The long Discovery space craft depicted in the latter half of "2001: A Space Odyssey" was derived from the nuclear rocket. It was suggested that the radioactive part of an Orion-style space craft be put far away from the crew compartment.
We can probably can thank Fred Ordway (Marshall Spaceflight Center engineer) who Kubrick brought on board as technical consultant back then. (And of course for the look of the ships that are still so iconic over 50 years later I shouldn't leave off Harry Lange.)
The 2001 spacecraft was implied to be a NERVA-type nuclear rocket (ie push working fluid through a high temperature reactor), rather than an Orion type (propulsion via small nuclear explosions).
But yeah, "crew module, long thing, engine" was how these were, virtually always, depicted in sci-fi.
Pictures of Orion concepts have been widely distributed for decades, but not this one. Going into space with an air-breathing nuclear bomb powered jet engine. That is truly weird. How fast was it supposed to be going in atmosphere, I wonder. Did it carry reaction mass for vacuum so it could keep going out of the atmosphere?
The trouble with nuclear rockets is that although you have plenty of energy, you still need to carry reaction mass - air, or water, or something - and a lot of it. That becomes the limit on delta-V.
(The great frustration of rockets: not only do rockets need something to push against, they have to carry it with them.)
> not only do rockets need something to push against, they have to carry it with them
I think you meant "something to push with. But anyways, nuclear explosions make their own hot gasses out of the reactants, and the problem with that is getting that to be directed and also to not get the ship -you know- blown up in the process.
A better approach is to have a nuclear reactor to heat reaction gasses to much higher temps than chemical reactions allow for, thus increasing ISP a lot. The main problem with this is that nuclear reactors need a lot of cooling, even and especially after you shut them off, and the reaction gasses are going to be your only way to cool them. Alternatively you can carry huge radiators -- really huge, because in space you don't get to exchange heat with an atmosphere or a body of water, so you can only radiate or ablate away the excess heat, and either way would require huge amounts of extra mass. Another problem is that stop/start latency with nuclear reactors is huge, so they would only work for interstellar travel, I think. I'm sure if you carry enough reaction mass then nuclear reactors can work well for interstellar trips.
Nuclear explosions don't have "reactants". There's just a few Kg of Uranium or other fuel and a little conventional explosive to trigger it, and that's all. That's not enough mass to propell anything of significant size outside of atmosphere. The speed at which the mass is ejected from the engine counts, of course, but a nuke won't give the same speeds as an ion engine for example.
Aldebaran spacecraft proposed to "intake" air. But it's mass means it would have to intake A LOT of air. And that engine, as described in the article, doesn't seem to compress the air before each bomb expands it. I don't think it would work.
IIRC, the Orion project proposed to wrap each bomb in one ton of polypropylene. It would provide mass and also reduce radiation fallout.
Uh, is it really clear to say that rockets "push against" something? That makes it sound as if they could absolutely not work in space, which they obviously do.
"They push against their own exhaust" seems to be the idea that motivates the pushing explanation, but to me that just invites the question "using what?" and makes things even more complicated. At least in my opinion.
I think Newton's 3rd ([1], forces and reaction forces) is a better explanation.
See also this image from the article. The design of the Aldebaran is a giant flying boat, with air intakes in the wings to help create the nuclear exhaust exiting the reaction chamber nozzle.
Here's the famous XKCD radiation dosage chart for scale: https://xkcd.com/radiation/ . The highest scale in the chart, the yellow boxes, represents 50 Sieverts, of the dosage received from standing next to the Chernobyl core for ten minutes just after meltdown. A conservative estimate is that one launch on this thing would expose the crew to 5000 Sieverts, or 100 Chernobyls worth. Furthermore, we've sen how simple atmospheric nuclear testing irradiated the entire planet for half a century (see the Kodak film story and low-background steel), any prolonged use of this thing would have caused cancer rates to (ahem) skyrocket worldwide due to distribution of nuclear fallout into the atmosphere.
Let's not romanticize stupid ideas. Leave this one in the dustbin of history.
This would be neat to see in space where the fallout wouldn't be an environmental issue. I have to wonder if anyone with significant credentials has considered a high-thrust nuclear ion-drive yet. Certainly sci-fi has!
