BF2S Forums D&ST - Science

presidentsheep wrote:

http://www.naturelich.com/archives/images/trebuchet.jpg
problem solved?

Well, chemical rockets and even nuclear explosion powered vehicles are probably not really ideal for repeated launch of massive things.  A space elevator would alleviate that since once it's in place, you just tow stuff up instead of using combustion, fission, or fusion as a thrust source, but there is still a materials science issue to deal with...

Flaming_Maniac wrote:

I can't believe you are seriously talking about launching spacecraft from earth with nuclear powered rockets.

Even Wikipedia thinks that's dumb.

http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29 wrote:

Early versions of the vehicle were seriously proposed that would have taken off from the ground, with significant associated nuclear fallout; later ones were proposed for use only in space.

http://forums.bf2s.com/viewtopic.php?pi … 7#p3274737

Also:

Freeman Dyson, group leader on the project, estimated back in the 1960s that with conventional nuclear weapons, each launch would cause on average between 0.1 and 1 fatal cancers from the fallout.  Danger to human life was not a reason given for shelving the project – those included lack of mission requirement (no-one in the US Government could think of any reason to put thousands of tons of payload into orbit), the decision to focus on rockets (for the Moon mission) and, ultimately, the signature of the Partial Test Ban Treaty in 1963. The danger to electronic systems on the ground (from electromagnetic pulse) is insignificant from the sub-kiloton blasts proposed.

Flaming_Maniac wrote:

I don't really care if you said space elevators would be better, even remotely considering nuclear rockets viable for ground to orbit transportation viable is beyond ridiculous. The environmental impact, the non-fatal ramifications, the fatal ramifications...jesus. You're really willing to kill someone for a space launch? Did you consider the population has more than doubled since 1960? That population is growing at an exponential rate? That advancements like this are not one-off deals, that we need something that can be done over and over and over?

Alright Mr. CherryPicker, let's look at what I actually said:

SenorToenails wrote:

Right, and one could argue that the appropriate launch vehicle is an orion vehicle with 800 nuclear detonations.  Or suppose you wanted to make a far larger spacecraft than 4000 tons?  Perhaps 4000000 tons?  Should we still use chemical rockets to bring the pieces to space?  Orion vehicles would be far more efficient in that case.  Of course, a space elevator would solve both those issues (potentially) but that doesn't exist yet.

SenorToenails wrote:

Well, chemical rockets and even nuclear explosion powered vehicles are probably not really ideal for repeated launch of massive things.

I did say it would be more efficient, yes.  But that is far from advocating it.  You go ahead and keep your moral highground though.

Flaming_Maniac wrote:

What you said is shit like this

SenorToenails wrote:

Should we still use chemical rockets to bring the pieces to space?  Orion vehicles would be far more efficient in that case.

Uh, yes, we should still use chemical rockets to bring pieces into space, because that is the only method we have of doing it that is remotely feasible. By which I mean, not spewing nuclear fallout every launch and more closer to reality than science fiction. The fact that you are sustaining the argument against at all is what is so ridiculous.

And again, you've cherrypicked from what I said.

Of course, mankind is not building spacecraft of that magnitude, so chemical rockets make perfect sense for orbital missions.  Hopefully, that won't always be the case and mankind will actually try to build a larger spacecraft and get to another planet.  And hopefully by then we will have a better method to get things into orbit.

Flaming_Maniac wrote:

I'm not taking anything out of context. What you said is what you said.

And what I said is that it is more efficient, but not ideal.  Where am I condoning it?

Macbeth wrote:

Kinda looks like you're back tracking there Senor.

Not really.  Each time I said that nukes would be more efficient than chemical rockets, I plug a space elevator as being a better idea.  Accepting a reality that it is faster to use a more energetic propulsion method to launch large things into LEO does not translate into a gung-ho desire for NASA to start using them.

Maybe I can put it this way:  If mankind really needed to launch 4000 tons into space and needed to do it in a hurry, I could support an orion vehicle.  Until that point, I will await the space elevator.

