The most recent effort was led by Friedman, whose team from the Planetary Society and from Cosmos Studios, a media company based in Ithaca, NY, actually built a solar-sail-powered spacecraft in Russia called Cosmos 1. It did not launch because of rocket failures. Now, Friedman is working on a satellite called Cosmos 2 that is similar to NASA’s design but uses inexpensive Mylar, a basic plastic material. “Mylar is easy to get, is manufactured in large quantities, and is adequate for short flights,” says Friedman. “If you want to do an interplanetary mission, which is part of NASA’s future plans, you would need something longer lasting and more ultraviolet resistant, so you would use a more exotic material.”
But the most complex part may be deploying sails after a spacecraft has been launched out of the earth’s atmosphere. Once the NASA satellite is aloft, a computer will command a heater to burn a high-strength fishing line to open four spring-hinged panels, exposing the solar sail. Fifteen seconds later, another so-called burn-wire system will cause four booms to unfold. The booms will pull the solar sail off a center spindle, unrolling it in four different quadrants, says Alhorn. The satellite will remain in low earth orbit for between five days and two weeks, during which researchers will track and analyze the satellite.
The deployment mechanism is the most interesting part of the spacecraft, says Friedman. His craft will use an inflatable deployment system to expand the sail to a diameter of 30 meters. Unlike with NanoSail-D, his plan is to control the satellite with the sail.