Soviet nuclear rocket test

I read somewhere that the Soviets tested a nuclear rocket engine in space in
the 80's. What were the results of these tests and why hasn't anyone
followed up on this?

If a nuclear rocket engine is 20 times more efficient than a conventional
cryogenic engine, does this mean that the rocket only needs to carry 1/20th
the fuel? This could mean that a Saturn V would only be 30m tall instead of
110m.

The only problem with nuclear thermal engines is that they expulge
radioactivity but this could be solved by better casings around the
radioactive core.

"Legato" wrote in
:

I read somewhere that the Soviets tested a nuclear rocket engine in
space in the 80's. What were the results of these tests and why hasn't
anyone followed up on this?

If a nuclear rocket engine is 20 times more efficient than a
conventional cryogenic engine, does this mean that the rocket only
needs to carry 1/20th the fuel? This could mean that a Saturn V would
only be 30m tall instead of 110m.

The only problem with nuclear thermal engines is that they expulge
radioactivity but this could be solved by better casings around the
radioactive core.

http://www.kbkha.ru/?p=8&cat=11&prod=66

RD-0410, designed by Khimavtomika (Chemical Automation?)

Nuclear rocket engines don't generally have high thrust, just high
specific impulse (Isp). The Soviet NTR was a low thrust development
equivalent to early NERVA models, but pretty sophisticated. The
most powerful NERVA with 250,000 pounds/thrust and was designed to
operate in vacuum.

The general concept is to launch NTR stage into orbit with a
conventional booster, to avoid possible release of radioactives
into the atmosphere. Thus far, nuclear propulsion hasn't been needed
enough to overcome the political opposition and further development
costs.

A manned Mars mission might change that.

--Damon

Legato wrote:
I read somewhere that the Soviets tested a nuclear rocket engine in space in
the 80's. What were the results of these tests and why hasn't anyone
followed up on this?


AFAIK, they never did that in space, but the US on the other hand did
fly a nuclear isotope-powered ion engine spacecraft in 1970:
http://www.astronautix.com/craft/sert.htm
The Soviets did take a crack at designing a nuclear thermal rocket
engine more than once over the years; in fact, they once designed a
nuclear-thermal powered ICBM: http://www.astronautix.com/lvs/yardicbm.htm
That went nowhere, but they did build a nuclear thermal rocket engine
prototype like our NERVA: http://www.astronautix.com/engines/rd0410.htm
that apparently underwent suborbital flight tests.
Specific impulse was great at 910 seconds; but thrust-to-weight ratio
sucked at 1.80, so you could forget a surface liftoff using these
engines, and they would be limited to upper stage use, and they would
have been very expensive to make to boot. The big problem with any
nuclear thermal engine is that not only do you need lots of heavy
shielding to protect the crew or payload of the rocket from the
radiation the engine puts out, but you never use up more than a small
fraction of the total possible heat output of the nuclear fuel in the
reaction mass during operation of the engine... if you could actually
make full use of the total heat generation possible before the fuel
decayed into lead, you'd be talking a isp of around _9,000_ seconds, not
900.
But the engine would melt or blow up if you ever tried that in anything
under a day or two's time, minimum.
Which is a pity, as otherwise you wouldn't be talking SSTO, but more
like Single Stage To Mars, in best Golden Age Sci-Fi tradition.
In case you've never seen it, this is what happened when we took our
Kiwi nuclear thermal engine and purposely made it go supercritical to
the point of failure to see what would happen if a NERVA-powered booster
ever failed on the pad:
http://www.wps.com/archives/wxvax7.e...ages/ktntb.gif
I always wondered what happened to this classified program:
http://www.fas.org/nuke/space/c08tw_2.htm
When this thing first came out, they were talking about generating the
thrust of a Saturn-V F-1 first-stage engine from a reactor around the
size of a 55 gallon barrel.

Pat

Damon Hill wrote:
http://www.kbkha.ru/?p=8&cat=11&prod=66

RD-0410, designed by Khimavtomika (Chemical Automation?)

Nuclear rocket engines don't generally have high thrust, just high
specific impulse (Isp). The Soviet NTR was a low thrust development
equivalent to early NERVA models, but pretty sophisticated.

Sure had a lot of odd little goodies down at the base of that mounting
frame, didn't it?:
http://www.astronautix.com/graphics/r/rd0410.jpg
What are all those small cylindrical things anyway?
And did you ever see so much plumbing on a rocket engine in your life? :-\

Pat

On 6 Jan, 07:36, Pat Flannery wrote:
Damon Hill wrote:
http://www.kbkha.ru/?p=8&cat=11&prod=66

RD-0410, designed by Khimavtomika *(Chemical Automation?)

Nuclear rocket engines don't generally have high thrust, just high
specific impulse (Isp). *The Soviet NTR was a low thrust development
equivalent to early NERVA models, but pretty sophisticated.

Sure had a lot of odd little goodies down at the base of that mounting
frame, didn't it?:http://www.astronautix.com/graphics/r/rd0410.jpg
What are all those small cylindrical things anyway?
And did you ever see so much plumbing on a rocket engine in your life? :-\

The quoted thrust is 3.59 tons - rather short of S5. The quoted gas
temperature is 3500 with a specific impulse of 910 of just under 9km
sec. It does seem a little bit Nervaski.


