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Solar Sail News and Upcoming JPL Missions 118

Posted by ScuttleMonkey
from the stiff-breeze-of-progress dept.
abkaiser writes "I had the opportunity to interview a supervisor at NASA's Jet Propulsion Laboratory. The JPL is putting together several missions utilizing solar sail technology. The interview and article detail where NASA and the JPL are in using solar sails for applications and research.You can read the article or skip ahead to the cool pictures of prototype and proposed solar sails. The article addresses NASA's JPL solar sail missions, but not other commercial or private projects like Cosmos 1."
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Solar Sail News and Upcoming JPL Missions

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  • by neonprimetime (528653) on Monday February 20, 2006 @05:09PM (#14763314)
    Did you see the pic [andybrain.com] in that article?
    Look closely and you'll see a well drawn Astronaut!
    I wonder if his kid took part in writing this article? :-P
  • Cosmos 1 (Score:4, Insightful)

    by Tablizer (95088) on Monday February 20, 2006 @05:14PM (#14763335) Homepage Journal
    The Planetary Society gathered private funds to launch the first solar sail probe: Cosmos-1. It was basically a proof of concept. However, the Russian launch system failed. One part of me was disappointed that a great scientific test failed, but the other says, "that is what you get for outsourcing to low-wage countries". I suppose I should get used to it. For good or bad, "free" trade is not going away anytime soon.
    • Re:Cosmos 1 (Score:5, Informative)

      by Rei (128717) on Monday February 20, 2006 @05:49PM (#14763513) Homepage
      The real problem isn't that they went with the Russians, but that they went "bargain shopping". There's a reason why they got such a cheap ride (cheaper than the Russians normally offer with Proton or Soyuz): the Volna wasn't designed as a satellite launch vehicle. The USSR wants to get rid of its old ICBMs, and so undertook a program to convert them to satellite launch vehicles.

      Soviet ICBM maintenance has been way underfunded (as previously mentioned, they don't want most of them), and so when you modify a poorly maintained launch vehicle, well... it's not too surprising if it fails. More simply, if you launch on any vehicle that doesn't have a very extensive flight record for the type of task that you want to use it for, you're taking a big risk.
      • The real problem isn't that they went with the Russians, but that they went "bargain shopping"....The USSR wants to get rid of its old ICBMs, and so undertook a program to convert them to satellite launch vehicles.

        Maybe it is double-cutting: they took the cheapest route available in a low-wage country. Does the US or Europe offer a comparable "cheap" road to the sky?
                 
        • Re:Cosmos 1 (Score:2, Interesting)

          by Paua Fritter (448250)

          Does the US or Europe offer a comparable "cheap" road to the sky?

          The US military has also converted some of its old ICBMs into peaceful launch vehicles [spacetoday.org]. I guess they are competing with NASA, because there's some regulation that these facilities can only be offered to US government or government-sponsored agencies.

          Get used to it folks! What with the US anti-missile shield, in a couple of decades time there'll be thousands more missiles entering the second-hand market from such places as Russia, China, Indi

      • Russia and USA has a similar launch history WRT to failures. The real issue here is that the group went with what it could afford to get it done quickly. The gamble failed.
      • Hmm, whoops, replace "USSR" with "Russia" and "Soviet" with "Russian". They were Soviet ICBMs, but not any more, and I should use present terms when talking in present tense. Sorry :)
      • I've often wondered about the reliability of ICBMs, both Soviet and American. If there had been a nuclear exchange, how many warheads would have made it to the target? How many would have made it out of the silo? My guess is not many. Probably a reasonably higher percentage of American ICBMs would have hit their targets, but I would think there would still be failures.
      • There's still a point in using unneeded military hardware even if the chances for a failed launch are high. First of all, it gives some incentive to actually get rid of ICBMs instead of letting them rot in a warehouse where Abdul the friendly arms dealer can get his hands on them for a bottle of vodka. Second, the cost per kg to orbit is lower than anything else at the moment.
    • Re:Cosmos 1 (Score:3, Insightful)

      by darkmeridian (119044)
      One part of me was disappointed that a great scientific test failed, but the other says, "that is what you get for outsourcing to low-wage countries".

