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Science

New Space Propulsion System Uses Sun's Magnetic Field 124

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.
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New Space Propulsion System Uses Sun's Magnetic Field

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  • Oops, Voyager is not being abandoned, actually Pioneer 10 being abandoned [nasa.gov]. 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

  • Hmm. . .

    1. Anti-matter propulsion-variant of the old "Orion" propulsion-by-nuclear-explosion system. This presupposes that we can manufacture and store sufficient amounts of Antimatter. But it does give us a drive capable of putting men out in the stars.
    2. Remember Quantum Teleportation, a month or three ago ???. Assuming we master the not-inconsequential trick of maintaining structure and function during transport, this may actually be the one that works. . .
    3. Send information, not people. This one requires lots of electronics and/or nanotechnology. Why ship people to Tau Ceti ?? Build them on-site. Alternately, clone and in-vitro them, then teach the resultant kids via robotics and advanced AI (Note: James Hogan suggested this idea in a novel, 10-15 years ago...). This is a one-way, colonization-trip concept. . .
    4. Just a few concepts, none of which seem more than a century away. . .

  • by jd ( 1658 )
    Yeah. Especially as the latest Mindwarp study shows that Sun's magnetic field is three times slower than Microsoft's, on a Pentium.

    Having said that, a Microsoft spokesperson is apparently going to announce that ActiveField will be integrated into Windows 2000.

  • Would the right honorable gentlemen allow a comment?

    This is getting scary... it's like C-SPAN's weekly coverage of UK Parliament and /. are converging... and I like it. Whoa!

    Seriously, I think conversation here would benefit from a little more courtesy like the above post.

    I yield the floor.



    _damnit_
  • As well, I would recommend you reading 'Mining the Sky' by John Lewis. Mars really isnt that worthwhile of a place, yet. We should start by building mining, farming, and manufacturing operations on the moon and near-earth asteroids. A Mars mission would require a rather heavy spacecraft, which would be much easier to produce out of lunar ore.

    We should concentrate on setting up an industrial and agricultrual infrastructure around the earth and moon before we head after the other planets. Once we get the ball rolling, it wont be long before everybody and their uncle has their own cheap spacecraft :)
  • >Why not use RTG's?

    Because RTGs attract loons.
  • A sailboat can go in other directions because it has a keel. The keel can block the vector away from the wind, allowing the various forces toward the side to be used.

    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.

  • Depends on what the interstellar wind does. It could act as a brake, accelerate the probe still further, or even blow it off course, depending on the direction it'd going in and the angle the sail is.

    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.

  • 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

    ---
  • 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.
  • 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.
  • >This, I believe, was the underlying concept
    >behind The Andromeda Strain (Michael Criton?).
    This exact plan, with a few differences, was the idea behind Clarke's "The Songs Of Distant Earth." One of my favourite books, actually.

    Yeah, Michael Crighton wrote "Andromeda Strain". One of the two books he's written that I actually enjoyed, the original Jurassic Park novel being the other one. I remember reading Jurassic Park about a year before the movie came out... better in print, I think.
  • 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.

    Unfortunately, the top speed achieved here is more like 0.0025 c ... 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.

    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.
  • You use gravity to swing around in another direction. Or if you're someplace interesting such as Jupiter's intense electromagnetic fields, you might be able to get a kick from those.

    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.
  • 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.
  • 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.

    Not possible. The reason it is efficient is that it doesn't expend any energy to get the propulsion (apart from dissipative losses in maintaining the magnetic field). The solar wind will only push the craft away from the sun. Too bad. You'll just have to slingshot around some planet if you want to get back.

  • You may want to talk to Buzz Aldrin, he's got similar ideas. This is an idea that has been bouncing around for a couple years, and is gaining momentum.

    Vote for representatives who fund 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....
  • Microsoft is expected to introduce ActiveField. :)

    /* We can't get through ONE topic around here without a Microsoft shot, can we? */
  • 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.
  • Actually, Pioneer 10 is still functioning and returning data 27 years after launch! Amazing. The latest status can be seen here. [nasa.gov]

    mike
  • There's Bob Forward's ideas on light sails. He proposed (and has written a couple of so-so novels about) a multi-stage light sail.

    Essentially, you'd need a number of very powerful lasers and the solar system's biggest Fresnel lens, both of which would remain in the system and provide power to the craft. The light pressure pushes the sail at a reasonable speed to wherever.

    Eventually when you need to switch from accelleration to decelleration (so as to remain in the destination system), the main body of the sail detaches from the payload (which retains a smaller sail, pointing in the opposite direction). The main sail then deforms just enough to focus a lot of light at the small sail. This slows down the ship for an insertion orbit into the system.

    It's interesting, but would require a hell of a lot of engineering work to build. On the plus side that laser would probably keep alien invasions at bay.
  • 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
  • Maybe we can get one of these new, fast spacecraft to zap over to Pioneer 10, with spare parts to replace those that have worn out. Then, it should have considerably more power.

    (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.)

