• Question: how do you launch a rocket?

    Asked by Riley to Hester on 4 Mar 2021.
    • Photo: Hester Baird

      Hester Baird answered on 4 Mar 2021:

      Another great question Riley! Rockets work by burning fuel (such as liquid oxygen and hydrogen) and firing out the exhaust gases from the engine through a nozzle. If you imagine letting go of a balloon filled with air, the air escapes from the balloon and the balloon flies off in the opposite direction. This is the same idea as how a rocket works.
      Rockets need huge amounts of fuel to get into space, which is why they are so big, as a lot of room is needed to store the fuel. The rocket is also split into sections, called ‘stages’. The stages each have engines and take turns to ignite and burn their fuel. Once the fuel in one stage is burnt, the stage separates from the rest of the rocket, so that the rest of the rocket doesn’t have to carry all of the weight from the empty stage. The empty stages often then re-enter and burn up in the Earths atmosphere soon afterwards.
      There are lots of videos online of rocket launches that you can watch – the SpaceX launches are very cool to watch. The exciting thing about the SpaceX Falcon 9 rocket is that rather than just dumping the first stage and letting it break up in the atmosphere, the first stage is designed to fly back down to Earth and land, so that it can be re-used!

Comments

  • Photo: gest133bye

    gest133bye commented on :

    How do you ensure that the robots are eco friendly and what materials do you use to make them because they will need to be very strong to make the planes?

  • Photo: Hester

    Hester commented on :

    Great question – unfortunately at the moment, rockets aren’t very eco-friendly. It takes a lot of fuel to put something into space, which means the rockets have to be very big and use a lot of materials, which have to be transported from around the world. In recent years, companies and space agencies have started trying to develop fuels which are eco-friendly, to replace the polluting fuels which are used currently. Other companies, such as SpaceX, have designed their rockets so that parts of them can be re-used, so that we don’t have to use as many resources to make each rocket.
    Like you say, the material used to make rockets must be very strong to withstand all of the forces involved in launching into space. But, it also needs to be light, otherwise we would need even more fuel to carry the weight of the rocket. Materials such as aluminium are used as they are both strong but light. Unfortunately, aluminium also melts at high temperatures so a heat shield has to be made to protect it from the heat during the launch process.