Slashdot Mirror
New Space Propulsion System Uses Sun's Magnetic Field
0b1 writes "ABC Science News has an interesting article on a new space propulsion system, that may beat voyager to the edge of the solar system." Fascinating. Seems like a lot less hassle than a light sail. For a little more info about this and other proposed "no propellant" space propulsion systems, check this NASA page. Lots of interesting concepts, all unfortunately still at the "dream" stage of development.
Oops, Voyager is not being abandoned, actually Pioneer 10 being abandoned. It might have passed out of the heliopause in May, but further readings should be taken. They won't be.
I am familliar with the artemis society, yes. There are others too, like www.permanent.com and half a dozen others i dont know off the top of my head. The OSM is similar to those, but it will operate in a different way. For starters, anybody can contribute to the OSM in terms of ideas/resources, and anybody can ride in it as well. One thing ill bring up now, the purpose of the osm is to allow people to get into space so long as they have an adventurous spirit, good health, and they pay 90-100% of their total wealth to the osm. (rockets do cost money) That may sound a little extreme, but anybody can pay it, and were looking for pioneers here. Not space tourists.
:\
The OSM is more of a conduit for space access. someone could start a business repairing satellites, and go through the osm to get up there. Similarly, any person who wants to take part in building the new frontier can go. And even organizations like artemis could hitch a ride with the OSM. Thats how I see it.
The 'open source' aspect of this will be applied to the engineering. The OSM web site will allow people to submit designs and work with existing ones in a bazaar fashion. The good ideas will get picked up on, and eventually one idea will be decided upon as the vehicle of choice to carry us up into orbit. (I already have a fairly solid idea if anybody wants to hear it - pmarsh@alaska.net)
expect to see the OSM site up and running soon. I would have finished it sooner, but im crap with web design.
This is off topic, but may be interesting..
I say this with feelings of despair and impotence: It seems that the entire future of space colonization is in such a 'dream' state. Sure, its nice sending out probes to give us information a decade down the road, but do we really have to wait that long before we go?
To put it succinctly, I want to be a space pioneer. Im sure a lot of other people want to as well.. I often see people talking about how they long for a trip to space, and wish that they could do something about it. I think that the time is ripe for a revolution..
I propose this: an organization that imitates the model of any open source software project, with the goal of designing and ordering the construction of the hardware necessary to get people into space, and plan out missions to which this organizaiton will devote its resources. Essentially, we design it, we have it built, we pay for it, and we fly in it. Sound plausible?
This is the project that I am undertaking, which I call the 'Open Space Movement'. Currently, its in an experimental stage; I dont know how many people would go for this. I am constructing the website to this, which would serve as a forum and drawing board for those interested. (i do need help with perl/sql/html through.. if anybody is interested in helping)
If anybody wants more info on this, contact me at pmarsh@alaska.net
Just a few concepts, none of which seem more than a century away. . .
Having said that, a Microsoft spokesperson is apparently going to announce that ActiveField will be integrated into Windows 2000.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Would the right honorable gentlemen allow a comment?
/. are converging... and I like it. Whoa!
This is getting scary... it's like C-SPAN's weekly coverage of UK Parliament and
Seriously, I think conversation here would benefit from a little more courtesy like the above post.
I yield the floor.
_damnit_
_damnit_
It's my job to freeze you. -- Logan's Run
>Why not use RTG's?
Because RTGs attract loons.
If a field can be generated which is not a sphere, the distortion may generage some sideways motion. But then the sail would have to be turned off for a while to allow the Sun's gravity to slow the ship's away motion, thus leaving the sideways motion.
If an off-center sail can be created which has no more outward force than the Sun's gravity, the resulting sideways force would dominate. But it won't provide as much acceleration as running with the wind with all sheets out.
i agree.
If there was any way to tack, then you might be able to exploit the interstellar wind to get just a little bit more acceleration.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Personally, I don't think the sails are even the most interesting thing in that article. I mean, don't get me wrong, being able to get a 2.2lb payload to Pluto in 3 weeks with only a 10x10 meter sail is pretty amazing. But something like that is really only good for deep space probes, since there's not much in the way of braking.
What's more interesting are the tether systems that they talk about later in the article. We're talking about a practical, propellant-free (we'll ignore the corrections for tidal pull) transit system for getting things to the Moon and back quickly, and Mars and back in what I would consider a reasonable trip (for the time being). Not to mention the ability to cheaply rid the sky of all our LEO trash.
