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Solar Sail News and Upcoming JPL Missions
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."
It looks like a square Jiffy Pop to me.
NINJA SPIRIT - The Ancient Art of Insanity
Did you see the pic in that article? :-P
Look closely and you'll see a well drawn Astronaut!
I wonder if his kid took part in writing this article?
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.
Table-ized A.I.
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.
Why is the JPL working with solar sails? Aren't they the Jet Propulsion Laboratory? Isn't this a bit out of their department?
There are 11 types of people in the world: those who can count in binary, and those who can't.
Why do people continuously append the word "technology" to technical terms ? ...
"Solar sail technology" ?? "VoiceOver IP technology", "Internet protocol technology",
Is it to differentiate the hi-tech solar sails from the crappy ones that you find at walmart ??? Sorry, really off-topic, but its just one of those things that tick me off...
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.
Did anyone else see that episode of Deep Space Nine when they used a solar sail space ship? Obviously NASA did.
"Just call me Girly Blank"
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!
- Tempestdata
Well, the sun is a thermonuclear explosion, so there is a lot of crud flying away from it. Some particles are quite massive and not as fast moving as photons. As I understand it, it is mainly this slower moving smoke that will be used by a sail.
Oh well, what the hell...
Actually, solar sails are pushed by photons. The force generated on a solar sail by the solar wind (all of the "crud") is about an order of magnitude lower than that generated by photon momentum transfer. OTOH, the proposed Mini-Magnetospheric Plasma Propulsion (M2P2) system does use a "magnetic sail" of sorts to obtain thrust from the solar wind.
There is one big detail these amateur scientists have not accounted for : space is full of stars. For any photon coming from the sun, there are millions that come from the exact opposite direction. Why do you think it's dark outside ? because those photons anihilate electromagnetically against each other.
You would be correct if, when you looked outside, the sky were uniformly grey - there would be equal amounts of light of all colors coming from all directions, resulting in zero net solar pressure.
However, if one looks around in space, one will rapidly see that there is a WHOLE LOT more light coming from the sun than from any other direction. Aside from everyday experience, one can prove this just by recalling that there are shadows on the moon's surface caused by sunlight. If all the light from other stars was large in comparison to the light of the sun, the Moon's surface would appear (from Earth and Neil Armstrong's P.O.V.) almost uniformly grey.
As for why the sky is dark, it has nothing to do with the photons of other stars interfering with one another. It has to do with dust and the incomprehensibly vast distances between stars. The light from other stars appear as pinpricks of light because they are so far away. Stars that are really far produce weak light (recall light intensity decrease by 1/r^2 - or do you recall that, since you obviously know nothing about how physics and astronomy really work), and a lot of that light gets intercepted by dust long before it reaches our eyes.
So, in short, the myth that you speak of is itself a fallacy. There is a tangible and harnessable force from the solar wing.
...just use that new (patent pending) Warp Drive thingy.
It must have been something you assimilated. . . .
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 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.
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.
I prefer the "u" in honour as it seems to be missing these days.
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, 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!
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I gathered some concept of a spinning wheel of solar sails FTA, much like a traditional windmill. I like that design approach best, providing renewable thrust in both directions (albeit better in one).
I hope, when they die, cartoon characters have to answer for their sins.
Start counting your photons as they pass by, then tell me where they're coming from. It's dark outside because of the inverse sqaure law. We see more photons from the sun than we do from other stars because it's a lot closer. Photons anihilate? Perhaps you're grasping at virtual particles or superposition, but you're trying to fit it in somewhere that it's irrelevant. Anyway, since NASA is working on this (at a slow pace), there obviously already is funding for it.
It really is a pity these "amatuer" scientists don't realize that space is full of stars. (Is this a joke? It's hard to read sarcasm...)
