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Japan Successfully Deploys First Solar Sail In Space

timothy posted more than 4 years ago | from the beginner's-luck dept.

Space 284

An anonymous reader writes "This morning the Japanese space agency, JAXA, successfully unfurled a solar sail in space for the first time. Solar sails offer the best hope for deep space exploration because they eliminate the need to carry fuel. The Japanese spacecraft IKAROS created centripetal force by spinning, allowing it to launch the 0.0003-inch-thick sail. While deployment is a challenge in a zero-gravity environment, spacecraft — unlike airplanes — don't have to contend with drag, so with each photon that hits the sail helps the spacecraft gather speed."

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come sail away (3, Funny)

54mc (897170) | more than 4 years ago | (#32529162)

I thought those crazy japanese were angels, but much to my surprise, they climbed aboard their starship and headed for the skies.

It's my childhood future... (4, Interesting)

History's Coming To (1059484) | more than 4 years ago | (#32529202)

Jetpacks? No. Flying cars? No. Sentient robots? No.

Solar sailing? Oh yes! I love this, it's one of the signals that we're living in the future, if you grew up on Clarke, Asimov et al. Required reading: Clarke's "A Wind From The Sun", Stross's "Accelerando".

Re:It's my childhood future... (1)

owlstead (636356) | more than 4 years ago | (#32529360)

Do you mind if I add Vacuum Flowers of Michael Swanwick? The persona of Rebel Mudlark flew / crashed a solar system if I'm not mistaken. It's only a small part of the book, but I had much fun reading about all the strange worlds in there.

Re:It's my childhood future... (1)

owlstead (636356) | more than 4 years ago | (#32529378)

A solar sail, not a solar system. D'oh!

Re:It's my childhood future... (4, Informative)

pluther (647209) | more than 4 years ago | (#32529368)

And don't forget Forward's Flight of the Dragonfly in that list.

So, when can I take the space elevator up and catch a sailship for Mars? And do I have to learn Japanese first?

Re:It's my childhood future... (1)

noisebar (1641161) | more than 4 years ago | (#32529426)

As a teenage, I was fascinated by the story in A Wind From The Sun. Since then, I've been waiting for it to become a reality.

Re:It's my childhood future... (0, Offtopic)

Monkeedude1212 (1560403) | more than 4 years ago | (#32529480)

Sentient robots? No

That's [xkcd.com] debatable. [xkcd.com]

Re:It's my childhood future... (1)

toygeek (473120) | more than 4 years ago | (#32529878)

Indeed, "The Wind from The Sun" is a great short story, and that particular compilation of short stories is just wonderful. I happened to get it at a used book store for $2 and it is my my most prized SF book for sure. If anybody wants to know what solar sails might be able to do in the future, this is a *must read*!

Re:It's my childhood future... (2, Informative)

chill (34294) | more than 4 years ago | (#32530246)

It seems you missed this story [slashdot.org] on the first commercially available jetpacks back in March.

Re:It's my childhood future... (2, Interesting)

Topwiz (1470979) | more than 4 years ago | (#32530324)

The book version of Planet of the Apes has one.

Re:It's my childhood future... (3, Interesting)

Sir_Lewk (967686) | more than 4 years ago | (#32530512)

I'll second that recommendation for Accelerando. That's the book that convinced me solar sails are way way cooler than chemical rockets.

It's even available as a free ebook [antipope.org] , though I of course recommend picking up a hard copy.

Focus (5, Insightful)

AnonymousClown (1788472) | more than 4 years ago | (#32529284)

Did anyone else have the thought that, here are the Japanese, designing and building spacecraft to further explore our Universe and progress mankind's knowledge.

Here are we, the US, once the leaders of space exploration, have spent billions of dollars to go back and relive some glory (Moon shot) and canceled that, we have canceled the Shuttle program with no other vehicle to replace it, and in the process put a halt to much basic research.

We're kind of like that pathetic ex High School jock that's trying to relive his glory days.

Re:Focus (5, Funny)

Anonymous Coward | more than 4 years ago | (#32529344)

We're kind of like that pathetic ex High School jock that's trying to relive his glory days.

But we threw 4 touchdowns in one game, man. IN ONE GAME!

Re:Focus (1)

AffidavitDonda (1736752) | more than 4 years ago | (#32529354)

But the shuttle is only relevant, if you want to bring people into space, which I think isn't the way to go for now. All we want to do, is bring equipment up there, satellites, telescopes, shoot robots to Mars...

Re:Focus (1)

paeanblack (191171) | more than 4 years ago | (#32529562)

But the shuttle is only relevant, if you want to bring people into space

The shuttle is only relevant if you want to deorbit satellites from LEO intact. Launching equipment, launching people, and bringing people home can be done cheaper by other means. Hauling a pair of wings to space and back on every trip is not very fuel-efficient.

Re:Focus (3, Insightful)

Symbha (679466) | more than 4 years ago | (#32529652)

I will only point out that Hubble would have been a complete failure, without the shuttle.
The reason to have a manned space program, is entirely about the unforeseen.

When we do need to send Bruce Willis up to the asteroid to blow it out of the way, we are really going to wish we had a suitable manned space program.