With a reliable and cheap transit system to the moon, we can actually work on building a moon base that can be used for low gravity work and for staging deep space missions. Combined with the international space station, it'll really give space exploration a boost. Same thing goes for Mars. Who knows... with the ability to do long term low-gravity research, we may be able to develop the propulsion system we need to make the next jump.
-Todd
---
"The details of my life are quite inconsequential..."
Remember that in the solar system, you are orbitting the sun. To move "into the wind", you tilt your sail so that it reduces your angular momentum, then the sun's gravity will pull you in. Similarly, to move "out" in the system, you tilt your sail so that it increases your angular momentum. To "stop at an arbitrary point" (like a planet), you just match orbits with your target.
As far as I know, some friends of mine at Carnegie Mellon were working on a solar sail robot this summer. So it's not as much of a pipe dream as some have claimed it must be.
This is cool, but what we really need to do is build space elevators, and begin mining the moon and asteroids. That should definitely be possible sometime within my lifetime. Once we have the elevators, we can easily build several interstellar spacecrafts which we could send to other solar systems. Even if the craft only travels at 0.01c, we could reach other solar systems within a few thousand years. Naturally these crafts would have to be extremely large, and capable of supporting a few thousand people indefinitely. But this should be possible. In less than a million years we would have colonized many different worlds, and maybe even discovered other intelligent life. But people need to realize that we can't just sit around and be happy living on earth, waiting for FTL travel to be invented. We need to be more proactive and start being explorers and pioneers NOW.
I agree that low earth orbit is the goal we should aim for now; but, tethers are not the way to do it. If you have a material that is strong enough per unit mass to serve as a practical space elevator, it is also strong enough to store compressed gases for a rocket in a lightweight package. Either storing compressed hydrogen and compressed oxygen to make a very high performance rocket with an enormous chamber pressure and a specific impulse of 540 seconds. Or to make a very cheap ship by storing compressed steam with a specific impulse of 280 seconds. This is similar to the ( extremely ) compressed air rockets in Lary Niven's tales of known space.
"Off-the-shelf" wasn't an option here, although you're correct about the costs of starting a production line for short product runs.
These 'toilet seats' were in fact one-piece molded toilet _stalls_ for use in B-52 bombers. Imagine a flying porta-john, if you will, now mil-spec it and only order a couple dozen. I'm amazed it only cost $1000.
The "$1000 toilet seat" myth sticks around mainly because it's fun to make fun of the DoD.
Winglee estimates "a minimum system can provide a typical thrust of about 3 Newton continuous (0.6 MW continuous power), with a specific impulse of 104 to 105s) to produce an increase in speed of about 30 km/s in a period of 3 months."
Actually, the old square-riggers relied on the difference in angles of the sails on the fore and aft masts to maneuver. Some of them could sail quit close to the wind.
Suppose you had two magnetic sails tied together on a long teather. Tidal forces would tend to keep the whole structure perpandicular to the sun. By varying the length of the teather and the power to plasma, you should be able to generate a net thrust tangential to the direction of the solar wind.
send me to mars with the proper tools to colonize and you don't have to have a plan to bring me back. Leave me there. That's fine- I really don't mind. I'm sure there are a number of other people who feel the same. What happened to the good ol' days of shipping colonists off to the new world and leaving 'em there to...oh,say...colonize?
intercepting the solar wind [4 Mb, MPEG format];
the M2P2 Current system [8 Mb, MPEG format].
cthulahoops wrote: That's what I'm thinking. If they can get to .05 c then they can get a probe to alpha-centauri in not too much over twenty years + 4 odd years return time for some pretty data. Close up readings of another Star in our life time == good thing.
... or maybe 3 tenths of one percent of lightspeed. The fastest this technique could get a probe to Alpha Centauri would be, oh, 1600 years. Realistically, we need at least an order of magnitude improvement to get it down to a century or so, when it might be worthwhile trying, assuming we can develop long-lived space probes.
Unfortunately, the top speed achieved here is more like 0.0025 c
This is easy to work out -- light speed is ~300,000kM/s and the solar wind is ~1000kM/s. As you can see it's a long way off.
We'd still need a plasma drive of some sort to provide continuous acceleration -- this collector is a start in that direction but it's not yet there.
lake effect weblog
{Network engineer in Chicago--looking for work!}
And I won't mention setting off a fusion explosion nearby so your sail can get a kick from that...
