[NNagain] Hurling rocks into Earth's gravity well

David Bray, PhD david.a.bray at gmail.com
Mon Mar 17 12:38:24 EDT 2025


100% Sebastian about the Moon Is a Harsh Mistress - and glad to see someone
else read that great book.

I'd go for burning hydrogen - not hydrogen fusion - if we can extract water
from the Moon with solar power as the initial kick-starter. We will need
the hydrogen for future rockets launched from the Moon's lower gravity to
Mars and beyond too...


On Mon, Mar 17, 2025 at 10:01 AM Sebastian Moeller via Nnagain <
nnagain at lists.bufferbloat.net> wrote:

>
>
> > On 17. Mar 2025, at 13:41, Douglas Goncz A.A.S. M.E.T. 1990 via Nnagain <
> nnagain at lists.bufferbloat.net> wrote:
> >
> > Hello Dr. David.
> >
> > The gravity at the surface of the Moon is larger than might be expected
> since the volume to radius ratio is as r squared, so that with a difference
> of 100 times that is a factor of 100x in gravity at surface we can predict
> that the rocks they'll be throwing at us we'll be falling up that is thrown
> out of the gravity wall for 1/10 the trip roughly and falling down that is
> falling into that gravity well for 9/10 of the trip causing an overall
> Factor of enormous acceleration. Offhand I would say the process would
> achieve 80% of escape velocity.
> >
> > The Australian science agency has a nice chart out for asteroid type
> objects on their website. It summarizes the relationship between the many
> many small rocks which are in our system and the very few large rocks which
> accompany them as they move at various speeds knowing only statistical
> information about how many rocks of which size and how fast they're moving
> and what energy the net result is
> >
> > They quote figures of atta joules. So once given the upward that is
> towards the Earth impetus a mere Boulder could do really significant damage
> assuming that the transit time could be controlled carefully in their was
> either accurate aiming or some type of midcourse correction to get the
> target secured.
> >
> > Trying to find my way back on topic to Net neutrality. Maybe a moon base
> could be set up with a transmitter powered by a small nuclear reactor
>
> Mmmh, radionuclear power generation seems realistic, a nuclear reactor
> less so, given that you somehow need to dispose of waste heat eventually
> and vacuum ist a good isolator... then again, for a sufficiently large moon
> base you might actually want a heating source to make up for the radiative
> heat loss.
>
> That said, you know what they say about the moon being a harsh mistress,
> eh?
>
>
> > receiving signals from Earth and retransmitting them to make the
> connections for data and voice. Compared to lofting a satellite having the
> time to construct such an item on the surface of the Moon would be
> advantageous the way it seems to me. I'm pretty sure that a satellite would
> have to be put into place in orbit with its power supply and all that and
> that's what starling does bloody bloody blah.
> >
> > By the way I'm running for president.
> > / / < GONCZ2028 > /
> >
> >
> > Cheers
> > Doug
> >
> >
> >
> >
> >
> > On Mon, Oct 7, 2024, 10:04 AM David Bray, PhD <david.a.bray at gmail.com>
> > wrote:
> >
> > ...
> > >
> > > Meanwhile China probably will land humans on the moon within the next
> four
> > > years of whomever is the next U.S. President. That may happen before
> the
> > > U.S. returns to the Moon. Either way, a "base" on the Moon by 2035
> (which
> > > is PRC's goal) even if it's robots - or humans with the risk of loss of
> > > life) raises some challenges in terms of SIGINT, GEOINT, and the
> general
> > > ability to hurl rocks into Earth's gravity well....
> > >
> >
> >
> > _______________________________________________
> > Nnagain mailing list
> > Nnagain at lists.bufferbloat.net
> > https://lists.bufferbloat.net/listinfo/nnagain
>
> _______________________________________________
> Nnagain mailing list
> Nnagain at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/nnagain
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/nnagain/attachments/20250317/c0271dd1/attachment.html>


More information about the Nnagain mailing list