^2

For something with a diameter of 950km (475km radius) and the same density as the Earth:

g=G*[(4*pi*(475km)^3)/3]*[5.52g/cm^3]/[(100km)^2]
=> g = 0.733m/s^2

Your calculation is just a TAD bit off.
Bloodoflamb
5 / 5 (3) Apr 24, 2010
Just what would a "Community Organizer" know about anything other than graft and protection rackets?

He's not a community organizer. He's the president of the United States. He WAS, at one point, a community organizer. He was also at one point a law professor. But YOU were, at one point, a child. Are you, at this moment, a child? I would say yes, though you might disagree.

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