Plan B From Outer Space

Rand

I admit all of the above. I could go on all day about things but the key is that with ISS and the large number of vehicles that can go there, (CRATS is nothing without a destination), you have a beginning. The Shuttle C is thrown in there simply to keep NASA in the game after ESAS falls apart. Saving money is never the government's goal but getting a system up and running within the amount of money that politics allows is what they want. NASA has ignored this at their peril for decades.

The Shuttle C is thrown in there simply to keep NASA in the game after ESAS falls apart.

Why is "keeping NASA in the game" important?

Maybe the best way to reform NASA is to let it die a natural death of bureaucratic sclerosis, and replace it with something for the twenty-first century.

Maybe the best way to reform NASA is to let it die a natural death of bureaucratic sclerosis, and replace it with something for the twenty-first century.

Meanwhile back in the real world where politics rules NASA does have a level of support and is going to be doing some things. Sorry but CRATS is not going to happen unless ISS is there.

CRATS is not going to happen unless ISS is there.

DoD doesn't care whether or not ISS is there. Neither does Bob Bigelow.

DoD doesn't have the money to pay for their existing overruns much less new ones.

Have you read the GAO report on just how bad the DoD procurement of space and weapons systems is doing these days?

All that means is that the DoD is going to have to reform its space procurement procedures and goals. Unlike NASA, what it does is actually important.

Oh I agree, but there is a larger problem in the business, which is that the number of people who want to be aerospace engineers continues to fall. You know yourself Rand that it is getting worse, much worse out there. Without the cadre of people necessary to do the work, there is little chance of any real reforms as the majors retreat more and more into relying on the "process" and not enough on talent.

I'd like to address one small comment:

the number of people who want to be aerospace engineers continues to fall

You shouldn't imply motivation here; there is a difference between wanting to be an aerospace engineer and being able to be an aerospace engineer. This is not to rant against government schools and their poor math/science preparation of students (though I could do that all day) but against the industry as it is. I went to college to study aerospace engineering, and when I left college in 1991, the military was cutting back, the airline manufacturers were laying off as they consolidated, there was almost no private general aviation industry, and NASA was (and remains) moribund. Just what exactly was I to do, wait for an existing engineer to die off? Instead, I went into computers, at which I've been quite successful.

So there are probably more people who want to be aerospace engineers than who have the opportunity, because the market is so small. (That said, two of my cousins roughly my same age are aerospace engineers gainfully employed.) If the market expands, the demand for engineers will outstrip the supply, which will push up wages for the engineers, which will create an incentive for more people to become engineers. It's amazing how that whole invisible hand thing works.

Jeff

I agree, but also today it is well known that Aerospace engineers are near the bottom in compensation. It is my position that Senior engineers should make $500k per year and fresh in's should make $100k

That will solve the problem.

...all you of Earth are idiots!

You see!? You see!? Your stupid minds! Stupid! Stupid!

*runs*

Dennis:

By fiat? I think it would be great if engineers were better compensated than entertainers, but where would the money come from? How would the market, in other words, support paying engineers that much, unless the supply of engineers falls further worldwide, or the demand rises dramatically?

All that means is that the DoD is going to have to reform its space procurement procedures and goals.

Step Two will be the stumbling block, as always:

http://socsci2.ucsd.edu/~aronatas/project/cartoon.math.gif

Meanwhile back in the real world where politics rules NASA does have a level of support and is going to be doing some things.

In the real world, most people outside of Huntsville, Clear Lake, and Titusville don't work for NASA.

The number of Congressional districts affected by NASA is quite small (and growing smaller all the time with consolidation -- that might actually be one reason Griffin resists using EELV).

Space cadets may rant and rave about Shuttle job losses at KSC, but if you look at NASA's figures, the total losses are comparable to the economic impact of just one Air Force base -- and BRAC has closed a lot of Air Force bases.

Dennis, DoD procurement has always been screwed up. So what?

You shouldn't assume that everything connected with military space has to be done by Space Command just because it has "space" in its name. Space Command is really ICBM Command -- the American equivalent of the Russian Strategic Rocket Forces.

Did you notice the recent statements from USAF sources about how they want an ASAT/ABM weapon on a manned forward-deployed fighter? Right now, that means the F-22 but it's easy to see it evolving into the first generation of space fighter, and ACC has a lot more clout than Space Command. Space Command is not the Air Force; Space Command merely works for the Air Force. Air Combat Command *is* the Air Force.

