Japan To Launch Solar Sail Spacecraft "Ikaros"

separsons writes "On May 18th, Japan's Aerospace Exploration Agency (JAXA) will launch Ikaros, a fuel-free spacecraft that relies completely on solar power. The spacecraft's 46-foot-wide sails are thinner than a human hair and lined with thin-film solar panels. After a rocket brings the craft to space, mission controllers on the ground will steer Ikaros by adjusting the sails' angles, ensuring optimal radiation is hitting the solar cells. If the mission proves successful, the $16M spacecraft will be the first solar sail-powered craft to enter deep space."

Comments

Icarus?

[Kelson]

It's always seemed like a bad idea to name anything after a figure whose claim to fame was that he ignored warnings against exceeding the tolerances of his vehicle, causing it to break up and kill him.

Re:Icarus?

[Gerafix]

To be fair the Japanese don't have to do metric/imperial conversions so they should be fine.

Re:Icarus?

[drinkypoo]

This whole thing is so Anime-esque I can barely stand it. Not only does it have an unfortunate name, but it's an English acronym, the name is pulled from classic Greek... Now all we need is some Shirow suits and we've got a movie.

Re:Icarus?

[srussia]

Talk about misnomer. This thing goes away from the Sun, not nearer it. Or maybe they meant post-wax-melt Icarus.

Re:Icarus?

[SputnikPanic]

Creativity points, though, for coming up with a name whose acronym gives the Greek spelling "Ikaros". I've always hated Latinized spellings or names for Greek mythological characters.

Re:Icarus?

[Lunix Nutcase]

The Latin spelling is Íkaros. So they are using the Latinized name.

Re:Icarus?

[A. B3ttik]

It's correctly spelled iKarOS and pronounced 'eye-car-oh-ess.'

Re:Icarus?

[a whoabot]

Shouldn't your name be "SputnikPanik" then?

Re:Icarus?

[a whoabot]

I highly doubt the Latins used "Ikaros" very often. Maybe when they were referring to the Greek. Ovid certainly used "Icarus": http://users.telenet.be/daedalus/Ovid/DaedIcar.htm.

Re:Icarus?

[insufflate10mg]

Are you being serious?

Re:Icarus?

[Lunix Nutcase]

The spelling "Icarus" is derived from the Etruscan spelling which was Vicare.

Re:Icarus?

[Anonymous Coward]

Isn't that Apple's new product?

Re:Icarus?

[a whoabot]

That's possible, but I would doubt it. Greek words and names were usually transliterated by the Latins with "c" for Greek kappa (and "us" for cases with Greek second-declension masculine[omicron-sigma/"os"]). And this was done even after Etruscan had gone extinct. Maybe the tradition of transliterating as such came from the Etruscans, I don't know.

Re:Icarus?

[Pharmboy]

iKarOS?

Sounds like an open source project to replace the faulty code in the oft crashing Toyotas. Using a Darwin kernel.

Re:Icarus?

[osu-neko]

It's always seemed like a bad idea to name anything after a figure whose claim to fame was that he ignored warnings against exceeding the tolerances of his vehicle, causing it to break up and kill him.

Yeah... "Daidalos" would have been a better name I would think. Or "Daedalus" if you prefer Latin spellings (which I assume you do, since you titled your post "Icarus" instead of the more accurate to the original Greek "Ikaros").

Re:Icarus?

[wienerschnizzel]

Reminds me of the shock I experienced when I found that one of the biggest brand of condoms in the US is called 'Trojan'. It can either refer to the people of Troy that got totally pwned or to the Trojan Horse from which the guys got out once they were inside...

Re:Icarus?

[radtea]

This thing goes away from the Sun, not nearer it.

Nope. Tilt the sail so there is thrust against the direction of orbital motion and the ship will fall inward toward the sun. Think of the spacecraft with the sail at 45 degrees to the radial direction ot the sun, so light is reflected along a tangent to orbit in the direction of motion.

So long as a solar sail craft is in orbit, it can either raise or lower its orbit more-or-less at will, although it is easier nearer the sun than further out. Once it is out of orbit, however, it can't ever return.

Re:Icarus?

[mdielmann]

Sounds like a reminder, too. "Fly this puppy too close to the sun and your wings will melt off and you'll turn into a rock."

Re:Icarus?

[Kiffer]

Of it can refer to the physically impenetrable Walls of Troy which were only breached through cunning trickery...
Much like when she takes all your condoms and secretly pokes holes in them through the packaging so that she can have your baby... actually that's more likely to happen the other way round but anyway.

Re:Icarus?

[HiThere]

Not sure about that. I've seen claims that a lot of the thrust of a solar sail would be due to the solar wind...which would tend to stick, and thus couldn't be tacked against.

Also, solar cells tend to absorb photons, capturing their momentum, and when they re-radiate it (at a lower frequency) the direction is random.

If this is correct, then the simple model of solar sails tacking using reflected light is at least an oversimplification, and possibly so much of an oversimplification that it doesn't properly predict the effects.

Re:Icarus?

[blumpy]

It should have been named "The Crazy Eddie Probe", Motie technology FTW!

Re:Icarus?

[Anonymous Coward]

As long as we got Mamoru Oshii and not some hack like Michel Bay I'm all in, although I do approve of American casting, I propose Milla Jovovich and Megan Fox as love interest.

Captcha: surreal

No shit.

Re:Icarus?

