• Question: just a theory of mine, however would it be possible to use light communication is some way to give probes orders, hence speeding up the process as it could be faster

    Asked by TheNerdyWeeb to Andrew, Hina, Ian, Kathryn, Leah-Nani, Xu on 12 Jun 2018.
    • Photo: Leah-Nani Alconcel

      Leah-Nani Alconcel answered on 12 Jun 2018:

      Radio wave communications to space probes already travel at the speed of light.

    • Photo: Hina Khan

      Hina Khan answered on 12 Jun 2018:

      I work with teams in photonics and laser to look at sending light signals between satellite for inter-satellite communication and also to send data. This is something we are researching and is very much possible. You can send signals as packets of light, called photons, to send data and information between satellite to increase communication in a satellite constellation. It is very exciting to see the being developed and put into practise.

    • Photo: Kathryn Burrows

      Kathryn Burrows answered on 12 Jun 2018:

      Keep coming up with theories, especially like that! My work on the ACES project was to model just how radio waves between the ISS and the Earth were affected by things like the atmosphere. Radio waves were used to send time stamps with the clock signal back down to Earth.

    • Photo: Andrew Margetts-Kelly

      Andrew Margetts-Kelly answered on 12 Jun 2018:

      We use light already; but these days we mostly use microwave frequencies of light (radio waves). So in terms of the time it takes to for the message to travel it is already as fast as it can go (i.e. at the speed of light).
      —
      Keep those theories coming though, it shows you are thinking and exploring the possibilities.
      —
      and… On the topic of your theory though you are absolutely spot on. You deserve a merit or something.
      Laser comms between spacecraft is an active area of research. The reason it is not common place at the moment is because it is actually very difficult to point the laser in the right direction (mechanically difficult and also relativity messes up your timings). Once this is solved lasers will allow us to transfer more data, faster and with less power. It is a holy grail of data downlinks for satellites and is very important so that spacecraft can keep generating more and more data.

    • Photo: Ian Jones

      Ian Jones answered on 12 Jun 2018:

      The speed of light in space is faster than the speed of light travelling through some medium (such as water, for example). The “refractive index” is a measure of how much it slows down.

      The refractive index of a fibre optic cable is 1.44, so the speed of light is 1.44x slower in fibre than in space. Therefore, if you had a series of low orbiting satellites, you could potentially speed up the Internet by sending the light signals through space rather than along fibres!

      So…. good theory!

Comments