A spaceplane is like a special kind of airplane that can fly very high up in the sky and even go to space! It has special parts, like engines and wings, that help it go really fast and really high.
When it takes off, it goes up like a regular airplane but as it gets higher, it starts to go faster and faster until it goes so fast that it can break through the earth's atmosphere and go into space!
Once it's in space, the spaceplane can do all sorts of things like go around the Earth, do experiments, and even deliver things to different places in space.
When it's time to come back to Earth, the spaceplane turns around and heads back down. It slows down as it gets closer to the ground and then lands like a regular airplane at a special airport.
So, a spaceplane is like a super special airplane that can go to space and come back down again!