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

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: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: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.