'Mars by 1965, Saturn by 1970'

[Christopher]

This was the inofficial moto of a very promising spacefaring poject started 1958: Orion

If it would have been completed, humanity would had made interplanetary flights for 40 Years by now.

There were two main problems: First, there was the fallout for planetary starts. Second, there was the cold war and the danger of a "nuclear race in space".

In the end, the Partial Nuclear Test Ban treaty made it illegal.

 

Now what about a world where it has been done and the promise was fullfilled?

How would humanity live with the nulcear pulse propulsion as a common, widespread propulsion technique?

 

While I have some ideas, I do not plan anything around that right now. But perhaps a few of you find something intersting in the entire idea. Maybe an early spacefaring alien civilisation uses the idea?

[Old Man]

Re: 'Mars by 1965, Saturn by 1970'

 

I'm kind of picturing Gamma World or Fallout with spaceflight here.

[tkdguy]

Re: 'Mars by 1965, Saturn by 1970'

 

One of my old ideas was having an alternate world where space flight was more common than it is right now. Make a few tweaks in history and science, and you're good to go!

[Christopher]

Re: 'Mars by 1965, Saturn by 1970'

 

I'm kind of picturing Gamma World or Fallout with spaceflight here.

Indeed, the Planetbound start is the main problem:

Either you got radiation by using the main drive to start, or your need a hell of lot of rockets + drydock to build that 880 - 4000 ton thing in space.

But, once you have it there there is no reason it every needs to come back down. You can just re-use it. When you only start the main drive a save distance from earth (or whereever you just started from), it is suprisingly save.

 

But what fascinates me the most is the sheer efficiency of the idea:

- you don't have to use the notroious wieght saving/fragile designs you have with current tech. In fact you have to make it big and stable (880 tons is the minimum weight with human crew). It's build "like a battle ship or submarine". So, no problem fitting Live support, stellar radiaton shielding and lot's of food on it.

- we could have done a mars mission in 125 days (both ways), with eight astronauts and about 100 tons of payload. All with technology from the early 80's

- even the saturn and it's moons would have been in reach

- the mars + moon mission togehter would have been cheap. Even if the underestimated the cost by 20 times, it would still be only as expensive as the entire apollo programm

- in part they rejected it because it had too much payload. They couldn't even think of enough missions that needed that much stuff.

[McCoy]

Re: 'Mars by 1965, Saturn by 1970'

 

hate to be the mercenary weasel here, but what do atomic bombs cost? How much is spent every time you need to make a course change? IIRC, a nuclear fission explosion used a small percentage of the uranium or plutonium, but since that is also the reaction mass none of the unspent "fuel" can be recycled/reprocessed.

 

Wouldn't a constant thrust powered by a nuclear reactor be more fuel efficient?

[Christopher]

Re: 'Mars by 1965, Saturn by 1970'

 

hate to be the mercenary weasel here' date=' but what do atomic bombs cost? How much is spent every time you need to make a course change? IIRC, a nuclear fission explosion used a small percentage of the uranium or plutonium, but since that is also the reaction mass none of the unspent "fuel" can be recycled/reprocessed. [/quote']

Ironically the fuel efficiency get's better the heavier the vehicle and for most parts you can just use the smalest possible bombs for anything from a 880 to 8,000,000 tons design. Most of the potential (and even the created) energy will remain unused, but overall the mass/thurst ratio is simply superior to any chemical rocket of our time.

True fusion bombs could increase the efficiency a lot. Not because of it's higher energy, but because you can build the bombs a lot smaller (no minimum criticall mass).

 

Wouldn't a constant thrust powered by a nuclear reactor be more fuel efficient?

Perhaps. But how can you generate enough thrust that way? Also, in space it is more difficult to refuel on watter and water is both moderator and energy carrier for nuclear reactors.

Overall it's way easier to produce an uncontrolled explosion than a controlled reaction (first we build the bomb, then the reactor). I mean we have psuedo-fusion bombs for a few decades now but still try to make it work as a generator.

[Tom Carman]

Re: 'Mars by 1965, Saturn by 1970'

 

Perhaps. But how can you generate enough thrust that way? Also, in space it is more difficult to refuel on watter and water is both moderator and energy carrier for nuclear reactors.

Overall it's way easier to produce an uncontrolled explosion than a controlled reaction (first we build the bomb, then the reactor). I mean we have psuedo-fusion bombs for a few decades now but still try to make it work as a generator.

 

Actually, we had controlled fission reactors before we had bombs. Very few bombs used purified U235; most use plutonium which is produced in reactors. Water is only one of several reactor moderators. We use it in power plants because our plants are basically steam generators, and it's convenient that water does double-duty as both coolant and moderator.

[Christopher]

Re: 'Mars by 1965, Saturn by 1970'

 

Actually' date=' we had controlled fission reactors before we had bombs. Very few bombs used purified U235; most use plutonium which is produced in reactors.[/quote']

A reactor designed to produce plotonium or one that is used to produce energy? There is a great difference between both results.