SenorToenails wrote:

The entire point of project orion was to launch huge spacecraft.  Like, proposals for up to 8 million tons.  The space shuttle can carry 26.8 tons to LEO, but the early designs for spacecraft using nuclear propulsion started at 4,000 tons...what kind of rocket could get that off the ground?  Of course, it would take 800 0.15kt nuclear detonations to carry that 4000 ton spacecraft to LEO.

Not a problem, problem is with treaties concerning nuclear usage.

Flaming_Maniac wrote:

you take pieces into space and assemble it there...

Not a problem either, problem is getting the funding from imaginary market.

SenorToenails wrote:

That would defeat a huge benefit of the project.  It would take 200 shuttle missions to get all that mass into LEO.  There have only been 132 shuttle launches since the program started in 1981.

Of course it would not defeat the huge benefit of the project. At the moment it takes 12 months to travel in Mars, with nuclear spacecraft we could travel there in 4 weeks. That is an enormous advantage for what options we have now.
We have had (and still have) so few shuttle missions because "space exploration belongs into long term profit category, it's not a short term profit like it should be".

Assembling in space is a viable solution and better stacking station in space would be tremendous help in our future projects. It would help (possible) space elevator project too. As space elevator needs a big counterweight, stacking station could serve as one while serving as an assembly station for space shuttles. First we should overcome with couple problems though, for one, space debris may end the whole space elevator project until we figure out how to get rid of it.

Will see if LiftPort has our first operational space elevator ready by 2014

Here's about tether propulsion if anyone's interested, it may be the most feasible idea of launching a spacecraft.

Flaming_Maniac wrote:

I can't believe you are seriously talking about launching spacecraft from earth with nuclear powered rockets.

Flaming_Maniac wrote:

even remotely considering nuclear rockets viable for ground to orbit transportation viable is beyond ridiculous. The environmental impact, the non-fatal ramifications, the fatal ramifications...jesus. You're really willing to kill someone for a space launch? Did you consider the population has more than doubled since 1960? That population is growing at an exponential rate? That advancements like this are not one-off deals, that we need something that can be done over and over and over?

Flaming_Maniac wrote:

By which I mean, not spewing nuclear fallout every launch and more closer to reality than science fiction.

There's nothing dumb in it. It's not a one massive explosion, it's a series of light explosions to create the energy to push the spacecraft forward. It is likely as safe as riding a nuclear submarine and. Only downside is if the spacecraft happens to blow out, but even then it's not a nuclear explosion that occurs and the fallout is not devastating like killing millions of people. It's more like killing 20 people over the long years, it is quite as dangerous as walking on the streets of a big city and getting a cancer from car fumes.

Back in the sixties it was found out how safe nuclear propulsion actually is, and frankly we have made at least some progress from those days.

Nuclear propulsion
The time we could save with nuclear propulsion, be it from the ground launch or launching from space, is tremendous.

It's also a viable option to launch each nuclear spacecraft (two - four would be more than enough) only once from earth and dock them it in the space station and use chemical shuttles to move back and forth from that space station.

Edit, edit, edit...

Last edited by BLdw (2010-08-12 08:17:40)

what's the other 1%, out of interest

Execution materials, assisted suicide, most prominently many facets of military engineering

Never say never.

BLdw wrote:

Flaming_Maniac wrote:

your link -> releveant link to http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion ->

My link has a list of "proposed and theorized nuclear rocket propulsion" options. It is there because, while we have made basically backwards progress in (space) rocketry in the last 50 years (as I stated earlier), we still have, ironically, quite many options to choose from.

But we are not talking about those other form of propulsion, we are talking about nuclear explosion powered vehicles. None of the other forms of nuclear propulsion equal the performance and technical feasibility of nuclear explosion.