In the meantime, China has military spaceplane hardware on the runway right now. Unlike Shuttle C, that's something that could get the attention of people in more than six Congressional districts.

By fiat? I think it would be great if engineers were better compensated than entertainers, but where would the money come from? How would the market, in other words, support paying engineers that much, unless the supply of engineers falls further worldwide, or the demand rises dramatically?

The government is almost $300 billion overbudget on its space and defense related programs. A good part of that is that they are relying on obsolete processes and treating engineers like plug in subroutines in that process.

When a company comes along that starts paying engineers what they are worth, then you will see the revolution happen. This can be done under the FAR process and now is a time that the check writers in DoD are desperately looking for a way out of a failing system. You pay them top dollar and demand performance. The industry would be transformed within 5 years.

I have a couple of complaints about the Shuttle C. First, it looks to be less efficient and more costly than DIRECT (especially if Shuttle C continues to use SSME's). Sidemounted cargo means more deadweight in the overall system and using SSME's means higher cost either fixed or per launch, maybe both. I don't see any political advantage to it either. Many jobs will be lost either way.

Second, ISS is not designed to be an assembly station (that is, a place to put things other than the ISS together in orbit). As I see it, you can turn it into one by sacrificing the microgravity environment (and the respective research). There are various restrictions on the operation of the station (like only being able to dock 10 times a year, so I hear) that follow from the need to maintain the low vibration environment. The US would have to get its partners on board with this new plan, particularly the EU and Japan who will be running significant microgravity experiments on board. The orbital inclination is also poor for lunar missions. Requires a little more delta v and has fewer launch windows.

IMHO, it'll be more productive to place a second, small station in a lower inclination orbit and use that. Then you can get a station designed for the purpose and in a better position.

How about 40 degrees? :)

Could this be the missing link that explains Mark's blind allegiance to the Old Guard?

Could "Mr. James Whittington of JSC Engineering and Science Contract Group" be a relative of his?

http://amelia.db.erau.edu/nasacds/200709Disc1/research/20070026635_2007025737.pdf

As I see it, you can turn it into one by sacrificing the microgravity environment (and the respective research).

Please indicate all of this microgravity research of which you speak.

As far as an assembly platform, the folks that I talked to, who designed the dual keel always said that it was a nice thing to have but not necessary. If you look at the incredible success that NASA has had in the assembly of the station, including moving around modules when the orbiter is not there, I think that one is put to rest as well.

Karl

Of course it is less efficient, the point being? Ares 1 is efficient, but look at the cluster f*** that it is. The point is that by using 95% of the existing hardware, that we absolutely know all of the costs of, and the paperwork is in order on, it is a solution that can be done quickly.

Karl, Griffin has already eliminated most microgravity research. Also, the official plan says that US "involvement" in ISS will end in 2016 (or 2018, depending on who you talk to).

If scientists wanted to continue using ISS after 2016-2018, they would need to come up with money to maintain the station, replace end-of-life systems, and keep it in orbit. Since they can't even come up with the money to build experiments, that's a nonstarter.

Anyone who wants to use ISS for orbital assembly will also have to come up with the money to keep the station going, of course. The real question is not whether ISS is optimal for orbital assembly but what is the cost of maintaining compared to building a new special-purpose facility in a better orbit.

Another factor might be the disposal plan: NASA doesn't currently have one. They can't just let ISS do an uncontrolled reentry. If they can't decide how to get rid of it, then they'll have to hang onto it whether they want to or not. Unless they can get someone else to take it off their hands (which probably means paying someone to take it).

I'm not sure why we even need Orion, though, in this scenario. If it's a LEO-only vehicle, why waste money to build something that competes with the private sector? I thought that the idea was to get NASA out of LEO, and force them to focus on the "beyond."

Rand

Sorry I did not see this before. I would like more than anything else for Elon to be successful with the Dragon, if he is then NASA can kill Orion, it won't happen before. Elon's promises to performance ratio is not high enough for the government or the astronaut corps to take that risk.

Elon's promises to performance ratio is not high enough for the government or the astronaut corps to take that risk.

Doctor Griffin, I presume? :-)

The problem with that argument is two-fold:

First, it assumes that Elon Musk is the sum total of the private sector. He isn't.

Second, it assumes that risk is something unique to the private enterprise and can be avoided by adhering to a socialist cost-plus development model.

