A couple of things here. Remember this, it's important to all space travel local to the sun. Everything is in orbit including the sail. Speed is relative to both the direction of motion around the sun (in the crafts orbit) and the angle of the sun's light on the sail. Keeping the mirror parallel to the sunlight rays sustains the current orbit. Without the suns gravity and obrital motion this thing goes now where. So when the ship is ready, the sail is moved so the light from the sun hits it full on, perpendicular to forward motion of the ship. Now one would instinctively think, the ship would moving with the sail in front with the light 'pulling" it along.Quote:
Fine, lovely how does it slow down?
So the pressure of the light pushes the ship out as it goes around the sun making its obit larger and large while increasing velocity. The sails have to constantly move around the ship to keep the mirror always facing the sun and perpendicular to orbital motion. In this case always pointing to the center of orbit. It takes a long time to achieve velocity since the light is gently pushing against the sail or mirror. (hows that for light versus mass discussions?).
So how does it stop.... reverse the angle of the suns rays to indirectly counter the orbital motion. In otherwords, turning the sail opposite to the motion of the craft so that light no longer pushes against it. No that light no longer pushes the craft, it slows and when that happens it's orbit decays, meaning gets closer to the sun and your forward momentum stabilizes based on the suns gravitaional pull. You can't stop it. There is no reverse force to do so.
Imagine the mathematics.
//EDIT Rust, if this misison would have succeeded ALL of mankind would benefit. And the RKA is not the old soviet empire. It's an international organization, they launch stuff we all use. All major space Agencies have plans for one. Hell the Japanese deployed sails in 2004 but that was just a test of the technology. Cosmos 1 launched on the soviet rocket for ONE reason. To save money. Looks like the gamble failed unfortunately. This isn't the first time the project has suffered. :(
