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Project Orion

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Re: Project Orion

#51

Post by vhodges »

rbanffy wrote: post #49
vhodges wrote: post #33

Earlier quoted context omitted.

replying to all... The story you're thinking of is King Davids Spaceship by Jerry Pournelle. It IS a co-dominion story (so same universe as The Mote in Gods Eye w/Larry Niven) A few other uses of Orion in fiction that I am aware of: The Ship 'Michael' (as in avenging angel) from Footfall (Again by Niven and Pournelle). And the ship from Orion shall rise by Paul Anderson. A CBC Miniseries featuring a (faked) Orion der…

> A CBC Miniseries featuring a (faked) Orion derived interstellar ark supposedly launched in the 60's and the people that have been living on it for almost 40 years. I think it was from SyFy. It was so bad it could only be SyFy. Could be a good murder mystery, if it were not ruined by the whole fake ship idea.

Yes, it was on SyFy, but was a CAD co-production so aired on CBC here.

Re: Project Orion

#52

Post by ianburrell »

api wrote: post #47

Thermonuclear Orion could (on paper) reach 10% the speed of light. Proxima Centauri in about 50 years using technology contemporary with the Beatles and Woodstock. This is why I have trouble dismissing the Fermi paradox. Either intelligent life that can engage in space flight is very rare (as in less than one per galaxy per billion years) or we are in a wildlife preserve or a zoo.

Project Daedalus could reach 10% speed of light. But that didn’t use thermonuclear bombs but laser-pumped inertial confinement fusion. It also didn’t use physical pusher but magnetic nozzle. We don’t know how to do them with our technology but should be possible. There are followons that are more doable but slower.

I have seen Wikipedia quote 10% for regular Orion but not finding any sources. I find that speed unlikely with all the trouble that Daedalus and others went through to get interstellar pulse rockets. I see 6ksec impulse for could-build-now Orion, 100ksec for theoretical improvements, and Daedalus would be 1Msec. Regular Orion probably maxes out at 1%.

Fission Orion is infeasible for interstellar because need huge quantities of fissionables, maybe 10-100x weight of ship. Fusion has advantage of using cheap elements.

Re: Project Orion

#53

Post by shagie »

nyrath wrote: post #25
AnimalMuppet wrote: post #15

Earlier quoted context omitted.

"King David's Spaceship". I believe it was by Niven, but I'm not sure.

"King David's Spaceship" aka "A Spaceship For The King" by Jerry Pournelle

It certainly is that book.

The wiki https://en.wikipedia.org/wiki/King_David%27s_Spaceship

It's been a long time since I read it... but the specifics of that part of the story:

> Back in Haven, Dougal's men used the acquired knowledge to build a primitive crewed spaceship, adopting a low-tech design of Robert Goddard—a rapid firing cannon using high-explosive shells detonating behind the ship to provide propulsion (but which might blow up the ship). Because the ship would not be airtight, only members of MacKinnie's company (who still had their space suits) could pilot it, and because it would only be able to carry a minimal payload, Graham (the lightest of the company) volunteered and was chosen as pilot. Before the launch, MacKinnie proposed to her, and she accepted. As soon as Prince Samual's World was unified, and in the presence of unsuspecting Imperial witnesses, Graham's ship was launched and achieved orbit, although it could not re-enter the atmosphere (meaning that the Imperials had to rescue Graham). King David then immediately requested that Prince Samual's World be admitted to the Second Empire as a self-governing world capable of crewed space travel, not as a colony.

Re: Project Orion

#54

Post by RajT88 »

rbanffy wrote: post #49
vhodges wrote: post #33

Earlier quoted context omitted.

replying to all... The story you're thinking of is King Davids Spaceship by Jerry Pournelle. It IS a co-dominion story (so same universe as The Mote in Gods Eye w/Larry Niven) A few other uses of Orion in fiction that I am aware of: The Ship 'Michael' (as in avenging angel) from Footfall (Again by Niven and Pournelle). And the ship from Orion shall rise by Paul Anderson. A CBC Miniseries featuring a (faked) Orion der…

> A CBC Miniseries featuring a (faked) Orion derived interstellar ark supposedly launched in the 60's and the people that have been living on it for almost 40 years. I think it was from SyFy. It was so bad it could only be SyFy. Could be a good murder mystery, if it were not ruined by the whole fake ship idea.

This one I believe:

https://en.m.wikipedia.org/wiki/Ascension_(miniseries)

You have to rate a show like this relatively if you are watching on a network filled with crap. It was not bad for a SyFy show!

