"Paul Preuss - Venus Prime 2 - Maelstrom" - читать интересную книгу автора (Preuss Paul)

curving up Mount Popocatepetl, so that the projectile would be at an altitude of more than five kilometers
when it reached the required escape velocity of 11.2 kilometers per second. In this way, air-resistance losses
would be minimized, but a small amount of rocket power would be available for any necessary corrections.

WellтАУit makes more sense than VerneтАЩs Moongun, but not by much. Even with 200 kilometers of launch
track, the unfortunate passengers would have to withstand 30 gees for more than half a minute. And the cost
of the magnets, power stations, transmission lines, etc. would run into billions; rockets would be cheaper, as
well as far more practical.

I am sure that тАЬAkkad PseudomanтАЭ would have been surprisedтАУand delightedтАУto know that men first circled
the Moon aboard Apollo 8 at Christmas 1969; the date he gave in his novel was June 28, 1961. Incidentally,
he was not the first to propose this scheme: the Winter, 1930 Science Wonder Quarterly has a beautiful Frank
R. Paul illustration of a line of giant electromagnets, shooting a spaceship up a mountainside. It could very
well have served as the frontispiece of Zero to Eighty.

A few years after reading Dr. NorthrupтАЩs book (which is still full of interesting ideas, including a remarkably
sympatheticтАУespecially for the timeтАУtreatment of Russian technology) it occurred to me that he had made one
slight mistake. He had put his electric launcher on the wrong world; it made no sense on EarthтАУbut was ideal
for the Moon.

First: thereтАЩs no atmosphere to heat up the vehicle or destroy its momentum, so the whole launching track can
be laid out horizontally. Once itтАЩs given escape velocity, the payload will slowly rise up from the surface of
the Moon and head out into space.

Second: lunar escape velocity is only one-fifth of EarthтАЩs, and can therefore be attained with a
correspondingly shorter launch trackтАУand a twenty-fifth of the energy. When the time comes to export goods
from the Moon, this will be the way to do it. Although I was thinking of inanimate payloads, and launchers
only a few kilometers long, suitably protected human passengers could be handled by larger systems, if there
were ever enough traffic to justify them.

I wrote up this idea, with the necessary calculations, in a paper titled тАЬElectromagnetic Launching as a Major
Contribution to Space-Flight,тАЭ which was duly published in the Journal of the British Interplanetary Society
(November, 1950); it may be more conveniently located in my Ascent to Orbit: A Scientific Autobiography
(Wiley, 1984). And because a good idea should be exploited in every possible way, I used it in fiction on two
occasions: in the chapter тАЬThe Shot from the MoonтАЭ (Islands in the Sky, 1952) and in the short story
тАЬMaelstrom IIтАЭ (Playboy, April 1965, reprinted in The Wind from the Sun, 1972). This is the tale which Paul
Preuss has ingeniously worked into Venus Prime, Volume 2.

Some twenty years after the publication of тАЬElectromagnetic LaunchingтАЭ by the BIS, the concept was taken
much further by Gerald OтАЩNeill, who made it a key element of his тАЬspace colonizationтАЭ projects (see The
High Frontier, 1977; Gerry OтАЩNeill is justifiably annoyed by the Star WarriorsтАЩ preemption of his title.) He
showed that the large space habitats he envisaged could be most economically constructed from materials
mined and prefabricated on the Moon, and then shot into orbit by electromagnetic catapults to which he gave


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 ARTHUR C. CLARKE'S VENUS PRIME: VOLUME 2

the name тАЬmass drivers.тАЭ (IтАЩve challenged him to produce any propulsion device that doesnтАЩt fit this
description.)