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If a hypothetical space colony were on the other side of the sun from earth, would it be possible for them to communicate?

If so how would this work?

The only thing I can think of would be bouncing waves off other bodies orbiting the sun that share a line of sight. Is this possible? Has it been done?

brysgo
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2 Answers2

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First of all, the sun is almost never directly in the path of transmission. What actually happens is that the sun is in the beam path of the antennas. As the Sun puts out a lot of radio noise, it interferes with the signals. So, how can one combat this? There's 3 ways that I can think of:

  1. Reduce the beam width. Use a laser instead of a radio waves, or a larger dish, or a higher frequency. All will reduce the effective beam width. This reduces the amount of interference from the Sun.
  2. Reduce the bandwidth. This is commonly done with Mars missions near opposition. Just don't send as much data. This works surprisingly well, although you usually don't get science back.
  3. Set up a relay satellite of some kind. The best would be to set one up at L4 or L5 for the Earth Sun point. Any point will either be in view of this point, or the Earth. This also helps in ranging information to find the exact location of satellites, it could be a handy thing.
PearsonArtPhoto
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  • Good point, I was thinking how large the sun was and not how far all the communicating parties are from it. I still think option three is the most robust. I could imagine orbiting a gas giant and needing a relay to communicate. – brysgo Jun 08 '14 at 00:59
  • So at the local environment of a planet, you might need more, but that'd have to be done individually. It could take quite a few actually, the needs would need to be carefully thought out. But with 1 satellite, you can guarantee coverage within the solar system, provided you can escape your local effects, so... – PearsonArtPhoto Jun 08 '14 at 01:33
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    I think #2 is a very realistic approach. Basically, accept your environment and work around it. Although I have to admit, historically, we're pretty terrible at that as a species. – corsiKa Jun 08 '14 at 02:11
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A constellation of 3 satellites in polar orbit around the sun should give sufficient coverage as repeaters to the other side of the solar system. This would probably be the most reliable method of maintaining communication.

EDIT to include comment from TidalWave:

You could instead position one (or more) satellites at the Sun-Earth Lagrangian points SEL4 or SEL5 for the same benefit.

ThePlanMan
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  • Wow, I can't believe I didn't think of satellite relays orbiting the sun. Is that what they are currently being used for, or would they need to be repurposed? – brysgo Jun 08 '14 at 00:17
  • @brysgo I don't know of any satellites currently being used for this purpose, but technologically speaking it's feasible. – ThePlanMan Jun 08 '14 at 09:22
  • Broadly, no. A sun will either block, or pose massive interference to any electro-magnetic communication.

    What medium were you hoping to use, that might get round that?

     – Robbie Goodwin Jan 11 '22 at 21:58