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."

Comments

The whole concept

[Dunbal]

Of a solar sail is rather neat. Problem is they can never accelerate outside of our solar system. Once they hit the termination shock that's it, no more power. I wonder if someone has done the math to see what the max theoretical speed they could reach is. Of course they could probably do more if they put the sail away, slingshot around Jupiter back close to the sun and deploy the sail again once they pass the sun.

The problem however is that the "sail" only works in one direction - "away from the sun". Unlike a sailboat which can sail at an angle to the wind because it has a keel and can therefore push back against the wind, the only thing a solar sail can do is spin on its axis. It cannot change direction on its own. And the pressure you get decreases dramatically with distance from the sun, too. Still, nice to know the concept works. I'm sure practical applications will be found. This is not a method of interstellar travel, however.