Russian Space Based Nuclear Reactor and Engine

[Tea Party Space Czar]

I am not sure if we have people who are willing to dig through and translate this but Russia wants to fly this in 2018.  This would be awesome if they are successful.

http://zakupki.rosatom.ru/1410010656646

http://russianspacenews.com/rosatom-and-kurchatov-institute-making-thermo-nuclear-battery-for-space/

http://rbth.asia/articles/2012/11/09/roscosmos_changes_direction_on_prototype_17829.html

Megawatt class... you could fire off a few VASMIR engines with a megawatt class reactor in space.  Think about that - in LEO you could change orbits so easily.  Fly to the moon in a day.

[aceshigh]

Yeah, but VASMIR needs 200Mw for their 39 days Mars mission profile.

What is the watt per gram of the Russian reactor?

[Tea Party Space Czar]

Its why I posted it - need Russian interpretation. 

This is something NASA should be doing - a 1 Gigawatt Space Based Nuclear Reactor.

[aceshigh]

Its why I posted it - need Russian interpretation. 

This is something NASA should be doing - a 1 Gigawatt Space Based Nuclear Reactor.

your nickname is CZAR and you canīt translate Russian

[gospacex]

Its why I posted it - need Russian interpretation. 

This is something NASA should be doing - a 1 Gigawatt Space Based Nuclear Reactor.

The Russian article is nearly fact-free.

US isn't building space reactors because it is not at all obvious they would be useful in the next 10-30 years.

[Bob Shaw]

Which country will it land on when the whole thing goes badly, badly wrong? Maybe we should start the betting!

Seriously, this just sounds like another grandiose bit of Russian space vapourware, like all the other terrific projects they have promoted since they, too, discovered PowerPoint.

[sghill]

Its why I posted it - need Russian interpretation. 

This is something NASA should be doing - a 1 Gigawatt Space Based Nuclear Reactor.

your nickname is CZAR and you canīt translate Russian

*ahem*

BWAHAHAHAHAHA!!!!  That. Is. Hilarious...

Seriously though.  Russian space pronouncements are a VERY different animal than Russian space achievements.  The former are numerous and never happen.  The latter are stolid and real.

[cordwainer]

NEP is quite doable and NASA has used radio-isotopic thermal generators before in spacecraft. Building one of this size and power would have radiation and heat-management issues that would have to be overcome. I would have more faith in the Gas turbine modular helium reactors that OKBM and General Atomics were designing.

[momerathe]

I'm glad *someone* is giving NEP a close look. Europe will never do it for ideological reasons, and NASA has its.. unique political funding situation.

I would really like more detail on this "thermo-nuclear battery", and what's its special sauce is (or whether it's just hype). What sort of working fluid do you need for 1500šC operation?

[RanulfC]

Its why I posted it - need Russian interpretation. 

This is something NASA should be doing - a 1 Gigawatt Space Based Nuclear Reactor.

The Russian article is nearly fact-free.

US isn't building space reactors because it is not at all obvious they would be useful in the next 10-30 years.

Not because there is no "obvious" use because we CAN and do have a lot of ideas both for reactors and NTRs. The main problem is there is no will (and hence budget) for their development. I have no doubt if Russia were to actually TRY and build a large scale (and a 1gigawatt reactor would be one ) that the US will back Europe to the maxium in demanding that the Russians in fact NOT deploy it. Ever.
The good news is that if they DO pursue this then we might actually see some funding provided for the US Space Nuclear Power program... Not going to hold my breath though.

Randy

[savuporo]

The project was announced in 2009

http://www.21stcenturysciencetech.com/Articles_2012/Fall-Winter_2012/Interview_Koroteyev.pdf
http://osnetdaily.com/2014/01/russia-advances-development-of-nuclear-powered-spacecraft/

NSF thread: http://forum.nasaspaceflight.com/index.php?topic=2534.msg497446#msg497446

[chapi]

I'm glad *someone* is giving NEP a close look. Europe will never do it for ideological reasons, and NASA has its.. unique political funding situation.

Looks like despite ideological reluctance, there is at least one running research project in Europe in this area (funded by EU rather than ESA), dubbed Megahit (http://www.megahit-eu.org).

[momerathe]

a hybrid NTR/NEP would be a pretty interesting concept.

I would have thought the challenge would be designing the reactor to perform efficiently in both modes. Maybe using the working fluid and then transferring heat to the propellant in a heat exchanger would get around that. Have to be one hell of a heat exchanger, though.

I'm not sure I buy the afterburner concept though. Running the working fluid through a generator is going to remove energy from it, lowering the subsequent transfer of energy to the propellant. I doubt the energy you'd add back would compensate for it.

[Soralin]

I'm not sure I buy the afterburner concept though. Running the working fluid through a generator is going to remove energy from it, lowering the subsequent transfer of energy to the propellant. I doubt the energy you'd add back would compensate for it.

If you're trying to maximize the energy output to your propellent (i.e. thrust), then yeah, that won't work.  But if you're trying to maximize how much thrust you get out of each unit mass of propellent (i.e. specific impulse), then it will.  You're transferring that energy into a smaller amount of propellent, so you get more out of each bit of it.

So instead of releasing x amount of propellent, you might release only 1/10th of it, and use the energy from the other 9/10ths to accelerate the first 1/10th, and the latter 9/10ths can loop around through the reactor again.  Also, remember the distinction between fuel and propellent, fuel generates energy, which is applied to propellent to generate thrust.  In a chemical rocket the same substance fills both roles, but in a typical nuclear engine, they're two different things.  Using the energy from the same amount of fuel, and applying it to a smaller amount of propellent gives you higher specific impulse, at the cost of less thrust.

[momerathe]

For a constant power (ignoring various system inefficiencies) you can only increase the ISP by, as you say, reducing the mass flow rate. The problem is that I'm not sure that's so easy...

/struggles to remember thermodynamics lectures from 20 years ago

Essentially, you need to be pumping enough LH2 to absorb all the heat from the cold end of your heat engine. However, this also depends on the temperature (because the working fluid holds less heat per unit mass at a lower temperature)

Ignoring latent heat (because for LH2 it's very small) and the starting temperature (because it's very low) you end up with M approximately proportional to Q/T.

But for an ideal heat engine Q1/Q2 = T1/T2, thus M stays constant.


Having said all that, perhaps you could get rid of some of the heat with radiators, and reduce the mass flow rate that way... but then you'd be reducing the overall power of your system yet further...


But in any case, if you've got a bi-modal NTR and you want to increase the ISP the easiest way is probably run it in NTR mode some of the time and NEP mode the rest

[cordwainer]

Have always wondered if you could make MITEE designs Quad or Quin-modal. The reactors are small enough that you might be able to create a bimodal design that directs the cryogenic fuel to a turbine and recovers heat energy efficiently enough that you would actually be operate in NEP mode and NTR mode or a combination of both. Designs can also be made to run at high enough heat and low enough pressure to separate hydrogen monatomically for low thrust/high Isp NTR thrusters, add lox augmentation as well and you have a lot of throttle in terms of thrust options.

[savuporo]

http://tass.ru/en/science/820985

"We are scheduled to complete a prototype of a megawatt-class nuclear reactor for space flight in 2018, and we will do so," Pershukov told journalists on the sidelines of the 59th session of the IAEA General Conference.