I see a number of questions concerning the practicality of these things, and I figure I'd jump in with my 2 cents:
Solar Sails are:
- Extremely efficent: no reaction products need to be carried up, and no fuel is needed.
- Light: Very important in deployment concerns, where weight=money. Sail material is often Mylar or Kevlar, which is much lighter and more stable than rocket fuel.
- Nonexhaustive: The sun is always there. I suspect the solar wind tapers off as you get further out, but if you are going out of the system anyway, you're probably going to need some other form of propulsion.
Solar Sails are not:
- Easy to deploy: You need a great amount of sail area to obtain a decent acceleration, and all that sail has to be brought into orbit and unfolded somehow. This NASA solutions tries to solve this big problem.
- Quickly Accelerating: You won't pull huge numbers of g's with a solar sail, but the important thing to remember is that they provide (relatively) constant slow acceleration over a long period of time, as opposed to a quick acceleration over a short period of time. In the end, they achieve the same result in about the same time frame.
- Active: Control of thrust must be achieved through manipulation of the sails, and not manipulation of the thrusting medium, as opposed to a liquid rocket, where thrust can be controlled by adjusting flow and mixture. Once again, maybe by varying the strength of the magnetic bottle, NASA can achieve more active control.
Seems reasonable to me, especially with the NASA improvements.
I wonder if you could somehow reverse the polarity on the magnetic bottle and use the wind to pull the craft in towards the sun.
"I'm an old-fashioned type of guy. I worship the Sun and Moon as gods. And fear them."
It wasn't broken. It was in the wrong place. Hughes moved it to the (more or less) correct place by slingshotting it around the moon.
They would come up with exactly nothing. With a rule that subcontractors can't make a profit, who would you get to subcontract? The profit motive has done wonders for technology, esp the kind that requires the bending of iron. Did you envision combining an Open Source style development with unlimited government funds to create new propulsion systems for NASA?
The idea of using a giant magnetic field as a solar sail is fascinating. I'm wondering what other uses such a large magnetic field (20 KM) could be used for. It seems to be modeled on the earth's own magnetic field...could it then be used to protect passengers and instruments from radiation/cosmic rays in space as well as for propulsion.Might it also be used as a "deflector shield" to protect against collisions with small, interplanetary debris (dust, small meterorites etc). Perhaps a combination of technologies could make quite a fast craft - M2P2 + ion drive (DS1) or nuclear drive (Cassini) could create a decent means of travelling within the solar system. Interseting, no? If anyone who really knows about this stuff cares to comment, I'd love to hear aninformed opinion on this....
Never by hatred has hatred been appeased, only by kindness - the Buddha
Microsoft is expected to introduce ActiveField. :)
/* We can't get through ONE topic around here without a Microsoft shot, can we? */
Save the whales. Feed the hungry. Free the mallocs.
Called COSMAC IIRC. Rad hard, ultra low power, CMOS silicon on saphire process. It's a RISC-like 8/16 bit architecture.Do a search on some of those words and you'll probably hit something. Ah, go to google and search for RCA COSMAC. You'll get lots of hits.
Good judgement comes from experience, and experience comes from bad judgement.
- W. Wriston, former Citibank CEO
Actually, Pioneer 10 is still functioning and returning data 27 years after launch! Amazing. The latest status can be seen here.
mike
I remember years ago that at least one of the UFO abductee/contact types talked about how the ETs ships moved the ETs were supposed to have told him about "magnetic lines".
So, now science is catching up with UFO-ology?
cool.
One method that's been proposed is a prize for accomplishing some goal (like being the first to return 1kg of martian soil). This provides motivation, but doesn't give the subcontractors any incentive to add $1000 toilet seats to their designs.
For those who have asked "how do you return", a few people have pointed out that you can slingshot around a planet to change your direction. But in practice, you don't bother: With most (all?) deep space probes the only things that get sent back are radio signals.
It's still way too slow for interstellar travel, but this technology might be used to more cheaply explore our own solar system. But given the slow acceleration rate, I wonder if regular chemical propellant would still be better for nearby planets.
Does anyone know at what distance this would become faster and/or more cost-effective than chemical propellant? Could it be used for an unmanned trip to Mars, or would chemical propellant still be the better choice? What about Jupiter?
