http://www.astronautix.com/lvfam/orion.htm

http://216.239.41.104/search?q=cache...=en&ie=UT F-8

http://ffden-2.phys.uaf.edu/213.web....ionfusion.html

The URLs above describe a sort of ship that's possible to build using
nuclear fuel. In the 1940s and 1940s nuclear pulse units - miniature
a-bombs - were proposed as a means to propel spacecraft. This
resulted in Project Orion, which was cancelled with the signing of the
Nuclear NonProliferation Treaty in 1963.

Since that time the same technologies that were explored to create
inertial confinement fusion were also explored to create very small
inertial confinement fission - so called, micronukes. Micronukes -
nuclear hand grenades, can be used directly for propulsion, or
indirectly as triggers for relatively clean mini-H-bombs. In either
case, total energy yeilds are such that total containment of the blast
is feasible, and we end up with spaceships the size of ocean liners to
supertankers - capable of flying across the solar system with ease.

Check it out;

http://www.niac.usra.edu/files/studi...f/76McNutt.pdf
http://fusionenergy.lanl.gov/Documen...tfrefs8-99.PDF
http://128.97.43.7/bapsf/papers/Gekelman-laserJGR.pdf


http://hypertextbook.com/physics/mod...on/index.shtml
http://hyperphysics.phy-astr.gsu.edu...e/fission.html

Lithium-6 Deuteride produces 10 kiloton TNT equivalent explosion when
0.156 kg of it are detonated. At 0.82 gram per cc, this means that
190 cc of the stuff are needed for each blast. A sphere 7.1 cm across.

A 2 ton TNT equivalent fission trigger consisting of 100 mg of
Plutonium is made from wire about the size of a paperclip. If made
from the world's existing stockpile of nuclear weapons;

http://www.nrdc.org/nuclear/nudb/datab19.asp

There would be plenty to go around. Also, Deuterium is abundantly
available in the world's water supplies. And, Lithium-6 consists of
7.4% of the world's supply of Lithium. The US imported 3,000,000 kg
last year

http://minerals.usgs.gov/minerals/pu...ium/450301.pdf

A minimum traditional weapon (not the advanced type supposed here)
contains about 5 kg of Plutonium. So, we have about 50,000 kg
available from current weapons stockpile. So;

50,000,000 grams Pu - 0.1 gram -- 500 million triggers
3,000,000,000 grams Li-6/yr - 156 grams -- 19.2 million units/year

Deuterium is relatively unlimited - since its abundantly available in
the world's water supply.

So, we have enough materials to last us 25 years with 20 million
blasts per year.

156 grams expanding with 10 kiloton 41.84e15 joules of energy - has an
average velocity of;

E = 1/2 * m * V^2 -- V = SQRT(2*E/m)
= SQRT(2*41.84E15/0.156)
= 23,160,532 m/sec

So, if our weapon's experts can design a miniature nuclear explosion
that efficiently deposits the bulk of its energy into the reacting
medium, we can obtain exhaust velocities exceeding 20,000 km/sec!

Compare this with the Space Shuttle's 4.5 km/sec exhaust speed !!!

Okay, with this kind of performance its easy to see that we can do
amazing things.

For example, to move 20 million kilometers (2e10 meters) at 1/10th gee
constant (after escaping Earth) - accelerating half the time and
slowing the other half - to land softly on Mars (assuming its 20
million km away at the time) requires

D = 1/2 * a * t^2 and V = a * t -- t = V/a -- D = 1/2 * a *
V^2/a^2

D=V^2/(2a) -- V = SQRT(D*2*a)
= SQRT(2e10*2*0.982)
= 198,191 m/sec
= 198.2 km/sec

To get to the half way point, and the same amount to slow - with
slight variations due to the relative speeds of the planets which
amount to a few 10s of kilometers per second.

So, a spacecraft that could achieve a 500 km/sec final velocity would
be able to execute a constant 1/10th gee flight to Mars and back, when
it was near Earth.

This trip would take; t = 198,191 /0.982 = 201,823 seconds = 56 hours

to each half way point. A round trip wold take 224 hours - LESS THAN
10 days!

The amount of propellant needed to carry on board would be given by;

Vf = Ve * LN(1/(1-u)) --- u = 1 - 1/EXP(Vf/Ve)
= 1 - 1/EXP(500/20,000)
= 0.0247

Less than 2.5% of the spacecraft mass is needed to be the pulse units
described above.

Okay, so 20 million blasts per year of 0.156 kg pellets translate to
3,000 tons again - divide this by 2.5% - obtains 124,800 tons per year
carried to and from mars in this way.

Of course, this is very inefficient. The most efficient way to carry
stuff by rocket is to have the exhaust speed equal the final speed.
So, if we carry sufficient propellant to energize it to match the
final speed - and pack it around the pellets - then, we can compute;

u = 1 - 1/EXP(Vf/Ve)
= 1 - 1/EXP(1)
= 0.6321

But, this 63.21% is energized to 500 km/sec. That's 125 GJ per kg of
propellant. 20 million pellets, each producing 41.83e15 joules of
energy, yeilds 836.6e21 joules per year. This gives 6.7 trillion kg
of propellant. Divide this by 0.6321 and we obtain 10.6 trillion kg
of rockets. Multiply by 0.3679 to obtain 3.9 trillion kg of payload.

So, an energy efficient rocket fleet would have enough fuel to carry
nearly four billion tons of payload to and from mars each year - with
flight times meaasured in Weeks - and do this for 25 years. That's
100 billion tons. Or 15 tons for every man woman and child on the
Earth!

Clearly, we have the capacity to set up the sort of interplanetary
trading between Earth and mars that we now enjoy throughout the
world's oceans.