  • What happened to the solar sail race that was planned, to mark the 500th? anniversary of Columbus?

    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.

  • 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.

  • 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. :)
  • 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.
  • 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'.

  • 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>
  • 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.
  • 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.

  • 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)
  • Not nessecarly.
    The new designs call for a in-ship recycling center....water, air, waste, all recycled....and you grow your food....no more packaging.

    Its all live off the land...even while traveling thru space.

    I've got a signed book from Zubrin....he is brilliant and I would like to see both Mars and the moon colonized within 30 years....think we can make it happen?
  • Hey, thanks for the pointer. I did some checking and, yes, the Voyagers used an 1802 derivative, but Pioneer 10 turns out to not have an on board computer. The instruments just send out their data continuosly. Basically, Pioneer 10 is a very remote peripheral attached by a 9 light-hour link to a computer at Mission Control. Amazing.

    Check out the minutes of the Pioneer 10 Virtual Conference [nasa.gov] for more details.

    mike
  • 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.
  • by Anonymous Coward
    "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*

  • 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.
  • Hmm... 'night' in space ... This IS for space travel you realise? .. The sun doesn't just blink out every 12 hrs in space. And besides, you'll always have momentum even if there's less acceleration causes by planetary solar eclipses.

    One thing I wondered about is the article is dated April 8th ... wonder if it's been lying on Rob's cutting room floor for a while..
  • It's not all that long. Consider the minimum distance from the Earth to Mars is about 35 million miles and the max speed of this thing is about 180,000 miles per hour. That puts travel time at somewhere around 8 days.

    Of course, that assumes it accelerates instantly and never has to slow down for entry. Which are not the case. It also assumes a straight line trajectory, which wouldn't happen.

    Still, even if you half the speed and triple the distance you've got a trip time of only about 7 weeks. It's a vast improvement from the current 6-7 months trip time.

  • Here [spacer.com] is a slightly more in-depth article.
  • It might stop accellerating eventually, but that doesn't mean it'll stop, It's still got plenty of inertia, especially if they get the speeds their talking about.
  • I strongly suspect that the same dictionary definition should be displayed at the top of every page.
  • by Octal ( 310 )
    >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
  • Didn't you READ the article.

    With this technology Vlassic can corner the market on interplanetary pickle shipments...


  • 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.
  • 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.

  • 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.
  • 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
  • One of the more radical suggestions I've seen is: Don't come back.

    Replace the many tons of return fuel with the equipment to create a colony and lab equipment to analyze the samples on Mars. Only later, when increased interplanetary travel has made investment in the necessary infrastructure practical, do the original colonists get to come back for a vacation.

    This plan has the advantage of not risking any possible contamination of Earth by returning astronauts. Even long term medical problems would have become visible before the first return trip. (Not that such is a risk is great, as demonstrated by the Martian metorites that have already "contaminated" Earth.) But, every little bit helps convince the PointyHaired Politicians.

    Despite this rather extreme level of commitment, I believe NASA would get volunteers if they asked today....

  • With a big bowl of corn chips. :P
  • Re: The magnetosphere thing: You could probably tow yourself by a 10-mile cable if you're worried about messing with the crew (not to mention the scientific instruments). Hell, I'll bet you could use that same cable to generate a hell of a lot of energy while you're at it -- think of it as recycling.

    ----

  • real strong rope?

    Bzap. Lightning. Fire fire fire.

    I'm sure that's not exactly what you meant.. but it would also give you one hell of a ride if the "rope" got caught in a twister.
  • . . . Mars mapping probe. . . that wouldn't be - um Mars Surveyor now would it?

    "The number of suckers born each minute doubles every 18 months."
    -jafac's law
  • "3.Send information, not people. This one requires lots of electronics and/or nanotechnology. Why
    ship people to Tau Ceti ?? Build them on-site. Alternately, clone and in-vitro them, then teach the
    resultant kids via robotics and advanced AI (Note: James Hogan suggested this idea in a novel,
    10-15 years ago...). This is a one-way, colonization-trip concept. . ."

    This, I believe, was the underlying concept behind The Andromeda Strain (Michael Criton?). The aliens send out a buzillion little plastic pellets, with a genetically engineered organism that survived on the pellet material and gamma rays, as a message to other life, unfortunately, the organism had a nasty habit of mutating into something that caused all the blood in the human body to spontaneously, and instantly coagulate.

    "The number of suckers born each minute doubles every 18 months."
    -jafac's law
  • 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

  • >Sounds like a cheap way to get to Mars. Getting BACK, however...

    I was thinking the same thing....
  • Of course one could use a planet to gravitationally return the crew to earth, though sustaining 20-30 g's for 20 minutes is a tad rough on the body. So we have to aero-brake as part of the turnaround (per 2010). Of course, we lose momentum. So we generate and store frictional energy in our heat shield during braking, radiating it for reacceleration after our turnaround. Only bummer is that our visit is still less than 4 hours. So we get a power rewinder for our camera! Problem solved.
  • Heh, gotta love Forward's novels... Ya, so the literary worth ain't all that great, but a lot of the physics/engineering ideas are quite cool...

