So why do we still use rocket fuel?
Why do we still try to
launch people into space in portacabins mounted on the front of what are, to
the untrained eye, bloody great missiles? Why aren’t we reaching to the stars
in city-sized megaships that travel at 5 to 10% of the speed of light,
harnessing the power of the atom to claim our birthright?
Well, the first is a
pretty obvious flaw, and one that nuclear everything
seems to suffer from. Setting off nuclear bombs is usually a pretty bad idea,
what with the radiation and the fallout. Setting off dozens, one after the
other, high above the world, would have been a very bad thing, expanding the
phenomena of “Downwinders” to potentially the entire world, with a conservative
estimate putting between one and ten deaths directly attributable to each
launch from the Earth into space by a nuclear pulse engine. And that is ignoring
any problem you might have from accidents. Imagine the tragic events of the Space
Shuttle Challenger in 1986, or the Space Shuttle Columbia in 2003, and add the
danger of nuclear fallout and atomic explosives to the mix, as well as the fact
that these ships would be the size of the Shard or possibly the Empire State
Building, and travelling far faster meaning the debris would be travelling
further and faster as well. When you look at it like that, purely from a
practical point, nuclear pulse engines launching from the Earth are suddenly a lot
less appealing.
Then you have to look at the context of the time.
This was
at the height of the Cold War, with East and West just waiting for an excuse to
lay into each other. The Cuban Missile Crisis was still fresh in the minds of
the world when the project was ultimately shelved, and President Kennedy
himself is said to have been appalled by the project when he was introduced to
it. Project Orion proper was set up in 1958 (although the thinking behind it
dates back to 1946, and arguably even further, if you consider the idea of
using controlled chemical explosions as rocket propulsion part of the same
chain of thinking. In which case it goes back to 1881 with that particular idea
coined by Russian explosives expert Nikolai Kibalchich) and the project was
shelved in 1963 with the signing of the Partial Test Ban Treaty, which forbade
the testing of nuclear weapons underwater, in the atmosphere or in outer space,
which rather pulls the rug out from under Orion. Understandably, the Russians
were concerned with a rocket powered by nuclear bombs capable of moving at, at
a reasonable estimate, 5% the speed of light, and justifiably so when the US
military took interest in it.
They were interested, for example, in how you’d mount naval
weapons on a Project Orion craft, and it turns out firing artillery shells at
targets when you’re moving at even 1% of the speed of light is a bit of a
waste, as the kinetic energy outstrips any sort of chemical explosive by an
order of magnitude. So the thinking went on to all those atomic bomblets you’d
be using to get into space in the first place, and would it be possible to use
a few spares as nuclear artillery? You’d be dropping them faster than anyone
could track, vaporising anything it touched, happily taking “Mutually” out of
“Mutually Assured Destruction”. If you only intended to silence any opposition
to you, you’d only need one and you’d be able to stop anyone ever building
another simply with the threat of hypersonic nuclear artillery strikes turning
the offending nation into a smouldering crater. It could have brought a rather
rapid end to the Cold War, as the Americans could have annihilated Moscow
without so much as a two-minute warning. So understandably, with the Cold War
being the way it was, and Kennedy trying to bring an end to it peacefully rather
than dragging it to the stars, the project was officially shelved.