B Communication Options With Future Deep Space Probes?

[sophiecentaur]

Maybe the Moon could be used as a zone plate to provide some gain and extend range - it is less noisy than the Sun.

A zone plate has only half the area of a reflector.
What advantage(s) would it have? It’s flatness would need to be as accurate as a paraboloid for the same performance.
I think the Sun would not be much use.

 

[Devin-M]

There’s a pretty detailed description from 2:55 to 14:46 of a potential solar gravitational lensing mission concept:

 

[sophiecentaur]

I think the Sun would not be much use.

A bit too sweeping a statement but when a coronagraph is used (to shadow the imagers from the Sun), there will always be a Poisson /Fresnel spot appearing in the centre of the shadow. The Sun is very bright (magnitude -26), compared with the object we'd be imaging an object of very high magnitude - say 30? in the presence of the Sun's Fresnel spot.
There's the 'gain' of the solar lens fighting the Fresnel spot 'magnitude. Maybe a suitably shaped coronagraph could have a more diffuse Fresnel spot to reduce the effect of the extraneous light. The guy in the video seemed very enthusiastic and could have been over-egging his story by several orders of magnitude. Also, the cost could of JWST proportions +.

Also, the old SNR factor comes into play again; imaging / detecting is not the same as Signalling.

 

[Motore]

The guy in the video seemed very enthusiastic and could have been over-egging his story by several orders of magnitude. Also, the cost could of JWST proportions +.

https://www.nasa.gov/directorates/s...xel_Imaging_and_Spectroscopy_of_an_Exoplanet/

 

[Devin-M]

https://www.nasa.gov/directorates/s...xel_Imaging_and_Spectroscopy_of_an_Exoplanet/

“Even in the presence of the solar corona, the SNR is high enough that in 6 months of integration time one can reconstruct the exoplanet image with ~25 km-scale surface resolution, enough to see surface features and signs of habitability.”

 

[thewowsignal]

Discussion in this thread is based on the speed of the light. This of course assumes, that the speed of the light is the fastest way to transfer information. And of course it is. Today. Yesterday nobody realized, that our civilization's communication is limited to some 300k km per second. Tomorrow the situation may change, if only our understanding of the Universe expends. I think this forum is a very good proof, that it is not going to happen soon.

 

[russ_watters]

Discussion in this thread is based on the speed of the light. This of course assumes, that the speed of the light is the fastest way to transfer information. And of course it is. Today. Yesterday nobody realized, that our civilization's communication is limited to some 300k km per second. Tomorrow the situation may change, if only our understanding of the Universe expends. I think this forum is a very good proof, that it is not going to happen soon.

How can we have a conversation about a FTL communications strategy if we don't know of a FTL process upon which to base one? That's such a weird criticism. We work with what we have/know.