Re:Focus (1)

c6gunner (950153) | more than 4 years ago | (#32530656)

I'm shocked that it's been almost 2 hours since you commented, and NOBODY has butted in to spout some nonsense about how the manned program is unnecessary because it would have just been cheaper to launch a new Hubble.

Re:Focus (4, Informative)

0xdeadbeef (28836) | more than 4 years ago | (#32529382)

Can you count [nasa.gov] ?

Re:Focus (0)

Anonymous Coward | more than 4 years ago | (#32529582)

Can you count [nasa.gov] ?

Constellation is still listed there, as are ESA missions like XMM-Newton.

Re:Focus (2, Insightful)

Charliemopps (1157495) | more than 4 years ago | (#32529622)

I can count the number of non-scientists excited about those projects on 1 hand. Does that count? If NASA continues only to accept projects that do not interest the general public they are going to completely lose funding within a few decades.

Re:Focus (2, Insightful)

0xdeadbeef (28836) | more than 4 years ago | (#32529776)

No, you can't, because the highest you can go is 0x1F.

Re:Focus (1)

Jah-Wren Ryel (80510) | more than 4 years ago | (#32530638)

I can count the number of non-scientists excited about those projects on 1 hand. Does that count? If NASA continues only to accept projects that do not interest the general public they are going to completely lose funding within a few decades.

Fine by me. That will just remove all the political ill-will that's been focused on holding back commercial space development.

Re:Focus (5, Informative)

BJ_Covert_Action (1499847) | more than 4 years ago | (#32529666)

Meh, don't bother. It's hard to convince the people who keep posting this kind of shit that the American space industry is anything but dead. Nevermind the fact that NASA still has the most impressive space research facility on the planet (JPL) or that they are working on various lifting technologies that include everything from hypersonics to extremely advanced aerodynamics (AMES research facility). Nevermind the fact that American business are now starting to launch vehicles into space, without existing government contracts, unlike almost any other nation on the planet. Nevermind the fact that Cassini has just detected evidence that methane based lifeforms may exist on Titan. Nevermind the fact that NASA is trying to land a rover the size of a mini cooper on mars.

Nah, we can just forget all of the missions that NASA has currently studying the Sun, Mercury, Pluto, Saturn, and just about every other interesting object in our solar system because Obama killed the space industry, dontcha know?

As old as it gets to see people post this kind of crap all over the internet, there is absolutely nothing that will convince them that America, space industry included, is nothing more than a washed up has been that is wallowing in its own filth these days. It's like trying to talk reasonably to a kid who has his fingers in his ears and is shouting, "La la la la la I can't hear you!" They'll only learn otherwise when they make the conscious decision to remove those fingers and grow up.

Re:Focus (4, Insightful)

Sycraft-fu (314770) | more than 4 years ago | (#32530086)

Certainly does seem that way. There just seems to be a subculture of Americans, of which Slashdot has more than normal, that love to hate on America. Whatever America does, it's bad. They see the nation in a continually bad light. The flipside of that is usually that they look at other nations with rose coloured glasses. They see only the good, they don't see any down side. The fail to see that there are problems with any nation, as nations are made up of people and we are all flawed.

For some I think it is just because the see that America may be sliding from a position of dominance and they take that to a nihilist extreme where it means America will become nothing, a 3rd world hellhole or worse. For some reason it never occurs to them that there have been other places like, say, England, or France that once were superpowers and now are just very nice places to live.

Whatever the case, it does get rather annoying. Criticizing the problems America has is healthy, and necessary. Only though looking at the faults and trying to correct them can you get better. Just hating on America all the time is stupid and unproductive.

Re:Focus (1, Troll)

abigor (540274) | more than 4 years ago | (#32530574)

It's not just the US - it seems there are people in every modern western society who hate their country/the west in general. They think that "we" owe the rest of the world for all eternity, even if it means our own destruction. Stupid and unproductive, like you said. I experience it on a regular basis from hand-wringing self-loathers.

Re:Focus (3, Informative)

revjd909 (749913) | more than 4 years ago | (#32530216)

The part that's most frustrating is "What's the size of the NASA budget?" And how does that compare to the size of our military budget? We could have a colony in space or on the moon by now, if we weren't spending close to $1 trillion/year making war. Here's a little look at more of what Japan's planning: http://pinktentacle.com/2010/06/futuristic-mega-projects-by-shimizu/ [pinktentacle.com]

Re:Focus (1)

oatworm (969674) | more than 4 years ago | (#32530542)

Correct - instead of spending $1 trillion/year making war, we could instead spend an additional $1 trillion/year on various entitlements like Europe. Whether that's a good thing or a bad thing depends on your point of view, of course; many people would rather just keep the $1 trillion in their pockets and not redistribute it all over the place.

The reason we're (by "we", I mean everyone, not just the US) not spending a bunch of money on sending people to space is because, outside of a few die-hards on Slashdot and physics symposiums, nobody wants to. There are a variety of reasons for this - pure self-interest (spend the money on health care instead!), a lack of immediate return on investment in manned spaceflight (so, what did getting someone to the moon do for us, really?), high risks (the various Space Shuttle accidents) - but they're there.

