Mid 20th century interplanetary cruiser.

Since I am fairly new here I am not sure if anyone else has posted this before. My friend worked on this project many many moons ago. Recently I talked to an Air Force officer and he told me this project maybe brought back. A new tool he has is today's super computers. They can accurately simulate atomic explosions. Here is the link to the original project. www.youtube.com...

Recently I talked to an Air Force officer and he told me this project maybe brought back.

With a suitable shock absorber, why not.
Oh, politics. That's why. A whole bunch of nuclear explosions overhead will not be an easy sell.

The ship would be built in orbit using the SLS. It would have taken 1000 atomic bombs to reach orbit, fall out would be terrible. The original project could not have been built in orbit since it was way before the Saturn V. a reply to: Phage

a reply to: USSGOBLiN

The ship would be built in orbit using the SLS.

Carrying a bunch of fissionable material. Nasty stuff.

It would have taken 1000 atomic bombs to reach orbit, fall out would be terrible.

Yes.

Actually with some tweaking the fallout was deemed to not be that bad.

Though it relied on extremly purpose built nukes, launching at sea ect plus a few methods that are still classified.

All those problems will be null and void if they can figure 100% fusion.

Orion has always facinated me.

a reply to: Phage

A whole bunch of nuclear explosions overhead will not be an easy sell.

Or boosting a bunch of small atomic weapons to orbit.

Launching Orion any where near Earth would be problematic.

- Launching from Earth would destroy the assembly area and launch complex.
- There would be fallout, but it would have been no worse than low-yield atomic tests in the 50's or 60's. However, by the 60's it was considered that any fallout was too much; thus the Atmospheric Test Ban Treaty.
- Launching from low earth orbit, the x-ray pulse from the bombs would cause an electromagnetic pulse (EMP) in the atmosphere which would damage elecronics and the power distribution network (the x-rays ionize the upper atmosphere, which creates a large voltage potential that finds its way to ground).
- X-rays from a nuclear detonation in space that do not intersect the atmosphere travel along way. The flux within several thousand miles is sufficient to damage unshielded satellites from LEO to geosynchronous orbit.
- Free electrons and ionized atoms from each pulse would be trapped by Earth's magnetic field, with the effect of greatly (albiet temporarily) increase the particle radiation level in the Van Allen Belts. This would also damage unshielded satellites.

Still, it's a bitchin' idea, and the video in the OP is excellent and y'all should take an hour to watch the whole thing.

For a kick-ass read, try "Footfall" by Larry Niven & Jerry Pournelle. It's a bit dated, now (the Soviets figure prominently). In response to a dire situation, we build an Orion and launch it from Earth. Describing the scene in the crew cabin during launch: "God was knocking, and He wanted in BAD."



P.S. It always irks me that NASA gave the name "Orion" to its planned next-generation spacecraft. In my mind, there's only one Orion, and it's not a wimpy little capsule.

a reply to: Saint Exupery

For a kick-ass read, try "Footfall" by Larry Niven & Jerry Pournelle.

Good Book. In that one the risk and fallout was offset by the threat of the aliens who were dropping rocks on cities, dams and conquering the Earth with advanced warfare.

So a little radioactive pollution and crashing rockets filled with bombs wasn't too bad by comparison.

Who we going to get to lift the 'devices' that hasn't suffered multiple failed launches lately?

The Russians?

Throwing bombs in your wake to provide thrust is a terrible waste of energy. By the way, FootFall was pure science fiction.

Radiation concerns aside, wouldn't the sudden and powerful push caused by each explosion kill the astronauts through very high g's?

originally posted by: wildespace
Radiation concerns aside, wouldn't the sudden and powerful push caused by each explosion kill the astronauts through very high g's?

No apparently not. On take off the acceleration would not exceed 5 g's ( Apparently they got it down to 2g's) and in space it could be set at 1g. The whole things designed around a very big and very effective shock absorber.

originally posted by: wildespace
Radiation concerns aside, wouldn't the sudden and powerful push caused by each explosion kill the astronauts through very high g's?

That's the real beauty of Orion: With every other type of space propulsion system, you have to ruthlessly minimize the mass of the spacecraft. With Orion, the more massive you make it, the lower the g-load during each pulse. Thus, not only is a big, luxurious crew module desirable, it is nearly essential.

Of course, part of the mass can be a whole lot of shielding, so radiation from the nukes can be completely blocked.

I find it counter-productive that a lot of the energy from nuclear explosions will have to be absorbed by the dampener and huge mass of the spacecraft. Will this really be more effient than burning fuel?

originally posted by: wildespace
I find it counter-productive that a lot of the energy from nuclear explosions will have to be absorbed by the dampener and huge mass of the spacecraft. Will this really be more effient than burning fuel?

Yes and no.

The acceleration and final velocity you can get are far far far superior than anything chemical rockets can achieve.

It was worked out by Freeman Dyson one of the projects leads that theoretically you could get 8 million tons into orbit in one launch if you built it to its maximum ( most Orion designs were 5,000-10,000 tons and bear in mind the shuttle could only lift 100 tons) . As for speed it could of got 1% speed of light 10% maybe. Again far far far superior to Chemical rockets.

originally posted by: intrptr
a reply to: Saint Exupery

Who we going to get to lift the 'devices' that hasn't suffered multiple failed launches lately?

