Warp technology allows ships move at warp speed. In the "Star Trek" universe, for example, the measurement of the speed that the spaceship is moving is called the warp factor. However, thrusters and impulse power propel spaceships at sub-light speed. Warp factor 1 is equal to the speed of light. The speed ranges up to warp factor 9.99. In some circumstances "Star Trek" spaceships can go faster than warp 10, although rare.