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."

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:Icarus?

[Lunix Nutcase]

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

Re:Icarus?

[a whoabot]

Shouldn't your name be "SputnikPanik" then?

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: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:meh

[H0p313ss]

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

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 [wikipedia.org] 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.

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: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?