ISS service extended!

[Klingon Admiral]

Since when are we even trying for continuos fusion? As far as I know both tokamak and stellarator approaches aim for pulsed fusion, at least in the "foreseeable future" (whatever this means in fusion power-time).

[crazyewok]

Since when are we even trying for continuos fusion? As far as I know both tokamak and stellarator approaches aim for pulsed fusion, at least in the "foreseeable future" (whatever this means in fusion power-time).

Well the main issue anyway is we cant get it energy positive.

But with a engine thats not a issue if you use another power source, you just want it to move not power the ship (though that would be a bonous if it did that aswell.)

[Klingon Admiral]

But what you are talking about is not nuclear pulse propulsion. Nuclear pulse propulsion does not require any form of onboard reactor (unless one wants to have a very sophisticated design). Nuclear pulse propulsion is dropping a nuke (or many) from the back and riding the shockwave. I think I don't need to elaborate why this is a VERY bad way to get something into orbit.

[crazyewok]

Nuclear pulse propulsion is dropping a nuke (or many) from the back and riding the shockwave.

Or if you look at project Daedulas droping dueturium pellets and ignited them with lasers to push the ship. Same principle but diffrent excecution.

[quote=Klingon Admiral;909364

I think I don't need to elaborate why this is a VERY bad way to get something into orbit.

Edited January 15, 2014 by crazyewok

[Holo]

manned Saturn missions

Link? I didn't think that there had been any serious study on (non-interstellar) manned exploration beyond Jupiter at all.

Edited January 15, 2014 by Holo

[Kryten]

Link? I didn't think that there had been any serious study on (non-interstellar) manned exploration beyond Jupiter at all.

Sorry, my mistake. I knew they'd done a study based around the Discovery II from 2001, including the same general mission, but it's movie rather than book Discovery (i.e. a Jupiter mission). OTOH, given they're willing to do studies based around explicitly move-inspired spaceships with fusion engines, there probably is one somewhere, I just haven't found it yet.

[SFJackBauer]

Or if you look at project Daedulas droping dueturium pellets and ignited them with lasers to push the ship. Same principle but diffrent excecution.

Yes you do. Don't write something off with statements based on your own non substantiated opinions and media induced fear of all things radiation. According to most of the sceintists that were on the project it was a VERY effective way to get things in orbit, better than chems.

Cause from what I read on the subject safety was something that could have been worked on and even with the fission designs safe guards could have been put in place to reduce fallout. Research got canned (well went black) before they had a real chance to look at this. Secondly with a pure fusion detonated device you wont have those problems period. And a pure fusion device its very possible, just no one in the private sector anyway has had reason to look at it.

For the record Im not saying we should build a 8 million ton super orion tomorrow and launch it over new york city. What Im saying is the project should be looked at again useing modern tecnology and models and IF it could be safely used a amedment in the nuclear test ban treaty for non military research into the craft. You cant argue with just LOOKING.

The problem with those massive "Project Orion" or "Daedalus" is that all the engineering steps are jumped over in order to create a final design. Sure, for a million ton spacecraft, plucking nukes out of its rear-end will be much more efficient than having a 1000 F-1 engines burning kerosene, but how do we test it? What is the proposal for a small scale, technology demonstrator, which shows that all the engineering problems are solved? How the crew is protected? How reliable is the nuke delivery system? And how controllable it is - what happens if it fails? These are questions that have been answered hundreds of times in case of chemical rockets, a bit for electrical (milinewton) propulsion, and a little bit for NERVAs. Outside this realm, everything is possible, nothing is concrete.

You can't look at the propulsion system isolated - it is part of a package, of a spacecraft.

[mdatspace]

Snip.

You hit the nail on the head. You cannot just look at thrust and Isp and say this rocket works, especially when that rocket is being propelled by nukes.

[Champ]

That first picture is the NASA Docking System. It's a beautiful piece of engineering with many structural constraints, electrical and fluid connections, electronics, sensors, actuators, etc... It's a relatively small yet crucial component, but it has been in development for over 18 years (and it still hasn't flown). Yes, 18 years for a docking ring. That's how long it takes to develop real space hardware in the real world.