    Sorta like dirty stories for enginerds :P
  • 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.
  • Since it's supposed to cost less than a couple million bucks to put one of these sail systems on a craft (and it's pretty small to boot) I figure you could use multiple propulsion(sp?) methods. Use the efficient super-speed sail to run the long leg outward and then switch on a rocket or something for local commuting. coreman's right, you won't be able to tack--that requires both air and especially WATER to provide side-ways resistance to the hull of the boat. Ain't happening in space. There's exactly one acceleration direction for a solar wind sail--STRAIGHT out from the sun. But if you've got some thrusters, you could at least steer as you go faster and Faster and FASTER outward. Turning around a car going 200 mph is pretty hard. I don't think many humans are gonna be riding an inter-planetary sail craft with no brakes.
  • 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...
  • by Pope ( 17780 )
    No, but you can play MP2s on it.
  • 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.
  • I don't imagine there'd be much to see. Both probes are well out of the plane of the ecliptic and nowhere near any known large bodies (Voyager 1 was shot out of the plane of the ecliptic after its rendezvous with Titan) and are well on their way out of the Solar System at a rate of some 16km/sec.

    More information on the current status of the probes can be found at

    http://vraptor.jpl.nasa.gov/

    "Cake or death!" (E. Izzard)
  • 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!!
  • If I'm not mistaken, Pioneer was slower than Voyager was, and thus was overtaken. Pioneer's control systems and power output have decayed to such a point that it would be nowhere near useful now, anyway.
  • That'd be a cool webcam site!
    NASA probably decided against it in case the pictures of little green men waving at the camera caused an international panic...
    --
  • To go in any direction, you put your ship in a path where the magnetic sail accelerates it toward a planet. Then use the planet's gravity to swing around in the direction you want to go.

    I'm sure people with the proper tools, such as the Satellite Tool Kit [stk.com] orbit calculator or Orbital Mechanics CDROM [tripod.com], can make some interesting launches by using the Earth and Moon to redirect trajectories [hughespace.com].

  • 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.

  • Whose thinking about going manned? I mean, we haven't even been back to our own moon in, what, 25 years? Methinks that this sort of thing would be a huge bonus for going to someplace relatively close to the sun (Mars).

    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.

    ----

  • 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.
  • Ever go sailing? You can go in directions other than that the wind is blowing; you just need to use a little finesse. Interesting that the solar winds could represent the trade winds of the new age, carrying us to more literal "real worlds".

    ----

  • There are two possible answers to this problem. The first would be to slingshot around whatever planet you were headed for, and head back on a reciprocal course. This, however, has the problem that any landing craft would have to get down to the surface and back on-board the mothership rather quickly.

    On the other hand, you could use the new drive to propel you towards the planet you are investigating, insert into an orbit, then use standard rockets to get back to earth. This has the benefit of time, and is more efficient than current means because only half the rocket fuel would need to be carried on-board.
  • See the previous topic concerning the Cassini project for reasons why RTGs are frowned upon. I wouldn't recommend getting into that here.
  • by crayz ( 1056 )
    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
  • You should get in contact with The Mars Society, http://www.marssociety.org/. I think they'd fit with your vision -- especially with the recent NASA budget slash-and-burn. The Mars Society is pushing for an implementation of Robert Zubrin's 'Mars Direct' settlement plan. You should email them with your "open space" idea, it sounds great to me.

    Also read "The Case for Mars" by Zubrin if you haven't yet. The guy is an ex-NASA bigwig who makes a very convincing case that we could go to and permanently settle Mars TODAY using off-the-shelf technology, for a cheap price too.

  • That's unfortunate. The general population knows nearly nothing about space travel, and fears any kind of radioactive substance greatly. Even, if through some blind quirk of chance, Cassini did come crashing into the earth, it would burn up in the atmosphere and dispurse plutonium dust over several hundred thousand kilometers. It would be spread so that that sensitive instruments probably wouldn't able to rest it. After all, the population tolerates nuclear testing, right? That released much more (by an order of magnatude or two) more radiation into the atmosphere than Cassini would have. There is absolutely no reason NOT to use RTGs unless you are within the orbit of say.. Mars, in which case solar power *could* be sufficient. Damned reactionaries.
  • Comment removed based on user account deletion
  • I find that last link interesting. Why is Hughes sending an broken communications satellite around the moon? Just for the hell of it? To prove it can be done?
  • Yeah, there was something recent about the death of Pioneer V. The fact that it survived 10 times beyond it's normal lifetime makes me thing the Voyager probes will not drop dead anytime soon.
  • I can't find the recent news item that Voyager has been sent its last commands. It has a few instruments still operating, but its antenna will drift away from the Earth in September unless new commands are sent. It has to be kept operating until its instruments report it has left the Sun's influence or the size won't be known (I don't remember whether solar magnetism or solar wind is still being measured). I think funding is the problem.
  • 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.

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