The exciting thing about private space exploration is that it will finally give those with the capital and the desire to send people to space the opportunity to do so directly, instead of waiting for various bureaucracies to get into alignment. Will it get us into the moon anytime soon? No, but, once we get there, we're going to stay there.

Re:Focus (1)

astar (203020) | more than 4 years ago | (#32530338)

Precise is good. US manned space exploration is dead. Indeed, there s reasonable evidence that OMB is in charge of NASA. From there, it is reasonable to wonder about the future of unmanned space exploration by the US.

On the other hand, what do I know? Perhaps you can point to concrete officially announced plans for a manned misson even to a lagrange point?

And if everything is all so sensible and rosy, it is odd that there is substantial concern that Obama et al is violating the law with his cutbacks. So he says "not quite". Ah well, the recession is over.

Re:Focus (1)

c++0xFF (1758032) | more than 4 years ago | (#32529690)

I hadn't thought about it before, but Pioneer and Voyager are still on that list. Considering the science that's still being done by Voyager (mild, but still ground-breaking), I think it's more than appropriate.

Maybe one day we'll contact Pioneer 11 again.

Re:Focus (1)

copponex (13876) | more than 4 years ago | (#32529440)

No, we're an ex jock with a coke problem they are still in denial about. We're wondering why we're always broke, when the answer is under our proverbial noses. [youtube.com]

Re:Focus (0)

Anonymous Coward | more than 4 years ago | (#32529502)

You must be one of the jocks if your competitive side makes you grow nationalistic feelings and an irrational bond to a loose and undefined group of people/piece of land most of whom/which you have no knowledge of of or personal connection to.

Who care what country does what.

Re:Focus (1)

blind biker (1066130) | more than 4 years ago | (#32529580)

We're kind of like that pathetic ex High School jock that's trying to relive his glory days.

Absolutely not. If only the US tried to revive the old glory! Instead, it's more akin to a guy watching TV all day and drinking beer, overweight, lacking curiosity, enthusiasm, courage. His greatest ambition is watching the Super Bowl.

The USA could not get back to the Moon even if she wanted to - the knowledge is lost, gone. There is no past glory, because the Apollo program could not be re-created today, without a massive investment in research. The Apollo program is not past glory, it's lost glory, and don't fool yourself thinking the USA is ready for the next step - the USA would need to return to the Moon just to re-learn how that's done, before thinking of the next step.

Re:Focus (1)

Nyeerrmm (940927) | more than 4 years ago | (#32529740)

Of course we could go back to the moon in 5-10 years if we wanted to -- we just need the budget. Constellation (which I believe should be shut down) was perfectly capable of getting back there, if only it were funded properly.

The research we need is in ways to do it better and cheaper, because Apollo-level funding was an apparition of the cold war and was unsustainable. Things like propellant depots, electric propulsion, radiation shields, and long term life support are what we need.

Going back to the analogy, the high-school jock is perfectly capable of doing new things, he just needs a kick in the pants to show him that he can't keep doing it the old way, because he doesn't have the youthful body (politically-expedient funding) that he used to.

Ya! The US has done nothing! (5, Insightful)

Sycraft-fu (314770) | more than 4 years ago | (#32529594)

I mean they most certainly didn't recently deploy two rovers to Mars that WILDLY exceeded expectations. They didn't then also deploy another, fixed, lander which while not as wildly successful exceeded it's planned mission significantly. Nope, none of that happened...

Oh wait, yes it did.

Please, while the US space program is not without troubles, it isn't as though it is at a standstill. NASA continues to do some amazing work, and much of it like the landers are pure science, to further our knowledge.

Stop with the US hate that is so popular on Slashdot. The US is not perfect, no nations is, indeed no human endeavor is. There's plenty to criticize and that includes in the space program. However trying to pretend as though they accomplish nothing of note is silly. Two successful recent Mars missions shows that. No, they weren't manned, neither is this Japanese craft. Putting people in space is dangerous and often not worth the expense. We can learn a lot with remote operated equipment.

Re:Focus (1)

geekoid (135745) | more than 4 years ago | (#32529738)

"nd in the process put a halt to much basic research."

False.

Re:Focus (2, Interesting)

sexconker (1179573) | more than 4 years ago | (#32529846)

Seems to me that the US and Russia (and the Germans working on both sides) did all of the leg work in the field.

Seems to me a satellite, however fancy, is orders of magnitude simpler than manned space travel.

Seems to me Japan doesn't exactly a military to waste money on, on account of that whole World War II thing. Or two current wars. Or failed banking and auto industries. Or morans who bought houses they couldn't afford. Or...

Seems to me the US is shying away from public space exploration, while the private industry prepares to take over.

You show a complete lack of understanding of the situation. You might as well post about how Japan has better residential internet speeds than the US.

Re:Focus (1)

oatworm (969674) | more than 4 years ago | (#32530692)

Actually, Japan is still cleaning up the mess from when its banking sector collapsed in the early '90s; it's a big part of the reason that Japan's public debt is nearly 200% of GDP [wikipedia.org] . How did it collapse? Well, back in the late '80s, the Japanese were heavily speculating in... you guessed it... real estate [wikipedia.org] .

