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Thinking out loud: You need an ingenious design that allows the laser sail to double as a directional antenna. And you pick a frequency which is not radiated by
by guelo 11y ago
Thinking out loud: You need an ingenious design that allows the laser sail to double as a directional antenna. And you pick a frequency which is not radiated by many other objects in space so it's easier to pick up the dim signal. And then you build a ginormous radio telescope bigger than any ever built before. Luckily you have a decade or two to build the telescope after the probes are launched.
- Jtsummers 11y agoAnd/or establish a chain of these spanning the distance between here and Alpha Centauri. They don't need to actually stop, but if enough are traveling at lower speeds or depart sufficiently late in the program then they'll be in position to act as repeaters. Possibly larger probes (which would travel slower) that have more power available for reception and retransmission.
- paulmd 11y agoPlanar directional antennas have been done before, in EHF-type frequencies (most research has focused on 2.4 GHz and 5 GHz for obvious reasons). Lower-frequency signals would probably be harder. No idea what a nice clear frequency might be though, particularly out in the interstellar medium. Depending on what maneuvering profile these things will have, it might be desirable to have a "semi-phased" design that can be steered to a limited degree without physically moving the spacecraft. And, it also goes without saying that this antenna probably needs to be flexible or at least articulated in order to deploy. NASA has previously done some really interesting antenna designs with genetic algorithms. You just need to figure out what the goodness function here should be. https://ti.arc.nasa.gov/m/pub-archive/1244h/1244%20(Hornby).pdf https://ti.arc.nasa.gov/m/pub-archive/1244h/1244%20(Hornby)....