Does NASA's "promise to performance ratio" suggest a low risk of failure? How many times has NASA tried to develop a Space Shuttle replacement in the last 25 years? How many times has it succeeded? Why are Ares and Orion both floundering right now?

Remember when Lockheed got $1.5 billion to build X-33 and failed?

Remember when Mike Griffin got over $100 million from NASA to build a suborbital vehicle (X-34) and failed?

The astronaut corps won't risk Elon's capsule? Well, maybe, maybe not. Have you asked them? What makes you so certain that NASA's Orion capsule will be safer, given that *no* capsule and expendable rocket have ever been very safe or reliable? NASA's Apollo capsule scared Scott Crossfield -- and the Apollo 1 fire showed he was right. On the other hand, former NASA astronauts like Rick Searfoss and Hoot Gibson are working with companies like XCOR and Benson Space. They aren't scared off just because it's private enterprise. If the astronaut corps is really scared of Elon's capsule, perhaps that's an indication that capsules are not a great idea?

IMHO, it'll be more productive to place a second, small station in a lower inclination orbit and use that. Then you can get a station designed for the purpose and in a better position.

Correct me if I'm wrong, but aren't Bigelow's Genesis modules in a 41.5 degree orbit? And IIRC his future inflatable space stations are going in that orbit, too. It would certainly be more productive to use his facilities rather than the International Budget Buster.

Dennis, you make a good point about microgravity research. I've looked around and haven't been impressed by the US's feeble efforts in this area. Still as I mentioned, the Europeans and Japanese seem serious about it even if the US isn't (that also addresses Edward's point). And they have a say in the eventual fate of the station. Further, the station in the 2010-2016 will have much higher scientific output than it does now. That may still be embarassingly paltry, but it'll be better than today.

Dennis, I don't see how you can claim Ares I is efficient. It uses an SRB which has two major problems, low ISP and no upgrade path. They aren't going to use a wider or longer SRB. The Ares I starts capped at a mediocre level of performance compared to a normal liquid bipropellant rocket. And that's ignoring the vibration problems, the safety problems of an SRB, and the high prelaunch mass.

Edward, NASA has a disposal plan for the ISS - controlled reentry into the Pacific Ocean. It's been there since the begining of the program as far as I know.

Correct me if I'm wrong, but aren't Bigelow's Genesis modules in a 41.5 degree orbit? And IIRC his future inflatable space stations are going in that orbit, too. It would certainly be more productive to use his facilities rather than the International Budget Buster.

I will be more than happy to change my tune when they arrive in orbit and actually carry a human crew.

Dennis, I don't see how you can claim Ares I is efficient. It uses an SRB which has two major problems, low ISP and no upgrade path. They aren't going to use a wider or longer SRB. The Ares I starts capped at a mediocre level of performance compared to a normal liquid bipropellant rocket. And that's ignoring the vibration problems, the safety problems of an SRB, and the high prelaunch mass.

But, but, it is safe, simple, and soon! You did get the memo didn't you?

the Europeans and Japanese seem serious about it even if the US isn't (that also addresses Edward's point).

Not unless the Europeans and Japanese are willing to greatly expand their spending to pick up the full cost of maintaining and upgrading ISS. There's no evidence of that.

Edward, NASA has a disposal plan for the ISS - controlled reentry into the Pacific Ocean. It's been there since the begining of the program as far as I know.

Really? Can you tell me when that plan briefed and approved by Congress as well as the international partners? I bet you can't. :-)

Would you want to be the NASA Administrator who goes before Congress and tells them you're going to dump a $100 billion space station into the ocean?

Then there's the safety problem. The Committee on the Engineering Challenges to the Long-Term Operation of the International Space Station found that a controlled reentry required the ISS propulsion module to be 99% reliable (a requirement it probably can't meet) and even that reliability would not achieve NASA's goal of 1 in 10,000 chance of casualties.

"Sorry I did not see this before. I would like more than anything else for Elon to be successful with the Dragon, if he is then NASA can kill Orion, it won't happen before."

NASA killed Orion forty-five years ago. And now, they are using the name for the current bucket of bolts to make us forget the fact.

The schedule had us visiting the moons of Saturn by 1975. If only...

The schedule had us visiting the moons of Saturn by 1975. If only...
Those plans, and $4.50, will get you a mocha at Starbucks. The difficulties of building and testing Orion would almost certainly have been insurmountable. Consider the difference between static testing of a conventional rocket engine, vs. static testing of a nuclear pulse engine.