Perhaps you are familiar with the inverse square law? The amount of energy available from a star is inversely proportional to the square of your distance from the star. The distance from the sun is 1AU - approximately 500 light seconds. The distance to the nearest other star is 4.3 light years. The amount of push available from the sun is at least 31924759790000 times greater than the push from any other star. Rather than there being millions of photons from other stars for every one from the sun, there are quadrillions from the sun for every one from other starts.
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This Wiki Entry has a good explanation.
Solar sail craft are already in orbit, around the Earth or Sun. They don't fly directly toward or away from the sun; instead, the sail can be angled to push the craft's orbit higher or lower, or shift from a terrestrial orbit to a solar one.
It's not too far removed in principle from how sailing ships can sail into the wind.
Live simply, that others may simply live. -Gandhi
Gravity would be one method. The article states that sails on the scale they are talking about would only be effective out to about 200 AU (a little bit past Pluto, if I remember right). Even that far out, gravity is still significant (otherwise Pluto wouldn't feel any reason to stick around like it does). I've heard some people mention tacking, like sailboats, to get propulsion against the direction the light is moving, but spacecraft don't have keels. I can't figure out a geometry that would work for that.
Just be careful guys, I'm at work and i had to go to the restrooms to laugh properly. DONT LOOK AT THE PIC if you're at the job!
Caltech solar sail enthusiast's list of Books about Solar Sails
...
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 solar sails plus five essays, four poems, and introductions by Arthur C. Clarke and Isaac Asimov. The profits from this anthology are to go to the World Space Foundation to help fund a solar sail project.
1 Foreword: The Winds of Space Arthur C. Clarke fw
3 Introduction: Sailing the Void Isaac Asimov in
9 The Wind from the Sun ["Sunjammer"] Arthur C. Clarke nv Boys' Life Mar '64
33 To Sail Beyond the Sun (A Luminous Collage) Ray Bradbury & Jonathan V. Post pm *
41 The Canvas of the Night K. Eric Drexler ar *
53 Ice Pilot David Brin ss *
67 A Solar Privateer Jonathan Eberhart pm, 1981
69 Sunjammer Poul Anderson nv Analog Apr '64
95 A Rebel Technology Comes Alive Chauncey Uphoff & Jonathan V. Post ar *
105 Argosies of Magic Sails--Excerpts from "Locksley Hall" Alfred Tennyson, Lord pm
107 Ion Propulsion: The Solar Sail's Competition for Access to the Solar System Bryan Palaszewski ar *
115 The Grand Tour Charles Sheffield ss Analog May '87; as "Grand Tour"
137 Lightsail Scott E. Green pm *
139 Rescue at L-5 Kevin J. Anderson & Doug Beason ss *
153 Lightsails to the Stars Dr. Robert L. Forward & Joel Davis ar *
163 The Fourth Profession Larry Niven nv Quark #4, ed. Samuel R. Delany & Marilyn Hacker, Paperback Library, 1971
219 Goodnight, Children Joe Clifford Faust ss *
231 Solar Sails in an Interplanetary Economy Robert L. Staehle & Louis Friedman ar
245 Afterword Arthur C. Clarke aw
Jonathan Vos Post, former Adjunct Professor of Astronomy, Cypress College
Nah, it ain't the gravity. Pluto's just lazy.
A blog about stuff.
It's Bush's fault. He's Hitler, you know.
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 draft, obviously, and I hope that others more knowledgable than me can make corrections where applicable.
Plan for Mass Space Colonization
I)Funding
1.Cut military funding in half.
a.~210B a year
b.Withdraw all troops stationed outside of US
c.Stop all non space military research
2.Cut all Agricultural Subsidies
a.unknown monetary savings, considered significant.
3.Taxes
a.raise taxes on highest tax brackets and corporations
1.increase revenues by up to 50B
2.those affected are also the biggest benificiaries of research and
construction contracts.
II)Internationalizaion
1.US offers cooperation with all nations who express interest
2.cooperative funding methods utilized to maximize returns
3.cooperative science research to maximize returns
III)Energy
1.outlaw personal consumtion of petroleum products
2.encourage local production of food and products
3.increase public transportation with an express intent to transfer knowledge
and methods learned to colonial situation
4.possibly oulaw powered personal vehicles
IV)Science
1.internationalizaion of research (see II)
2.complete open sourcing of all types of research
3.heavy emphasis on practical space and foreign world technology.
