LEO to Lunar Orbit shuttle?

[Anonymous No.1835799]

http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket

So, /sci/, say we put a big-ass version of one of these in orbit powered by something like a scaled-up version of the SAFE-400 reactor.

How possible would it be to get it to Lunar orbit? If it is possible, you can have it shuttle cargo and crew to the Moon and back, and all you'd have to do is get the payload to low earth orbit, which is relatively cheap.

What say you, /sci/?

[Anonymous No.1835874]

[Inurdaes !V1sPhobos. No.1835930]

>>1835799
>So, /sci/, say we put a big-ass version of one of these in orbit powered by something like a scaled-up version of the SAFE-400 reactor.
>big-ass version of one of these in orbit
There's your problem. That won't be cheap.

[Anonymous No.1835937]

>>1835930

But compared to the cost of spacelifting the rockets and fuel needed to reach the moon every time you want to do a launch?

[Inurdaes !V1sPhobos. No.1835952]

>>1835937
Personally I'd just build a space elevator.
Your proposal would go nicely with it, though.

[Anonymous No.1836601]

>SAFE-400 reactor.

Yeah, good luck getting approval for that. NASA got shit from putting a plutonium battery on the LM. Can you imagine the shitstorm that a full blown reactor would cause?

[Anonymous No.1836637]

This is a very promising technology indeed. But it would really shine in interplanetary missions, where travel times with high-ISP engines like this could be reduced substantialy (months instead of years).

For Earth-Moon space, the trip would actually last longer than with chemical propulsion, because it has low acceleration.

[Anonymous No.1836644]

>>1836601

Thats not a big problem, there are other countries capable of launching things to space than the US, and some would not give a shit.

[Anonymous No.1836869]

>For Earth-Moon space, the trip would actually last longer than with chemical propulsion, because it has low acceleration.

Yes, but it'd be a lot cheaper. And if you can give it enough power, you can get a decent amount of thrust while keeping the SI relatively low.

[Anonymous No.1837368]

I was wondering about something.

Even if it's just to reach GEO a VSIMR could be interesting to push the first element of a space elevator or even of a solar station.

But I've been said that Slow acceleration are bad when it come to Orbit to Orbit maneuver, it is right ?

[Anonymous No.1837381]

reactors in space? greenpeace would never allow it. what if we polluted the space with radiation?

[Anonymous No.1837446]

>>1837381

>Implying space isn't extremely radioactive already

[Anonymous No.1837499]

>>1837368
>But I've been said that Slow acceleration are bad when it come to Orbit to Orbit maneuver, it is right ?

Well it depends on what you need it for. If you need to keep a platform in orbit, or make changes to the inclination or height of the orbit, and time isn't a factor, Ion engines are good.

But for orbital shuttles like I suggested in the OP, you'd need something a lot more powerful than the 200kW VASIMR engines that are going onto the Space Station. Those engines only provide 5N of thrust. By comparison, the OMEs on the space shuttle provide a combined thrust of over 50,000N.

You'd need a power output on the order of several Megawatts to match that. Or lower the engine efficiency to the point where you'd need to lift massive fuel tanks to orbit, which defeats the point. Which is why you'd need something like a reactor to provide that much power.

Of course, keeping a Megawatt reactor cooled in space is another matter entirely.

[Fwibbib No.1837511]

>>1837446

I have a slight feeling that he was being SARCASTIC.
*facepalm*
but to be fair the space whales would get radiation poisoning...

[Anonymous No.1837570]

>>1837511

[Anonymous No.1837604]

What was /sci/ reaction when congress passed the new space plan?

[Anonymous No.1837622]

>>1837604

[Anonymous No.1837638]

>>1837604

"The new heavy lifter better be superior in all ways to Constellation."

[Anonymous No.1837658]

Hey retarded fags, news flash vasimir is shit. It has less thrust per MW slower isp and more mass than a Hall effect thruster. They have been in space since 1971 and are ready to fly today. The only thing vasimr has over competing technology is public relations that get fools like you to drink the coolaid.

[Anonymous No.1837674]

>>1837658

"In spacecraft propulsion, a Hall thruster is a type of ion thruster in which the propellant is accelerated by an electric field."

This appears to be the same thing as VASIMR.

[Anonymous No.1837676]

>>1837638
>>1837604
clearly you tards have never read anything from the knowladgable people.

