What makes space travel possible?

What is the word in greek for green planet? Why was the hot air balloon invented by the brothers? Why the stars are stick on the sky? Instrument used for taking bearings by the use of gyro compass? What the condition called when you have the feeling that whatever is happening is already seen by you? Which conditions vary on other planets? What happend to Apollo 15? What was the name of the spaceship that took the first man to the moon? What makes a rainbow? What are the answers for The 39 Clues mission ten? Can gamma rays travel through empty space? On Christmas Eve in which year did Apollo 8 become the first manned spacecraft to orbit the moon? What is the tag question of sun rises in the east? What was the average speed of the Apollo when it traveled to the Moon in three days? Streams of protons and electrons emitted from the Sun produce? What constellation represents the Great Bear? Who founded TV? Which is bigger Hellas crater or borealis basin? Where are images formed on farsighted people? How do astronauts moving around withimn the shuttle while in space?