Space Ship One, the first private manned space ship, is known for its unusual fuel. What is it?

water
148
hydrogen
588
sodium hydroxide
427
rubber
447
SpaceShipOne is an experimental air-launched rocket-powered aircraft with suborbital flight capability at speeds of up to 900 m/s using a hybrid rocket motor. Tier One uses a hybrid rocket motor supplied by SpaceDev, with solid hydroxyl-terminated polybutadiene (HTPB, or rubber) fuel and liquid nitrous oxide oxidizer. It generates 88 kN (20,000 lbf) of thrust, and can burn for about 87 s (1.45 min).
correct this question
Tschuka
reach: rather globalrocketstechnology