[Anonymous Coward]

The name "Ikaros" probably has more to do with how the Japanese localize foreign more than using the Greek spelling. It generally goes by closest sound and Icarus sounds like "ee-caw-row-sue" to the Japanese which gets written as in katanana. The katakana is written as "ikarosu" in roomanji and the "u" in the send of "su" is dropped because sometimes they don't say "u" at the end of a sentance (Which is why in spoken japanese sentences are more often ended in "dess" or "arimass" than "desu" or "arimasu").

Re:Icarus?

[FelixNZ]

If only it was built into the hull of a wrecked WWII Battleship, and it would be complete.

Re:Icarus?

[Captain Nitpick]

Not sure about that. I've seen claims that a lot of the thrust of a solar sail would be due to the solar wind...which would tend to stick, and thus couldn't be tacked against.

Those claims are wrong. The force on a solar sail due to solar radiation pressure is about a thousand times that of the solar wind.

Also, solar cells tend to absorb photons, capturing their momentum, and when they re-radiate it (at a lower frequency) the direction is random.

The solar cells are going to be absorbing a small fraction of the incoming photons. If the sail is designed properly, the rest will be reflected in a controllable direction.

If this is correct, then the simple model of solar sails tacking using reflected light is at least an oversimplification, and possibly so much of an oversimplification that it doesn't properly predict the effects.

Your assumptions are wrong, and the model is correct.

MESSENGER has used its mostly reflective solar panels to make deliberate course changes. The basic physical principle is already proven, not just in the lab, but in space. JAXA is examining the practicality of building large solar sails, not whether they will work at all.

Re:Icarus?

[Anonymous Coward]

http://fc01.deviantart.net/fs50/f/2009/335/c/4/Ikaros_Vector_by_Major_Kusinagi.png

Re:Icarus?

[ld a,b]

Well, what is the efficiency of one of those sails once space garbage has poked a few holes on it?

Without knowing much, I would think that thrust is directly proportional to surface. So minus the hole, it wouldn't be that bad in principle.

However, an impact into a hair-thin layer of tin-foil spells massive damage even for tiny objects. And the larger the sail, the larger the chances it meets some macroscopic particle.

I hope this works. This would be our best chance if not for travel per se, at least to accelerate probes into unknown space up to reasonable speed.

Re:Icarus?

[HiThere]

The efficiency isn't changed much by having a few holes punched in the sail, and meteors actually do less damage to the sail than they do to something thicker. The sail doesn't stop them, so they don't turn into heated balls of vaporized stone. Generally that hole caused by a meteor in a resistive craft is several times the size of the meteor. If it leaves a pit an inch across, the original was probably smaller than a pinhead. (This is just my rough guess...I don't know enough to calculate it...but figure the collision at, say, 10 miles/sec. ... which is a gentle collision as such go, but not unreasonable. Though if you're both in orbit, and headed the same direction it could be a LOT less, even down to inches/hour, which wouldn't put much of a hole in much of anything.)

Thin sails

[Ricken]

The spacecraft's 46-foot-wide sails are thinner than a human hair and lined with thin-film solar panels.

Won't that easily break if something even touches it? (lots of space rock going a few km/s out there, or am i totally off?)

Re:Thin sails

[d1r3lnd]

Well yeah, but you could make it 100x thicker and all that debris whizzing around would still poke holes in it. This way, it's light enough to be a.) cheap to launch and b.) actually efficient enough at harnessing the solar "wind" to move its mass.

Re:Thin sails

[natehoy]

No, I suspect that's an expectation, but if the materials are built right it'll have some rip-stop capability so it'll just make a hole. That will affect the solar sail, but not significantly until you get a lot of them.

The alternative is to make something that is heavier and less effective, which will still get punctured if a bit of debris goes through it.

After all, things in space are usually not moving very slowly in relation to each other, so anything that touches it is likely to go right through anyway, regardless of the material. I suppose with something like this, the less resistance the material puts up the less its course is going to be screwed up by a space rock.

It's also relatively unlikely (though certainly not impossible) for them to have a strike in the first place. Look at how cluttered Low Earth Orbit is with Mankind's crap, and how many active satellites have ever been knocked out of commission by our own cesspool of concentrated garbage in LEO? Two that I recall, and they hit each other. I know there have been occasional stories about impacts, but they aren't terribly common, and the chances of them dwindle off rapidly past LEO and Mankind's junkyard.

Plus, $16 million?!? for a deep space probe that requires no fuel? That's chicken feed in terms of space travel. The Japanese could probably mass-produce them for $12 million a pop or less given economies of scale, send 10 of them out in different directions, lose 8 of them to debris strikes and whatever, and STILL get better science longer than pretty much anything short of nuclear we could send up today.

Re:Thin sails

[Anonymous Coward]

Sure, but 46 feet wide is a pretty small target in the vast, empty vacuum of space. Beefing up the thickness wouldn't make it tough enough to resist impacts at the velocities that space rocks would be hitting it at anyway. And if an object with mass hits your solar sail, probably it's better for it to punch clean through and impart as little kinetic energy into your vehicle as possible, so that it doesn't get knocked off course as badly.

