/sci/ - Science & Math

[Anonymous No.8783532]

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

[Anonymous No.8783547]

>>8783532
Stealin' teh gravety whells on ova' plarnets en past bye.

[Anonymous No.8783569]

>>8783532
That shit where we shoot lasers at a thing to accelerate it

[Anonymous No.8783573]

>>8783569
>Itty bitty photons vs. celestial bodies.
Whatever, buddy, whatever.

[Anonymous No.8783577]

>>8783532

nuclear propulsion has been technically feasible for decades but is incredibly illegal.

[Anonymous No.8783584]

>>8783577
>This

[Anonymous No.8783612]

>>8783577
Can't it be built in orbit ?

[Anonymous No.8783622]

>>8783612
the treaty says no nuclear shit in space.

[Anonymous No.8783959]

>>8783622
>watch your mouth young man

[Anonymous No.8783968]

>>8783612
Building it isn't illegal, starting it up is.

[Anonymous No.8784005]

>>8783968
thought it was illegal to even station nukes in space

[Anonymous No.8784008]

>>8783612
no. It is completely illegal to put nuclear bombs in orbit.

This is because of FOBS. Thanks for ruining everything FOBS

[Anonymous No.8784064]

>>8783622
Outer system probes have had reactors sine forever, though. So everybody is orbiting at least a little nuclear shit.

[Anonymous No.8784067]

>>8783532
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.

[Anonymous No.8784068]

>>8784064

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

You see the difference, senpai?

[Anonymous No.8784079]

'electrothermodynamic propulsion' or something like that

[Anonymous No.8784148]

>>8784068
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.

[Anonymous No.8784151]

>>8784148
>radioactive materials

Ooops.

[Anonymous No.8784163]

>>8783532
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.

[Anonymous No.8784174]

>>8784008
I suppose the USA could simply drop out of the treaty and do what it wants to do.

[Anonymous No.8784186]

>>8784163
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.

[Anonymous No.8784234]

>>8784186
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.

[Anonymous No.8784236]

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

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

[Anonymous No.8784245]

>>8784236
In the case of medusa it'll be out front

[Anonymous No.8784267]

Definitely nuclear propulsion as what was said numerous times before.

[Anonymous No.8784293]

>>8784245
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?

>>8783532
>fastest form of space propulsion
What does he even mean by that?

[Anonymous No.8784294]

>>8783532

NERVA Rockets

[Anonymous No.8784304]

>>8783532
What do you mean by fastest? Highest acceleration, greatest delta-v? Maximum theoretical speed?

[Anonymous No.8784314]

>>8784304

Yes to all of those

[Anonymous No.8784331]

>>8784008
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?

[Anonymous No.8784337]

>>8784331
The potential for a surprise first strike

[Anonymous No.8784338]

>>8784331
The risk of having a nuke dropped on you with no warning, but we have better missiles now so it doesn't matter

[Anonymous No.8784347]

>>8784008

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.

[Anonymous No.8784380]

>>8784347

the nuclear material has to get up there somehow, anon

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

[Anonymous No.8784482]

>>8784331
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.

[Anonymous No.8785143]

>>8784380

True

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

[Anonymous No.8785879]

braaaaaaaap

[Anonymous No.8785924]

>>8784245
>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.

[Anonymous No.8785940]

>>8785143
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.

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

No idea if spoiler tags work here.

[Anonymous No.8785944]

>>8784245
>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.

[Anonymous No.8785966]

Zubrin's nuclear saltwater rocket

[Anonymous No.8786015]

>>8785940

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

[Anonymous No.8786182]

>>8784338
Nope. Our missiles suck dick

[Anonymous No.8786203]

>>8785940
WHAM
.
WHAM
.
WHAM
.
WHAM
WHAM
.
Footfall was a great book.

[Anonymous No.8786306]

>>8783532
nuclear bombs

[Anonymous No.8786309]

>>8785944
Haha, holy shit that mental image.

[Anonymous No.8786317]

>>8783532
my new prius is pretty snappy

[Anonymous No.8786355]

>>8786317
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

[Anonymous No.8786439]

>>8786355
Do you work in prius's advertising department
That sounds fucking retarded, even for a meme post.

[Anonymous No.8786631]

>>8786439
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.

[Anonymous No.8786642]

>>8786355

>soup up the suspension

[Anonymous No.8786684]

>>8784079
https://en.wikipedia.org/wiki/Magnetic_field_oscillating_amplified_thruster

[Anonymous No.8786746]

>>8784347
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)

[Anonymous No.8786763]

>>8786746
And, of course, the politics of it would be, to put it very mildly, tricky.

[Anonymous No.8786773]

>>8786203
Lead me.

[Anonymous No.8786777]

>>8786015
Not that I can think of, but Forward chipped in on the mathematical underpinnings of "Integral Trees," iirc.

[Anonymous No.8786780]

>>8783532
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 >>8783577 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.
>>8784008
>bombs
But the only form of propulsion that involves bombs in pulse propulsion, which is scifi-tier and tremendously wasteful.

[Anonymous No.8786786]

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

[Carbon No.8787826]

>>8783532
solar sails, nuclear propulsion

apparently the memedrive