Here's an idea:
:)
use solar wind to push a probe out to the fringes of the solar system... then kick in the ion propulsion engines, and you're off to the races. Saves a _lot_ on power that could be better used once you've reached the end of the sun's influence.
And unlike solar sails, it's a hell of a lot easier to turn of a field than it is to crumple back up a mylar sheet. Most people can barely get their tents back into the bags... bow to you expect a space probe to do it?
- Greg
(Mind you, there wouldn't seem much point to it, given that a craft carrying the parts could equally carry instruments and do the work itself. On the other hand, getting Pioneers 10 and 11 in fully-working order would be neat, and worth it for the coolness quotient.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
There was tonnes of stuff about it in Scientific American, and then... ...nothing. Silence. It was somewhere between the surreal, a conspiracy theorist's wildest dream, and a monumental botch-up by someone.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
The end of the tether should be on top of a mountain or a really tall tower. Iain Banks suggests a tower 25 kilometers high. If you can make the tether, probably you can make the tower without much of a problem.
"Be nice, veer left, and never stop thinking" Iain Banks - Walking On Glass
I wonder how this thing stops?
I wonder how it can head cattycorner to the wind?
I wonder how it can tack?
It has no keel like a real sailboat has. The counterforces developed by the keel is what enables sailors to sail in directions the wind is not going.
All in all, an interesting idea and one with lots of potential. Even if the only thrust possible is radially outward from the sun.
I think Congress should mark Pioneer 10 and the two Voyager probes as National Monuments. At least that way they can continue to get funding. Imagine being that little probe, after working so diligently to retrieve data on the outer planets for us, only to be abandoned in space all alone in the night. Brings a tear to my eye.
:)
Plus, that way when we DO get FTL travel, some smart ass won't try to vandalize them.
"Though it may take a thousand years, we shall be FREE."
According to the articles referenced for this story, the system requires "a few kilowatts" to produce a magnetic field of the required strength. That's a lot of power. If one uses solar panels to provide, they must be big.
The amount of power in sunlight is roughly 1400 Watts per square meter, divided by the square of the distance from the sun (in AU). Thus, at Jupiter's distance, the power is down to about 50 Watts per square meter. If the panels are 100% efficient, they must be about 4.5 meters on a side to produce 1 kiloWatt. Real panels are more likely to be about 25% efficient; thus, one needs panels about 9 meters on a side to provide a single kiloWatt. If the "few" kilowatts mentioned is really 4 kiloWatts, the panels would need to be about 18 meters on a side. That's getting pretty darn big -- and, of course, more massive, decreasing the acceleration of the craft.
At the distance of Saturn, about 10 AU, the panels need to be twice as long on each side to provide the same amount of power.
Solar panels + magnetic fields might work in the inner solar system, but it won't provide much oomph in the outer solar system. A ship could accelerate to a high speed before reaching Jupiter, say, but it would be unable to use its magnetic system to slow down as it passed Neptune or Pluto.
Michael Richmond "This is the heart that broke my finger."
mwrsps@rit.edu http://stupendous.rit.edu
Actually, the 'space elevator' idea is over 20 years old. Arthur C. Clarke and another author (whose name, unfortunately, escapes me at the moment) released books nearly simultaneously, which outlined this very concept. Once again, science fiction has beaten science to the punch.
I believe that one of the books was entitled 'The Fountains of Paradise'.
It was a joke! When you give me that look it was a joke.
These elevators would have to be VERY long.
As an excersize, go outside and grab onto the ground. Now, let your feet fly up in the air due to the spinning of the Earth. You'll find out quickly that you are not spinning fast enough on the surface of the Earth to do this.
"How high do you have to be?" you ask.
You would need to be in geosynchronous orbit. That is about 20,000 miles above the surface. It is possible that wo could make a material to withstand those forces, but the travel time would be rather long. Plus, the whole tether idea makes me nervous.
Personally, I'd like to see SSTO (Single Stage To Orbit) planes that take off and land in regular airports. (I know, there are problems with that too.)
Matt
I don't think manned is an option. A 10-mile magnetosphere would probably mess up your passengers at ground zero.
<TROLL VERACITY=TRUE>Besides, given current technology, manned space is a waste of money. That's why the NASA budget cuts are doubly criminal - cutting basic science, but NOT the space station.</TROLL>
Preferential Voting: easy as 1-2-3
From what I recall, Voyager can no longer transmit pictures back, but is still operating somewhere near Saturn. It's done about 60-65% of it's intended journey.