Re:Thin sails

[drinkypoo]

I don't know anything about this project, but one strategy for handling micrometeorite impact in large deployed thin-film solar panels (which is what these sails really are... plus "steering mechanisms"... thin-film ion drives?) is to deliver massively more sail area than is required, and to use a grid network design in the sails themselves such that power is carried through highly redundant parallel paths. If you lose a large percentage of the total sail area, you still retain the ability to operate. Nanosolar material is supposed to have this characteristic; it uses a large grid of tiny cells with redundant paths such that it still allegedly provides good voltage and current if it is partially occluded by shadow or even if there are portions missing. I'd love to find out if it's true, but I can't seem to buy any :p It can be compared in a coarse sort of way to the ability of some combat aircraft to fly while missing large portions of their wing surface or with less than the full complement of engines operational. In that case, and hopefully in this one, portions of the surface can be removed by impact without substantially perturbing the neighboring area. If the material is sufficiently resistant to deformation beyond what is desirable, and perhaps even pre-scored to break gracefully, it might be possible for a micrometeorite to pass through without significantly affecting the craft beyond a small reduction in power production, or perhaps in maneuvering ability, depending on the impact location.

Re:Thin sails

[AikonMGB]

Yes, you are right -- micrometeoroid impacts are definitely an issue that you have to deal with when you are using thin-membrane materials in space. Hopefully the engineers will design features called "rip stops" (among other names) into the sail to prevent tears from spreading through the sail. These are usually accomplished by putting a grid of perforations throughout the sail -- when a tear encounters one, the circular shape spreads the tensile stresses across the adjacent material, reducing the likelihood that the tear will propagate. This way a micrometeoroid impact won't ruin your entire sail, just the local grid element.

There are probably other methods of implementing rip stops, but I haven't read any significant literature on them. Anything bigger than a micrometeoroid, and you have bigger problems -- but in this case, a traditional satellite would have just as big a problem.

Aikon-

Re:Thin sails

[yariv]

Macroscopic objects are extremely rare (even microscopic objects are rare). Space is mostly, well, empty. The craft will cover some space, so it's expected to encounter something, but nothing big. The Sail can't be thicker, the sail area to mass ratio is what defines the efectiveness of the sail. As long as tiny holes in it won't cause it to collapse in some way or tear down, I can't see any problem.

Even if it's destroyed, it's very cheap...

Re:Thin sails

[hackingbear]

There is not much air resistance in space. A way would be to operate a radar actively detecting incoming objects and flap-down or rotate the whole sail in less than seconds?

Re:Thin sails

[SnarfQuest]

I believe that "Saran Wrap" is about this thin, but you still trust it to protect you from the mold growing on the leftover beans in your fridge. Thin doesn't mean it has to be extremely fragile.

Re:Thin sails

[yariv]

...harnessing the solar "wind" to move its mass.

I guess you didn't mean this, but just to avoid confusion. There is something called "solar wind", charged particles ejected from the sun, it has nothing to do with this sail. The sail uses light pressure, the pressure of light emitted by the sun.

Re:Thin sails

[GungaDan]

You're thinking about it wrong. They've seriously reduced the odds of side-impact damage with this clever thinner-than-hair technology. Glass half full, right?

Re:Thin sails

[JohnnyDoh]

TFA doesn't say that the sails are thinner than a human hair, just that the solar cells on the sail are...

Re:Thin sails

[Anonymous Coward]

it's good but for complex orbital mechanics, nuclear batteries are the way to go. Cassini has 3 batteries and is still doing science as I type this post. The advantage of sdolar sails is it's elegant, simple and cheap.

Re:Thin sails

[Chris Burke]

I guess you didn't mean this, but just to avoid confusion. There is something called "solar wind", charged particles ejected from the sun, it has nothing to do with this sail. The sail uses light pressure, the pressure of light emitted by the sun.

I'm pretty sure it uses both, seeing as how both light and charged particles will impart momentum to the sail when they hit it. Ihe solar light pressure is larger, so it's accurate to say it's powered by light pressure. But the solar wind does have something to do with it. :)

And obviously the photovoltaic aspect is based solely on photons. :)

Solar power in deepspace

[Anonymous Coward]

Can anyone shed some light on how solar power is viable in deep space?

(pun intended, of course)

Re:Solar power in deepspace

[GreyyGuy]

I think it is mistaken on some of the details. A solar sail works by being pushed by photons, just as a regular sail works by being pushed by the wind. A solar panel collects light and turns it into electricity. And solar panels are much thicker than a human hair. I don't doubt that it does have some solar panels but doubt it is as much as the article seems to imply since the panels are still much weightier than a solar sail needs to be.

Re:Solar power in deepspace

[drinkypoo]

A solar panel collects light and turns it into electricity. And solar panels are much thicker than a human hair.

A solar panel is anything flat and, in this context, photovoltaic. The part of a typical solar panel where the magic happens is much thinner than a human hair; it's the junction between two materials. The rest of it is just there to protect that part (and to enable its production during manufacturing, of course.) But since thin-film solar panels have been around for more than a little while, you have no excuse for not knowing about them and yet simultaneously "contributing" to this discussion. Thin-film panels are now cost-competitive with crystalline panels and are expected to eventually be much less expensive due to their reduced energy cost of manufacture. This also reduces the time to energy payback, which was around seven years with crystalline panels in the 1970s. (I have GOT to find my source on that again, must be in some old homedir someplace...) And in space, nothing non-structural has to hold up its own weight or survive winds (aside from the solar wind) so it can be as thin as will provide sufficient tensile strength. Like, say, a sheet of plastic.