Our Solar system is a gravitational well that tends to put things in solar orbit. You really want the waste products to leave the solar system, which isn't terribly difficult, or you want them to land on the sun itself, which is exceptionally difficult.
Our Solar system is a gravitational well that tends to put things in solar orbit. You really want the waste products to leave the solar system, which isn't terribly difficult, or you want them to land on the sun itself, which is exceptionally difficult.
Yes, it is counter intuitive but it takes less energy to leave the solar system get to the sun (you have to cancel out the Earth's orbital speed). Something learned from Kerbel Space Program.
Time ago I read that the cheapest way to do it (energy wise) is going very far away, let's say entering Pluto's or Neptune's orbits, cancel out the orbital speed there (it's lower than Earth's one) and then fall into the sun. It takes quite a bit of patience.
In practice in the real solar system, the cheapest way to get from Earth to the Sun is to use Jupiter. Launch to there and reverse-slingshot to cancel out the orbital velocity and drop directly towards the Sun. The Parker Solar Probe would have done this, although decided not to because of the complications in designing to handle both the cold of Jupiter and the heat of the Sun.
Seems small. The proposed Super Orion would lift 8 million tons to orbit. From wikipedia:
> The biggest design above is the "super" Orion design; at 8 million tons, it could easily be a city. [...] This extreme design could be built with materials and techniques that could be obtained in 1958 or were anticipated to be available shortly after.
The long Discovery space craft depicted in the latter half of "2001: A Space Odyssey" was derived from the nuclear rocket. It was suggested that the radioactive part of an Orion-style space craft be put far away from the crew compartment.
We can probably can thank Fred Ordway (Marshall Spaceflight Center engineer) who Kubrick brought on board as technical consultant back then. (And of course for the look of the ships that are still so iconic over 50 years later I shouldn't leave off Harry Lange.)
The 2001 spacecraft was implied to be a NERVA-type nuclear rocket (ie push working fluid through a high temperature reactor), rather than an Orion type (propulsion via small nuclear explosions).
But yeah, "crew module, long thing, engine" was how these were, virtually always, depicted in sci-fi.
NERVA makes sense with all the "tanks" along th length of the Discovery spacecraft from that movie.
Pictures of Orion concepts have been widely distributed for decades, but not this one. Going into space with an air-breathing nuclear bomb powered jet engine. That is truly weird. How fast was it supposed to be going in atmosphere, I wonder. Did it carry reaction mass for vacuum so it could keep going out of the atmosphere?
The trouble with nuclear rockets is that although you have plenty of energy, you still need to carry reaction mass - air, or water, or something - and a lot of it. That becomes the limit on delta-V.
(The great frustration of rockets: not only do rockets need something to push against, they have to carry it with them.)
> not only do rockets need something to push against, they have to carry it with them
I think you meant "something to push with. But anyways, nuclear explosions make their own hot gasses out of the reactants, and the problem with that is getting that to be directed and also to not get the ship -you know- blown up in the process.
A better approach is to have a nuclear reactor to heat reaction gasses to much higher temps than chemical reactions allow for, thus increasing ISP a lot. The main problem with this is that nuclear reactors need a lot of cooling, even and especially after you shut them off, and the reaction gasses are going to be your only way to cool them. Alternatively you can carry huge radiators -- really huge, because in space you don't get to exchange heat with an atmosphere or a body of water, so you can only radiate or ablate away the excess heat, and either way would require huge amounts of extra mass. Another problem is that stop/start latency with nuclear reactors is huge, so they would only work for interstellar travel, I think. I'm sure if you carry enough reaction mass then nuclear reactors can work well for interstellar trips.
Nuclear explosions don't have "reactants". There's just a few Kg of Uranium or other fuel and a little conventional explosive to trigger it, and that's all. That's not enough mass to propell anything of significant size outside of atmosphere. The speed at which the mass is ejected from the engine counts, of course, but a nuke won't give the same speeds as an ion engine for example.
Aldebaran spacecraft proposed to "intake" air. But it's mass means it would have to intake A LOT of air. And that engine, as described in the article, doesn't seem to compress the air before each bomb expands it. I don't think it would work.
IIRC, the Orion project proposed to wrap each bomb in one ton of polypropylene. It would provide mass and also reduce radiation fallout.
By pushing against it they are pushing with it
Uh, is it really clear to say that rockets "push against" something? That makes it sound as if they could absolutely not work in space, which they obviously do.