Dan. -- So what if it's spelt wrong, nobody's perfect
LOL!!!
Brilliant. Someone moderate this *way* up!
--
I was watching the great BBC series The Planets last night on ABC Australia, and it was the episode on the Sun. This is great series btw, very approachable.
The interviewees described what they think was the heliopause interacting with a coronal mass ejection. Voyager 2 monitored the CME pass at +100 days from the Sun, and then it monitored a massive magnetic disturbance at +400 days. So NASA thinks that the heliopause caused this disturbance, and it's approximately 4 times the distance from sun as Voyager is now, which means that Voyager will meet the heliopause in another ~ 60-65 years (uncertainty on my part - Voyager accelerated every time it bypassed a planet, but hasn't since Neptune), as it has been travelling for 22 years now.
I don't know if the RTGs or Voyager itself will survive that long.
Andrew van der Stock
The energy used to accelerate the ion stream is normally provided by solar cells. Once the craft is out far enough for the solar winds to die off, I suspect that the solar radiation too would be very weak. (scales like 1/r^2). You could always pack along a plutonium reactor I guess...but what kind of impression would a parcel of artificial fissile material make on our neighboring solar system. 8)
Still awfully slow if you want to actually send _people_ anyplace.
Isn't Microsoft going to be annoyed that NASA used Sun's magnetic field, and not thiers?
After all, the total magnetic disturbance from all those unsold copies of BoB (on floppy) would be phenomenal....
First? Nah.
If its gonna beat Voyager to the edge of the solar system....Captain Jayneway's gonna be plenty pi**ed.
"The original notion of space sails is to unfold a large aluminum coated Mylar blanket, face it to the sun, and let sunlight and the solar wind push the craft deeper into space.".....they've obviously overlooked one important fact. What happens at night when the sun goes in..huh? Everything comes to a stand still and thats no good. NASA..please think things through first. Honestly.....
It can be VERY useful. Suppose you want to send a probe to Saturn. Launch it normally, use M2P2 to propell it to Saturn at a low cost. Braking can be done using the same aerobraking manouver used for the Mars mapping probe (whose name escapes me at the moment). Now, it is moving as slowly as they want it to be (within orbital mechanics of course).
Where is Voyager now anyway?
And is it still sending data/pictures back to us? That'd be a cool webcam site!
(Please, no lame Trek jokes!)
So using M2P2 a craft could beat voyager to the edge if the solar system. And ?? So ??
:)
It's powered by the solar wind, which means that it's not going to get you very far interstellar wise, and I'm sure scientists prefer slower craft to study the planets.
So while I'm sure it's a good idea, I'm just wondering what _practical_ use it has. (and yes, I know all about the supposed lack of practical uses of flight etc
At least their acronym doesn't rip off Star Wars *grin*
--- There isn't any problem that can't be solved by a small, low yield nuclear device, is there??
Is it piloted by R2D2 then ?
hey, there are some really smart people at NASA. i'm sure they've thought of that possibility, and are making batteries in case that becomes a problem. perhaps they'll bring the energizer bunny along with them. or, even better yet, maybe they're setting up the mylar blanket as a dual energy converter, absorbing the light reflecting off of the moon to give power at night. then again, they might just decide that when the sun goes down and they're halfway past jupiter that they need to pull over to the side of the road and take a nap. whatever the fix they come up with for this monumental problem, i'm sure they'll thank you for bringing to their attention the fact that they didn't think this through first, unlike the degree of thinking through that went into your enlightening post. perhaps you should walk into NASA and demand a research and development job. i'm sure they've got positions open for such monumental thinkers as you...
It does work out well that you can "solar-sail" without the sail but there is the problem of being single direction. I thought I had read about a more advanced version of this that actually used a rail gun/linear accellerator configuration that would allow you to accellerate in either direction. Take a look over at the advanced propulsion section at JPL, the 30 year plan stuff, out beyond Future X and the stuff being done for Shuttle replacements. Keep in mind, you can't tack like a sailboat without air to provide perpendicular lift.
Here is a slightly more in-depth article.
>If laboratory work and tests in space succeed, Winglee hopes to launch an M2P2-equipped spacecraft in 10 years that would become the first to leave the Solar System.
