This speed is measured with respect to the space station the spacecraft was originally launched from. in interstellar space the gravitational pull from the stars is negligible, because the stars are extremely far. the spacecraft turns its main rocket engine on for a time period of 6.5 hours. the rocket engine provides a thrust of 896 n of force. what is the new speed of the craft after the engine is turned off? the mass of the spacecraft is 1380 kg. the rocket engine is very efficient, it uses only a very small amount of rocket fuel during this whole acceleration process without changing the mass of the craft.