A solar sail converts photon impact to momentum. Anything photons are absorbed or reflected by is a solar sail. A solar panel converts a portion of photon impact to electricity, trading photon velocity for electron velocity. These are not incompatible goals. As far as I understand, a reflective solar sail actually imparts more velocity than an absorptive one, but both work.

Re:Solar power in deepspace

[yariv]

It's in TFA. A strip on the cell is covered by cells, it is not indicated how wide it is, but it's probably pretty narrow. The sail is 7.5 micrometers thick, the cells are 25 micrometers thick. I don't know how heavy is the craft, the sail area is a bit less than 200 square meters (200 square meters minus the hole behind the main body).

Re:Solar power in deepspace

[SnarfQuest]

They have a flashlight mounted under the solar sail to provide the becessary light when they get too far from the sun. That's why they need the solar panels, to provide power to the flashlight when it's too dark for the sail to work otherwise, which also powers the solar cells.

Re:Solar power in deepspace

[Anonymous Coward]

Actually, I did it just to make people like you have a rageful fit. Thanks for the show!

(see what i did there?)

Re:Solar power in deepspace

[TheRaven64]

You're joking, but there were some serious design proposals from the '70s and earlier to use a large laser on Earth (or, ideally, near Earth) to power a spacecraft. With a large solar panel in orbit around a star driving a laser, a craft with a solar sail could continue to accelerate deep into interstellar space. The acceleration would be small, but a fraction of a g adds up when it's constant over a period of years.

Re:Solar power in deepspace

[Anonymous Coward]

Thanks for the tip, Maddox.

Re:Solar power in deepspace

[hardburn]

The xkcd blog had an entry about this a while back. it showed that in combination with a large mirror to reflect the beam several times, you get several orders of magnitude in efficiency improvement.

Re:Solar power in deepspace

[HiThere]

Both work, but they have different operating characteristics. An absorptive solar sail can only impart velocity directly away from the sun. A reflective solar sail can impart momentum at an angle, because the angle at which the photon leaves the sail also imparts momentum.

Unfortunately, both kinds are affected by the solar wind (which is usually approx. directly away from the sun, but can vary wildly when it's distorted by magnetic fields. And which can't be tacked against, unless you charge your sails sufficiently with a charge opposite to that of the incoming wind...and maybe not then. (Even if this would work, it's impractical.)

So solar sailing can be expected to be tricky, and difficult to develop. Highly worth it, though, for slow freight. (Which means automating it enough [and hardening it enough] that it doesn't need to carry a life support system, and doesn't depend on remote controllers when the solar wind and magnetic fields are kicking up a storm.)

Re:Solar power in deepspace

[Chris Burke]

Unfortunately, both kinds are affected by the solar wind (which is usually approx. directly away from the sun, but can vary wildly when it's distorted by magnetic fields. And which can't be tacked against, unless you charge your sails sufficiently with a charge opposite to that of the incoming wind...and maybe not then. (Even if this would work, it's impractical.)

Nonsense! Simply build a keel of conductive material on the spacecraft that will give the ship a preferred direction of motion through the Luminiferous Aether and you can tack 'upwind' as easily as you tack up a river!

Re:Solar power in deepspace

[BJ_Covert_Action]

Simply build a keel of conductive material on the spacecraft that will give the ship a preferred direction of motion through the Luminiferous Aether and you can tack 'upwind' as easily as you tack up a river!

Generally speaking, having a surface charge on your spacecraft is dangerous. It tends to induce errors in the internal electronics and it can also enact a magnetic moment on the spacecraft itself. Of course, if the surface charge can be modeled in advance then such effects can be accounted for, but that adds a whole new layer of complexity to the design.

Re:Solar power in deepspace

[BJ_Covert_Action]

While your discussion of thin film solar cells is true, most solar cells deployed in spacecraft are covered in doped cover glass to help protect the solar cell and extend its life (constant bombarding from various wavelengths that the cell is not manufactured to absorb decreases lifetime). That said, while thin film solar cells do exist and can be used, they will have a significantly reduced lifespan when compared to glass covered hard cells. I am sure the designers of this mission accounted for this reduced lifespan, but it should be noted that using thin film flexible cells, as opposed to glass covered cells involves a trade-off. Also, thin film cells have slightly different thermal problems that need to be dealt with. Whereas rigid cells usually have a heat rejection path designed into them, thin film cells may not. Although, this can easily be accounted for by painting the 'back' side of the solar cell the right color and using the whole damn thing as a radiator.

And just to discourage any [citation needed] stuff, please seeThe Fundamentals of Space Systems - Vincent L. Pisacane, Chapter 6: Space Power Systems. Section 6.5: Solar Cell Arrays, Subsection 6.5.1 Array Construction. ... for a general discussion of conventional solar cell architecture for space applications.

Re:Solar power in deepspace

[BJ_Covert_Action]

You know I never actually read the XKCD blog but damn, that was an interesting theory. The final death ray design phase reminds me, starkly, of Nikola Tesla....

Re:Solar power in deepspace

[Chris Burke]

You know, I'm thinking there just might be an additional problem or two with my "space keel" idea. :)

Re:Solar power in deepspace

[BJ_Covert_Action]

Possibly. =P

meh

[jt418-93]

the bjorans did this centuries ago :)
repeat

Re:meh

[CohibaVancouver]

the bjorans did this centuries ago

While I enjoyed this episode of DS9, it really wasn't clear to me how this Bajoran ship left Bajor's surface, did a de-orbit burn to start its journey into space and then did a re-entry onto Cardassia. They conveniently glossed over that piece.