      Excuse me, but Russian expendable launch vehicles (ELVs) are at least on par with that of the United States' in terms of performance and reliability. But accidents in spaceflight still happen, on both sides of the pond. Misplaced jingoism really has no place in scientific exploration.
      • Excuse me, but Russian expendable launch vehicles (ELVs) are at least on par with that of the United States' in terms of performance and reliability..... Misplaced jingoism

        I did not mean to imply that Russian rockets were less reliable. If I offended anybody, I apologize.
                 
  • by Macka (9388) on Monday February 20, 2006 @05:22PM (#14763364)

    At the tender age of 12 (some 29 years ago) I submitted a drawing of a space ship powered by sails as part of a school homework assignment. I got the idea after visiting a friends house and seeing a strange ornament displayed in their window. It was a glass dome and inside were 4 paddles mounted cross wise (horizontally) on a vertical support. One side of each paddle was black and the other white (or silver, its hard to remember now). On a nice sunny day the paddles would start to spin. I was so enchanted by this I never forgot it, and dreamed about flying through space on solar sales for years after. I never guessed that one day I might actually get to see it in action.

    • by Anonymous Coward
      They even used your drawing [andybrain.com] for the article!
    • by romu105 (872251) on Monday February 20, 2006 @05:30PM (#14763412)
      The principle that was actually at work in the window-paddle was not, in fact, the conversion of the photons' momenta into kinetic energy of the paddle, which is the principle behind solar sails, but the black side of the paddle would absorb the photon, increase in temperature and warm the air just above the black surface. The air would then expand, causing the paddle to rotate.
      • You're right that it has nothing to do with photon pressure, but even today its not well understood how it actually works. What you posted was just one contributor to the motion.

        There are good sites out there about it.
      • by Otter (3800) on Monday February 20, 2006 @05:46PM (#14763498) Journal
        I had been taught that the greater kinetic energy on the black side caused the rotation. I decided to break with local tradition and do some research before calling you an idiot and a Microsoft spy -- apparently we're both wrong [howstuffworks.com].
        • Shut your hole, ya God damn Microsoft spy.
        • I think the concept behind the solar sail depends on the solar wind (ions streaming from the sun) and not the radiation pressure of the photons. (however the spinning globe thingie works :) )
          • I remember reading an analysis about that once. The solar wind DOES contribute. Unfortunately the ions tend to stick (you get twice the push if you can convince them to bounce) and increase the mass of your sail over time.

            Radiation pressure contributes as well. Most sails are silver because reflected light provides twice the momentum as absorbed light. I can't remember what the proportion is, but both effects are significant. The charged ions carry a lot more momentum, but there are a lot fewer of them
        • While the GP's details were off, his point is still valid: Solar sails do NOT work by the same principle light-mills work, because light-mills require an atmosphere.
          • by Anonymous Coward
            Except...from the bottom of the above linked web page:

            By the way. It is possible to measure radiation pressure using a more refined apparatus. To make it work you have to use a much better vacuum, suspend the vanes from fine fibers and coat the vanes with an inert glass to prevent out-gassing. When you succeed the vanes are deflected the other way as predicted by Maxwell. The experiment is very difficult but was first done successfully in 1901 by Pyotr Lebedev and also by Eenest Nichols and Gordon Hull.
        • Actually, you're both right in principle. The effect IS from the black side absorbing heat and thus warming the air around it (increasing it's kinetic energy). It's just that it's only around the edges that the temperature gradient can give the vane a net push.
          • Oh for goodness sake!
            "The photons hitting the black side of the vanes will be absorbed transferring their momentum to the vane. Those hitting the white surface will be reflected transferring up to TWICE their momentum to the vanes.

            1) In a vacuum: The above concept dominates and the white vanes trail the black vanes.

            2) In a poor vacuum: the air on the black side of the vane gets heated and the air molecules give an extra "kick" to the black vane side overriding the photon momentum transfer causing the black
            • Oh for goodness sake!
              "The photons hitting the black side of the vanes will be absorbed transferring their momentum to the vane. Those hitting the white surface will be reflected transferring up to TWICE their momentum to the vanes.


