# Space travel

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Posted (edited)

Hi, so yesterday i was just pondering and i came up with an idea that a space ship would release a nuclear bomb which was timed to detonate at a distance far away enough as to not hurt the craft, but close enough to absorb kinetic energy from the explosion, after a series of such detonations the optimal range to minimize damage but optimize absorption of kinetic energy would be at the center of the explosion where particles from what i understand reach close to light speed.

I must add, to see if my idea would work i googled stuff about the subject and found that an almost identical idea had already been proposed called the "Orion Project". So what are the problems in order to make this work?

Could it be possible to get anywhere near light speed?

Edited by Fantasci

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Janus    674

The original Orion project was abandoned due to nuclear test ban treaties. So there would be a ton of political problems to deal with (not a lot of people would be happy with someone launching the nuclear bombs or even the materials to build them into orbit so that the ship could be built.

But even if we could clear those hurdles, near light speed velocities are not not in the cards. While there is no theoretical limit to the maximum speed for any rocket, there is a practical one. Basically it works like this: the higher your effective exhaust velocity, the higher final velocity you can reach for any given amount of fuel.

A high end estimate for the exhaust velocity for such a craft works out to be ~ 1,000,000 m/s or 1/300 of c.

At this exhaust velocity, you would require 19 kg of fuel per kg of payload to reach just 1% of c. If you want the ability to come to a stop again, this increases to 402 kg of fuel per kg of payload.( this huge increase is caused by the fact that the fuel you will use to slow down becomes a part of payload mass you are accelerating up to 1% of c in the first place.)

It gets much worse when you try to get to significant fractions of the speed of light, as Relativistic effects begin to compound the amount of required fuel.

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This is a very interesting theory and I would really want to investigate in that. Thanks for bring up this idea!

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Phi for All    4741

(not a lot of people would be happy with someone launching the nuclear bombs or even the materials to build them into orbit so that the ship could be built.

Space policy globally is nowhere near being firm enough to trust states with weapons bigger than handguns. We've come a long way and we have a long way to go.

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HB of CJ    19

Lots of websites on the old failed proposed Orion Project. A series of very bad ideas. The ultimate in a extremely dirty Rube Goldberg machine. Gone by the wayside along with the plutonium breeder nuclear reactor scheme. But ... apparently at one point our and their scientists were looking kinda seriously at it.