As Mark Twain once said, history doesn't repeat itself, but it does rhyme.

Good F---ing Gracious (0)

Anonymous Coward | more than 4 years ago | (#32529894)

Good god, I think posts like the parent's are just stupid. Do you truly think the Japanese did this all on their own? Was it not for years of research, much of which occurred within the U.S., that this could be possible? Has not the U.S. set the stage of modern space exploration? Did not the U.S. send a robot to Mars to find water? Does not the U.S. have outer space telescopes scanning the universe? And so on?

Grow up. Although you seem to fail to realize it, the U.S. doesn't always need to be first. The support of the U.S. government lets researchers more or less be able to pick and choose which problems it finds most interesting, which is good, and not be that sniveling kindergardener that needs to be in the front the of the line every time.

Re:Focus (1)

grumpyman (849537) | more than 4 years ago | (#32529978)

Sounds like Al Bundy :)

Which force? (4, Insightful)

icebike (68054) | more than 4 years ago | (#32529312)

Centripetal or Centrifugal?

Spinning creates what is commonly called Centrifugal force, and the tethers of the sails constitute what is generally referred to as the Centripetal force.

About here is where some physicist jumps up and tells me everything I learned in the past is wrong and I should shut up and sit down.....

Re:Which force? (2, Funny)

Fluffeh (1273756) | more than 4 years ago | (#32529346)

About here is where some physicist jumps up and tells me everything I learned in the past is wrong and I should shut up and sit down.....

Yes. Sit down and shut up. Also, because you didn't pay attention the first time you learned it, I won't waste time explaining it again.

*smirk*

*sips coffee*

Re:Which force? (5, Funny)

Anonymous Coward | more than 4 years ago | (#32529358)

Obligatory xkcd:

http://xkcd.com/123/

Re:Which force? (0)

Anonymous Coward | more than 4 years ago | (#32529364)

About here is where some physicist jumps up and tells me everything I learned in the past is wrong and I should shut up and sit down.....

No offense, but it is obvious that you didn't actually learn it. Centrifugal force is what exists when people forget Newton's first law of motion.

Re:Which force? (2, Funny)

sammyF70 (1154563) | more than 4 years ago | (#32529468)

What exists when people forget Newton's first law is a Darwin Award contender (possibly with a posthume leading role in the next anti-drug campaign movie).

Re:Which force? (1)

blueg3 (192743) | more than 4 years ago | (#32530140)

Or when they insist on using a non-inertial reference frame.

Re:Which force? (2, Informative)

pluther (647209) | more than 4 years ago | (#32529450)

You are correct. Centripetal force is the force exerted by the tethers holding the sail to the spacecraft. (Force from the edge towards the middle).

Centrifugal force is what pulls the sail out. (Force from the middle to the edge.)

Also, there's no such thing as centrifugal force: as explained by, who else, xkcd [xkcd.com]

Re:Which force? (1)

pluther (647209) | more than 4 years ago | (#32529522)

Also, TFA had it right.

The writer of the summary changed it for some reason.

Re:Which force? (1)

PatPending (953482) | more than 4 years ago | (#32529504)

[Emily Litella]

What is all this fuss I hear about centipedes being forced out? It's terrible! Centipedes have enough problems as it is!

[/Emily Litella]

Commence Whining (4, Insightful)

RobinEggs (1453925) | more than 4 years ago | (#32529338)

Commence whining about the death of the US Space program, the US falling behind other nations, and how it's all the (Pick one: Obama, Bush, Clinton, Bush Sr.) administration's fault in 3.....2......1....blastoff.

Don't get me wrong, it's all basically true; it's just tiresome whining to listen to.

Re:Commence Whining (0)

Anonymous Coward | more than 4 years ago | (#32529448)

Hard to have it both ways...

We either catch up by dropping less immediately relevant spending areas (NASA) or keep falling behind in every area except space technology.

Re:Commence Whining (1)

Monkeedude1212 (1560403) | more than 4 years ago | (#32529498)

I blame Jack Thompson. If he had pushed just a LITTLE harder against violent video games, none of this would have happened.

And don't ask how, I hate spelling out every little detail. Figure it out.

Re:Commence Whining (1)

pluther (647209) | more than 4 years ago | (#32529592)

What killed the American space program was not any one administration (let's start with Nixon for that, and include every president since).

It was the American people themselves, with their apathy, demand to be constantly amused, and lack of imagination.

We've all heard it:
"We went to the moon, there's nothing there!"
"Why spend money in space when there are still problems on Earth that need solutions?!"

That said, though, NASA, as defunded as they are, are still doing some pretty damn awesome things - just not with manned exploration (or solar sails).

Re:Commence Whining (3, Interesting)

Nyeerrmm (940927) | more than 4 years ago | (#32530152)

It's a common theme -- but I think its a little misguided. It occurs to me that part of the problem is that NASA thinks of Apollo-level funding as the rule rather than the exception.

Done right, we could do quite a bit with the current Human Spaceflight (HSF) budget. Given that the post-Apollo budget levels are relatively consistent, it seems that current funding level is the politically sustainable level, without external influences (i.e. Cold Wars). If there had been no space race, I can't help but think that NASA would be much better at doing impressive things on the HSF side on their more modest budget.