              Um, yeah, thus showing that light pressure is not the mechanism by which these things spin, since they spin the wrong way (they also reverse directions if you allow them to cool). If you'll read the rest of the thread you'll find that the explanation isn't quite as simple as the
              • "Um, yeah, thus showing that light pressure is not the mechanism by which these things spin, since they spin the wrong way (they also reverse directions if you allow them to cool)"

                Yes, but only in an atmosphere as the rest of the quoted explanation states.
                • They don't spin at all in a hard vacuum. That was one of the demonstrations used at the time to show that radiation pressure wasn't what was spinning these things.

                  Radiation pressure has been demonstrated, but they used very carefully balanced vanes suspended by threads. The vanes themselves need to be coated in inert glass so that outgassing isn't a factor. It's a very difficult experiment, not something that can be stored in the cupboard in science classrooms.

                  Radiation pressure works nicely in space tho
    • by paeanblack (191171) on Monday February 20, 2006 @05:31PM (#14763418)
      I got the idea after visiting a friends house and seeing a strange ornament displayed in their window. It was a glass dome and inside were 4 paddles mounted cross wise (horizontally) on a vertical support. One side of each paddle was black and the other white (or silver, its hard to remember now).

      That was a radiometer. http://images.google.com/images?&q=radiometer [google.com]
  • Why is the JPL working with solar sails? Aren't they the Jet Propulsion Laboratory? Isn't this a bit out of their department?

    • Why is the JPL working with solar sails? Aren't they the Jet Propulsion Laboratory? Isn't this a bit out of their department?

      JPL never really had anything to do with jets as we know them today. My understanding is that when it was founded by some Caltech faculty and students in the 40's to do rocket research, "rocket" was kind of a dirty word due to lingering memories of German rockets in WWII. Rockets were also commonly called jets until the mid to late 40's. One of JPL's first successes was the develo

      • JPL was transferred to NASA...

        Having worked at JPL, I can tell you that it's still part of CalTech. I has, however, a contract from NASA to run NASA's unmanned exploration of space, and all NASA probes and sattilites are run from their.

        And, to answer the original question, if solar sails are going to be used to power probes, the research would naturally be run through JPL for the above reason.

        • Having worked at JPL, I can tell you that it's still part of CalTech. I has, however, a contract from NASA to run NASA's unmanned exploration of space, and all NASA probes and sattilites are run from their.

          True. What I meant by "transferred to NASA" was that the oversight was shifted to NASA from the Department of Defense. JPL is "managed for NASA" by Caltech, which is unique among the NASA centers - JPL employees (as I'm sure you know, but others may not) get their paychecks from Caltech rather than NA

  • Reminds (Score:4, Interesting)

    by Belseth (835595) on Monday February 20, 2006 @05:34PM (#14763439)
    Always reminds me of the short story Sunjammer. It brings to mind the massive racing yachts. Ever since I read the story in my teens the slow motion image of the ships colliding has stuck in my mind. I'd love to see a solar sail race. The scale alone would be epic.
  • Bajorans? (Score:1, Funny)

    by reachums (949416)

    Did anyone else see that episode of Deep Space Nine when they used a solar sail space ship? Obviously NASA did.

    • Did anyone else see that episode of Deep Space Nine when they used a solar sail space ship?

      Yep. I started out by whining about how the dialogue clearly implied that the distance they were travelling was interstellar, and that you can't do that in a solar sail of that size in a single episode, you'd need warp drive, that's the whole POINT you fools!... but then shut up, because it was a really damn good episode. Do I lose geek points for that? :-)

      Solar sails are well nifty things... I really wish it wasn

      • Ah yes. But didn't they hit some tachyon flow or some such and actually go to warp...

        I think they started out saying that the distances involved weren't possible as well (due to the limitations of the solar sail).

        But then what do I know?
  • by tempestdata (457317) on Monday February 20, 2006 @05:48PM (#14763509)
    Or if there is a better way. I know NASA is all about research and pushing forward the boundaries of science. But I think they are spreading themselves out too thin. Especially if you consider how little money they get.

    I have noticed that when I take on too many part time coding projects, I get none of them done right. I have a limit amount of personal coding time (maybe 1 day a week total) and working 1 hour on each of my projects doesn't get me very far on any of them. I do them all half-assed or never even complete them.

    This is what I see happening with NASA.