BLdw wrote:

Flaming_Maniac wrote:

wikipedia wrote:

There were also ethical issues with launching such a vehicle within the Earth's magnetosphere. Calculations showed that the fallout from each takeoff would kill between 1 and 10 people (a claim that has been disputed: see radiation hormesis).

Nuclear explosion powered propulsion in the atmosphere is dumb. Period.

In 99% of cases, engineering that kills someone when it works is not acceptable, and this is no exception.

Should we not use engineering applications, that might cause harm or in the worst possible situation cause a death of someone, then?

Big fucking difference between malfunctioning equipment and signing a death warrant every time it works correctly. Big fucking difference between "risk" and "acceptable losses".

BLdw wrote:

Flaming_Maniac wrote:

But we are not talking about those other form of propulsion, we are talking about nuclear explosion powered vehicles. None of the other forms of nuclear propulsion equal the performance and technical feasibility of nuclear explosion.

I don't quite understand what to answer. Did you read any of the other links?

Yes, I read all of them. They either

a) closer to science fiction than reality
b) are a major health/environmental issue
c) do not have the same technical capabilities of the nuclear explosion rockets that we have been talking about

BLdw wrote:

Flaming_Maniac wrote:

Big fucking difference between malfunctioning equipment and signing a death warrant every time it works correctly. Big fucking difference between "risk" and "acceptable losses".

Ok, nice. Care to answer my question?

We should continue to use engineering that could possibly result in the death of someone. The use of a pencil is an example of an engineering application that could result in harm and in the worst case scenario could result in a fatality. To draw any sort of parallel between potentially fatal engineering equipment and certainly fatal engineering equipment is beyond logical fallacy.

Flaming_Maniac wrote:

a) closer to science fiction than reality
b) are a major health/environmental issue
c) do not have the same technical capabilities of the nuclear explosion rockets that we have been talking about

What of the other options are closer to science fiction than reality? I don't deny that nuclear pulse propulsion might be the most effective for blasting away from earth, but do I care about this? No, not really. I answered to newbie13 how nuclear propulsion is on its way and how it will give us to better cards for space exploration. I did not answer what is the most powerful tool to get us out of the earth, I answered a more feasible method than the current use of chemical propulsion.

Flaming_Maniac wrote:

To draw any sort of parallel between potentially fatal engineering equipment and certainly fatal engineering equipment is beyond logical fallacy.

What about our industry, transportation, nourishment? You do understand that even if we did 100 nuclear pulse propulsion launches from earth, it would cause less death casualties/diseases than our factories, or cars, or passive tobacco smoke, or deaths caused from food-related poisoning? Do you have any idea how much more radiation one coal plant spews around than one nuclear pulse propulsion launch from earth could cause?

This is a short term/long term profit problem. We rather wait 100, even 1000 years polluting, poisoning and killing ourselves here because it is ethically wrong when one nuclear spacecraft launch might cause a death of 10 people in the same period of time as half a coal plant. Few seems to care that even the one launch could get us more information about space (moon and Mars especially) and solve more problems around nuclear propulsion than we had ever imagined. At the moment nuclear spacecraft is the only way we are able to obtain helium 3 feasibly, and frankly this situation is not going to change any time soon... probably not until we get more of helium 3 in our hands.

Neither is the nuclear propulsion the final tool to use, it is the tool to get the information about all-around safe method for us to use. This seems to be illogically difficult thing to grasp for some. We rather use every other method we think is necessary to gain the access to what we want, doesn't seem to matter how many people suffer from it or how many deaths are caused by it, than actually try to improve the situation fast so our loss wouldn't grow forever more.

Building a power plant might cause long term deaths and yield short term profits that are minimal in the long run.
Launching a nuclear pulse propulsion spacecraft from earth might, also, cause long term deaths but it is likely to yield long term profits that are benefits us greatly in the long run.

The whole wikipedia citation of how one launch would kill 1 between 10 people is unproven and is based on the lack of threshold when calculated.

Last edited by BLdw (2010-08-12 14:08:57)