$17B is a pretty good chunk of change, and the fact that its been increased despite an across-the-board budget cut on other non-defense discretionary spending shows that there is some significant support for it. We (the space community) tend to think of 1% GDP as the "correct" amount that should be spent on space exploration. Maybe if we get used to the idea that what we have now is closer to normal, we'll be much better off.

Re:Commence Whining (1)

D Ninja (825055) | more than 4 years ago | (#32529920)

administration's fault in 3.....2......1....blastoff.

Won't happen. We don't have any rockets for a successful launch because the U.S. Space program is dying.

Re:Commence Whining (1)

grumpyman (849537) | more than 4 years ago | (#32529998)

X Prize did push this sector from a private angle.

A Victory ... provoking thought (1)

abbynormal brain (1637419) | more than 4 years ago | (#32529356)

Very cool - given the lack of gravity. Definitely a technological win - should lead to other technological advancements. However, with all the "debris" (like micro or larger meteorites) in the solar system (not to mention the outside of our solar system), is this hope for long distance space travel actually practical? Solar sails seem really fragile.

Re:A Victory ... provoking thought (0)

Anonymous Coward | more than 4 years ago | (#32529466)

Lack of gravity? I think you'll find that there is plenty of gravity at the solar sail's location. Some of that gravity is from very far away places!

I agree it is difficult to unfurl the sail while traveling along a null spacetime geodesic in a vacuum. But the spacetime in which the geodesic lies is curved.

Deploying Pierce Brosnan in 3...2...1 (3, Funny)

Firehed (942385) | more than 4 years ago | (#32529366)

Seriously. If you're going to make a real-life attempt at a Bond plot, at least change the name of your giant solar sail.

Origami (0)

Anonymous Coward | more than 4 years ago | (#32529374)

I'm guessing all that origami expertise helped out...

pro skills (1, Insightful)

Anonymous Coward | more than 4 years ago | (#32529380)

from now on if anyone asks me who's leading space development, I'm no longer going to say 'well no one really, I guess russia has the best plans going on' to 'fuck yeah JAXA all the way'

warp drive is better (0, Flamebait)

fullgandoo (1188759) | more than 4 years ago | (#32529388)

Sailing might be ok from a recreational point of view, but unless we get warp drive, space exploration is a dead end. Speaking figuratively, that is.

Best we concentrate our energies in that direction.

Re:warp drive is better (1)

Monkeedude1212 (1560403) | more than 4 years ago | (#32529512)

Whats wrong with automated space flight with solar sails & Cryogenic sleep chambers? It's worked for Sci-fi movies.

Re:warp drive is better (1, Interesting)

Anonymous Coward | more than 4 years ago | (#32529604)

Whats wrong with automated space flight with solar sails & Cryogenic sleep chambers? It's worked for Sci-fi movies.

Brain damage?

While most of the dogs were fine, a few of the revived dogs had severe nervous and movement coordination damage, causing them to be mentally disabled, and demonstrating behavior that was deemed "zombie" like. This has been pushed further by the media which named them "zombie dogs".[3] There is concern that this technique, if used on humans could result in brain damage similar to those suffered by some of the dogs in the experiment.

http://en.wikipedia.org/wiki/Suspended_animation [wikipedia.org]

Re:warp drive is better (2, Insightful)

Nyeerrmm (940927) | more than 4 years ago | (#32530290)

Somehow I think it will be easier to get some form of suspended animation working than to develop a functioning FTL drive.

Re:warp drive is better (1)

grimJester (890090) | more than 4 years ago | (#32529614)

Yes. I was going to go to work tomorrow, but I'll stay home concentrating on warp drive.

Re:warp drive is better (1)

istartedi (132515) | more than 4 years ago | (#32529806)

Sailing is OK from a recreational point of view, but unless we get steam engines, looking for a new continent is a dead end.

What if the warp-drive experiments turn out to be, you know, kind of dangerous? The kinds of things you don't want to do on earth or even in LEO? It would be nice to have a decently fast way of getting out to, oh, say, the Heliopause where you could conduct the experiment safely. Then, if a shower of warp-speed comets don't get propelled out of the Oort Cloud and destroy Humanity, we'll know that warp is safe to operate near the home planet.

1st step in something useful for deep exploration. (3, Insightful)

hadesan (664029) | more than 4 years ago | (#32529460)

One question, how does it stop with no fuel (aka an ability to brake?)

Also, how well does the membrane hold up to minuscule debris? Is it durable for extended voyages (outer solar system, extra solar)?

What is the maximum velocity it could reach with the available solar wind prior to it ending at the heliosheath?

If they could combine it with something to scoop up stellar gas, along with something to process the gas into energy for steering and braking, you would have something useful.

And please no Uranus comments for my subject line...