No. That's how long it takes to develop real space hardware in the real world with our actual policy and economy.

With different policy, different economy and different level of commitment (fear can make us do wonders !), in 18 years, we went from V2 (1944) to Mercury (1962)...

[Nibb31]

No. That's how long it takes to develop real space hardware in the real world with our actual policy and economy.

With different policy, different economy and different level of commitment (fear can make us do wonders !), in 18 years, we went from V2 (1944) to Mercury (1962)...

Yes, but as I said earlier, our actual policy and economy may be inefficient, but that is the environment that we have to work with for the foreseeable future. All systems have their inefficiencies, and it's simply not realistic to believe that we will suddenly overcome those inefficiencies in the next 20 or 30 years.

In the real world, the political and economical constraints exist and are just as real as the laws of physics. They can't just be handwaved away.

[crazyewok]

Sure, for a million ton spacecraft, plucking nukes out of its rear-end will be much more efficient than having a 1000 F-1 engines burning kerosene, but how do we test it? What is the proposal for a small scale, technology demonstrator, which shows that all the engineering problems are solved? How the crew is protected? How reliable is the nuke delivery system? And how controllable it is - what happens if it fails? These are questions that have been answered hundreds of times in case of chemical rockets, a bit for electrical (milinewton) propulsion, and a little bit for NERVAs. Outside this realm, everything is possible, nothing is concrete.

You can't look at the propulsion system isolated - it is part of a package, of a spacecraft.

You hit the nail on the head. You cannot just look at thrust and Isp and say this rocket works, especially when that rocket is being propelled by nukes.

What is it with people on this site and not being able to read?

I never said we should build one a million ton orion tomorrow. What I said is that there should be more RESEARCH done to explore the problems you suggested. In fact before the project was canned a small scale test was suggested. Research thats all Im saying.

[Nibb31]

Reality strikes again:

- It's not possible to test it in the atmosphere because atmospheric nuclear tests are banned since 1963.

- It's not possible to test it in space because nuclear tests in space are also banned since 1967.

- It's not possible to test it underground because nuclear tests underground are also banned since 1996.

- It's not practical to test it in orbit because there are too many risks of damaging LEO/GEO satellites and it would leave clouds of radioactive particles and debris that could be a hazard for future missions.

- It's not practical to test it on escape trajectories, because it would simply be too expensive for the sort of subscale proof-of-concept testing that is required.

- It's not practical to test it anywhere because the negative political impact would put too much pressure on the administration.

There are reasons Orion was cancelled. It is simply not a viable project for the foreseeable future, for many many reasons. Forget it.

Edited January 16, 2014 by Nibb31

[crazyewok]

It is simply not a viable project for the foreseeable future, for many many reasons. Forget it.

Then we may as well just pack up shop and stop human space endeavours as chem rockets are not taking us anywhere with efficiency, no beyond the moon anyway and not in any capacity to allow cheap access.. Chemical Rockets are of no good, we need a alternative.

All the problem you suggested expect point 3 are POLITICAL problems anyway. They are human caused boundaries not scientific barriers and can be changed if people had the guts and will.

As for problem 3? Research was being done on that problem until it got canned.

You give up to easly. Its to hard or there one barrier and you fold. And I only see one REAL problem amognst the ones you listed, I dont count political ones as they can be changed. Infcat the only reason peacefull nuclear tests were banned was because russia at the time were being difficult. They are self imposed problems.

Edited January 16, 2014 by crazyewok

[Klingon Admiral]

If a nation announces to actually start develop an orion prototype, I would petition hard for this country to be put out of existence. Permanently.

[crazyewok]

If a nation announces to actually start develop an orion prototype, I would petition hard for this country to be put out of existence. Permanently.

Then your a closed minded paranoid fool.

I have no time for people with irrational fears.

There is no harm in haveing a look and seeing if some of the problems cant be ironed out.

Ok if it turns out it deffinatly wont work then fine. But to ban even looking at it because of ones own fears? No diffrent that the irrational fears of the masses in the dark ages.