Really? Can you tell me when that plan briefed and approved by Congress as well as the international partners? I bet you can't. :-)

So what? This is a no brainer. You drop the ISS into the biggest unpopulated spot on the planet.

Would you want to be the NASA Administrator who goes before Congress and tells them you're going to dump a $100 billion space station into the ocean?

By the time NASA decides to deorbit the ISS, it'll be a simple choice. Controlled reentry or uncontrolled reentry. Assuming they have that choice.

Then there's the safety problem. The Committee on the Engineering Challenges to the Long-Term Operation of the International Space Station found that a controlled reentry required the ISS propulsion module to be 99% reliable (a requirement it probably can't meet) and even that reliability would not achieve NASA's goal of 1 in 10,000 chance of casualties.

I don't see the problem. If the built in propulsion isn't reliable enough (and there'll be plenty of time to improve it over the years), then attach a system that is.

Can you tell me when that plan briefed and approved by Congress as well as the international partners? I bet you can't. :-)

So what? This is a no brainer. You drop the ISS into the biggest unpopulated spot on the planet.

No, Karl, it is not a no-brainer. A civil servant can't just destroy a $100 billion government space station without getting approval from the politicians first. Which NASA hasn't done, no matter what you think.

I don't see the problem. If the built in propulsion isn't reliable enough (and there'll be plenty of time to improve it over the years), then attach a system that is.

What makes you think NASA has such a system? Can you show me where Congress has budgeted money for it, or do you expect it to appear out of nowhere?

And you didn't read. The Committee said that even *with* such a system, controlled reentry would probably not achieve NASA's expected casualty goal.

The difficulties of building and testing Orion would almost certainly have been insurmountable. Consider the difference between static testing of a conventional rocket engine, vs. static testing of a nuclear pulse engine.

"It can't be done! It can't be done!"

Except it was being done. They built a working model using conventional explosives. Nuclear bombs work. The ablation test worked because that was the first thing they noticed and got the whole thing started in the first place.

The only thing insurmountable is the lack of vision and nay-saying that wins the day when people let fear overcome reason.

"It's too complicated!"

Except the complications are modular in nature. Nukes are complicated but we already know how to meke them. Everything else is much less complicated and works better with more mass.

BTW, some people have it backwards saying perhaps Orion would be useful once in space but it's too dangerous for getting to orbit. It's in getting mass to orbit that Orion is really useful (and scales enourmously well) Conventional or other means (solar sails) work fine once your out of the gravity well.

If we needed it for survival you'd find out how simple Orion is/was.

Use 2 shuttle-c like vehicles to boost first a 90,000 lb tank of LO2 and then a scaled down version of the external tank (ET) full of LH2 to orbit. The shuttle orbiter could hook up to the reduced size ET just like it does to the big one, and then fill up with LO2. It could use that tank to go to the Moon and back carrying a lunar lander in the cargo bay. To return, it would aerobrake into Earth orbit, cool down a bit and make a regular descent leaving the lunar module orbiting the Moon. The next time they went, they could carry only a new descent stage for the lunar landing module and some other goodies to take down with them like a rover or the start of a habitation module.

Ken: you need to put aside the rose colored glasses and think critically.

No, it wasn't being done. Not even close. The complications were not modular in nature; the systems were such that realistic tests could not be done except on the entire, full scale system. Working out the bugs would have been hideously expensive.

The conventional explosive tests bear very little resemblance to a real Orion system. The physics of hypervelocity jet interaction with the plate changes radically as the speed increases. And scale matters -- subscale demonstrations cannot be substituted for full scale tests, in Orion engines or in chemical rockets.

They had planned a system where a full scale pusher plate could have parts of its response tested with huge sheets of chemical explosives. Even this would simulate only parts of the system. Propagation of the jet from the pulse units and energy deposition could only really be tested in flight, since it will vary with air pressure and the changed environment from previous explosions. The systems for putting pulse units into position were complex (Rube Goldberg-ish, IMO) and would have required extensive full scale testing.

I very seriously doubt the system could ever have been made to work reliably, if at all. I imagine it could be made to work in the future, but only in space, and only once there's a large infrastructure on the moon or in free space for doing full scale static tests.

Jeff

From your post above about salaries. It seems that the Defense department is starting to get it. I noticed some senior engineering positions here in Huntsville that are paying as much as $141k per year.