Re:meh

[H0p313ss]

They call it science-FICTION for a reason. And this is Trek you're talking about.

Re:meh

[Pharmboy]

If you want overly technical scifi-babble about the technology and methods used in Star Trek, I suggest you watch Voyager instead. The stories aren't nearly as good, but they use lots of $2 words.

Re:meh

[Anonymous Coward]

$2 words???!!! I thought you were supposed to watch Voyager because of 7 of 9...

Re:meh

[DerekLyons]

And NASA first used light pressure in an interplanetary probe decades ago... Mariner 3 and Mariner 4 both used light pressure to assist in controlling attitude during the trans Martian cruise phase of their flights. (That's what the paddles on the end of the solar arrays are for.)
 
It wasn't used on later Mars missions because the craft became too large and heavy to use that method.
 
Which is the real drawback of light pressure sails - from a purely mathematical standpoint they're the most efficient propulsion system around. From a practical standpoint, their limited performance and sharp limits on payload prevent them from being useful for much.

Re:meh

[bill_mcgonigle]

$2 words???!!! I thought you were supposed to watch Voyager because of 7 of 9...

So, give him partial credit for getting '2' right, then.

Re:meh

[trytoguess]

That's true, but even in terms of Trek, you can't help but wonder why when Sisko recreated a Bajoran lightship, he had the ship launch from a space station, instead of the surface of Bajor. He was supposedly going for a almost genuine (with the exception of zero g) experience afterall.

Coolness Factor and Project Name

[decipher_saint]

Very cool project, I can't wait to see this baby in action!

That said, someone already mentioned the project vehicle name, but we all know it should have been Odin: Photon Sailer Starlight.

I suddenly feel very nerdy, much more so than normal.

Re:Coolness Factor and Project Name

[Yvan256]

I suddenly feel very nerdy, much more so than normal.

Are you suddenly speaking more fluently in Javascript or Klingon?

Re:Coolness Factor and Project Name

[decipher_saint]

I just had a conversation over IM in regex patterns about Jack Kirby, there is no hope for me now...

Where's it going?

[Anonymous Coward]

Anyone know where it's going? "Deep space" isn't much of an answer, as it includes everywhere that isn't Earth. Does it have a destination besides "away"? The article does not say...

Re:Where's it going?

[gyrogeerloose]

Anyone know where it's going? "Deep space" isn't much of an answer, as it includes everywhere that isn't Earth. Does it have a destination besides "away"? The article does not say...

As far as I can tell, it's an experiment to test the propulsion system with no other purpose. Here's a slightly better article about it.

Re:Where's it going?

[Fritz T. Coyote]

Earthquakes, Volcanoes, Climate Change, Wars, Plaques, vanishing bees and the possibility that George Lucas might make another movie? All of these are signs that the 4 Horseman are saddling up and getting ready for a ride.

So "away" is good enough for me.

Hopefully to a planet that was not colonized by the Golgafrincham B Ark.

Re:Where's it going?

[SnarfQuest]

With a name like "Ikaros", it's obviously going to have a parabolic flight path.

Re:Where's it going?

[SnarfQuest]

Ever see "Star Trek: The Movie"?

Re:Where's it going?

[kevinmenzel]

I assume you mean "Star Trek: The Motion Picture", unless you meant the 2009 movie which I have seen called "Star Trek: The Movie" a few times... but that would appear to be off topic?

Re:Where's it going?

[GungaDan]

As the term "deep" harbors pornographic connotations, I'd wager it's heading toward Uranus.

Re:Where's it going?

[c 0xFF]

As far as I can tell, it's an experiment to test the propulsion system with no other purpose. Here's a slightly better article about it.

Then what a waste. Seriously.

One thing I admire about NASA is its ability to pull in secondary and tertiary missions. If you're just going to send it flying, at least put on a simple camera and send it somewhere useful. Fly by the outer planets, or visit the asteroid belt, or try for a comet or KBO. Surely there's at least one object in the solar system within range for simple observations.

Re:Where's it going?

[gyrogeerloose]

If you're just going to send it flying, at least put on a simple camera and send it somewhere useful. Fly by the outer planets, or visit the asteroid belt, or try for a comet or KBO. Surely there's at least one object in the solar system within range for simple observations.

Yeah, I know what you mean, but where is the power to run the experiment going to come from? They didn't include an RTG on the spacecraft and a few square feet of solar panels is aren't going to provide enough power for long. All the articles I can find are short on detail but it appears as if the thing is no more than the minimum amount of hardware necessary to run a test of the solar sail. Even its launch was piggybacked with another spacecraft.

Re:Where's it going?

[Pikoro]

[points] -> That way.

What could possibly go wrong?

[armyofone]

"The craft's 46-foot sails come equipped with solar cells thinner than a human hair. When solar particles hit the cells, they generate power for Ikaros. Mission controllers on the ground will steer the craft by adjusting the sails' angles, ensuring optimal amounts of radiation are reaching the solar cells."

What could possibly go wrong?

Re:What could possibly go wrong?

[RevWaldo]

Possible outcomes:

1) try > succeed > learn

2) try > fail > learn

Given the amazing low price tag for the mission, both are good outcomes.

