Excellent Project Orion Documentary

[crazyewok]

But unlike the laws of physics situations and technology does change.

Can you honestly predict what situations or technology will be around 10 years from now or even 100?

I dont know were your from but the worlds political and technology situation doesn't exactly stay stable.

[Aghanim]

There were also plans to coat the entire launch site in graphite so that launches would produce little to no fallout.

EMP wouldn't have been as much of an issue as one would assume. Orion warhead sizes were relatively small (in the kiloton range rather than megaton) compared to the bombs needed to create a substantial EMP.

Read here for everything you need to know about Orion: http://www.projectrho.com/public_html/rocket/enginelist.php#id--Pulse

"A more sophisticated objection to using Orion inside an atmosphere is the sci-fi horror of EMP melting all our computers, making our smart phones explode, and otherwise ruining anything using electricity. But that actually is not much of a problem. EMP is not a concern unless the detonation is larger than one megaton or so, Orion propulsion charges are only a few kilotons (one one-thousandth of a megaton). Ben Pearson did an analysis and concluded that Orion charges would only have EMP effects within a radius of 276 kilometers (the International Space Station has an orbital height of about 370 kilometers). So just be sure your launch site is in a remote location, which you probably would have done anyway."

How does coating the launch site with graphite reduces fallout?

@Nibb31: At least its a software problem not a hardware problem

[Airlock]

How does coating the launch site with graphite reduces fallout?

Apparently it reduces ablation. It was to be used on the Orion's pusher plate as well.

Read here: http://www.spacedaily.com/news/nuclearspace-03h.html

"Evidence of this obtained from nuclear tests was the foundation for further research into the feasibility of a pusher plate. It was discovered that ablation (erosion) of the surface of a pusher plate could also be reduced by coating it with graphite. Coating the launch pad in similar fashion would minimise ablation of the surface and therefore create very little fallout indeed. Airbursts are relatively clean from a fallout point of view."

[crazyewok]

The big problem still would be a catastrophic failure on launch.

Granted Nuclear bombs are not as bad as nuclear reactors if breached and wont melt down but a failed launch would mean hundreds of nukes falling down. Which granted wont exactly be going off as they would not have been detonated but the cases could break.

That be negated by launching out at sea. If it fails and the nukes come tumbling back down then 2000 + m under the seas not likely to have much effect, we have put worse in the ocean. But there are defence concerns as what if a less than friendlily group recover one of the nukes ect

[Chris P. Bacon]

As much as I love the Orion, I can't ever see us launching one anytime soon. There's just too much anti-anything nuclear in our culture. I still remember the protests and demonstrations in '99 when Cassini-Huygens was supposed to fly by Earth for a gravity assist, with Michio Kaku leading the battle cries in the news, and it just had a little RTG on it.

NASA still keeps a small group working on keeping the Orion tech modern, and they've done a pretty good job of scrubbing everything "nuclear" from the name and the documents, now referring to it as "external pulsed plasma propulsion", but short of diverting that extinction-event asteroid, I doubt we'll ever see one constructed.

Hopefully we'll see something that can surpass Orion in both thrust and ISP, but until that day, I'll remain a fan. It's a shame we couldn't have gotten an interstellar probe out there prior to the test ban treaty.

[Airlock]

As much as I love the Orion, I can't ever see us launching one anytime soon. There's just too much anti-anything nuclear in our culture. I still remember the protests and demonstrations in '99 when Cassini-Huygens was supposed to fly by Earth for a gravity assist, with Michio Kaku leading the battle cries in the news, and it just had a little RTG on it.

NASA still keeps a small group working on keeping the Orion tech modern, and they've done a pretty good job of scrubbing everything "nuclear" from the name and the documents, now referring to it as "external pulsed plasma propulsion", but short of diverting that extinction-event asteroid, I doubt we'll ever see one constructed.

Hopefully we'll see something that can surpass Orion in both thrust and ISP, but until that day, I'll remain a fan. It's a shame we couldn't have gotten an interstellar probe out there prior to the test ban treaty.

If space-based infrastructure ever becomes a reality, I can envision an Orion, or something akin to it, being built on the surface of the Moon or Mars. Perhaps through asteroid mining.

Now I feel a need to share this...

Edit - Here's the wiki about it: http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion#Medusa

"The Medusa design is a type of nuclear pulse propulsion which has more in common with solar sails than with conventional rockets. It was proposed in the 1990s in another BIS project when it became clear that ICF did not appear to be able to run both the engine and the ship, as previously believed.

A Medusa spacecraft would deploy a large sail ahead of it, attached by cables, and then launch nuclear explosives forward to detonate between itself and its sail. The sail would be accelerated by the impulse, and the spacecraft would follow.