- Ian Parker

"Pat Flannery" wrote in message
dakotatelephone...


Legato wrote:
I read somewhere that the Soviets tested a nuclear rocket engine in space
in the 80's. What were the results of these tests and why hasn't anyone
followed up on this?


AFAIK, they never did that in space, but the US on the other hand did fly
a nuclear isotope-powered ion engine spacecraft in 1970:
http://www.astronautix.com/craft/sert.htm
The Soviets did take a crack at designing a nuclear thermal rocket engine
more than once over the years; in fact, they once designed a
nuclear-thermal powered ICBM: http://www.astronautix.com/lvs/yardicbm.htm
That went nowhere, but they did build a nuclear thermal rocket engine
prototype like our NERVA: http://www.astronautix.com/engines/rd0410.htm
that apparently underwent suborbital flight tests.
Specific impulse was great at 910 seconds; but thrust-to-weight ratio
sucked at 1.80, so you could forget a surface liftoff using these engines,
and they would be limited to upper stage use, and they would have been
very expensive to make to boot.

Is the shielding the main reason for the bad thrust-to-weight ratio?

I personally think the nuclear thermal engine still has lots of potential,
although probably not for liftoff engines since the risk of contamination
during a crash is simply too great. Shielding need not be a problem in space
if the engines are located far from the crew quarters, the 2001: A Space
Odessey spaceship Discovery seemed to have such a configuration.

Has anyone tried heating the fuel (e.g. water) with microwaves?

On Jan 5, 9:35*pm, "Legato" wrote:

I read somewhere that the Soviets tested a nuclear rocket engine in space in
the 80's. What were the results of these tests and why hasn't anyone
followed up on this?

They did cold-flow tests on a NERVA-like engine at the PNUTS/URDF-3
facility in the Semipalatinsk nuclear testing range, but AFAIK never
got to the point of a nuclear test. There were some Russian-American
exchanges involving that program back in the early 1990s -- Google
"nuclear rocket" with "Semipalatinsk".

Separately, the USSR flew a series of reactor-powered radar satellites
that the US called RORSATs.

And finally there were two flights of an advanced reactor power source
called TOPAZ.

Legato wrote:
Is the shielding the main reason for the bad thrust-to-weight ratio?

Probably not - the basic concept results in a poor thrust-to-weight
ratio, as was the case in NERVA. There was a plan to use a different
design for Dumbo that would give higher thrust, but that didn't go
anywhe http://www.dunnspace.com/dumbo.htm

I personally think the nuclear thermal engine still has lots of potential,
although probably not for liftoff engines since the risk of contamination
during a crash is simply too great. Shielding need not be a problem in space
if the engines are located far from the crew quarters, the 2001: A Space
Odessey spaceship Discovery seemed to have such a configuration.

Has anyone tried heating the fuel (e.g. water) with microwaves?


In the case of the designed nuclear thermal engines, the fuel was either
liquid hydrogen or ammonia, not water.
There was a concept floated for a water-powered nuclear rocket using a
navy submarine reactor at one time, but it never got anywhere near the
design stage.
Any time you introduce another change in form to your energy use
(reactor heat to generator, generator to electricity, electricity to
microwaves, microwaves to heat water) you lose efficiency and up weight.

Pat

Allen Thomson wrote:

Separately, the USSR flew a series of reactor-powered radar satellites
that the US called RORSATs.


There's info on them and their reactor design he
http://www.svengrahn.pp.se/trackind/RORSAT/RORSAT.html

And finally there were two flights of an advanced reactor power source
called TOPAZ.


That's he http://fti.neep.wisc.edu/neep602/SPRING00/lecture35.pdf

Pat

On 6 Jan, 12:50, "Legato" wrote:
I personally think the nuclear thermal engine still has lots of potential,
although probably not for liftoff engines since the risk of contamination
during a crash is simply too great. Shielding need not be a problem in space
if the engines are located far from the crew quarters, the 2001: A Space
Odessey spaceship Discovery seemed to have such a configuration.

The crew of a nuclear spacecraft would experience higher doses of
radiation. No this is NOT the nuclear reactor, it is the low thust. To
get to the Moon (say) you need to burn for 10mins or so at LEO and
then have subsequent burns of 15mins at peregre. This means a longer
time in the Van Allen belts.

If you are using the quadrature principle and are doing a figure of 8
round the Moon or Mars, you can send astronauts up with enough sdtores
to last them a matter of hours and no reentry vechicle, all of what
they need being in quadrature. You get a nuclear rocket to quadrature
by a series of short burns as described above.

As far as Mars is concerned, one potential use of a nuclear rocket
would be to travel from quadrature to LMO and from LMO to rendez vous.

Has anyone tried heating the fuel (e.g. water) with microwaves?

Kinetic theory tells us that the mean energy of a degree of freedom is
kT/2. Hydrogen at 3500C (k*3773) travels faster than anything else.
Only pure hydogen therefore gives velocities of 9km/s.



- Ian Parker