"They push against their own exhaust" seems to be the idea that motivates the pushing explanation, but to me that just invites the question "using what?" and makes things even more complicated. At least in my opinion.
I think Newton's 3rd ([1], forces and reaction forces) is a better explanation.
[1]: https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion
> rockets need something to push against, they have to carry it with them.
(Emphasis added)
The rocket exhaust is "pushing against" the rocket itself, propelling it forward.
Rocket exhaust goes <- which creates the equal and opposite force -> which pushes against the mass of the rocket sending it on its way.
Some visuals https://interestingengineering.com/science/project-orion-the...
PDF in this article is a 404
See also this image from the article. The design of the Aldebaran is a giant flying boat, with air intakes in the wings to help create the nuclear exhaust exiting the reaction chamber nozzle.
https://up-ship.com/blog/wp-content/uploads/2010/02/image25....
Gorgeous. Maybe there is a universe...
What a time of dreaming big…
Here's the famous XKCD radiation dosage chart for scale: https://xkcd.com/radiation/ . The highest scale in the chart, the yellow boxes, represents 50 Sieverts, of the dosage received from standing next to the Chernobyl core for ten minutes just after meltdown. A conservative estimate is that one launch on this thing would expose the crew to 5000 Sieverts, or 100 Chernobyls worth. Furthermore, we've sen how simple atmospheric nuclear testing irradiated the entire planet for half a century (see the Kodak film story and low-background steel), any prolonged use of this thing would have caused cancer rates to (ahem) skyrocket worldwide due to distribution of nuclear fallout into the atmosphere.
Let's not romanticize stupid ideas. Leave this one in the dustbin of history.
Very cool, but you seem to be confused. I’ve not endorsed or romanticized any specific idea.
Who made the estimate?
This would be neat to see in space where the fallout wouldn't be an environmental issue. I have to wonder if anyone with significant credentials has considered a high-thrust nuclear ion-drive yet. Certainly sci-fi has!
> the fallout wouldn't be an environmental issue.
"It's outside the environment."
> has considered a high-thrust nuclear
Of course we have. Always start at NTRS: https://ntrs.nasa.gov/citations/19690000736
> Certainly sci-fi has!
Our Solar system is a gravitational well that tends to put things in solar orbit. You really want the waste products to leave the solar system, which isn't terribly difficult, or you want them to land on the sun itself, which is exceptionally difficult.
Our Solar system is a gravitational well that tends to put things in solar orbit. You really want the waste products to leave the solar system, which isn't terribly difficult, or you want them to land on the sun itself, which is exceptionally difficult.
Yes, it is counter intuitive but it takes less energy to leave the solar system get to the sun (you have to cancel out the Earth's orbital speed). Something learned from Kerbel Space Program.
Time ago I read that the cheapest way to do it (energy wise) is going very far away, let's say entering Pluto's or Neptune's orbits, cancel out the orbital speed there (it's lower than Earth's one) and then fall into the sun. It takes quite a bit of patience.
Right, this is a bi-elliptic transfer, which is delta-v-cheaper than a Hohmann transfer for widely separated orbits. https://en.wikipedia.org/wiki/Bi-elliptic_transfer
In practice in the real solar system, the cheapest way to get from Earth to the Sun is to use Jupiter. Launch to there and reverse-slingshot to cancel out the orbital velocity and drop directly towards the Sun. The Parker Solar Probe would have done this, although decided not to because of the complications in designing to handle both the cold of Jupiter and the heat of the Sun.
I’m okay with waste products on an orbit that doesn’t make them rain on Earth for a few dozen millennia.
Why would it be okay to rain the waste products on earth in a few dozen millenia. Do you think life will be over by then?
All the really dangerous isotopes have decayed by then.
Seems small. The proposed Super Orion would lift 8 million tons to orbit. From wikipedia:
> The biggest design above is the "super" Orion design; at 8 million tons, it could easily be a city. [...] This extreme design could be built with materials and techniques that could be obtained in 1958 or were anticipated to be available shortly after.
On Wikipedia "List of stories featuring nuclear pulse propulsion"
https://en.wikipedia.org/wiki/List_of_stories_featuring_nucl...
See "To Mars by A-bomb", a documentary about project Orion.
https://www.imdb.com/title/tt1039992/
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(2010)