    On the other hand, I can get a lot done if I just focus on 2 projects or 3 at the most. Focus all my free coding time and energy on the 2 or 3 that I have time to do. This way I actually do a good job on the few things I do pursue, and I actually finish up on them.

    I think this is what gave NASA its early successes. They focused and pushed in specific directions.. that and they had a lot more money back then.

    I wonder if NASA would be better to slim down and focus on two or three goals and and drop everything else. Put it on their todo list, but not actually work on it, till higher priority goals are met. They have a severe shortage of resources, and they aren't the most efficient at using them (being a government agency after all), they could slim down and use all their resources to accomplish a smaller set of goals.. but actually ACCOMPLISH them.. not just probe around in different random directions. This scattered approach is not letting them devote enough resources to actually finish anything.. and the projects that do finish, end up taking so long that the public looses interest.

    For instance, if NASA took on a task similar to putting a man on the moon. Say.. putting a man on mars.. or putting a base on the moon. Pick one, and dedicate all their research towards it. I think something like this would excite the public more, and perhaps even get more funding. The public isn't as impressed when NASA says "Oh we've been prodding around at these 20 different technologies that may one day be feasible and we could one day use but they are atleast 20 years away from being usable." But if NASA said "we have accomplished 4 of the 25 goals we have set for putting a base on the moon, we are working on 5 more goals and we are hoping to have them done by the end of this year. If everything goes as planned we should have a base on the moon in 10 more years, construction could start as soon as 3 years from now"

    Now THAT sounds exciting!
    • I wonder if NASA would be better to slim down and focus on two or three goals and and drop everything else.

      First, it might be harder to distribute personell that way. The specialties might be different for each project. If you have a little bit of everything going (such as both manned and robot missions), then you can more easily keep a variety of skills around.

      Second, I think a bigger problem is lawmakers: they cancel and then uncancel missions back and forth, up the funding, then down it again, etc. The
    • Well, ya know, if NASA were run by the military we'd already have nuclear-fission powered spacecraft keeping dutiful watch of the skies. Maybe in a few decades time but it'll still all be robots I'm thinking.
      • You're overlooking the fact that the military has its own space-militarization programs, and these have never resulted in fission-powered spacecraft. The real reason isn't because of military noninvolvement (since the military has always been involved), but because of treaties signed in middle of the previous century that categorically prohibited nuclear weapons and even fission testing in space. Several designs had been worked out on paper, and some were even slated for prototyping, but the projects were
    • Especially if you consider how little money they get

      NASA got 16.2 billion dollars for 2005. Give me 16.2 billion dollars and I'll get us up to 12 escape velocity launches a day, with beer and pizza money left over. Watch this space, I submitted a story about it lately, and to my surprise it wasn't rejected out of hand, but is in the pending queue...

    • It's Bush's fault. He's Hitler, you know.
    • Here is a plan. (Score:3, Insightful)

      by AoT (107216)
      I was reading about a few things lately, like the coming peak oil and the fact that we do not have enough resource on earth to support the way we live. So I figured, fuck earth. Let's go. Give me your thoughts on the plan. I realize that much of this is contingent upon political impossibilities and scientific possibilities; but I think we need to start somewhere. I also realize that there are parts of the technology herein that may turn out to be unfeasable. That is an inevitability.

      Note: this is a rough dr
      • Give me your thoughts on the plan. this is a rough draft, obviously, and I hope that others more knowledgable than me can make corrections where applicable.
        I couldn't come up with something more clueless if I drank all the alchohol I've drunk over the past thirty years in a single night.
      • I was reading about a few things lately, like the coming peak oil and the fact that we do not have enough resource on earth to support the way we live. So I figured, fuck earth. Let's go.

        Yes, because outer space is known for its wealth of usable, reachable resources...

      • I wish things were that way, but that is impossible in the world of today. Doing all that is the equivalent of ignoring many other problems our society faces at the moment.

        Aren't you worried about drug research? What if AIDS kills us all before we reach step III?

        This scheme might work if it is accepted at a global scale, but that will not happen, because our world is a world of contrasts. I believe your plan might become reality if the whole planet becomes a single nation. In that case space explorati
      • You should add to the list researching of methods to adapt animal biology to space. For example, improved radiation hardening and radiation repair mechanisms, skin modifications to allow short-term unprotected exposure to hard vacuum, extended ability to operate without breathable oxygen (say, 15 minutes in vacuum without a critical reduction in physical capability), modifications to eliminate zero-gee related infirmities (bone density reduction, fluid redistribution, etc).

