A '''rocket''' is an object which gains thrust by expelling a hot gas out of its back. There are two major types of rockets: solid fuel and liquid fuel. Rockets have been used since ancient times and more recently were used for [[space travel]] since many rockets are able to carry their own [[oxygen]]. | A '''rocket''' is an object which gains thrust by expelling a hot gas out of its back. There are two major types of rockets: solid fuel and liquid fuel. Rockets have been used since ancient times and more recently were used for [[space travel]] since many rockets are able to carry their own [[oxygen]]. |