Interstellar travel is when humans, robots, or spacecraft travel between stars, which are the bright points of light you see in the night sky. To make interstellar travel possible, humans or robots would need a very powerful engine to make the journey. This engine would use huge amounts of energy to create a force that pushes the spacecraft forward. It would be so powerful that the spacecraft would move faster than the speed of light, which is the fastest speed possible. Even at this speed, it would still take years or even decades for a spacecraft to travel between stars.