        Advanced topics might include res
    • Or if there is a better way. I know NASA is all about research and pushing forward the boundaries of science. But I think they are spreading themselves out too thin. Especially if you consider how little money they get.

      A billion here, a billion there, pretty soon we're talking about actual money. We should just redirect the money to direct research grants in fields which are useful (spend a billion dollars to develop a solar sail, get another method for getting an expensive vehicle from one point where i

    • I have noticed that when I take on too many part time coding projects, I get none of them done right. I have a limit amount of personal coding time (maybe 1 day a week total) and working 1 hour on each of my projects doesn't get me very far on any of them. I do them all half-assed or never even complete them. This is what I see happening with NASA.

      On the other hand, I can get a lot done if I just focus on 2 projects or 3 at the most. Focus all my free coding time and energy on the 2 or 3 that I have time

    • I wonder if they're doing it right too, but not in the same way.

      NASA is great at doing advanced research and basic tehnologies. That's their core competency, and they should focus on that, the stuff that nobody would ever try to do because there's no obvious profit to be made.

      Anything that's more routine and potentially profitable should be outsourced either to another division inside the government (a space corps?) or, better, to an external company. Government agencies are notorious for being hams
    • You are right - they had the cash to do it so many years ago. With the Russians and us in the Cold War, the Moon landing, spacecraft launch, etc - they were all given tons of money to get the job done. That is not the case today. I think we'd be a whole lot better off as a human race if we had taken the production effort behind the 100,000 icbms and put it into space achievements. Of course, given my cynical outlook of the governments, we'd probably just have Death Ray Lasers and zero-grav void-breathing s
  • ...just use that new (patent pending) Warp Drive [slashdot.org] thingy.
  • by kurtu5 (866923) on Monday February 20, 2006 @06:19PM (#14763692)

    Neil Murphy Dismisses the notion on a nonphyiscal solar sair right off hand. "We use aluminized plastics and nanotubes. You really do have to have a physical sail. Magnetic fields interact, but not in the same way." What about Robert?

    Magnetic sails proposed by Robert Zubrin [nasa.gov] can be seen in the middle of this NASA page. So is it or is it not feasible?

    Perhaps Mr Murphy has time invested in physical sail research...

    Me? I just wanna be a fry cook on Venus.

    • Oops, it was actually Winglee who suggests injecting plasma into a more modest magnetic field in response to the critique of Zubrin's ten kilometer coil.

      "What we're proposing to do is create a magnetic bubble to deflect the solar wind," Winglee explained

      Is this feasible? Its 5 something, time to go home.

  • interesting physics (Score:5, Interesting)

    by bcrowell (177657) on Monday February 20, 2006 @06:25PM (#14763737) Homepage
    One interesting thing about the physics of solar sails is that, counterintuitively, the worst possible thing to do with one is turn it perpendicular to the sun's rays. You actually get the maximum rate of transfer of kinetic energy if the sail is at 55 degrees to the rays, rather than 90 (explanation here [lightandmatter.com], p. 149). There are also some pretty counterintuitive physical results about ordinary water sailing, e.g., that it's possible for some racing sailboats to complete a closed-loop course at an average speed greater than the speed of the wind!
  • by Anonymous Coward
    Caltech solar sail enthusiast's list of Books about Solar Sails [caltech.edu]

    ... Project: Solar Sail - editor: Arthur C. Clarke, managing editor: David Brin.
    Penguin Books, 1990. ISBN: 0-451-45002-7
    A collection of essays and short stories about solar sails. This book was part of a fund-raising effort for the World Space Foundation....

    Locus describes this as:

    Project Solar Sail ed. Arthur C. Clarke (NAL/Roc 0-451-45002-7, Apr '90 [Mar '90], $4.50, 246pp, pb); Anthology of seven stories, three originals, featuring
  • There was some debate some time ago about the interpretation of the photonic conservation of momentum, and weather a black sail or a mirrorred sail (on the illuminated side) would produce more thrust.
    Has this been settled?