V)First ten years
1.Vast majority of funding goes to research
2.heavy emphasis on getting off planet
a.large scale exodus
b.best choice: space elevator
VI)second 10 years
1.split funding between research on construction of exodus devices
2.construct space elevators, orbital platforms
3.research emphasis on non-terrestrial colonies, I.E. Space stations
VII)third ten years
1.beginning of small scale non earth orbit colonies
2.minimal construction of exodus devices
3.construction of orbital platforms and "arc" ships
4.heavy research on ground based hostile terrain colonies
VIII)final ten years
1.Full constuction of non earth orbital colonies
2.to be tranfered slowly to ground based colonies
A blog about stuff.
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 the illuminated side? And what about the back side too?
I was very interested in the discussion, and it seemed the argument was still going when I last checked a few years back...
Yep, an attractive gravitational force toward the sun. As the craft moves about the sun, it can orient its sail so that the thrust is in the opposite direction of its motion. It then slows down and its orbit decays, causing it to approach the sun. Sailboats can take into the wind because their keels are immersed in a dense, resistive fluid...woulnd't be practical (or necessary) for a solar sailcraft.
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 doing five years from now, let alone 25-30?
Remember the two year delay on the James Web Space Telescope (successor to Hubble) announced back in November? That's nothing. In addition to the congressional criticism of the no-science budget, we have things like:
http://www.newscientistspace.com/channel/human-spa ceflight/dn8689-nasa-to-divert-cash-from-science-i nto-shuttle.html
(Feb. 7) Wherein we learn that the Terrestrial Planet Finder has been delayed indefinitely, and more, such as "The budget announcement was "extraordinarily depressing", says Louis Friedman, executive director of the Planetary Society, a non-profit organisation in Pasadena, California, US, which promotes solar system exploration. "I would almost describe it as 'anti-science NASA' now, with these kinds of deep cuts." Seven missions, or areas of research, or listed as cancelled or postponed. Of the postponed, all but one is indefinitely.
The Planetary Society has a statement here:
(Feb. 16)
http://www.planetary.org/programs/projects/space_a dvocacy/budget_statement.html
with gems like, "The Bush Administration's proposed 5-year budget for NASA, just submitted to Congress, is an attack on science. The proposed budget directs three billion dollars (over five years) away from robotic exploration of the solar system to continue to operate the shuttle. Last year the Administrator said, "not one thin dime" would be so directed. Now we learn it is 30 billion dimes."
and
"In addition, a devastating 15% cut to science research funding -- including likely cuts to some approved 2006 research programs -- is being applied across all Earth and space science disciplines, and 50% is being cut from astrobiology research! This attack on basic science ironically comes at a time when the President announced in his State of the Union speech his intention "to double the federal commitment to the most critical basic research programs in the physical sciences over the next 10 years." Apparently the physical sciences do not include either Earth or space sciences."
If you think the much advertised "Vision for Space" is really going to get us back on the moon, then to Mars, you may be in for a surprise as well. Yes there's been all the talk about the new heavy lift and crew exploration vehicles. Even methane engines, so we can 'live off the land'. Guess again, and see:
http://www.spacedaily.com/reports/The_Moon_Program _The_NASA_Administrator_Is_Really_Planing_For.html
(Feb. 14). No methane engines, the Crew Exploration Vehicle diameter has been resized to five meters (can now be lifted by existing hardware), which the authors suggest was done to put the Crew Launch Vehicle on the chopping block. The Cargo Delivery Vehicle is gone, so we can't send control gyros to ISS after the shuttles retire in 2010. "This implies that the ISS won't be there at that time - or at least that NASA will not be supporting it."
