Tachyon 714 Light Sail

REQUIRES: Waterfall, Shabby, Resurfaced, Module Manager RECCOMENDED: Full Auto Strut, Tweak Scale, Mirror Shields <- (recommended, to keep your ship in the beam's shadow) and Kerbal Joint Reinforcement - Next, ALSO DISABLE GIMBAL ON THE PART

A rigid optical light sail for interstellar runs. The 2.8 m canister launches a seed pod 1.5 km ahead on carbon-nanotube tethers, where it unfolds into a 2 km dish held perfectly round by a carbon-composite ring truss. A laser fired from far behind your ship runs past it, kept off the hull by the ship's reflective shields, and lands on the sail, which tows the ship along on its tethers. The side facing the ship and the laser is a mosaic of some 2,800 polished silver-platinum mirror plates under a dielectric coating that reflects 99.99999% of the beam, the dish is 65 m deep, so the light bounces straight back instead of across the mirror. The beam is sized to the dish and lights every plate evenly, right out to the rim, except for the dark shadow your ship casts down its middle: the beam stops on whatever it meets first (ideally reflective shields), in your ship's exact outline. The far side is a dark carbon-nanotube backing. Every line anchors on the ring truss. Deploy only in Space.