Across
- 3. / A vehicle intended to be launched into space.
- 4. / The force between two contacting surfaces that slide or tend to slide over each other. It always opposes the motion or the tendency of motion of an object.
- 6. / A substance, as oil or grease, for lessening friction
- 9. / A person trained to pilot, navigate, or participate as a crew member of a spacecraft.
Down
- 1. / A device which makes use of air resistance to slow down the motion of an object.
- 2. / Made by humans; produced rather than natural.
- 5. / A tube-like transporting device which moves by ejecting gases in the direction opposite to its motion.
- 7. / Emission of energy in the form of rays or waves.
- 8. / The force which pulls an object towards the centre of the Earth by the Earth.