Correct me if I'm wrong, but hasn't Pioneer made it out already?
Two questions:
1. Assuming that you were moving straight out (that is, away from the sun), how would you decelerate, other than aerobraking or some other technique (i.e. how could you stop at an arbitrary point)?
2. In sailing, you can move into the wind by tacking - but that relies at least somewhat on the keel. How could one move in a similar fashion in space?
-Josh
IIRC, it should be possible to tack with a solar sail. You rotate your ship so that the sail will be producing thrust in opposition to your orbital momentum. Kills the orbital momentum and you start falling back towards the sun.
Problem: if you accelerate fast enough to actually get anywhere in space in a realistic timescale, the resulting gees have converted your space travlellers into chunky salsa on the rear wall. How does this new design propose to solve this?
WILTS:
Sail: Small Manageable
Power: Solar radiation focused through a lens.
'Course there's always positional alchemy.
Take two quantum fluctuations, big ones. The disturbance of space-time in one area equals the disturbance of space-time in the other in mass and form. Preserving form is the hard part.
One must avoid trying to create singular quantum events or you'll be sorry.
The ship sank. Get over it. (This sig was cut out from another's shirt and painstakingly hand-posted)
Ok so great, we can go places really really fast. They neglected one small detail - how do you get back? That sort of thing isn't very useful for a lot of the things NASA would like to do, like bringing back samples from different planets and moons.
--Ask a silly person, get a silly answer.
Pioneer 10 hasn't made it yet, but it is actually still operating (barely) and it's main (only?) experiment still operating is to measure the extent of the heliopause.
Does anybody know what type of computer the Pioneer and Voyager craft contain? I can't seem to find this level of detail on any of NASA's web sites.
mike
Umm... sailing works because there's water (or land, ice, etc.) there along with the wind. I doubt you'd be able to sail 'upwind' in space.
In order to really consider interstellar space, we must first master LOCAL space. I mean master it, like "here's my ticket, I want to visit Space Station 3", not "Hey, we managed to live through it... AGAIN!" Going up on a tail of fire is wasteful, polluting, inefficient, and dangerous. Elevators are MUCH better. We need a sky hook. The idea is REAL simple. Take a yo-yo. Swing it around your head. That's a sky hook. Your head = Earth. The yo-yo? The space station. Remember, the Earth spins. All we need is a real long piece of real strong rope, tied at or very near the Equator. (the Panama canal all over again! Only this time in Ecuador) We don't have the materials yet, but we're definitely, (from what I've read) within an order of magnitude, or so. Give it 25-50 years. And once we get a sky-hook in place, and an ELEVATOR takes you into space, rather than the hopelessly inefficient rocket, then we're set. There are, of course, any number of advantages. You could make the rope extra long, and run the ship you want to launch out to the very end. Then, just let go. Use the sling-shot effect to get going. Very cheap! Think of the commercial value! Tickets to the Hiatt in space? Come on, you think $300/night is cheap? Instead of spending kajillions to get a communications satellite into space, how about a few hundred/thousand? Deploy a satellite in days instead of years! The possibilities open up immensely, as soon as the sane, rational solution is opened up.
----
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
$1000 toilet seats come because the government specifications require a custom component and then they buy in small numbers. The design and assembly line set up costs of a custom toilet seat amortized over a million copies sold at Sears might be a few cents each. Build only 100 of them and it could literally be $1000 each. The government should learn better to specify "Off-the-shelf".
Or, go all the way to another star, and use it's solar wind to decelerate, slingshot around the star, then use it's solar wind to come back home.
We need to do this.
As someone else said, this could return a probe from Alpha Centuri within my lifetime.
"The number of suckers born each minute doubles every 18 months."
-jafac's law
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Unless of course your ship is moving faster than the escape velocity for that particular body, in which case your craft would be farther accelerated and flung out of the solar system faster than it was, or decelerated and dropped in toward the sun, depending on how you approched the massive body.
Wow. You get a NASA grant and people start paying more attention :) I'm an undergraduate grunt working with Dr. Winglee, and, of course, I'm also an avid slashdot reader. I'm computer science, not space physics, but I may be able to answer questions any of you might have. Also, I've been waiting for an excuse to post something on slashdot.