The fact you would risk nuclear war and mass genoside over a research project is primative and stupid beyond belief. Even at its unsafest a orion would have a 12 in 7 billion chance of killing you, a nuclear war your looking at a 1 in 10 or higher.

Edited January 16, 2014 by crazyewok

[NASAFanboy]

What I do support is using conventional exolosives to power large probes.

What I do not support is nukes. I don't want space exploration to kill the society it was supposed to save, and I'm unsure if the crew will survive the inital accleration without being crushed to a red paste.

Orion may be a good idea in the future, but as of now, its a wrong idea in the wrong society at the wrong time. While I am very optimistic about human exploration, with manned missions to Mars by 2040, a base by 2060, and research bases on the moon by 2030, Orion will not come to fruition anytime soon. Not that we need it, as a fusion/NERVA engine wouldnt need to have to build a new launch site during every launching.

Edited January 16, 2014 by NASAFanboy

[crazyewok]

What I do not support is nukes. I don't want space exploration to kill the society it was supposed to save.

It wont though. Nuclear does not automaticaly =bad. Not everything is a Hiroshima or chenobyl waiting to happen. A unrefined Orion was caluculated to AT WORST kill 12 people WORLD WIDE so thats 12 in 7 billion! You goverment likley makes more cold hearted descions that kill more for less benifit. Later on a recalculation useing some safety tecniques and more refined bombs was estmated to be <1 worldwide. It was to be launched at sea too from any habitated area, even if the it had failed to launch it world have ended up miles under sea and be no diffrent than the nuclear submarines the world has lost.

If humanity is to get any further than the moon we have to go down the nuclear route, chemical just doesnt cut it. Not for anything better than intra solar system probes.

[NASAFanboy]

It wont though. Nuclear does not automaticaly =bad. Not everything is a Hiroshima or chenobyl waiting to happen. A unrefined Orion was caluculated to AT WORST kill 12 people WORLD WIDE so thats 12 in 7 billion! You goverment likley makes more cold hearted descions that kill more for less benifit. Later on a recalculation useing some safety tecniques and more refined bombs was estmated to be <1 worldwide. It was to be launched at sea too from any habitated area, even if the it had failed to launch it world have ended up miles under sea and be no diffrent than the nuclear submarines the world has lost.

If humanity is to get any further than the moon we have to go down the nuclear route, chemical just doesnt cut it. Not for anything better than intra solar system probes.

If the space agency killed a single person, the resulting outcry and budget cuts will destroy it. There are mire propulsion methods than chemical, too, and they won't kill anyone even if the whole fuel tank blows.

Project Orion is overkill for inner solar system. In thw far future, we might have a couple heading to Neptune and Uranus, but that's about all that there is. It might be good for a seeder starship though, but I'm unsure.

It's simply too early to tell.

Also, studies show that Chemical HLV rockets like the SLS are enough to get us to Mars. So Orion development in the near future is out if the question.

Edited January 16, 2014 by NASAFanboy

[Kryten]

If humanity is to get any further than the moon we have to go down the nuclear route, chemical just doesnt cut it. Not for anything better than intra solar system probes.

That's nonsense, plain and simple. There are plenty of properly worked studies showing missions like NEO visit and Mars orbit to be possible using SLS, or vehicles in the same sort of size range-i.e. the kind of vehicle the vast majority of nuclear propulsion mission concepts assume to be available anyway.

[crazyewok]

If the space agency killed a single person, the resulting outcry and budget cuts will destroy it.

To put it blunty you wouldnt know if done right. even 12 in 7 billion impossible to link to anything. As I said far worse risks are taken and signed off on every day for even less important things.

Project Orion is overkill for inner solar system.

LEO and to the moon maybe but would be perfect for further than the moon and its a perfect thing to build on say a lunar shipyard if we ever make one. I mean if you built it on the moon whats that problem?

[crazyewok]

That's nonsense, plain and simple.

Depends on what your mission is.

If its just landing planting a flag and takeing a few samples then yes Mars is doable on chems. But anything further you need something with a bigger payload and which has more speed. Anything beyond mars even SLS small sacel mission would be impossible.

[NASAFanboy]

To put it blunty you wouldnt know if done right. even 12 in 7 billion impossible to link to anything. As I said far worse risks are taken and signed off on every day for even less important things.

