There are several advantages of space travel. First of all， it could provide man with new places to live in and new sources of energy. In addition， space travel helps people understand the universe better. Also space travel research does good to other research fields.

However， space travel also has some disadvantages. It uses up too much money which could be spent in other ways. Whats more， the idea of man living on other planets is unrealistic. Space travel could be dangerous， too.

In a word， though there are the disadvantages， I think space travel is a good thing. It is important for man to explore and learn about the universe.