Constellation ( ares 1 / ares 5 ) was IMPOSSIBLE. The cost overruns where so bad, that even IF we remove ALL development costs and the building of the rocket, nasa could not use them - the maintenance costs where enough - alone - to bankrupt them.

The Direct launcher meanwhile ( or basically, the thing they call "SLS" now is easier, better and can be upgraded. commercial will do humans.

fuck, did you ever even look at the fucking ares-1?
its a SOLID FIRST STAGE PEOPLE LAUNCHER
think hard about this; there is a reason that they dont use this. Basically, its fucking suicide. Ever wonder what rockets do when the engines start up ( ariane, shuttle, soyuz, falcon 1/9 etc )? they check out the engines. Try that with a solid fuel rocket. If you light it, its going up.

also, there are various "black zones" during ascent where there will be a complete LOV and LOC due the speed of burning debris of an exploding ares 1 first stage.


the bill? it isnt perfect, but it barely saved NASA HSF; a worthy compromise - although I would dearly, dearly like them to kick out ATK and their lobbying against anything which can fly without their fuckhueg expensive SRBMS. There is a reason why other rockets use small boosters and big hydrolox/ kerolox stages - its way safer and modifiable.

basically, anything solid sucks for people launchers.

[Anonymous No.1837681]

>>1837674
except for the fact that they are used in space right fucking now.

[Anonymous No.1837684]

>>1837658
>Hall-Effect thrusters

You do realize that hall thrusters burn out with use? With proper cooling, and enough propellant VASIMR engines can run indefinitely. They also easily scale.

[Anonymous No.1837690]

>>1837684
correct. this is nice, but not really a very big advantage. it should clearly be developed, but it isnt some silver bullet that can fix everything; it has its ( big ) problems.

[Anonymous No.1837712]

>>1837690

Everything has problems. Problems can be worked out.

[Anonymous No.1837735]

>>1837676


stop feeding the trolls.

[Anonymous No.1837764]

>>1837676

I feel as though I actually learned something.

[Anonymous No.1837780]

>>1837684
>>1837712
Yep superconducting magnets on your thruster work that out of the equation. Vasimr will also burn out, the magnetic field prevents most but not all of the plasma from contacting components.

Vasimr doesn't scale worth shit because no matter how big you scale it, it will still me more massive than an array of hall thrusters. You cant scale it down because the mass required for the cryocoolers to keep the superconducting magnets working don't scale that well.

[Anonymous No.1837785]

seems like it would be a good option for long distance journeys where you can keep adding acceleration over time without taking too much fuel with you. Might be good on larger scales for a 2ly satellite journey say.

[Anonymous No.1837793]

>>1837676
I agree 75% with this guy. The srb's we use now are megga suck money pits ~$100m each. I would however not be opposed to smaller expendable single segment srb's to attach when you want a little more payload capability. A solid done correctly really is more safe than a liquid, you can build the thing with zero moving parts if the liquid its tied to has adequate attitude control.

[Anonymous No.1838222]

>>1837780

Yeah, but by the time a VASIMR thruster broke down, you'd have gone through a dozen halls. And a hall array would be big and completely unwieldy if you want to apply more than a few Newtons of force.

[Anonymous No.1839142]

>>1838222
Hall effect have significantly less mass per Newton of thrust they also use less energy and fuel. You can design them to have replaceable consumables. They cost less also, making them superior in every way.

[Anonymous No.1839264]

>>1839142

Except operating life, and complexity. To provide thrust equivalent to a 200kW VASIMR, you'd need an array of over 100 hall thrusters. Noone's going to build valves and piping and circuits for 100 thrusters when they can get away with just one. It's way too complicated for a spacecraft.

[Anonymous No.1839334]

>>1839264
You can make the Hall thrusters with replaceable consumables.

Also your 100% wrong about the 100 hall thrusters. Your 200 kw vasimr has a thrust of 5N we have Hall thrusters with 3N so at most you would need two of them.

[Anonymous No.1839553]

>>1839334

The 3N hall thrusters have never gotten past very early prototype/tech demos, and when you operate them at such high power, all the advantages of hall thrusters over VASIMR disappear. They suck up more electricity, and they use more fuel.

[Anonymous No.1839990]

>>1837604
OH FUCK
THAT HAPPENED?
which one won? the senate or house bill?

[Anonymous No.1840230]

>>1839990
> which one won? the senate or house bill?
Senate. Thank fuck.