LCD 'Engine' For Spacecraft Attitude Control

Bruce Perens writes "Japan's IKAROS satellite, which earlier performed the first successful demonstration of a solar sail, has broken more new ground. Liquid-crystal displays — yes, like in your video monitor — were fabricated into strips on the edges of the solar sail. By energizing some of the LCDs and changing the reflective characteristics of parts of the sail from specular to diffuse, JAXA scientists successfully generated attitude control torque in the sail, changing the spacecraft's orientation."

I have a CRT

[Anonymous Coward]

"yes, like in your video monitor"
No, I have an old fashioned Sony CRT monitor.

Re:Useful for stationkeeping?

[gstoddart]

Just wondering if it produces enough torque to control a real spacecraft.

What, exactly, do you mean by a 'real spacecraft'.

IKAROS is real. It's in space. It's actually using this.

Have I missed something? From what I can tell, this is about as real as you can get.

Re:I have a CRT

[Culture20]

Number One, Make it so.

Riker had to be the worst first officer in Star Fleet; Picard had to keep telling him when to go pee.

Re:Next up...

[osu-neko]

This is essentially true. However, it's probably simpler to note that solar sails are pushed along by light pressure, generated by the photons hitting the sail. The photons, being light, tend to travel at light speed (by definition). There are other considerations besides the lack of a keel for why a spacecraft won't be exceeding that speed.

Re:Next up...

[electrostatic]

"...faster than the wind, DIRECTLY DOWNWIND."

There's a bit of a cheat in the directly downwind assertion.

While it true that the vehicle is going directly downwind, its propeller is rotating in the wind. This causes to blade to experience the wind at an angle, just like a sailboat tacking into the wind. And in addition to the "lift" force perpendicular to the blade forcing the car forward, its rotation is used to drive the wheels.

Very clever nonetheless.