One quick note on tethers, though (the sky-hook/elevator idea). That's a very promising new development, and a lot of research is going into that. It's totally different from magnetic sails, though, and it gets things off the ground and into earth orbit, and magnetic sails go from a bit away from the earth (I think we have to be outside the bowshock of the earth's magnetosphere). So, tethers could be used to get us off the ground, and a magnetic sail could then take us up, up and away.
It's undoable. The teather would have to be immense - think about the forces at work on that teather:
There's the linearly increasing weight of the teather(say 1 foot = 100lbs). You'd never find a material that could support it's own weight.
Then there's the payload, or orbiting sattelite attached to the teather - At some point on the teatherm the forces of gravity dissipate, and the mass at the end of the teather starts to pull the teather in the opposite direction - causing a huge stress point on the teather.
Then there's Anchoring the damn'd thing... And forget about it if that sucker ever snapped at some point BELOW the gravity threashhold - can you say jack and the beanstalk?
Nice concept though - but therare other ways...
Mylar sails is probably the closest that we'll come in the next 15 years to interstellar space travel if you want to be realistic. Unless we somehow find a way to fold space we're not going very far in the near future. The fact that they are trying to take advantage of the solar system's natural gravitational forces to send anything somewhere is creative. What I'd like to know is how much space is between Sol and Alpha Centauri? If the space between those two stars is great then will they really be able to rely on deep space forces to propel them into the closest solar system to Sol?
To be honest, I think a manned "cruise" to anywhere beyond Pluto would be idiocy at this point. We should really take a good study at our own solar system first hand before we try to run off to the next to see what's there. Everyone's eager to meet E.T.
"It's here, but no one wants it." - The Sugar Speaker
Hmmm...I hate to say it, but this has been around, in theory, for many many years It's not some 'new' concept or anything.
That's my 1/50 of $1.00 US
JM
Big Brother is watching, vote Libertarian!!
--Justin Mitchell
"2nd Place is a fancy word for losing" --Bender (Futurama)
I'm sure people with the proper tools, such as the Satellite Tool Kit orbit calculator or Orbital Mechanics CDROM, can make some interesting launches by using the Earth and Moon to redirect trajectories.
Well, as usual, there is no way to stop any momentum in space other than to use some form of counter-drive. In this case, to stop at "any arbitrary point", would require some form of reactive drive (normal rocket engines). But then, why would you want to stop at any arbitrary point? Generally speaking, you would want to end up in the vicinity of a planet or moon, in which case you could simply shut off the drive, and use that object's gravity to throw you into an orbit.
Mars Direct, only moreso. Using this, you could cut down on fuel mass and bring along (a lot) more supplies (and thus make life easier for our mars explorers -- imagine having frozen strawberries once a month instead of Tang).
In any event: this would make getting to the outer planets a lot easier. Instead of having to do a Voyager and visit each one, we could orbit an observer satelite around anything we find interesting out there well within a decade -- all the planets, Titan, Io, Europa; watch 'em all at the same time, 24/7.
Now *that's* a killer webcam site.
----
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
Why not use RTG's? Plutonium dioxide cells will generate much more power and won't dissapate as they move away from the sun.
Or then again, just use RTG's and ion engines.
----
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
Yeah, and the elevator should be real big and have bathrooms cause it'll be a long trip. There can even be a McDonalds in the elevator and other stores too, like a Spencer Gifts and maybe a paint ball area so you don't get too bored on the trip. Maybe there could be living quarters too, so the elevator could eventually become a center for intergalactic diplomacy, sorta like deep space 9. Wow, that'd be cool!
http://www.asi.org/
I'm not sure exactly when they plan to get people up there(there's a timeline, but I don't know how current it is) , but they have a mailing list and will have a chat on Saturday
go to:
irc.superchat.org
#luna
4 PM CDT Saturday August 22(the one coming up)
I'll try to remember to go there and ask them about the current status of their plans.
Comment removed based on user account deletion
Comment removed based on user account deletion
Light sails have such huge problems associated with them it is not even realistic. I really wonder what could be developed if the U.S. got together a bunch of top scientist, resources, and money (much like they did for the manhattan project)with strict non-profit rules (avoid any greedy crooked subcontractors)what kind of space device they could come up with.
Great we are in the middle of nowhere now how do we get back?
Click on the "related press release" link at the bottom of the page. A big communications satellite ended up in an unusable orbit. Hughes engineers managed to get it to a good orbit by sending it around the Moon. A Google search finds several reports.