General Question Radio Comms Moon Base/ Sat/Earth

[garyw]

To my knowledge about FO cable, the armor that's used as "Plenum" type for indoor use would be sufficient for a burial of 3-6" of dust.

I know Plenum sheilding, it's used in cable trays in most data centers. So the only real issue (Aside from great big rocks in the way) would be the huge temperature shifts experienced on the moon.

 

[Capt_hensley]

I know Plenum sheilding, it's used in cable trays in most data centers. So the only real issue (Aside from great big rocks in the way) would be the huge temperature shifts experienced on the moon.

Right, but if you burry it, some of that temp swing can be kept in the low temp range. Deformation of glass and polymers usually occur at high temp. The low temps might cause a slight contraction but this is controlled at the union or splices segment of the overall length of the cable. These will occur often enough to offset the issue of shrinkage in a given length.

I've seen lengths of FO cable used in the artic, that had cable heaters imbedded, and hermetically sealed after NO2 purge of the armor. The heaters were tested and then shut off, so far I don't know of a case where they were really needed.

 

[statickid]

Here's a good article:

http://galido.net/blog/index.php/itblog/information-technology/2012/04/25/how-does-the-internet-connect-between-continents#.UXW7JrXqnd4

"Both methods have merit, most satellites can handle far more data these days."

All the more reason to not use cable :thumbup:

" A large impact would present a repair opportunity."

I understand the idea of getting different trades and jobs into space, but using up resources and risking valuable spacecraft and lives to do repair work will not be the goal of moon bases.

HOWEVER... besides all that, I do enjoy imagining a cable laying spacecraft or ballistic spool flying half way 'round the moon unraveling all the while.

 

[paddy2]

Just an aside regarding cable;
The first cable laid between England and France snagged on a fishermans nets and he cut through it. Was in operation for less than 24 hrs!!!

 

[MaverickSawyer]

You could easily put a base on the dark side, in fact there are some buried NASA plans for that and the idea of a SETI-like installation shielded from our radio interferences by the Moon. Communications with Earth can easily be achieved using satellite relays, it's something we use everyday without even noticing it.

And BTW the "dark side" receives exactly the same amount of sunlight than the other

Like my [ame=http://www.orbithangar.com/searchid.php?ID=6031]Larson Base[/ame]?

 

[NukeET]

I don't see why not but I was thinking more along the lines of 4 spacecraft at 90 degress apart in orbit at 800km or so. At a high altitude you've got more coverage, better line of sight to other satellites and, hopefully, less orbit changes due to Mascons.

You could easily put a base on the dark side, in fact there are some buried NASA plans for that and the idea of a SETI-like installation shielded from our radio interferences by the Moon. Communications with Earth can easily be achieved using satellite relays, it's something we use everyday without even noticing it.

And BTW the "dark side" receives exactly the same amount of sunlight than the other

I considered this problem back in December 2011. What I did was I "deployed" 3 [ame="http://www.orbithangar.com/searchid.php?ID=5517"]Deep Space Communicaton Satellites[/ame] in the same lunar orbit, roughly equatorial, at 6000 km altitude, spaced 120 degrees apart.

Rough calculations from the image above yields:

No coverage from the sats over 12% of the surface, from 79 deg to 90 deg latitude.

100% coverage over 71% of the surface, from 0 deg to 64 deg latitude.

Partial coverage over 7% of the surface.

Like my Larson Base?

Yes. Just like [ame="http://www.orbithangar.com/searchid.php?ID=5594"]Niven[/ame]. :rofl: :facepalm: