hydrogen/chemical rockets are extremely wasteful

Status
Not open for further replies.
N

nec208

Guest
hydrogen rockets is extremely wasteful, if you look at a NASA rocket that ENTIRE thing is carrying liquid hydrogen and liquid nitrogen all so that a handful of people and a payload of less than a 5% of the mass of the entire rocket can get into space.

Nuclear ship you'd need a single reactor whether or not it's more powerful we do not know.Know one knows how to make :lol: plasma spaceship or fusion power spaceship may be 2 or 3 times more powerful than hydrogen or only 1 or 2 times more powerful we do not know how powerful .

rockets that shoot out a stream of photons are more efficient and can accelerate to higher speeds and are therefore better to use in the long run but know one knows how to build one or how much more powerful.
 
V

Valcan

Guest
Re: hydrogen rockets are extremely wasteful

First you said the N word. We all know nuclear rockets are just good for killing people.

But no seriously what type of nuclear rocket are you talking about and remember people freak out with just the idea of a nuclear rocket going into orbit.

And are you talking about in space or ground to orbit transport?
 
N

nec208

Guest
Re: hydrogen rockets are extremely wasteful

Valcan":2au7wjce said:
First you said the N word. We all know nuclear rockets are just good for killing people.

But no seriously what type of nuclear rocket are you talking about and remember people freak out with just the idea of a nuclear rocket going into orbit.

And are you talking about in space or ground to orbit transport?
You need a core and coolant to keep the core cool .No nuclear is safe it not like 60;s we know how to control it now.And a nuclear rocket is like small very small power plant.
 
V

Valcan

Guest
Re: hydrogen rockets are extremely wasteful

I ment which on did you mean orion.......well if its orion your screwed wont happen.

But so much of the $$$$$ spent on the space industry is in the People budget and in the support cost it drags us down.
 
M

MeteorWayne

Guest
Re: hydrogen rockets are extremely wasteful

nec208":3knr4wa6 said:
Valcan":3knr4wa6 said:
First you said the N word. We all know nuclear rockets are just good for killing people.

But no seriously what type of nuclear rocket are you talking about and remember people freak out with just the idea of a nuclear rocket going into orbit.

And are you talking about in space or ground to orbit transport?
You need a core and coolant to keep the core cool .No nuclear is safe it not like 60;s we know how to control it now.And a nuclear rocket is like small very small power plant.
And exactly how the heck do you get the thrust from a "nuclear rocket" to get off the ground? I have yet to see a realistic mechanism...
 
B

bdewoody

Guest
Re: hydrogen rockets are extremely wasteful

nec208":3q6r8wn5 said:
hydrogen rockets is extremely wasteful, if you look at a NASA rocket that ENTIRE thing is carrying liquid hydrogen and liquid nitrogen all so that a handful of people and a payload of less than a 5% of the mass of the entire rocket can get into space.

Nuclear ship you'd need a single reactor whether or not it's more powerful we do not know.Know one knows how to make :lol: plasma spaceship or fusion power spaceship may be 2 or 3 times more powerful than hydrogen or only 1 or 2 times more powerful we do not know how powerful .

rockets that shoot out a stream of photons are more efficient and can accelerate to higher speeds and are therefore better to use in the long run but know one knows how to build one or how much more powerful.
You are not going to get off the pad using liquid nitrogen (nitrogen is inert). The oxidizer is liquid oxygen. And like the other posters said no known means of nuclear propulsion comes close to having the thrust needed to get into orbit from the surface of the earth.
 
V

Valcan

Guest
Re: hydrogen rockets are extremely wasteful

I think what your talking about is a nuclear rocket for space propulsion. Which yes if it worked would be alot better for a mars mission or maybe missions to asteroids than chemical. I dont know which would provide more thrust to weight though. That or a VASIMR, i do figure the nuke would use more fuel though.
 
M

MeteorWayne

Guest
Re: hydrogen rockets are extremely wasteful

Reality check here...NO NUCLEAR PROPULSION METHOD IS GOING TO LIFT A VEHICLE FROM THE SURFACE!
 
V

Valcan

Guest
Re: hydrogen rockets are extremely wasteful

MeteorWayne":17clsjk2 said:
Reality check here...NO NUCLEAR PROPULSION METHOD IS GOING TO LIFT A VEHICLE FROM THE SURFACE!
If you where talking to me i ment it could be used to power a spacecraft from orbit to somewhere not from the surface.


fraid were stuck with rockets for now.

Though maybe one day we can use fusion rockets :)

http://www.voidgamers.com/images/data/p ... opship.jpg

I dream of a future with lots of dropships :p
 
C

CoreDave

Guest
Re: hydrogen rockets are extremely wasteful

Actually there was some sort of design for a nuclear powered cruise missle way back during the cold war. However the idea was scrapped because the US decided it would probably piss off their allies if they fired it over their airspace as it would have spewed out copious amounts of radioactive exhaust gasses....

Probably a none starter for space launch for the same reason ;)

What I would like to see is massive lighter than air (possibly nuclear powered) space launch platforms. Cut out a good fraction of the atmosphere and achieve a decent speed on their own then just hop into orbit from there.
 
N

nec208

Guest
Re: hydrogen rockets are extremely wasteful

I was reading that Ion rockets or plasma rockets have low thrust .So as of right now, they could never lift anything from earth do to the low thrust .But once in space they can produce this small thrust for a very long time thus almost trevel at the speed of light.But it will take months if not years before they can go that fast .



Well chemical rocket have high thrust but use up the fuel very very very fast .So cannot go faster than the speed of sound.If there was fuel every where they could travel at the speed of light.But they use up the fuel too fast.Also people say Ion rockets or plasma rockets are good for long trevel but not good for short trevel.And chemical rocket are good for short trevel but not long travel.

Not sure about nuclear or fusion .
 
N

nec208

Guest
Re: hydrogen rockets are extremely wasteful

MeteorWayne":1qzo3vnh said:
Reality check here...NO NUCLEAR PROPULSION METHOD IS GOING TO LIFT A VEHICLE FROM THE SURFACE!
Not sure about nuclear or fusion if they have high or low thrust ,If the thrust is too low they would never lift anything from earth.May be nuclear or fusion is like Ion rockets or plasma rockets only good for long trevel.

Well chemical rockets have high thrust but use up the fuel very fast.
 
P

Polishguy

Guest
Re: hydrogen rockets are extremely wasteful

MeteorWayne":1xu0q09m said:
Reality check here...NO NUCLEAR PROPULSION METHOD IS GOING TO LIFT A VEHICLE FROM THE SURFACE!
Project Orion could have. NERVA was also capable of it, to some degree (low thrust compared to kerosene-oxygen, but the same was true of early hydrogen-oxygen motors).

Back in the 1960s, the Nuclear Engine for Rocket Vehicle Applications program experimented with using nuclear reactors and liquid hydrogen as propellant. They would be twice as efficient (ISP 850 seconds) as hydrogen-oxygen chemical rockets (ISP ~450 sec maximum). The idea was that the heat from the nuclear reactor would turn the liquid hydrogen to gas, and the force of its expansion out of the nozzle would push the vehicle. This is Nuclear Thermal Propulsion. The program was scrubbed with the end of the Apollo Program (Without a Mission To Mars in the aftermath of Apollo, there was no visible reason for it). This is, IMO, the best replacement for chemical propulsion systems in the inner solar system (VASIMR is better for Outer Solar System).
 
M

MeteorWayne

Guest
Re: hydrogen rockets are extremely wasteful

Brian,
That's your evidence? Some scanned document of unknown veracity from 1957 so highhly redacted to make it worthless?

Show me some actual research, some peer reviewed reports, some hardware that showed this idea would have worked.

Or even simpler, propose a mechanism where thrust ratio for a nuclear rocket is greater than 1. If you're right, it should be in there...
 
O

orienteer

Guest
Re: hydrogen rockets are extremely wasteful

Nuclear power is thought of as using lo grade uranium. If we were to use weapons grade fuel I am sure we could generate enough force for a SSTO vehicle. The down side would be the weight of the firing chamber needed to direct the thrust downward and, of course , the radiation left behind at the launch site.
 
M

MeteorWayne

Guest
Re: hydrogen rockets are extremely wasteful

You're sure??? Again, show me a realistic mechanism, based on real physics, that can create the required thrust for whatever nuclear reactor or source you propose.
 
O

orienteer

Guest
Re: hydrogen rockets are extremely wasteful

Hiroshima, Nagaski
 
M

MeteorWayne

Guest
Re: hydrogen rockets are extremely wasteful

That has NOTHING to do with launching a spacecraft. What a foolish way to admit you can't show any realistic physics.
 
O

orienteer

Guest
Re: hydrogen rockets are extremely wasteful

Last time I checked, rockets work by igniting fuel so that their volume increases exponentially while directing the resulting thrust in a single direction, and therefore moving the vehicle in an equal and opposite direction.

Last time I checked the nuclear bomb creates the largest increase in volume with the least material, therefore controlling said reaction would indeed supply the thrust needed.

It should be noted however, that my original post was loaded with sarcasm towards Nec and his ideas of lifting large objects away from Earth with photon streams and Vasimr engines

Honestly Wayne, I believe you are a very intelligent person, but I have noticed before, both with my posts and others, that you have trouble reading between the lines sometimes.
 
P

Polishguy

Guest
Re: hydrogen rockets are extremely wasteful

orienteer":2dupp5oq said:
Last time I checked, rockets work by igniting fuel so that their volume increases exponentially while directing the resulting thrust in a single direction, and therefore moving the vehicle in an equal and opposite direction.

Last time I checked the nuclear bomb creates the largest increase in volume with the least material, therefore controlling said reaction would indeed supply the thrust needed.
Yes, and that's why a group of physicists, Freeman Dyson and Ted Taylor among them, worked in the late 50s and early 60s to use nuclear bombs to propel million-tonne spaceships. It was called Project Orion.
 
V

Valcan

Guest
Re: hydrogen rockets are extremely wasteful

"Honestly Wayne, I believe you are a very intelligent person, but I have noticed before, both with my posts and others, that you have trouble reading between the lines sometimes."

OMG i have this same problem. Is embarresing
 
M

MeteorWayne

Guest
Re: hydrogen rockets are extremely wasteful

But that's my point. There's no realistic way to channel the energy from a nuclear explosion into a stream that Mr Newton can use. Creating a bunch of shrapnel only gets pieces off the ground :)

That's what I saw.

Wayne
 
M

MeteorWayne

Guest
Re: hydrogen rockets are extremely wasteful

OK, I read some more, and with tiny nukes I suppose it is feasible, if not a realistic possibility that would ever be pursued.
 
S

Swampcat

Guest
Re: hydrogen rockets are extremely wasteful

MeteorWayne":3d6awh26 said:
Show me some actual research, some peer reviewed reports, some hardware that showed this idea would have worked.

Or even simpler, propose a mechanism where thrust ratio for a nuclear rocket is greater than 1. If you're right, it should be in there...
My reading on the subject indicates that earlier nuclear rocket engine research achieved T/W ratios from 3:1 for NERVA to greater than 7:1 for NERVA 2. Compared to, e.g., the 73:1 for SSME and 96:1 for SpaceX's Merlin, it's not all that good, but it's more than enough for use in space or on an upper stage.

It would be interesting to see what kind of T/W ratios could be achieved with further research, but my guess is that it would not be a good choice for ground launch.

As far as getting off the ground with nuclear rockets is concerned, I believe Project Orion could do that, but there are so many negatives to that approach that it is not likely to ever happen...unless, of course, intelligent elephants from space...uh, nevermind :D
 
Status
Not open for further replies.

ASK THE COMMUNITY

TRENDING THREADS

Latest posts