> Could be a good murder mystery, if it were not ruined by the whole fake ship idea.

Not quite what you are thinking, but you may enjoy Aniara:

https://m.imdb.com/title/tt7589524/

Re: Project Orion

#55

Post by Schroedingersat »

perihelions wrote: post #19
st_goliath wrote: post #6

An other quite interesting concept (also a little less "out there" and actually, successfully tested) is the NERVA engine, also linked at the bottom of the article[1]. It uses a nuclear reactor to heat up a single propellant (liquid hydrogen) which then rapidly expands as it goes out the nozzle at the end, resulting in quite high specific impulse and is more efficient than a chemical rocket. If we want to go really f…

There's one more: the boring idea of combining a closed, electric-generating nuclear fission system with an (electric-powered) ion engine. Both components being flight tested and not crazy.

What is the specific power of a nuclear reactor + heat engine + crew shielding + radiators? Naval reactors are on the order of a few watts to tens of watts per kg and they have the benefit of unlimited cooling.

Seems an order of magnitude short of PV.

Re: Project Orion

#56

Post by AtlasBarfed »

mpweiher wrote: post #28
marktangotango wrote: post #8

There was a classic science fiction story with a twist on this idea; a low tech species was about to be discovered by a more advanced species. And according to the rules of the more advanced species, any planet that wasn't capable of space travel would become a client or vassal, and a planet with space travel would be seen as a peer. The protagonist built a pusher style rocket using an explosive, and launched the lig…

> Footfall by Niven and Pournelle which featured launching the USS Missouri into orbit on an Orion style pusher Yes, there was an Orion. No they didn't launch the USS Missouri. The ship was called Michael and featured, among other crazy weaponry, X-Ray lasers of the SDI type, i.e. some material (ruby?) pumped by a nuke. The nuke would destroy the material, but in the process get it to lase X-Rays. Heck, if you're usi…

An orion spacecraft's best efficiency is a ship the size of millions of tons.

Yeah, you don't need to cross the T's on that as much.

Re: Project Orion

#57

Post by AtlasBarfed »

KineticLensman wrote: post #10
marktangotango wrote: post #8

There was a classic science fiction story with a twist on this idea; a low tech species was about to be discovered by a more advanced species. And according to the rules of the more advanced species, any planet that wasn't capable of space travel would become a client or vassal, and a planet with space travel would be seen as a peer. The protagonist built a pusher style rocket using an explosive, and launched the lig…

That doesn't sound part of Niven's Known Space canon. However, 'Footfall' by Niven and Pournelle does have an Orion, as does Invisible Sun, by Charles Stross. Nothing obvious in [0] [0] https://en.wikipedia.org/wiki/List_of_stories_featuring_nucl...

It was a Niven / Pournelle mashup. Also, Lucifer's Hammer is a fun read I recall.

Re: Project Orion

#58

Post by AtlasBarfed »

st_goliath wrote: post #6

An other quite interesting concept (also a little less "out there" and actually, successfully tested) is the NERVA engine, also linked at the bottom of the article[1]. It uses a nuclear reactor to heat up a single propellant (liquid hydrogen) which then rapidly expands as it goes out the nozzle at the end, resulting in quite high specific impulse and is more efficient than a chemical rocket. If we want to go really f…

I don't think it is "out there" really. It's pretty simple. Bombs, plate, boom. It went through a pretty thorough development cycle at General Atomics, and they didn't have modern simulators.

I think it would be great if we get a moon base going that could build it from regolith. Then you ship up the bombs in a few runs of Starship and you have a badass solar system exploration rig.

From the docs, they could get to Saturn in something crazy like 1 month.

Re: Project Orion

#59

Post by diamondlovesyou »

breppp wrote: post #3

Similarly crazy idea, https://en.wikipedia.org/wiki/Nike_Hercules A nuclear tipped SAM, blow all the missiles out of the sky together with the sky

> Like almost any thorny military problem of the 1950s, the solution was the application of nuclear bombs.

Magnificent.

Re: Project Orion

#60

Post by mikewarot »

ianburrell wrote: post #12

Project Orion is a really bad idea. I guess it could be a good idea in specific situation where have to get a lot of mass off the planet and don't care about the effects. Problem one is that detonating a series of nuclear bombs in the atmosphere. The first couple are close to the ground and produce local fallout, the higher ones produce global fallout. Problem two is that detonating nuclear bombs in space causes EMP.…

It wasn't as bad as you would expect. The total fallout on Earth from a launch would have been about the same as a single 10 Megaton air burst, which we were doing all the time back then.
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