The orbiting shuttle is traveling at constant velocity. d- b. Once in orbit , the shuttle keeps firing its engines to stay in orbit . Astronauts on the shuttle have no forces acting on them so they float . C- d. The shuttle would have to travel at a different speed to stay in orbit if it had more mass The weight of the shuttle is a little bit less in orbit than it is on the ground . e- f. The weight of the shuttle in orbit is zero