Watching an Orion rocket ship take off.

[Darmalus]

What would watching an Orion rocket take off look like? We all know what chemical rockets look like, but would a ship being pushed into orbit with a series of small nuclear bombs look much different? Would the nuclear saltwater rocket look like a chemical rocket, an Orion rocket, or something else?

[Dave]

See also: Atomic Rockets: Surface to Orbit, about halfway down the page.

[Akkleptos]

Simply put (and thanks to Dave's video), an Orion-type ship would get past the atmosphere first, and then it would begin blasting off its nuclear propellents. In near-zero atmosphere, the classic tell-tale signs of a nuclear blast are gone... No visible shockwave, just a sharp increase in temperature in the immediate vicinity of the blasts, by radiation (and I mean one of the ways heat travels, not necessarily what we commonly understand as "radiation", which of course would also be present, but would also be quickly left behind by the ship).

[Count Chocula]

Umm...a hella show when it blasts off the pad, followed by dancing spots in your eyes and possible blindness if you keep watching after it lights off the first nuke under the pusher plate. Like looking at the sun, times 100. If you're under its thrust line, that's really not a good idea.

[Akkleptos]

Umm...a hella show when it blasts off the pad, followed by dancing spots in your eyes and possible blindness if you keep watching after it lights off the first nuke under the pusher plate. Like looking at the sun, times 100. If you're under its thrust line, that's really not a good idea.

Certainly, onlooking such a strong open fire is not such a "bright" idea. But ny the time it sets of the first nuclear blasts, it might be too far away for the naked eye to notice more than bright flashes, what with the blasts being 20 kilometers away upwards, and the gods knows what weather conditions.

[ThomasP]

That was a neat video. I have a total nerd-crush on the Orion rockets.

Question though - are the booster rockets a necessity for the idea to work? I was under the impression that Orion's biggest advantage was as a heavy-lift workhorse. The solid boosters would seem to make that redundant, though I'd imagine it's a bit more eco-friendly.

I understand that NPP has very high thrust and Isp compared to anything else we can realistically field for the moment, which doesn't make it useless in space, but I am curious about that part.

[Marcus Aurelius]

Question though - are the booster rockets a necessity for the idea to work? I was under the impression that Orion's biggest advantage was as a heavy-lift workhorse. The solid boosters would seem to make that redundant, though I'd imagine it's a bit more eco-friendly.

I understand that NPP has very high thrust and Isp compared to anything else we can realistically field for the moment, which doesn't make it useless in space, but I am curious about that part.

The chemical boosters are certainly necessary to get the rocket off the ground and I suppose you would not want to use the NPP in troposphere either. Nevertheless, even if the NPP is engaged at 20 km altitude, it could easily provide much better lift capabilities than any chemical rockets. However, in the current and foreseeable political environment, I doubt using a NPP below thermosphere (or about 100 km) would be politically acceptable.

[Simon_Jester]

Personally, I don't consider that to be just a political condition. I was reasonably young when I first heard about Orion, and the first thing I thought of was "not on my planet, you're not!"

Granted, the propulsion bombs are effectively airbursts, granted all the "buts" that the defenders of the drive system use. It's still not a friendly thing to be using in someone's stratosphere.

[Bluewolf]

Personally, I don't consider that to be just a political condition. I was reasonably young when I first heard about Orion, and the first thing I thought of was "not on my planet, you're not!"

I see that too. When it was dicussed once with a few people I knew, the sentiment with some was "What if it goes wrong and blows up? Wont it rain nuclear debris on us?". Now these people were fine with nuclear energy too so its not as if this was a "rawr no nukes" idea. Imo Orion would need to be tested somehow beforehand and something worked out for it to be done. It is a very dicy idea and has to be handled with caution.

[TheLostVikings]

Personally, I don't consider that to be just a political condition. I was reasonably young when I first heard about Orion, and the first thing I thought of was "not on my planet, you're not!"

I see that too. When it was dicussed once with a few people I knew, the sentiment with some was "What if it goes wrong and blows up? Wont it rain nuclear debris on us?". Now these people were fine with nuclear energy too so its not as if this was a "rawr no nukes" idea. Imo Orion would need to be tested somehow beforehand and something worked out for it to be done. It is a very dicy idea and has to be handled with caution.

AFAIK the Orion project is so old that they originally though that we would be able to develop "pure" H-Bombs (i.e. without having to have an A-bomb to start the chain reaction), and thus that they would eventually be able to sidestep many of the problems that way. Of course we never actually got to that point, but a Orion drive that tossed out large Hydrogen pellets and jump started them by a laser would probably be relatively "clean".

[Bluewolf]

That does sound like a good idea yet I don't think the public would like that either. A lot of people think that only nuclear type bombs exist and forget H bombs etc and that is the problem. The public perspection will be, that you are using nukes and fear it going wrong or contaiminating people..

[Wyrm]

Using NPP in an atmosphere has the disadvantage of creating a fireball that has solar-level intensity. It will spread out beyond a reasonably-sized pusher plate and irradiate the sides of the spacecraft with EM radiation at best and actual radioactive fireball will scour the surface at worst. In space, you don't have that problem.

[Simon_Jester]

Most of my objections to Orion drives go away if you don't start lighting off the bombs in my own personal atmosphere.