Re:What could possibly go wrong?

[Sir_Lewk]

Uhhhh, not much? If the craft fails then they are only out a few million, same thing that happens when any other spacecraft fails (except they are usually far more expensive).

Generally we try to reserve the "What could possibly go wrong" meme for things that reek of a bad idea, like making walking titanium skeletal robots, giving them machine-guns and Austrian accents, then turning over control of them to google. Space sails are a pretty simple and much discussed idea, and lack any particularly bad failure modes.

Re:What could possibly go wrong?

[HiThere]

Well...

If they're large enough you could use them to burn down cities and wipe out food supplies, but I guess we already have pretty effective ways of doing that.

Preparation

[gmuslera]

In the case it or one of its successors are launched to another solar system, i suggest that it carry scaled down versions of the ninja turtles, so if some come back to this mote in god's eye will never figure how we really are.

IKONOS..

[Anonymous Coward]

They just couldn't pronounce IKONOS

This has to be a bad joke...

[ProppaT]

You know the only reason the Japanese named it Ikaros instead of Icarus is so they could finally laugh at us mispronouncing something for once. Wow, the Abbot and Costello routine around this one almost writes itself....

Re:This has to be a bad joke...

[renrutal]

You would be right if they were aiming for the name in english. Íkaros is his name in latin.

At least its easier to write than greek: , which Slashdot can't even parse...

Re:This has to be a bad joke...

[Opyros]

Actually, "Icarus" (or rather "ICARVS") is the Latin form of his name, see e.g. Ovid's Metamorphoses . "Ikaros" is a direct transliteration of the original Greek form.

Sunshine...

[Anonymous Coward]

Wait...isn't there a movie about this...where a Japanese captain of a space ship named Ikarus ends up burning to a crisp as the ship approaches the sun?

Sadly, the linked article...

[pongo000]

...is so infested with bad JS I can't view the actual text in FF. Anyone have a working link?

A Mote in Gods Eye

[monkaru]

This reminds me of the novel "A Mote in Gods Eye" by Larry Niven and Jerry Pournelle. Who knows, maybe one day we'll be that "mote". http://en.wikipedia.org/wiki/The_Mote_in_God's_Eye

Re:A Mote in Gods Eye

[bFusion]

Man I hope not, those Moties were pretty terrifying.

Fantastic book though, I should read that one again.

$16M seem cheap?

[A. B3ttik]

I would like to see the verification on all of these statistics from another source. I am hesitant to believe this because it costs about $450 MILLION just to launch a space shuttle once. If the article has more basis than mere rumor, this price tag cannot possibly include deployment. Maybe it's $16M on materials alone? Maybe salaries alone? Consider also that they plan on spending around $2B over the course of ten years, which is just $.3B more than the pricetag on a single Space Shuttle. I will be surprised if this actually comes to pass.

Then again, they ARE Japanese. They probably already have a nanobot-built space elevator on top of the Tokyo Arcology.

Re:$16M seem cheap?

[cowscows]

I'm thinking that $16M does seem rather low, but I would expect the cost to be significantly less than a shuttle launch. The shuttle is pretty big, very heavy, and also has to carry and keep alive a bunch of people through launch, orbit, and return. This solar sail is designed for a much simpler set of tasks, and likely weighs in at a small fraction of what a shuttle orbiter does.

Re:$16M seem cheap?

[Imrik]

As the article implies, the $16M price tag is the price of the ship, not including the price of using it. Given that it's being sent up as a secondary launch for another mission the price of using it should be pretty low.

Re:$16M seem cheap?

[confused one]

Building the Ikaros alone probably accounts for the $16M. I think JAXA HIIA launch cost is probably on the order of $100M (U.S.) although that cost could be shared as they can launch multiple satellites at a time (bounded by space and weight constraints).

Up The Irons!

[Anonymous Coward]

They should have Iron Maiden play at the initial launch.

Tachyon Eddy

[wisnoskij]

Now all we have to do is find a tachyon eddy and we could be on Cardasia in no time.

Melt

[Anonymous Coward]

The real question is, wont they melt when they get up too high?

Re:Melt

[kdemetter]

Well , they will certainly melt if they get too close to the sun , that's for sure.

Why not call it...

[Anonymous Coward]

Why not name it after Daedalus instead. The Japanese are ruining the sense of destiny we associate with the name Icarus, unless the rocket fails to reach escape velocity.

Is it just me or is Japan's space program awesome

[BetterSense]

I haven't really payed much attention to Japan's space program in the past...heck I didn't really know they had a space program. But they recently landed a probe on an asteroid, and returned it to earth with asteroid rocks. When I read that it was like, "Oh. Japan has a space program, and they actually did something scientifically interesting". It seems like space programs are all about bitching about government funding and endlessly redesigning ancient rocket designs and speculating about manned missions to other planets, and meanwhile Japan went to an asteroid and brought back rocks. So when they say they are going to make this solar sail thing, I believe that they are going to make this solar sail thing.

Gloster Meteor! (was: Re:Icarus?)

[ErkDemon]

Still, it's not as bad as when Gloster produced Britain's first jet fighter, and decided to call it the "Meteor".

As in, "Those things that, every time you see one, it always seems to be falling out of the sky in a screaming ball of flame before smashing into the ground".

