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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."
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.
the bjorans did this centuries ago :)
repeat
-.no
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.
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.
"This post contains words, known to the State of California to cause thought. Wash brain thoroughly after reading."
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.
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-
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.
This ain't rocket surgery.
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.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
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.
Who would win this election: Andrew Weiner vs Andrew Weiner's weiner.
Possible outcomes:
1) try > succeed > learn
2) try > fail > learn
Given the amazing low price tag for the mission, both are good outcomes.
Prisencolinensinainciusol. Ol Rait!
...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.
Now all we have to do is find a tachyon eddy and we could be on Cardasia in no time.
Troll is not a replacement for I disagree.
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.
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.
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