Re:1st step in something useful for deep explorati (5, Informative)

SixAndFiftyThree (1020048) | more than 4 years ago | (#32529694)

How does it stop? If it accelerates tangentially to the Earth's orbit, which is still the most efficient way to get to another planet, then it can decelerate by tilting the sail the other way. In each case, the acceleration vector will have a component outwards from the Sun; the ways to cancel that include furling the sail and waiting for the Sun's gravity to do the job, using a nearby planet's gravity, aerobraking in a nearby planet's atmosphere, or lithobraking. If none of the above work, then perhaps you can't stop. A bizarre scheme that has been suggested would be to bring a second, smaller sail along and use it to collect light reflected from the main sail towards the Sun (you cut the main sail loose and let it drift ahead of you), thus providing reverse thrust until the main sail is too far away. Hard to be sure how well this would work.

Debris hitting the sail? A few pinholes will make no appreciable difference to its performance. A real sail would have to be made with some sort of "ripstop" reinforcement.

Max speed? You have a misconception here: solar sails don't use the solar wind (much), but the pressure of the Sun's light. Since e=mc2, momentum equals e/c. I don't have the formula handy, but the important factors are the thickness of the membrane (thinner is better) and how close to the Sun you start (closer is better, provided the membrane doesn't melt). In theory, solar escape speed is attainable, if you're only pulling a small payload. Significant fractions of the speed of light are not attainable.

Scooping up the gas would need one **** of a scoop!

Re:1st step in something useful for deep explorati (5, Funny)

blueg3 (192743) | more than 4 years ago | (#32530156)

Lithobraking is an ingenious term for "fuck it, we'll just crash into the planet".

Re:1st step in something useful for deep explorati (1)

SixAndFiftyThree (1020048) | more than 4 years ago | (#32530322)

I forgot to say that, almost by definition, a solar sail is not very useful when you are far from the sun: the inverse square law works against you. Neither sunlight from behind you nor starlight from in front of you provides much thrust.

Even when you are near Earth orbit, sheer scale is a big problem. To propel a small spacecraft at useful acceleration, you need a sail the size of a small town (and I live in the USA, where small towns are not very small spatially). The sail also has to be very thin in order to save mass, perhaps a hundredth the thickness of the Japanese sail, so handling and controlling it will be tricky, as Clarke points out in _The Wind From The Sun_. He envisages the sail as one or a few huge panels; I wonder if many small panels would be easier, both to use and to manufacture. Oh, there are lots of problems to solve. And then you wouldn't (notwithstanding Clarke) use the sail for anything shorter than a trip to Mars.

Somebody will probably point out that if you could focus all the sunlight that falls on a small town, you could make a hostile spacecraft very uncomfortable, though you couldn't get them any hotter than the surface of the Sun.

Re:1st step in something useful for deep explorati (1)

ArbitraryDescriptor (1257752) | more than 4 years ago | (#32530476)

You could make a hostile spacecraft very uncomfortable, though you couldn't get them any hotter than the surface of the Sun.

Not good enough! *activates trap door to shark pit*
Send in the next scientist!

Re:1st step in something useful for deep explorati (1)

toygeek (473120) | more than 4 years ago | (#32530056)

One question, how does it stop with no fuel (aka an ability to brake?)

Flip it around at the half way point. Rockets. Solar parachute? That's question 1.

Also, how well does the membrane hold up to minuscule debris? Is it durable for extended voyages (outer solar system, extra solar)?

I thought you said you had one question. It would hold up just as well as a sailboats sail would with thousands of micro tiny itsy bitsy holes in it. Just fine, thanks.

What is the maximum velocity it could reach with the available solar wind prior to it ending at the heliosheath?

Hmmm this is three questions. I'm beginning to question the validity of your inquiries based on your lack of ability to count. The real answer to your question is yet another question: "Laden or Unladed?"

If they could combine it with something to scoop up stellar gas, along with something to process the gas into energy for steering and braking, you would have something useful.

At last, a statement instead of yet another question. A stupid statement, but still an improvement.

And please no Uranus comments for my subject line...

You can't say that and not expect one.

At what point in orbit does Uranus have it's maximum radial velocity?
At its semi-latus rectum.

Re:1st step in something useful for deep explorati (1)

toygeek (473120) | more than 4 years ago | (#32530080)

Damn typos. UnladeN not unlaDED.

That'll be a demerit on my geek card.

Re:1st step in something useful for deep explorati (4, Interesting)

DowdyGoat (1830958) | more than 4 years ago | (#32530100)

NASA had a proposed "Interstellar Probe" mission that was to use a 200 meter diameter solar sail to travel 200 AU in 15 years (the heliosheath, or edge of the solar system, is about 100 AU from the Sun). It was thought they could keep contact until 400 AUs distance. Link (go to the Interstellar Probe Report link there):

http://interstellar.jpl.nasa.gov/

This mission, as well as a proposed follow up mission (I think called Interstellar Probe 2) that would have had a bigger sail, gone twice as fast, and reached around 1000 AU, were both shelved quite a while ago. (There was a single NASA page on that second mission a long time ago, but I cannot find it now.)

You could use probes like these to sort of act as galactic weather probes, testing the interstellar space that our solar system would encounter in coming decades/centuries and seeing how that "interstellar weather" affects the Sun the the Earth's environment as we pass through it.