Inhabitat Articles

[BJ_Covert_Action]

This is a bit offtopic but it's becoming more prevalent and frustrating on slashdot. Is there a chance we could stop posting so many Inhabitat stories to slashdot? More often than not they aren't even stories so much as single paragraph posts that say, "Look at this really cool technology! Isn't it cool and, more importantly green?" They never even bother to go into a decent amount of technical detail about the really cool technology. Hell, in this case, the wikipedia article has more relevant technical details than the Inhabitat article. It's not like we put a post to slashdot every time a new wikipedia article on technology opens up. For that matter, if we are just posting links to websites about really cool technology, we could easily go digging through websites that are dedicated to the particular technology to get the really juicy bits of interest. For instance, when talking about Ikaros, why don't we try looking it up on one of the dozens of websites dedicated to cataloging spacecraft? Well that's not news is it? That's just cataloging interesting technology which, as far as I can tell, is all Inhabitat does.

I guess what I am getting at is that just because Inhabitat stumbled upon something cool they didn't know existed, it doesn't mean there is any news regarding that particular item. Now, if Ikaros launched recently, or if it's mission was underway, or if it was experiencing some technical difficulties, that would be something. The fact that the mission exists in the first place is neither a recent development nor particularly newsworthy. It seems like the firehose is getting clogged with Inhabitat submissions and frankly its starting to seem like slashvertising for the blog.

Mankind's Junkyard

[Strange Ranger]

"Maybe in order to understand Mankind, we have to look at the word
itself: "Mankind". Basically, it's made up of two separate words -
"mank" and "ind". What do these words mean ? It's a mystery, and that's
why so is mankind."

-Jack Handy

Re:Mankind's Junkyard

[dakameleon]

Basically, it's made up of two separate words -

"mank" and "ind". What do these words mean ? It's a mystery...

Well, I don't know about "ind", but for mank:

mank

      1. (British, slang) disgusting, repulsive
       

When he eats, he never closes his mouth. It's so mank

How fast does it go?

[northernfrights]

I wonder how much speed it picks up after a few months/years? I think I remember reading that these things go quite fast eventually, due to the perpetual acceleration. Speaking of which, is there any way to slow it down?

Minmatar Frigate, anyone?

[Orbijx]

I'm surprised that there hasn't been a single EVE reference to this project yet.

Soon as I saw this project, I thought, "It's like they're developing a Minmatar frigate of some sort!"

With that in mind, I genuinely hope that this project exceeds expectations, and that we may see more projects like this in our near future. Good luck and best wishes.

Re:Is it just me or is Japan's space program aweso

[Anonymous Coward]

That's an excellent attitude and it (unsurprisingly) mirrors my own thoughts on Japan's space program. They're doing *cool stuff* that can spark the imagination. And they're doing it for amazingly reasonable sums of money.

It's not very fast

[Anonymous Coward]

The amount of propulsion from a lightsail is very small: 1kWm^-2 / c = 3 microPascals.
The only quoted mass I can find is 315kg, and I can't tell if that includes the liftoff stages.
If a 200m^2 sail really needs to push the whole 315kg, it's not going anywhere. (65m/s after a year!)
To pick up useful amounts of speed in less than a decade, it will have to be lighter, by a factor of 10-100.

Rather irrelevant...

[denzacar]

The point was that Bajorans have made it to Cardassia long before either species had developed warp technology.
Kinda like as if Ikaros would suddenly made it to Alpha Centauri in a matter of minutes. And found Na'vi there.

Whether Bajorans used chemical rockets, space elevators or giant catapults to get their solar-sail ships to space in the first place is rather irrelevant compared to that.

Finally, an environmentally friendly spacecraft

[Anonymous Coward]

100% powered by the Sun? Awesome. I hope this starts a new trend of spacecraft that are environmentally friendly. Imagine how much we could slow global warming if we cut the carbon emissions from every spacecraft we sent out.

Space dust?

[junglebeast]

You know space isn't completely empty. There are particles floating around there. How is a solar sail thinner than a human hair going to hold up to being bombarded with small particles, especially if they fly it at any decent velocity?

Re:Space dust?

[northernfrights]

I'm guessing the answer is that it doesn't get 'bombarded', perhaps the occasional microscopic hole won't be problematic. At any rate, how is this any worse than any other craft we launch into space? The particles are going fast enough that the thickness of the material doesn't matter much, it's going to punch through.

Those Japanese sure can...

[Anonymous Coward]

...make the biggest gawd-damn miniature shit around!

Mythology FAIL (Re:Icarus?)

[wowbagger]

Daedalus flew too close to the sun, melted his wings, and died.

His father, Icarus, the creator of the wings, then landed and never flew again in mourning over his son, who's death Icarus was in part responsible for.

Re:Mythology FAIL (Re:Icarus?)

[the_humeister]

Daedalus flew too close to the sun, melted his wings, and died.

His father, Icarus, the creator of the wings, then landed and never flew again in mourning over his son, who's death Icarus was in part responsible for.

Mythology fail! Icarus flew too high and fell.

Re:Mythology FAIL (Re:Icarus?)

[Zenaku]

-1 Exactly Backwards.

http://lmgtfy.com/?q=daedalus+and+icarus/

Re:Mythology FAIL (Re:Icarus?)

[Anonymous Coward]

mythic troll is old...

Re:Mythology FAIL (Re:Icarus?)

[Foobar of Borg]

Daedalus flew too close to the sun, melted his wings, and died.

