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Japan Successfully Deploys First Solar Sail In Space
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."
I thought those crazy japanese were angels, but much to my surprise, they climbed aboard their starship and headed for the skies.
Joy! Beautiful spark of the gods!
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".
Please consider this account deleted, I just can't be bothered with the spam anymore.
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.
RIP America
July 4, 1776 - September 11, 2001
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.....
Sig Battery depleted. Reverting to safe mode.
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.
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.
L'esperienza de questa dolce vita (The experience of this sweet life) - Dante Alighieri, The Divine Comedy
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.
How are sites slashdotted when nobody reads TFAs?
I'm guessing all that origami expertise helped out...
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'
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.
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...
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.
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:
.0003-inch-thick sail," borders on painfully irrelevant.
/endnerdrage
"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 or one of JAXA's own website's 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
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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.
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.
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.
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.
God spoke to me.
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
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!
http://memory-alpha.org/wiki/Lightship Ancient grace and function.
...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.
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
The wind turbine generator of space engineering: all the hype, and just as ineffective.
an ill wind that blows no good
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.
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.
These posts express my own personal views, not those of my employer
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.
Nobodies Prefect
Tidbits for Techs Technology Blog
Damn typos. UnladeN not unlaDED.
That'll be a demerit on my geek card.
Nobodies Prefect
Tidbits for Techs Technology Blog
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!
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!
Lithobraking is an ingenious term for "fuck it, we'll just crash into the planet".
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.
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
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!
ITs not the first deployed one. Its the first usable one in space. Russia deployed one when mir was still up in space.
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.
They should patent it so the US can never explore space.
Deep exploration... INTO URANUS!
A HAW HAW HAW HAW!!!!
Now to read the actual post...
"Man, it's a good thing that planet was there, or we never would have stopped!"
http://www.youtube.com/watch?v=q4iiEj1lAhM
.
Prisencolinensinainciusol. Ol Rait!
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;
As the photons are reflected, and not just absorbed, angling the sail will give you thrust at another angle. Also, until you attain escape velocity, turning the sail to 90 deg will decelerate you to 0 eventually. As I understand it, any orbit should be attainable.
One question, how does it stop with no fuel (aka an ability to brake?)
You can use the sun's gravity to slow down, if you angle the sail so that it reduces your orbital velocity around the sun. But you probably wouldn't bother - just do a flyby of the planet you're looking at, then keep going to the next one.
Also, how well does the membrane hold up to minuscule debris? Is it durable for extended voyages (outer solar system, extra solar)?
At these velocities, minuscule debris makes tiny holes in the sail. So you lose 0.001% of your sail area. Not a big deal.
What is the maximum velocity it could reach with the available solar wind prior to it ending at the heliosheath?
You've got a misconception here. The solar wind is a stream of charged particles emitted by the sun - and solar sails don't use it. Instead, they use sunlight. So they can keep accelerating so long as the sun is brighter than the stars in front of them.
The opposite is true however.
have to contend with drag, so with each photon that hits the sail helps the spacecraft gather speed."
Only a very novice astrophysicist would ignore the fact that such a large sail is going to plow through dust too. And how many photons do you think it will take to counter the effects of even a small grain of dust, when the dust is stationary and you're clipping along at hundreds of km/sec? (or vice-versa for that matter - you could quite conceivably get hit by a spec of dust traveling at some fraction of c)
Space is a rough environment. Long-haul long-term propulsion that these sails target is going to end up like a butterfly went through a tornado too.
Slim odds you say? At least one probe we've gone planet-hopping with has been hit by a small asteroid, enough to knock its orientation off for a bit before it (thankfully) managed to correct itself. It's a big place, but when you're traveling for a number of years, at an ever growing rate of speed, the odds start catching up with you.
I work for the Department of Redundancy Department.
What, nobody's posted the obligatory xkcd reference yet?
Oh, wait--
http://www.geoffreylandis.com
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.
Turns out debris and micrometeoroid hits are almost irrelevant to sails-- they basically poke small holes in the sail, but the area removed is not enough to make a difference.
http://www.geoffreylandis.com
Next up, they will figure out how to use this to kill more whales. For research.