A theoretical improvement on a solar sail would be a "light sail"--you could set up satellites with powerful laser systems orbiting the Sun and use that focused and powerful light to push sails much faster. Some folks have hypothesized reaching 10% to 30% the speed of light using techniques like this if the lasers were powerful enough and coordinated enough. Assuming success, you could possibly send an unmanned probe to Alpha Centauri in a matter of decades. In this instance, you could theoretically use a solar sail to use the solar wind/light of the Alpha Centauri system to slow down once you started nearing it (although that could potentially add more travel time).

Things like these could be a relatively fast, cheap, and safe (as compared to nuclear) way to explore our external solar system (Kuiper Belt) and nearby interstellar space (Oort Cloud), and get a good handle on how our surrounding interstellar space affects our solar system. Very interesting stuff. I hope more of it happens!

Re:1st step in something useful for deep explorati (0)

Anonymous Coward | more than 4 years ago | (#32530772)

Deep exploration... INTO URANUS!

A HAW HAW HAW HAW!!!!

Now to read the actual post...

There is drag in space (0)

Anonymous Coward | more than 4 years ago | (#32529464)

Actually, there is drag in space. Radiation from the sun will exert a force on your satellite. A solar sail uses the change in photon momentum to accelerate. However, there are second order effects due to thermal heating of your space craft.

The Yarkovsky effect is due to asymmetric emission of thermal photons in a rotating object. This causes asteroid orbits to change slowly over time.

The Poynting–Robertson effect is even more obscure, and is due to the fact that the radiation field is not isotropic in a moving bodies frame due to special relativity. This causes dust-sized particles to slowly spiral into the sun.

Finally, there is the solar wind. This can give a thrust dependent on the size of the magnetic field bubble around an object.

Better Articles! (5, Informative)

BJ_Covert_Action (1499847) | more than 4 years ago | (#32529568)

Oh for fuck's sake why do we keep linking to Inhabitat for news on space missions? The Ikaros project is, indeed, a newsworthy and exciting piece of nerd information. However, linking to a stupid environmental blog that holds informational gems like:

"Solar sails offer the best hope for deep space exploration because they eliminate the need to carry fuel." (Hint: No, they don't. They don't do that at all. You need maneuvering thrusters to align your spacecraft before deployment. You need a power source to provide electricity to power your control motors when you get too far away from the sun. Saying solar sails eliminate the need to carry fuel is like saying that a spoiler eliminates the need for a gas tank on a car because it improves gas mileage. That is a completely asinine statement.)

And:
"spacecraft — unlike airplanes — don’t have to contend with drag," (Also untrue. Depending on what orbit/space environment you are in, you may still have to contend with the drag of Earth's atmosphere. If you are deploying in LEO, this could induce a significant moment on your spacecraft. Also, thank you for pointing out the difference between aircraft and spacecraft...that was really weighing on my mind while reading about a spacecraft mission that is proof-of-concepting a new technology).

And:
"Of course, aliens aren’t the only reason to want to travel through space without carrying rocket fuel. NASA is also working with solar sails to develop ultra-efficient spacecrafts. " (Aliens and ultra-efficient spacecrafts eh? That's your high-quality independent journalism right there? Give me a break this kind of stupid babbling about a very important mission does nothing but patronize the spacecraft industry and the folks who worked on this particular bird).

Let me give you a hint Inhabitat readers, if you want to track the progress of an impressive space mission, try going to a news site that actually is focused on space. Maybe you should check out: Centauri Dreams [centauri-dreams.org] or one of JAXA's [jspec.jaxa.jp] own website's [www.jaxa.jp] regarding the hardwork and impressive design that went into designing this mission. Perhaps you should read and link to some articles that actually contain interesting, relevant, tech-centric discussions of the mission rather than your latest, retarded, three paragraph, juvenile blog whose most interesting mission detail: "....allowing it to launch the .0003-inch-thick sail," borders on painfully irrelevant.

/endnerdrage

Re:Better Articles! (1)

Oidhche (1244906) | more than 4 years ago | (#32529910)

Solar sail still eliminates the most significant part of fuel usage. And it's not something that you'd use in LEO.

life.. (1)

Jorgandar (450573) | more than 4 years ago | (#32529578)

I always thought that it would be NASA that would be the first to announce the discovery of extraterrestrial life. Now i'm thinking Japan may have that honor.

As a side note, maybe this will spark a new "space race". That would be probably be a good thing at this point.

0.0003-inches ?! (1, Insightful)

Anonymous Coward | more than 4 years ago | (#32529616)

Are you serious? I've lived in Omaha, NE nearly my entire life, and I have no IDEA how thin that actually is. USE METRIC PLZKTHX.

I don't know if they think it's patriotic or what, but AS sucks, and this is the *world wide* web.

Re:0.0003-inches ?! (1)

SharpFang (651121) | more than 4 years ago | (#32529860)

0.0003 inch = 0.00762 millimetres
This isn't anything "amazing". It's a thin gauge alufoil.

Re:0.0003-inches ?! (0)

Anonymous Coward | more than 4 years ago | (#32530142)

And the news in question is from Japan, which is a metric country anyway.

Re:0.0003-inches ?! (4, Funny)

ArbitraryDescriptor (1257752) | more than 4 years ago | (#32530540)

Seven point six two micron: Full Metal Ja- er, sorry, just 7.62 microns.