Thinking critically...

the systems were such that realistic tests could not be done except on the entire, full scale system.

Not even close to true.

You start with a big slab of iron in full scale and shape of a proposed design with an ablative coating on the bottom. You fire off exactly one bomb. No need for any mechanism for placing the bomb for this test. Fire that sucker, then do some analysis.

They had looked at a complicated fluid ablation system, but that wasn't required. They had solid materials that worked just fine. It was the discovery that only a thin layer ablated in the first place that started the project.

Scale does matter. The more mass the simpler the pusher plate design becomes (within riduculous limits.) Riding this thing would have been more comfortable than a luxury car.

The systems for putting pulse units into position were complex (Rube Goldberg-ish, IMO)

Initially they were. But then they could have just dropped them through a hole with a wire fuse. When it reaches the end of the specific length of wire we get another pulse. We'd had atomic artillery for decades, this is much simpler. You don't even need to plug the hole during the explosion.

The conventional explosive tests bear very little resemblance to a real Orion system.

It's an external combustion engine. Must simpler than the car you drive.

The physics of hypervelocity jet interaction with the plate changes radically as the speed increases.

So the first design may not be optimal. You don't think we could add sensors and improve the design. The fact is, the sucker is going to fly because it has plenty of reserve oomph. Unlike a chemical rocket.

And scale matters -- subscale demonstrations cannot be substituted for full scale tests, in Orion engines or in chemical rockets.

I completely agree. We should have just built the damn think and let the politicians that killed the program go hang themselves.

They had planned a system where a full scale pusher plate could have parts of its response tested with huge sheets of chemical explosives. Even this would simulate only parts of the system.

Wait??? I thought you said you couldn't test parts??? So now you agree with me.

Propagation of the jet from the pulse units and energy deposition could only really be tested in flight, since it will vary with air pressure and the changed environment from previous explosions.

I agree at some point you'd have to build and fly the thing. Isn't that true for everything? The major parameter is this bomb going off. You can record the acceration for each pulse and determine how air pressure and speed cause variations. I seriously doubt this is a show stopper.

I very seriously doubt the system could ever have been made to work reliably, if at all.

Well, you win that argument until somebody actually does it. Then I win.

I imagine it could be made to work in the future

There's a safe bet.

but only in space

Because of the scary bombs??? As I said, it's in actually getting useful mass into space where Orion proves it's worth.

and only once there's a large infrastructure on the moon or in free space for doing full scale static tests.

non sequiter.

Should have taken off those rose colored glasses before posting. but you knew who anon. was in that last post. right? Sorry about that.

The conventional explosive tests bear very little resemblance to a real Orion system.

...and it wasn't just testing explosives. They built and flew a working model. Making this subscale model fly as well as it did was actually harder in many ways than a larger or full scale system would have been.

They expected not just to make something work, but fully expected missions to start. Engineering was the easy part. Saturn in 75!

Politics killed Orion. Not engineering.

Politics killed Orion. Not engineering.

And justifiably so, according to Dr. Freeman Dyson. Or do the opinions of the people who worked on the project count for nothing?

No, Karl, it is not a no-brainer. A civil servant can't just destroy a $100 billion government space station without getting approval from the politicians first. Which NASA hasn't done, no matter what you think.

Ok, you get approval first, then you splash it. I'm not seeing the problem here. It won't be worth $100 billion by that time.

What makes you think NASA has such a system? Can you show me where Congress has budgeted money for it, or do you expect it to appear out of nowhere?

Why do they need it now? And yes, I do expect the money to "appear out of nowhere". Congress would be given a choice between paying for the deorbit or the liability of landing on someone and costing much more. NASA is after all attached to the US budget, this isn't a serious problem.

And you didn't read. The Committee said that even *with* such a system, controlled reentry would probably not achieve NASA's expected casualty goal.

They assume several things like 5% chance of casualties in the event of propulsion failure. If that chance is instead under 1%, then everything is within NASA guidelines. I think better modeling of the debris field from ISS reentry would considerably improve that guesswork.

My vague impression is that you think we can run or store it omewhere in space. By the time someone starts making decisions on whether to splash it, it has passed the usefulness phase. Even if the US decides to auction the station off, the US is likely to retain responsibility and liability for the fate of the station.

Then the question is whether to splash or store it. I don't see a viable place for the ISS in LEO. Either it'll be low enough that someone will have to constantly boost its orbit (like now), or it'll be sufficiently high, but a potential source of space debris. The only solution, as I see it, is to move it out of the well used ranges of orbits. Either park it in the van Allen belts or in MEO.