The question I have is, like conventional sail vehicles, is it possible for the sailcraft to go faster than the solar wind?
The ship in Poul Andersen's The Makeshift Rocket uses beer for propellant.
You can't top that. You're always on the right heading, see? Heading froth into the stars!
Solar sails, indeed. [sniff!]
I've fallen off your lawn, and I can't get up.
... from the creators of Sailor Moon.
Somebody is forgetting about one of the most successful space program ever. Worse than not learning from our mistakes is not learning from our success.
My other signature is a car
OK so IANAS (sailor...) but I thought the ability to tack against the wind was due to the interaction between the hull/rudder and the water. There's nothing to um, grab onto in space, so I can't see how you can get any impulse in any direction other than directly away from the sun?
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.
Hmmm , reminds me of the book "The Mote in GOd's eye", where there is a ship with a solar sail using the sail to focus beams of light as a defence mechanism on another ship trying to investigate it.
http://en.wikipedia.org/wiki/The_Mote_in_God's_Eye
if (!signature) { throw std::runtime_error("No sig!"); }
...allowing it to launch the 0.0003-inch-thick sail.
Can't we at least get our science stories to use the metric system? Come on!
Really, I know what I'm doing...Ohhhh, look at the shiny buttons!
No, we're an ex jock with a coke problem they are still in denial about.
Anyone else read that as "an ex-cock with a joke problem", and trying to figure out how exactly that would work?
Debris isn't really something that the engineers need to worry about. Space is very, very empty - I read something once about how if you took all the matter in the known universe and evenly distributed it throughout the volume of the known universe, it'd work out to something like one hydrogen atom per cubic kilometer. If you launch something out of orbit, the odds of it striking another object in your lifetime are virtually nil, even objects of microscopic size.
[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]
Especially the human ones...
Bow-ties are cool.
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.
That's interesting. When I had first read of the project, they were proposing radiothermal generators and electric propulsion. There's more than one way to skin a cat.
Lithobraking is an ingenious term for "fuck it, we'll just crash into the planet".
Hey, it worked for the Saiyans...
Bow-ties are cool.
It's because they are stupid and ugly.
Just Kidding! :) Please don't liberate me!
If none of the above work, then perhaps you can't stop.
From the country that brought you Toyota
(oh no, I didn't just go there...)
Ron Jeremy.
Obligatory HTML:
http://xkcd.com/123/
As an addendum to this, NASA already has, or is currently planning (I can't recall) a solar sail project involving a cubesat and (IIRC) a 40 m^2 solar sail. I'll leave the googling for that mission up to the user.
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Begins and ends with a couple solar sailing around the solar system (at the end, he wraps all four of his hairy limbs around her in an affectionate embrace.) This was some decades ago; prescient, wasn't he?
Cranky educator.
Sci-fi authors, such as Robert Forward, have discussed the theories about this for a while. If you're in a gravity well, you are in a similar position to a sailing vessel. Gravity gives one constant acceleration vector, and the sail is the other. By tuning your sail (rotating in one direction or the other), you can get lateral motion (the angular momentum is based on the relative energies of the photon impacting and the photon leaving, and the difference in direction of those two photons). To 'furl' your sail, and leave the only force acting on your vessel being gravity, you just turn your sail perpendicular to the sun.
Of course, if you aren't in a gravity well, you probably aren't getting much light, either, and the next step is to wait til you get to a new gravity well (which will probably also have light for braking).
Also, if you're going to disparage the work of sci-fi authors such as Robert Forward, check their bios first. Forward has a doctorate in physics, and consulted for NASA. Knowledgeable sci-fi- authors are some of the best people to explain leading-edge science.
Sure I'm paranoid, but am I paranoid enough?
Solar Pirates! Enough said.
Agree. However, it's doubtful we'll ever get over nationalism. The best we've come up with so far to replace it are MLB, NFL, FIFA, ...
Go Uruguay.
"Tongue tied and twisted, just an Earth bound misfit
No Crazy Eddie tag?