Thank you Slashdot. (2, Interesting)

CrazyJim1 (809850) | more than 4 years ago | (#32529618)

I want to hear stories like this. I want to know if Solar Sails are viable. Back in highschool I wondered about a space ship propulsion device. My theory was to make particle accelerators to get the maximum propulsion out of hydrogen atoms and fire them out the back of the craft. The problem was you could run out of hydrogen. Its not something serious, but just trying to figure out something better than rockets. The solar sail sounds like it is plausible, and I'll be excited to hear this story develop. The last thing I was excited about was the Mars Rovers. How cool were those.

what about micrometeorites (1)

tenverras (855530) | more than 4 years ago | (#32529670)

I'll admit, I wasn't able to read the article yet, but am I the only one who thought of this? Was this covered in the article? With a sail so thin, that would be an easy thing to rip

Re:what about micrometeorites (1)

SharpFang (651121) | more than 4 years ago | (#32529788)

The big surface is to catch maximum amount of light, even far from the Sun. This doesn't need high tensile strength because the forces are minimal. So a micrometeorite will make a hole and...? Nothing. The sail efficiency is reduced by a tiny fraction. The strength applied by light is not nearly high enough to let the rip propagate.

say What? (1)

FatdogHaiku (978357) | more than 4 years ago | (#32529746)

...unlike airplanes — don't have to contend with drag, so with each photon that hits the sail helps the spacecraft gather speed.

Sorry, but I have complex instruments telling me that not only will there be drag, but that it will increase as the sail recedes from it's current solar power supply. My instruments are my eyes, and they tell me that a lot of the photons arriving here are going the wrong way to propel anything away from earth. You can verify my work by going to an unlit location on a clear night and taking note of all the starlight striking your eyes... Those are the wrong way photons and the weaker our sun shines on the sail, the more those photons will come into play. That said, there is also dust and what not along with small and large fast moving objects any of which can work against or at cross direction to a sail.

There really is no free lunch...
But sometimes you can find half price margaritas.

Re:say What? (0)

blair1q (305137) | more than 4 years ago | (#32530074)

Eff stellar photons.

Space is full of other things, like gas molecules.

Luckily, most of them are being emitted by the sun, and at great speed, so this sail will use them to accelerate to their average speed and direction.

After that, any additional speed gained from bouncing photons off the sail will have to contend with drag from the particles the vessel will then be overtaking.
 
...no drag in space...amateurs...

Ah the solar sail... (1)

amightywind (691887) | more than 4 years ago | (#32529816)

The wind turbine generator of space engineering: all the hype, and just as ineffective.

Solar sails good for inner solar system (1)

syousef (465911) | more than 4 years ago | (#32529932)

Solar sails get less practical the further you go out from the sun due to the inverse square law. Somewhere between Mars and Jupiter is about the accepted limit. Certainly not useable for exploring Uranus and Neptune for instance. You can define "deep space" many ways but inner solar system isn't one of them.

Re:Solar sails good for inner solar system (1)

blair1q (305137) | more than 4 years ago | (#32530092)

They'd better define it as this side of the oort cloud, because getting through that without powered guidance is a crap-shoot.

Re:Solar sails good for inner solar system (1)

John Hasler (414242) | more than 4 years ago | (#32530630)

> They'd better define it as this side of the oort cloud, because getting
> through that without powered guidance is a crap-shoot.

The density of material in the Oort is so low that you would have to pass through it thousands of times to have an appreciable risk of hitting anything.

Re:Solar sails good for inner solar system (0)

Anonymous Coward | more than 4 years ago | (#32530432)

So accelerate until Mars/Jupiter and coast from there. It's not like rockets can accelerate for that long..

0.0003-inch-thick? (0)

Anonymous Coward | more than 4 years ago | (#32530112)

0.0003-inch-thick? Come on, this is the 21st century. Measurements in metres (or centimetres, or millimetres, or microns, etc)

Amazing how America, the country that is so on the pace, so setting the pace, is often so behind in a few key aspects.
Next you'll be telling me the speed of light in yards per second!

Space has "drag" (0)

Anonymous Coward | more than 4 years ago | (#32530380)

The entire Solar System exists because of the Sun's gravity well. I doubt a Solar Sail could overcome the Sun's gravity well and explore interstellar space but IANA Physicist

hmm (0)

Anonymous Coward | more than 4 years ago | (#32530482)

ITs not the first deployed one. Its the first usable one in space. Russia deployed one when mir was still up in space.

Anybody else notice the fake photo ? (2, Informative)

boogahboogah (310475) | more than 4 years ago | (#32530700)

Looking at the photos in the referenced article, the fourth picture, showing the solar sail fully extended with all kinds of nice wonderful colors (photo from a perpendicular angle) cannot have been shot from the same camera as the other photos. Different color saturation, different focus, different depth, different starfield luminosity, a rather idealized picture of the earth. Offhand, I think this is an artistic or fictional or Photochop representation, and, it is not labeled as such.

It's nice that the Japanese have launched a sail, but that hoked up photo just killed it for me.

Patent Time (0)

Anonymous Coward | more than 4 years ago | (#32530770)

They should patent it so the US can never explore space.

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