| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 22.1 | | KATADN::BOTTOM | | Mon Nov 12 1984 09:40 | 2 |
| Wasn't the idea originally worked out in one of Robert Heinlien's books?
I could be mistaken but I believe it was The Moon Is A Harsh Mistress.
|
| 22.2 | | CASTOR::RABAHY | | Mon Nov 12 1984 14:22 | 20 |
| RE: .1
I also recall Robert Heinlein using the idea in "The Moon Is A Harsh
Mistress". It was first suggested as "a cheap way to ship massive tonnage
to Luna" during Manuel's and the Prof's visit to earth. Dr. Chan retorts,
"... has been proposed many times and always rejected ... Something to do
with air pressure." Supposedly, "the problem can be solved ... based on
extensive analyses by computer and on our experience with catapulting".
"The length of an escape-speed catapult is determined by the acceleration."
"... of twenty gravities is about optimum. ... three hundred twenty-three
kilometers in length ... aboveground to permit shock waves to expand. The
stator would stretch nearly horizontally, rising perhaps four kilometers
in three hundred ...- almost straight, as Coriolis acceleration and other
minor variables make it a gentle curve." The story goes on in greater
detail about escape speed being a "scalar" and how to deliver payloads
to Luna. Heinlein anticipates "Weather would be a problem, too." There
is nothing explicit about magnetics being used but I think it save to assume
that would be the motive force involved.
David.
|
| 22.3 | | KATADN::BLUM | | Wed Nov 21 1984 11:08 | 13 |
|
Correct again Bottom!! "The Moon is a harsh Mistress" did outline mass driver
usage for interplanetary transport. Additionally as mentioned "would make
a great weapon" it was used as such, and when used for launch of large
metallic objects from the moon would no doubt be virtually undefensible
against even with "star wars" technology because of the large masses involved.
We just have to hope the Russians dont read Heinlein!!!
|
| 22.4 | questioning the costs | 46692::SIMMONS | | Mon Jun 25 1990 16:13 | 16 |
| RE: <<< Note 22.0 by CASTOR::RABAHY >>>
* -< The Space Rail Gun Launcher >-
*papers on a 200 m railgun for accelerating 500 kg payloads to orbital
*velocity. Cost: 1 billion dollars. It hasn't been built yet, of course,
*but I suspect it will be soon -- it would make a great weapon.
Why on earth (pardon the pun) would a lousy 200 meter long rail gun cost
1 million let alone 1 billions dollars? The ~10 ft model was put together from
scrap parts (mostly) - indicating a bit of tolerance in construction. Perhaps
the last few sections would require close tolerances and special equipment due
to the times (velocity) involved; but 1 billion dollars worth? That's 5
million per meter!
Anybody know why?
|
| 22.5 | | 5874::SCOLARO | Loren Marie - born 2/2/90 | Mon Jun 25 1990 16:38 | 8 |
| Of course the railgun itself is fairly cheap. But you must consider
what is included in the cost. If one includes the powersources, the
capacitators and the excavation of the project (isn't it going to be on
a relatively isolated mountain?), I think $1B is not unreasonable. I
don't however think we need a polar shooting railgun, this is a blatant
star wars weapon. An equatorial firing gun might be a better idea.
Tony
|
| 22.6 | at $100 a spanner - 1 il is cheap | 60608::MANSFIELD | | Thu Jun 28 1990 00:07 | 3 |
| also there is the 100 dollar spanners and 5 dollars nuts to include in
the cost of building a rail gun - not to mention the very important
highlevel all encompassing and ongoing consulting costs.
|