LEO and to the moon maybe but would be perfect for further than the moon and its a perfect thing to build on say a lunar shipyard if we ever make one. I mean if you built it on the moon whats that problem?

Why the heck would we build a lunar shipyard to go to Mars?

Building the ship in LEO with technology proven by an lunar reserach base is good enough. That's like Colombus stopping at the Canary islands and bulding an entire new ship before going to America.

The first expeditions to Mars have no need of lunar shipyards. Later in the 2060's maybe, but not the first.

Three SLS launches are enough for a Mars mission that would stay on the surface for long time. Better than using nukes.

[Kryten]

If its just landing planting a flag and takeing a few samples then yes Mars is doable on chems. But anything further you need something with a bigger payload and which has more speed. Anything beyond mars even SLS small sacel mission would be impossible.

So? That's all the kind of missions there's any remote demand for.

[crazyewok]

So? That's all the kind of missions there's any remote demand for.

Im getting tired of going round in circles here but il humour you.

Its the only type of mission in demand because current lunch capabilitys and cost make anything more prohibitive. make it cost effective and you would have entire industrys moveing into orbit. With orion they projected with the huge pay loads for it to be 5 cents (1958 money) a Kg. That sort of economic cost and you would create a huge boom in solar resource minning, offword manufactureing ect It would be like putting in a high speed railwork in. At $20000 a Kg you just cant do that.

Edited January 16, 2014 by crazyewok

[Nibb31]

Then we may as well just pack up shop and stop human space endeavours as chem rockets are not taking us anywhere with efficiency, no beyond the moon anyway and not in any capacity to allow cheap access.. Chemical Rockets are of no good, we need a alternative.

Cheap access to space is never going to happen in the next 20 or 30 years anyway. The energy requirements to get a given mass into orbit are huge, and the engineering requirements to contain that energy within a given mass are always going to be expensive.

Do you think that a nuclear drive would be cheap? Fissile material is expensive to process and to handle, and hopefully it will remain that way.

All the problem you suggested expect point 3 are POLITICAL problems anyway. They are human caused boundaries not scientific barriers and can be changed if people had the guts and will.

But political problems are no less real. It would be impossible to cancel the nuclear test ban treaties, because that would allow Iran, Pakistan, or North Korea to irradiate half of the planet "for peaceful research purposes". The whole idea of allowing atmospheric nuclear tests to resume would be met by the opposition of 99% of the World's population. Heck, even the wackiest contributors of this forum disagree with you on that!

You can spit and rant as much as you want, you won't change the fact that it's politically unworkable. It's dead Jim. You need to get over it. It's not gonna happen.

Im getting tired of going round in circles here but il humour you.

Its the only type of mission in demand because current lunch capabilitys and cost make anything more prohibitive. make it cost effective and you would have entire industrys moveing into orbit. With orion they projected with the huge pay loads for it to be 5 cents (1958 money) a Kg. That sort of economic cost and you would create a huge boom in solar resource minning, offword manufactureing ect. At $20000 a Kg you just cant do that.

So because launch costs are prohibitive, you suggest building a fleet of $500 billion dollar space ships that run on Deuterium ?

Yes, you are turning in circles, repeating the same arguments, that we keep on debunking again and again. In another thread I gave you some other great examples of things that people thought were good ideas in the 50's. They also thought that the Ford Nucleon would be economical (a full tank of plutonium lasts the life of the car!) or that strip mining with nukes would be harmless and profitable. Heck, in the 70's, even the Space Shuttle seemed like a good idea!

No way would nuclear bombs turn out that cheap and easy to handle. If they were, some dictator would have blown Humanity to smithereens decades before an Orion spaceship could fly.

Simply decontaminating the launch area to prepare for another launch would cost billions. Let alone the processing and handling of the bombs, the extra security, the ship itself... Just about everything in Orion would cost hundreds of billions of dollars that nobody is willing to pay for because there is no ROI in space for such an investment and no economical purpose for such a huge upmass. Yes, it's that annoying economic reality again.

Edited January 16, 2014 by Nibb31