What's the fastest form of space propulsion we can achieve right now?

thought it was illegal to even station nukes in space

no. It is completely illegal to put nuclear bombs in orbit.

This is because of FOBS. Thanks for ruining everything FOBS

Outer system probes have had reactors sine forever, though. So everybody is orbiting at least a little nuclear shit.

Not sure if some of you guys are confusing nuclear powered rockets with Project Orion, or what. But nuclear powered thises and thats have been launched for decades. Apollo LM carried a nuclear generator to leave on the moon to power experiments, for example.

Orbiting radioactive material makes environmentalists mad from time to time, but is not against the law.

>systems powered via radiative heat
>systems propelled via actual nuclear explosions

You see the difference, senpai?

'electrothermodynamic propulsion' or something like that

I do, I was merely pointing out that there is no prohibition on putting radioactive and reactors into orbit., and that therefore "atomic space drives" are allowed.

Again I think folks are confusing Orion (Project Multiple Atom Explosions Fuck Year!) with drives that use nuclear energy for heating reaction mass or generating electrical power and ions and shit.

>radioactive materials

Ooops.

Last time I looked, the fastest human made objet ever was NASA'S Juno spacecraft at around 25 miles per second. So the answer is -- launching with a Atlas V and then getting a hellacious gravity-boost in an Earth flyby. The gravity-boost part is the critical part.

I suppose the USA could simply drop out of the treaty and do what it wants to do.

The Helios probes were faster. Helios 2 reached over 40 miles a second at perihelion. We can thus conclude that the fastest form of space travel is throwing yourself at the Sun using a Titan III-Centaur.

I stand corrected.

But in both cases. falling toward a huge mass from a great distance seems to be the best system we have for gong really, really fast.

Nuclear propulsion.
en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

Literally having exploding atomic bomb behind your back used as propulsion.

In the case of medusa it'll be out front

Definitely nuclear propulsion as what was said numerous times before.

Wow, as if Orion wasn't enough retarded.
Can't there be a very controlled stream chain reactrion instead of pulses/bombs? Maybe a nuclear core structured like a graphene string so the reaction goes gently - atom after atom?

>fastest form of space propulsion
What does he even mean by that?

NERVA Rockets

What do you mean by fastest? Highest acceleration, greatest delta-v? Maximum theoretical speed?

Yes to all of those

I'm a brainlet. Is there any actual risk on detonating nukes in space fairly close to Earth, or was it just a policy to defuse some of the tension during the Cold War?

The potential for a surprise first strike

The risk of having a nuke dropped on you with no warning, but we have better missiles now so it doesn't matter

Blame the Soviets for FOBS

I'm sure if there was a genuine need to build a space craft powered by a nuclear pulse propulsion engine, it would be built as an exception to the test ban treaty.

Obviously it would be built in high earth orbit. Something like that could not be launched from the surface, let alone from low earth orbit due to fallout.

the nuclear material has to get up there somehow, user

one way or another, it's riding a rocket up

We actually tried that accidentally destroying a lot of satellites. Also irradiated stratosphere, potential to blow away layers that keep the evil sun rays away.

True

But one doesn't need to put an Orion powered space craft into orbit by launching it via several hundred nuclear bombs either...

braaaaaaaap

>Your drive drags you through the expanding radioactive nuclear fireball of an exploding atomic bomb...

Sounds like a great idea. 17 of 17, would fly again.

Correct.. Can;t see the environmental lobby, and probably a lot of other people, loving the idea of lobbing all those nukes up to orbit to stock the Orion though. I'd guess we'll need to do this somewhere other than Earth, if we can find the radioactives.

[spoiler] Also -- "Footfall," by Niven and Pournelle, for a story that (spoiler) posits an emergency situation where an Orion is built and launched. [/spoiler]

No idea if spoiler tags work here.

>yfw the answer is weird pod racing

Put two of them on a wire.
When they are behind you, detonate.
When you are in front pull them along until you fall behind again.
Space Piston.
You can't make this shit up and call it science. This has to be a meme.

Zubrin's nuclear saltwater rocket

Didn't Larry Niven cowrite a similar story with Robert Forward?

Nope. Our missiles suck dick

WHAM
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WHAM
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WHAM
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WHAM
WHAM
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Footfall was a great book.

nuclear bombs

Haha, holy shit that mental image.

my new prius is pretty snappy

What if we take a prius, soup up the suspension, make the wheels out of metal, throw out the IC engine and put in the best electric motor we can get into it.

Then we put our supah-prius on the moon and drive it on a many kilometers long slot car like road straight into orbit. Hell if we plan our trajectory right we can even land it back on the road and do regenerative braking

Do you work in prius's advertising department
That sounds fucking retarded, even for a meme post.

The only part that is retarded is the need for machinery running at a gorillion rpm. So yeah it's pretty retarded.

It's fun though, because the moon has no air resistance wheeled vehicles should be able to reach absurdly high speed.

>soup up the suspension

en.wikipedia.org/wiki/Magnetic_field_oscillating_amplified_thruster

For the first few detonations or so, there are a few tricks you could use to minimize the fallout generated. The rest of the blasts would be high altitude airbursts. Such detonations are fairly clean as the fireball never impacts the ground irradiating/kicking up dust. (The main source of fallout.) You're also using fairly small bombs.

The real issue with a surface launch is that on your way generate EMPs. While such EMPs aren't quite as bad as Hollywood makes them out to be, they're still going to cause issues depending on where and in what direction you can launch. From a couple reports I've read a launch from a high latitude along the right trajectory would supposedly allow you to launch without disrupting very much. (Although those reports were decades old, the number of satellites in a polar LEO has grown dramatically. I doubt you'd be able to pull it off without some collateral damage)

And, of course, the politics of it would be, to put it very mildly, tricky.

Lead me.

Not that I can think of, but Forward chipped in on the mathematical underpinnings of "Integral Trees," iirc.

Depends how you mean.

New Horizons did 16.26 km/s with 5 rocket stages. Dawn had a higher overall delta-V expenditure, but it did so over the course of several years so it's not quite the same. Several spacecraft have achieved much faster velocities simply by descending into deep gravity wells around the Sun and Jupiter, but that's not really propulsion.

And of course there are ways to achieve more with currently-existing technologies... a conventional rocket with even more stages could increase delta-V (albeit only with ever-smaller payloads or ever-larger rockets). Ion propulsion has lots of room for growth even in a single-stage, though expending that much impulse would take decades. Solar sails can, in theory, achieve quite radical velocities with minimal payloads, especially if operating at low perihelion. As mentioned, some forms of nuclear propulsion are already viable and offer more delta-V than conventional rockets, but are avoided for legal, environmental and political reasons.
>bombs
But the only form of propulsion that involves bombs in pulse propulsion, which is scifi-tier and tremendously wasteful.

Ion propulsion and solar sails are two of the fastest i know of. They take a very long time to accelerate but if given the time they can hit insane speeds because the acceleration is exponential

solar sails, nuclear propulsion

apparently the memedrive