So far, most popular reporting implies that science is being scrapped for Shuttle/ISS. That would be bad news, after the "not one thin di
What you do with a computer does not constitute the whole of computing.
You think the sr-71 or the b-2 were the last black budget craft?
Been a LOT of people see the big black triangles. I wonder what propulsion they use to be very quiet and be able to hover or go very fast.
I don't see the military giving up really advanced tech to NASA or anyone, not if it's that good. And, (mangling some english here with a double negative) I don't see them *not* having more advanced craft than 3 decade old stuff like the b-2 or even older sr-71. The odds are pretty well against it. And they have had plenty of time to develop exoatmospheric craft.
You can't tack with a solar sail, but you can get thrust perpendicular to the sun's rays. Recall from the example of the space shuttle that if you want to change your orbit you normally thrust perpendicular to the direction of gravity anyway. If the space shuttle wants to come down it thrusts against it's direction of travel, slowing down. A solar sail lets you do this just fine. The only thing you can't do is fly straight at the sun... but I'm not sure why you'd want to, and you'd need an awfully big rocket to do that conventionally anyway.
Olber's Paradox sums it up. If the sky is uniform then all gas clouds and all distances will be full of star light, right? Hubble had to come along and say the Universe was expanding and redshifting the light into the cosmic background.
- 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 differentials between one side of the planet and the other. The day side will be hot and the night side will be cold, and there would probably be big winds because of this. Also, plants and animals from earth require day/night cycles to survive and be healthy.
One of the problems with providing shade is that the very useful effect of the solar wind will push the shades beyond venus or into it. This can be countered by having the shades orbit venus, and tack against the solar wind, turning their sailing surface at different angles in relation to their intertia to maintain the desired orbit. There would be a rather thick and tall ring of sails some distance out from venus, coordinating to reflect light in a manner which would lighten some areas of the planet while darkening others - mimicing the daycycle of terra. A fine-grained control over this lighting could be used to provide optimum lighting for a specific area growing a specific crop, or concentrated beam could be focused on the collector at a solar power station.This being slashdot, I am sure someone will think they're really clever by pointing that this same system could be used as a weapon, like a magnifying glass upon ants, at any target on the planet's surface. But be imaginative! The target would not be confined towards being on Venus, earth could be attacked too!
Warlike purposes aside, such a vast mirror system could also beam power to other parts of the solar system, or provide signalling across the vast reaches of space.
The problem is not only in the design of the sails, but in a factory to economically product the billions or trillions of them which will be required, and a system for placing them. Another system for co-ordination and maintenance will also be required. But all of these are conceivably do-able.
Please excuse spelling, grammar, and other assorted errors, as it's late and I am tired. If I had an job terraforming venus, you can be sure I'd be a lot more careful in preparing my proposals.
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.
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't be able to loose momentum. This sounds perhaps all quit simple.
If i'm wrong overhere then please describe by what physics a sail should work. I'm intrested in the answers.
I know you're out there. I can feel you now. I know that you're afraid. You're afraid of us. You're afraid of change.
Sail enthusiasts have faced continued disappointment from the early days; with the failure of Znamya, to the more recent failure of the Cosmos-1 spacecraft. 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.The Daily ACK - Eclectic posts by yet another hacker
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.
Oh my goodness, the slashdot editors actually revealed the words for a sighted acronym. Unprecedented!
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This space for rent. Call 1-800-SIGADVT to place your ad.
This is the original document without howstuffworks framesets. They don't even show you the original URL until you break out of their frames, those assholes.
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 sail, and we are looking for additional sponsors and supporters. We are also considering the NASA Centennial Challenge -- although it seems that it might be more focussed on a L1 mission (a gravitational libration point) than on the first flight of a solar sail. LOUIS FRIEDMAN
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 something like six angular minutes (should've been occluded by our sun and moon, but was visible due to gravitic "bending", aka gravitic lensing). Gravity can affect photons; gravity is defined as an attraction between two objects with mass; ergo, photons have (infinitessimal but nonzero) mass.