Even if we go with the Committee's odds above, we have a 5 in 10,000 chance of casualties. I bet we can do better, and you only need a factor of 5 improvement in the odds to eliminate this issue.

It won't be worth $100 billion by that time.

It's not worth a hundred billion now. Arguably, it has negative value.

Some of those reading this thread might enjoy watching video of one of the conventional explosive Orion prototypes:

http://www.youtube.com/watch?v=uQCrPNEsQaY

and might also enjoy watching a quick but comprehensive summary of Project Orion by George Dyson

http://www.youtube.com/watch?v=2ZyfuDPTzmk

One Shuttle-C-like concept I've wondered about is switching the location of the LOX tank and the cargo canister - it seems that you could get around the 15 feet payload size limit that way.

do the opinions of the people who worked on the project count for nothing?

Edward, since you bring it up you must know that Dyson was concerned about fission polution. He KNEW that Orion itself would work and was vastly superior to chemical propulsion. Von Braun even supported Orion.

So yes, I agree that the weight of opinion of the people on the project must be considered. However, regardless of who expressses it, the justification itself is what matters.

There are better atomic rockets than Orion. But if you want to get mass to orbit with something we have all the pieces in place now... Orion is it.

Tons of iron? Check. Nukes from 1 to 20 kiloton? Check. Graphite? Check. Big springs and shock absorbers? Check.

Nerve? That will come when some other country has an orbital battleship with hundreds of nukes on board.

Orion will probably never happen because we will probably come up with a better fusion rocket before any neccesity for Orions capability happens. All bets are off if we ever colonize and need to support that colony somewhere beyond the moon.

Ok, you get approval first, then you splash it.

Me??? Karl, I'm not the Administrator of NASA -- and if I were, I probably wouldn't want to commit political suicide.

I'm not seeing the problem here. It won't be worth $100 billion by that time.

I know you're not. It's apparent that you have little political experience, so buy a ticket to Washington, go see Senator Bingaman, and tell him his "national laboratory" isn't worth $100 billion and you want to destroy it. Then I think you'll finally understand.

What makes you think NASA has such a system? Can you show me where Congress has budgeted money for it, or do you expect it to appear out of nowhere?

Why do they need it now?

Non sequitar. You claimed NASA already has a plan for the disposal of ISS and has had one since the beginning of the program -- not that you could propose a plan based on some non-existant non-funded piece of hardware which you think NASA might develop in the future.

You also seem to be thinking that ISS is a United States space station. It isn't. It's an *international* space station. NASA can't unilaterally decide to drop it into the Pacific.

And yes, I do expect the money to "appear out of nowhere". Congress would be given a choice between paying for the deorbit or the liability of landing on someone and costing much more.

That's called a "false dichotomy," Karl. Those are not the only two choices. Congress could reject both of your choices and simply tell NASA to keep it in orbit and continue to operate it. As they've done every year up until now.

My vague impression is that you think we can run or store it omewhere in space.

Of course they can run or store it somewhere in space -- isn't that what they're doing right now?

By the time someone starts making decisions on whether to splash it, it has passed the usefulness phase.

Non sequitar. Scientifically, ISS never had a "useful" phase. Politically, you have yet to demonstrate why destroying it is useful. Dumping it into the ocean would embarass every Congressman who's been an ISS supporter as well as upsetting the international partners. How is that useful to the politicians?

Edward, since you bring it up you must know that Dyson was concerned about fission polution.

Er, yes, and he's not exactly the only one. Most sane people would be.

Von Braun even supported Orion.

So? Just because Von Braun did something doesn't mean we should do it. Von Braun supported the Nazi missile program that was bombing London, too. Does that mean we should support Nazi missile programs to bomb London?

So yes, I agree that the weight of opinion of the people on the project must be considered. However, regardless of who expressses it, the justification itself is what matters.

Not when the justification is insane. :-)

There are better atomic rockets than Orion. But if you want to get mass to orbit with something we have all the pieces in place now... Orion is it.

There are plenty of ways to get mass into orbit without atomic bombs.

There are plenty of ways to get mass into orbit without atomic bombs.

Yep, The difference is that chemical rockets must be highly effecient to get a little mass to orbit. Orion is highly ineffecient but gets megatons of mass into orbit in a single shot. Should we ever actually need that capability those that say it can't be done are the ones that would lool foolish.