Medusa performs better than the classical Orion design because its sail intercepts more of the bomb's blast, its shock-absorber stroke is much longer, and all its major structures are in tension and hence can be quite lightweight. It also scales down better. Medusa-type ships would be capable of a specific impulse between 50,000 and 100,000 seconds (500 to 1000 kN·s/kg)."

Edited August 9, 2014 by Airlock

[Northstar1989]

I have no problem with nuclear propulsion. I have problems with unrealistic proposals.

There's nothing unrealistic about Orion. Let's go through the issues one-by-one, shall we?

There are two ways of getting something like an Orion spacecraft into space:

That's absolutely not true. You can't constrain an argument to two false choices like that- it makes your entire argument invalid. But ignoring that...

- Launching an Orion spacecraft: Atmospheric nuclear blasts are a non-starter.

Atmospheric nuclear blasts are a non-starter, are they? You're forgetting that far, far more nuclear devices (and a much greater explosive tonnage) were detonated above-ground by the US and USSR during the Cold War before the Nuclear Test Ban Treaty- so that argument holds no water.

With the kind of tonnage an Orion could lift to orbit, you could end the world's energy problems with a single launch (with a set of giant mirror-based concentrating solar power satellites and associated Microwave Power Transmitters), send enough payload to Mars to build a 100-person permanent colony/research station (or 50-person with a temporary but long-term stay and return trip), or launch a hypergolic-fuel depot large enough to fuel decades of manned mission to other planets. And all for a REASONABLE cost... (the lack of thin payload mass margins margins means you could build craft to the same engineering standards as a submarine)

But, let's say you really CAN'T get politicians of the world to agree to allow atmospheric detonation of nukes (and an exception to the Nuclear Test Ban Treaty) for one of these noble purposes. What then?

- Orbital assembly: Hundreds of conventional launches and decades of work in LEO to build.

No, it really WOULDN'T take hundreds of launches. As already discussed, the 10-meter variant could be launched on a single suborbital trajectory by a Saturn-V, Nova, or SLS rocket. You don't need to give the Orion the 10+ km/s of Delta-V to make it to orbit: you only need to give it the 1000-1200 m/s or so of Delta-V necessary to escape the atmosphere with a straight-up launch. After that, the Orion is perfectly capable of propelling itself to orbit without any atmospheric nuclear blasts.

And even if you couldn't get the funding for a ultra-heavy lifter, you really wouldn't need to engage in orbital assembly. Simply launch an Orion with an empty magazine of nuclear charges (this is a large portion of the system's weight), and launch the nuclear charges on a separate trio of launches to rendezvous and transfer over the nukes (in a zero-G environment they really DON'T need to be handled all that delicately) one magazine sub-rack at a time (this variant of the Orion would have the racks built in 3x symmetry, with a central feeder mechanism.) For a total of 4 heavy (but not ultra-heavy) launches, using existing launch vehicles, you could assemble a small Orion in orbit with no actual construction- just the attachment of 3 nuclear charge racks to a central feeder mechanism (alternatively, you could build the empty racks into the empty Orion, and transfer over the nukes one at a time...)

In addition, nuclear bombs are not cheap and their mass production carries all sorts of proliferation problems.

The engineers who build Orion already worked out techniques to mass-produce sufficiently cheap warheads. That's why the majority of the files regarding Orion are still Top Secret.

But again, these problems have been discussed to death already. The idea is entertaining in (in a Fallout alternate universe kind of way), but totally unrealistic. I see no point in rehashing the same old arguments again and again.

You are not the ultimate authority on nuclear pulse rocketry. Did you consider that perhaps people would like to discuss this topic WITHOUT your troll- errrr, domineering posts taking over the thread?

Regards,

Northstar

Edited August 10, 2014 by Northstar1989

[Northstar1989]

Now I feel a need to share this...

Edit - Here's the wiki about it: http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion#Medusa

"The Medusa design is a type of nuclear pulse propulsion which has more in common with solar sails than with conventional rockets. It was proposed in the 1990s in another BIS project when it became clear that ICF did not appear to be able to run both the engine and the ship, as previously believed.

A Medusa spacecraft would deploy a large sail ahead of it, attached by cables, and then launch nuclear explosives forward to detonate between itself and its sail. The sail would be accelerated by the impulse, and the spacecraft would follow.

Medusa performs better than the classical Orion design because its sail intercepts more of the bomb's blast, its shock-absorber stroke is much longer, and all its major structures are in tension and hence can be quite lightweight. It also scales down better. Medusa-type ships would be capable of a specific impulse between 50,000 and 100,000 seconds (500 to 1000 kN·s/kg)."

That's really interesting. I had never heard of Medusa before. +1 Rep for awesomeness.

Regards,

Northstar