The Russians?

I've always thought that, if I was making a movie of "Footfall", Buran would have been one of the shuttles aboard Archangel Michael.

Throwing bombs in your wake to provide thrust is a terrible waste of energy.

Not really, when compared to a chemical rocket. Consider any one of them: Soyuz, Atlas, Ariane, Dragon; they are all huge towers of high-tech engineering and hundreds of tons of propellents that are all thrown away just to get a van-sized payload into orbit. A nuclear device packs more energy into a 100kg package the size of a thermos bottle than a 3 million kg Saturn V Moon rocket, and an Orion would carry thousands of such devices. In terms of delta-v per unit of mass & volume, nothing beats nukes. Who cares if the pusher-plate only gets 10% of the blast? The amount that it does receive is so phenomenal that you don't care about overall efficiency. Bill Gates doesn't care how much it costs to gas-up his private jet.

Incidentally, I thought that it was cool that "Michael" used the x-rays from the nuclear pulses to pump x-ray lasers aimed at the alien ships. This was based on ABM technology pioneered by the Strategic Defense Initiative. Link That's what I call 'efficient'.

By the way, FootFall was pure science fiction.

NOOOOOOOO... REALLY?!?!?!?

Sarcasm aside, "Footfall" was 'hard' science fiction, which means that all of the tech in it was based on known engineering principles and physics. Some of it was not what I would call practical (the precise description of the Fithp laser propulsion on their digit ships is a particularly egregious example), but it all could be built using known technology. Nothing was invented out of thin air, like faster-than-light drives, gravity generators, teleportation or ships with unlimited maneuvering ability like "Star Trek's" shuttlecraft, "Star Wars'" X-wings, BSG's Raptors, etc.

Orion may have been viable in the early 60's when it was conceived, but today I would imagine the EMP from an LEO nuclear detonation would fry every satellite around it for several thousand kilometers.

Though, it could possibly be done via traditional chemical propulsion, then switching to the nuclear pulses once out of Earth's SOI.

originally posted by: ScientificRailgun
Orion may have been viable in the early 60's when it was conceived, but today I would imagine the EMP from an LEO nuclear detonation would fry every satellite around it for several thousand kilometers.

Correct but for a minor nit-pick: EMP is caused by the x-rays ionizing the atmosphere, so it is an endo-atmospheric phenomenon even for an exo-atmospheric burst (especially for, I should say - the atmosphere absorbs the x-rays (the ionization is a side effect of this), so the x-rays travel further in thinner air, increasing the area ionized. X-rays from an exo-atmospheric burst can ionize air thousands of miles away. Out in space, of course there is no air.. The x-rays themselves penetrate and damage the satellites. EM damage is a residual effect of the free electrons and ionized atoms which enhance the Van Allen Belts. Generally speaking, satellites are pretty well shielded against VAB particle radiation, but not so much against x-rays (military sats are an exception) since the standard energy & flux are not great.

Though, it could possibly be done via traditional chemical propulsion, then switching to the nuclear pulses once out of Earth's SOI.

Very true, but the builders would run into a paradox: The Orion spacecraft must be very massive, but when launching with chemical fuel, mass is at an absolute premium. I guess we'll have to build a space elevator first!

a reply to: Saint Exupery

You're absolutely correct and I apologize for that. How could I forget something as simple as that?

I guess that's why I'm in IT and not astrophysics!

Thank you for clarifying.

I'd rather channel all of that nuclear energy into Nuclear Ion drives or EM thrusters. Blowing up bombs for propulsion seems like a crude mid 20th century Cold War era idea.

There are far more efficient ways to use the same energy now.

originally posted by: wildespace
Radiation concerns aside, wouldn't the sudden and powerful push caused by each explosion kill the astronauts through very high g's?

In the book Footfall the idea was to drop smaller yield nuclear devices into the wake of the ships thruster shield, a concave dish, far enough behind it that the detonation wave would push the rocket but not damage it.


Push, push, push, coast… push, push…

The whole design of the ship was heavy and strong enough to handle the impacts of the blast waves without being rattled by the shock of multiple detonations (uh huh).

Like opening your car door and throwing dynamite out to go off behind the car to keep it rolling, lol… sort of.

It was the hardest part of the book for me to read, everything up until that point was good, the finale left me tongue in me cheek.

originally posted by: wildespace
I find it counter-productive that a lot of the energy from nuclear explosions will have to be absorbed by the dampener and huge mass of the spacecraft. Will this really be more effient than burning fuel?

No it wouldn't You saw Gravity? The thrusters are programmed to counter momentum and direction from all sides at once, not just from behind.

The various life boats shes in show that pretty well, including landing jets in one and a fire extinguisher even to change direction.

Detonating bombs might be good to accelerate a rocket along a pre planned long duration trajectory but what about side thrusts for course correction in Zero G?

Sustained thrust is why they design jet engines and rocket motors that way.