His father, Icarus, the creator of the wings, then landed and never flew again in mourning over his son, who's death Icarus was in part responsible for.

Was that before or after Laius killed Oedipus and married Jocasta?

man who says impossible shouldn't interrupt man wh

[Thud457]

That's because their purpose is space exploration, rather than the dispensing of pork to key Congressional districts like NASA.

Two words

[MK_CSGuy]

Name FAIL

That name!

[kuzb]

Calling it the Ikaros is sort of like calling a new ship you build "The Titanic". It doesn't do a lot to inspire confidence.

Here's to hoping to works for them though, it's definitely ambitious and way cool.

deep space

[confused one]

spacecraft will be the first solar sail-powered craft to enter deep space

Depends on your definition of "deep space". I understood that to mean outside the solar system. A quick googling shows two definitions: 1. interstellar 2. interplanetary and beyond. So definitely not clear. In any case, it's somewhat moot since there's never been any solar sail-powered craft, ever, that succeeded in deploying its sail. Even in Earth orbit.

Good luck!

[NCG_Mike]

Really... I hope it works out well.

Lobster brains?

[Anonymous Coward]

Has anyone checked the module for stowaway Lobster brains?

+1 Informative

[Anonymous Coward]

A beautifully pedantic post which ignores not only the article, but the spirit of the conversation. Well done sir!

no brakes

[Anonymous Coward]

The only thing that concerns me about the interplanetary solar sail powered spacecraft is you have to very accurately aim at a far away star if you want to slow down.

Re:Is it just me or is Japan's space program aweso

[Anonymous Coward]

Japan's space program is merely to distract us from the giant robot army they are developing.

Re:Is it just me or is Japan's space program aweso

[BJ_Covert_Action]

But they recently landed a probe on an asteroid, and returned it to earth with asteroid rocks

Well, not exactly. They sent a spacecraft to an asteroid to hover above the asteroid, shoot a pellet at it, scoop up some debris, and come back. Instead, part of the system failed. The spacecraft landed to preserve its health while possible fixes were discussed. The landing caused the pellet shooting system to fail so no asteroid debris was collected for sure. The Japanese decided there was still some chance that something, somehow, ended up in the collection bin. They uploaded some patches to the spacecraft. The spacecraft started its journey home when more propulsion systems failed. The Japanese hacked components from three different thrusters (of four) to get one bastardized thruster working. And now it is about two months from touching down if it manages to perform all of its appropriate maneuvers with its single, bastardized thruster.

Now, that's not to trivialize the Hayabusa mission. Frankly I think it is one of the coolest space missions flying right now and I am hoping it does, indeed, have asteroid material within it. However, saying it has asteroid rocks on board is simply not true.

Also, yes, JAXA is kicking ass and taking names. It is amazing what a country of intelligent humans can do when you forbid them from developing weapons for half of a century. See also, the Japanese robotics industry. That said, JAXA is making a big push to have a presence in space right now because they see Space as one developing industry that will take off in the next few decades (as do many others). They also see robotics to be in this position hence their great achievements in that field. So, in conclusion, Japan is rocking hard in tech development because they are trying to ride the next PC wave if you will. Any entrepreneurs and investors in any other country would do well to take notes on this trend.

That said, they aren't the only ones doing really cool science right now. NASA also has solar sail and ion thruster proof of concept missions on the table (in fact, some of them use satellite buses that are only 10 cm x 10 cm x 30 cm), NASA is still developing the MSL, the Indians have a very successful lunar orbiter that detected water in lunar regolith, Armadillo Aerospace is still pioneering ahead with its work on hovering rockets for lunar landings, and the Chinese are starting to mature their launch capabilities giving them a significant presence orbit. In other words, it's not just Japan that's exciting, its everyone. But yes, I do agree that JAXA is kicking ass lately.

Re:Is it just me or is Japan's space program aweso

[Anonymous Coward]

The Japanese space program is even more awesome than you knew. They actually have a space elevator project. They don't invest heavily in it (they think they can do it with ~8 G$), but they definitely work on it. They have great engineers (famous for it) and that's exactly what you need for such project. The principles behind solar sails or the space elevator are well understood, it's only a matter of engineering problems and some material science. They try to solve the engineering problems now, so once will have the materials (matter of years, few decades at most) they can start deploying...

Re:Is it just me or is Japan's space program aweso

[Anonymous Coward]

The asteroid probe, Hayabusa, hasn't quite made it back yet--the re-entry is scheduled for June. And the probe is literally falling apart--it's running on one ion engine (which is actually two half-broken engines linked together in mid-flight), no thruster fuel, and one reaction wheel; even the main memory is starting to be corrupted. The fact that it's still alive and has a realistic chance of delivering asteroid sample back to Earth is nothing short of a miracle, and while the JAXA engineers deserve a lot of praise, the shortsighted Japanese politicians, who haven't even authorized budget for Hayabusa 2, do not deserve any. I hope for science's sake that NASA is never forced into operating on a shoestring budget like JAXA's program....

Re:man who says impossible shouldn't interrupt man

[Rhinobird]

I'm sure there's plenty of pork. But this being Japan, it's raw and wrapped in seaweed with vinegar rice.

Re:Is it just me or is Japan's space program aweso

[Anonymous Coward]

Also Hinode (Solar B).

Pantsu?

[Anonymous Coward]

I was half expecting a squadron of flying panties...

This is japan after all?