- SOLID PROPELLANTS - They are made by mixing a fuel , an oxidiser and a resin . After mixing , casting and curing , it solidifies into a rubbery grain . Rockets using solid propellants are simple to make but are not very efficient . Once ignited , they cannot be stopped .
- LIQUID PROPELLANTS - The rockets using liquid propellants are more energetic and more complex machines . Liquid fuel and oxidiser are stored in separate tanks and injected into the combustion chamber . They can be started or stopped any time .
- CYROGENIC ROCKETS - They are the most energetic but are most complex . They use liquid hydrogen as a fuel and liquid oxygen as an oxidiser . They are stored at very low cyrogenic temperatures .
- LAUNCH PADS - Launch pad is a place from where a rocket takes off . The first launch pad in India was very small built in Thumba in 1963 to launch the first rocket from India.
- NAVIGATION - It is the process of determining the vehicle's position , velocity and altitude (orientation) in space at any instant . For this purpose , accelerometers and gyroscopes are used .
- SPACE SHUTTLE - Unlike a rocket , a space shuttle is a craft that has been designed to be used again and again . It has huge payload bay to ferry satellites and space station - parts to orbit .
- SATELLITES - In astronomy , satellite is a body that orbits a planet . There are many artificial satellites such as communication satellites and space stations .
- SATELLITE PAYLOADS - They are the instruments located inside a satellite which serve a specific purpose .
- SPACE STATIONS - They are the large floating laboratories in orbit . It contains accomodation for the crew , laboratory space for doing work and a place for visiting spacecrafts to dock when they receive astronauts or supplies .
- DOCKING - It is the process of attaching one orbiting spacecraft to another so that men and material can be moved from one to the other . This is a critical operation because both spacecrafts would be moving at great speed .
- BINDING FORCE - The energy required by a satellite to leave it's orbit .