[RexMundi]

Re: 'Mars by 1965, Saturn by 1970'

 

Love me some Project Orion. To think of what might have been....*sigh* Ah well, at least it lives on in good SF.

 

~Rex

[Tom Carman]

Re: 'Mars by 1965, Saturn by 1970'

 

A reactor designed to produce plotonium or one that is used to produce energy? There is a great difference between both results.

 

Chernobyl is a good example of the differences. The Soviets used that reactor type for power generation, but it was designed for plutonium production. It was moderated by graphite but cooled by water. Consequently, the nuclear chain reaction DID NOT shut down when it lost coolant. Think of how catastrophic Fukashima Daiichi could have been if the reactors were still going full blast instead of just dealing with the residual heat from decaying isotopes.

[Christopher]

Re: 'Mars by 1965, Saturn by 1970'

 

There is still the problem to convert the energy generated into thrust.

 

There are some energy-intesive, low fuel drives right now (inclduing the ion drive we use for some time now). One first idea is the Longshot Project. But that is still a far cry from the results of the NPP Drive. Both in payload and in the acceleration times, making it unsuiteable for humans.

 

What you need for interplanetary space drive:

High Acceleration(specefic impulse), low fuel consumption.

Especially in the first point (the most important one for manned travel) the NPP simply overpowers every single one of our current and even some of our hypothetical drives. As it did 1970.

[AmadanNaBriona]

Re: 'Mars by 1965, Saturn by 1970'

 

Best low tech suggestions I've seen for a functional Orion lift phase have involved using a large underground bunker detonation with an exhaust tube to channel the blast while sealing itself up in the process.

Put the facilities in Antarctica and you significantly reduce the functional side effects of the program

[Beast]

Re: 'Mars by 1965, Saturn by 1970'

 

Didn't Footfall have the Orion drive spaceship down in a deep hole as a launch tube to increase the pressure like a bullet in a barrel,but also to limit nuke damage to the surrounding landscape

[Christopher]

Re: 'Mars by 1965, Saturn by 1970'

 

Best low tech suggestions I've seen for a functional Orion lift phase have involved using a large underground bunker detonation with an exhaust tube to channel the blast while sealing itself up in the process.

Put the facilities in Antarctica and you significantly reduce the functional side effects of the program

They to notead that antarktika would be the perfekt starting site for Planet based launch (something about the magnetic field there reduces the fallout significantly).

 

Using a bunker is one way and they did had a similar idea to use a concventional tnt as first explosion.

But that only helps for the first explosion for a manned vehicle or the mayor impuls of a unmanned one. Try to get a manned one into orbit with such a one-shot and your astronauts get...squishy.

One reason the ship has to be heavy is, that the heavier it get's the more impuls/bomb you can use without killing your astronauts.

[McCoy]

Re: 'Mars by 1965, Saturn by 1970'

 

Best low tech suggestions I've seen for a functional Orion lift phase have involved using a large underground bunker detonation with an exhaust tube to channel the blast while sealing itself up in the process.

Put the facilities in Antarctica and you significantly reduce the functional side effects of the program

If you don't count hot rocks melting glaciers from the bottom as a "functional side effect."

[Christopher]

Re: 'Mars by 1965, Saturn by 1970'

 

If you don't count hot rocks melting glaciers from the bottom as a "functional side effect."

I thin layer of graphit-based oil protects the pusher plate of the Orion Design from ablation through the blast. This was partially discovered when a steelplate took a atomic eplosion point blank and survived - with oily fingerprints still on it.

And the towers they placed the first atomic bomd on - it wasn't vaporized. It was destoryed but most parts where still there. Despite the damage everything in further distance had recieved.

[McCoy]

Re: 'Mars by 1965, Saturn by 1970'

 

I thin layer of graphit-based oil protects the pusher plate of the Orion Design from ablation through the blast. This was partially discovered when a steelplate took a atomic eplosion point blank and survived - with oily fingerprints still on it.

And the towers they placed the first atomic bomd on - it wasn't vaporized. It was destoryed but most parts where still there. Despite the damage everything in further distance had recieved.

Doesn't stop heat from radiating through the rocks. You are in effect placing an artificial volcano under the ice pack.

[Tom Carman]

Re: 'Mars by 1965, Saturn by 1970'

 

Using a bunker is one way and they did had a similar idea to use a concventional tnt as first explosion.

But that only helps for the first explosion for a manned vehicle or the mayor impuls of a unmanned one. Try to get a manned one into orbit with such a one-shot and your astronauts get...squishy.

One reason the ship has to be heavy is, that the heavier it get's the more impuls/bomb you can use without killing your astronauts.

 

I don't think the blast-in-the-bunker was intended as one-shot-to-orbit. It was probably intended to eliminate the initial ground-burst and ensure that all of the open-air blasts are the much-lower-fallout aerial bursts.

[RexMundi]

Re: 'Mars by 1965, Saturn by 1970'

 

Don't forget the Barge Launch. Just as a refresher: http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

 

~Rex