Yup...plus there's the consideration of how big a tower on the "dark side"
must be to phone home...to put it on topic. ;-)
73 de Lee, AA4GA
On Mon, Jan 21, 2019 at 1:56 PM Jeff Blaine <KeepWalking188@ac0c.com> wrote:
> I guess if I had answered "billions and billions" of on-topic questions
> on the reflector of a lot of years, I would probably not sweat the
> question of strict-topic-conformance very much either. Plus the question
> is interesting but that's just me.
>
> 73/jeff/ac0c
> alpha-charlie-zero-charlie
> www.ac0c.com
>
> On 21-Jan-19 12:47 PM, Steve Lott wrote:
> > How is this relevant to the Email Reflector
> >
> > Tower Talk. ????
> >
> > Steve
> > KG5VK
> >
> > On Mon, Jan 21, 2019 at 12:45 PM jimlux <jimlux@earthlink.net> wrote:
> >
> >> On 1/21/19 9:57 AM, k7lxc--- via TowerTalk wrote:
> >>> Howdy, TowerTalkians --
> >>> The recent Chinese moon landing on the dark side has me wondering
> >> how they communicate from back there. Since we're talking line of sight
> >> frequencies with no atmospheric scattering or repeater relay
> capabilities,
> >> what's going on? Inquiring minds want to know. Tnx!
> >>
> >> Relay satellite in a halo orbit at L2. L2 is on the far side of the
> >> Moon, about 450 million km from Earth (the Moon is around 385 million km
> >> from Earth)
> >>
> >>
> >> https://en.wikipedia.org/wiki/Halo_orbit
> >>
> >> Although we talk about it as a round circular orbit in a plane, in
> >> reality the orbit is more like the edge of a Pringles potato chip. It's
> >> not planar. There's a whole family of stable orbits that look like 3D
> >> lissajous figures.
> >>
> >> For what it's worth, there's also Moon libration, and some tall
> >> mountains near the Lunar south pole.. if you land there, you're
> >> technically on the far side, but the mountain is high enough to see over
> >> the edge, helped a bit by diffraction. There's also schemes to use
> >> diffraction from within Aitken Basin for comm without a relay (perhaps
> >> in an emergency, if your relay satellite dies)
> >>
> >>
> >> _______________________________________________
> >>
> >>
> >>
> >> _______________________________________________
> >> TowerTalk mailing list
> >> TowerTalk@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/towertalk
> >>
> _______________________________________________
>
>
>
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