My hgih school buddy and his father (who took me in when I was 16) both died of cancer about a year apart a few years ago. We do need to think before adding hazards.

We can't let fear overcome thought. Radiation is a part of life. It's not the boogy monster. We can and should thoughtfully mitigate hazards of all kinds. Irrational fear and politics keeps us from having cheap energy in this country. We could have road grids that charge our electric vehicles as we drive for pennies a mile, but we can't build a standard nuclear powerplant in this country. I see the staggering opportunity costs we are spending and it appalls me.

I do believe we can explore spacel with just chemical rockets. I just hate when people say we can't do something that clearly we could if we wanted or needed to. Some things can't be done, but they are fer less than the number of smug naysayer's out there.

The fact is that my dentist has subjected me to more radiation than Orion ever will. Don't confuse me with being an advocate of Orion. But don't tell me it can't be done either.

As for sanity. Whose the judge?

Yep, The difference is that chemical rockets must be highly effecient to get a little mass to orbit.

Which is not a problem because chemical rockets are (contrary to popular misconception) highly efficient.

Orion is highly ineffecient but gets megatons of mass into orbit in a single shot. Should we ever actually need that capability those that say it can't be done are the ones that would lool foolish.

Yes, and if I ever need a hole in the head, I'll use a power drill.

But I don't need a hole in my head, and we don't need to launch megatons of mass in a single shot.

The fact is that my dentist has subjected me to more radiation than Orion ever will.

True, because Orion will never be built.

we don't need to launch megatons of mass in a single shot

Not yet. Maybe never. But Orion would meet the need..

Orion will never be built

...I'm such a good straight man, don't ya think?

But seriously, before the test ban treaty, one bomb released more radiation into the environment than 100 Orion launches would. With some potential fusion designs (not possible today) zero radiation would be released.

One of the reasons not to endorse Orion is it would likely be limited to a government program. I endorse private enterprise. I might endorse Orion if it were a government service providing a launch platform for private ships. It could take dozens of ship to orbit with each launch. The asteroid mining guild would approve, don't ya think?

Duncan Young, that's some good thinking. It would move the cg laterally in a favorable direction, but would also move it aft, which might make stability a little more tricky at launch. Not necessarily something that couldn't be worked around though. On the down side, it doesn't really do what Dennis is setting out to do with his concept, which is to make minimal modifications to the existing system so we can keep flying after ESAS collapses. But still, it's something to keep in mind.

One thing to think about:

According to the studies that actually got done, Orion pulsejets get more efficient and cleaner per unit mass as the size of the lifter goes up. One extreme of the range was eight million tons to LEO with one single-stage vehicle, using 5MT or so per shot - of which nearly all would be fusion, therefore producing very little persistent radiation compared to the mass lifted.

One thing that hasn't been mentioned is reliability. If you are lifting ten million tons of vehicle plus payload, then if the first shot is a fizzle there isn't much of a problem. However, if the second shot fizzles...

Nevertheless, Orion is humanity's ace in the hole. Like nuclear weapons, the idea can never be un-invented. If things get really desperate, then Orion will be there.

For another application, see Pournelle and Niven's excellent book Footfall.

Loved footfall, which is where I first heard of Orion.

if the first shot is a fizzle there isn't much of a problem. However, if the second shot fizzles...

It's even more reliable than that. Up to half your pulses can be duds and you'd still be going up. The first non-dud gives you upward momentum and altitude; so as long as the third recovers for the second fizzling or you have sufficient altitude for a series of duds you're ok. All the while you accelerate at under 2 g's. Style and comfort and safety with a fantastic margin for error. There's even a high tolerance for not placing the pulse at exactly the right point.

My understanding is that even fission bombs can be packed in materials that absorb almost all the radiation. Of course people should be concerned about radiation but they shouldn't be irrational about it. If we limited hazards to only those below what Orion represents nobody would be able to drive or smoke. Being a non-smoker...

Does the second amendment give me the right to build Orion in my backyard? I hate that only governments get the good stuff! ;^)

Just thought of another thing, suppose only the first pulse goes off and say the airgun or whatever that's sending out the bombs fouls up. When you hit the ground the built in suspension treats the gound as just another pulse. It might even take passengers a while to realize that something wasn't quite right.

No, the bombs are not armed yet silly. You're not going to blow youselves up. Well, perhaps in the movie version.