    The problem was, the conservation of momentum equations most commonly used as a short cut in QM were very simplified compared to the classical step by step derivation, and were thus being incorrectly applied...

    So what is the best deal? Black sail or white sail or mirrorred sail on t
  • Everyone believing it will fly on schedule, please stand on your head.

    The first mission:
    Mission name: ST9 (Space Tech 9)
    Tentative launch date: 2010-2011

    Then we have more:
    Mission name: Heliostorm
    Tentative launch date: 2016-2020
    Mission name: SPI (Solar Polar Imager)
    Tentative launch daMission name: Interstellar Probe
    Tentative launch date: 2031-2035

    These are science. As we all know, the US gubmint don't hold with that science stuff. And does anyone out there believe that NASA have any clue what they'll be doin
  • There's a lot of talk about Mars exploration and possible terraforming, but there's much to support the idea that Venus may be easier to terraform. Two problems with Venus can be solved with the application of solar-sail technology:
    • 1. providing some shade. Venus is obviously a lot closer to the sun, but it's not so close that we can't provide adequate 'sunglasses'.
    • 2. providing day and night. Venus rotates very slowly - its day is about a year long! This causes lots of problems. First, it causes big heat
    • This is all fine, but what about the noxious fumes?
    • Ya know, that's all well and good, but I just wanted to point out that humans and some other terrestrial plants and animals can and do live in a long day cycle. Above the arctic circle, there are towns that don't see sun for up to 67 days each year, at winter solstice, and have continuous sun for over 4 days in summer (atmospheric refraction accounts for why its not balanced)
      • This is true, to an extent. Humans can live outside of the 'standard day', as can other forms of life. There is a limit to what is healthy, however, and I know some people who have lived in northern Sweden during the winter, who will testify to the depression it can cause. I am aware that the first humans at Venus could be exposed to artificial sunlight and have shades drawn for their sleeping time in an effort to minimize this damage. Since the planetary shading is required, anyhow, in order to the atmosph
  • Can it work such sail ? If i would throw a ball at you, you would be pussed.
    Photons have no mass, so they cann't push anyting.
    If it could the sail would heat up from the impact of photons.
    Still a photon has no mass so i doubt if it could transfer it's momentum to another object. Even heat energy would radiate away with no force resulting from it, just cooling.

    So then perhaps they could make them like a mirror, so incomming photons bounce back. Since a photon travels always with same speed, it couldn
    • Still a photon has no mass so i doubt if it could transfer it's momentum to another object.

      In special relativity, you don't need to have a mass to have momentum. A photon's momentum is h*nu/c, where nu is the frequency of the photon, h is Planck's constant and c is the speed of light.
    • Mass is only required for specific types of energy transferrence.

      We're only interested in using the energy present in the photons; converting it from kinetic (photon moving at c along a specific path) to kinetic (sail being "pushed" as it alters the vector the aformentioned photon was initially on).

      We don't need any mass; we just want the energy. BTW, you might remember an experiment involving the bending of starlight by our Sun during a total eclipse? The stars' apparent position was displaced by somet

  • Sail enthusiasts have faced continued disappointment [babilim.co.uk] from the early days; with the failure of Znamya, to the more recent failure of the Cosmos-1 spacecraft [babilim.co.uk]. Lets hope NASA has more luck than everyone else, despite the recently announced budget cuts for science funding in favour of the manned programme.

    Al.

  • I was reading in the current issue of Nature that NASA has mothballed nine space missions in 2006 in order to fund the shuttle transition program. Nature complains NASA is sabatoging one of its more successful and cost-effective branches.
  • I had the opportunity to interview a supervisor at NASA's Jet Propulsion Laboratory. The JPL is putting together several...

    Oh my goodness, the slashdot editors actually revealed the words for a sighted acronym. Unprecedented!

  • Sadly, the budget just submitted to Congress by the Administration drastically cuts space science and technology development including the in-space propulsion technology which was funding the solar sail work in NASA, and at JPL. I am not sure what will happen to their program. NASA has announced they will initiate a solar sail challenge sometime later this year and invited comments on the rules and prize(s). We, at The Planetary Society, are still planning to try again to fly a privately funded solar s

I've got a bad feeling about this.

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