My promised (well, actually, hoped for) rebuttal to Alexander Tabarrok's mistaken hit piece on the space tourism industry is up at TechCentralStation.

[Update at 10 AM EST]

I have to say that I'm underwhelmed by Professor Tabarrok's response to my rebuttal. He seems to have read it, or at least glanced at it, since he complains about my use of the (admittedly overused, but appropriate in this case, I believe) word "paradigm." However, he doesn't seem to have comprehended it, or if he did, he chose not to provide a substantive response.

He is still apparently unable to discern the distinction between orbital and suborbital, and between reusable and expendable, and why such a distinction is important. He accuses me of relying on "faith," when in fact I made a very clear and rational case as to why these new vehicles are different than the ones from which he mistakenly draws his misleading statistics.

In this last graf, he displays a fundamental lack of understanding of the economics of the space industry (disappointing--one would hope that as an economics professor, he could get that right, even if he doesn't understand the technical issues):

What's so great about space tourism anyway? Even though an increase in rocket safety of a factor of ten is not much when considering the safety of large numbers of people it is very significant when thinking about satellite launches or temporary low-orbit launches. A reduction of risk of this amount means much lower insurance costs that will open up space to new private development.

What's so great about space tourism is that it is the only market, or at least the only one that doesn't require some technology breakthrough beyond the development of low-cost vehicles themselves, that is sufficiently large to get us to the scale of operations necessary to reduce costs and improve reliability.

And if he believes that the high cost of launch insurance is the barrier holding back private space development, he understands nothing at all about the current launch industry, either technically or in a business sense.

David Masten isn't impressed, either.

"The difference in velocity between its flights and those of a suborbital vehicle, such as SpaceShipOne is a factor of four or five"

Actually closer to 8x

"The difference in velocity between its flights and those of a suborbital vehicle, such as SpaceShipOne is a factor of four or five"

Actually closer to 8x

How do you figure? Orbital is seventeen-thousand miles an hour. SpaceShipOne was about three or four, as far as I know.

I think this was a very good point by RS in his rebuttal. After all, aside from the wholly unimportant fact that it gulps oxidizer from the outside, a 747 is just as much a "rocket" as SS1, meaning it flies by a rocket effect. The most important difference is clearly simply that faster means more dangerous, and it does stand to reason that creeping up on faster speeds might be a better engineering approach then just leaping right to orbital speeds with whatever tech you can scrape up.

In fairness, as I understand it this was not the fault of the NACA/NASA crowd per se. I believe the modern approach was well underway in the late 50s, with the X-15 and DynaSoar projects. (Interesting that Tabarrok did not compare to X-15 or other rocket-plane statistics, much more relevant to the immediate future of suborbital tourism.)

But then came Sputnik and Gagarin, and arguably John Kennedy's need to out-macho Eisenhower and Nixon after his razor-thin win in 1960, not to mention any need to distract America from that Bay of Pigs thingy (Kennedy's speech to Congress proposing men on the Moon was given one month after the Bay of Pigs fiasco).

I believe people have argued that the subsequent need for haste and the injection of huge national pride issues is what derailed the aerospace establishment from its sober and sensible 1950s path of flying gradually to orbit, and introduced the man sitting on a firecracker model we have today.

Orbital is seventeen-thousand miles an hour. SpaceShipOne was about three or four, as far as I know.

I thought SS1 was about 1000ms (Mach 3 ish), with (quick calc) orbital velocity for a 250km orbit with a period of 90 minutes around 7,800ms.

It's more like 7 times.

I'm still more concerned about the energy requirements though, energy required and carried being the square of velocity IIRC.

Tabarrok's blog clueless rebuttal to Rand

Tabarrok mistakenly focuses on orbital rockets because he refuses to confront sub-orbital flight. The fact is a sub-orbital tourist rocketplane is more of a high-performance aircraft than a low-performance orbital-rocket. In fact since for most of it's flight SS-1 was an unpowered glider a more useful safety comparison would have been with sky-diving.

Tabarrok asks the following questtion:

"There are lots of millionaires willing to spend one or two million dollars for a flight into space but how many will risk a two to five percent chance of death?"

Okay, how many millionaires are willing to risk an even higher chance of death to be led up Mt Everest by a guide? Even if his technical argument were correct, his economic argument holds no water.

I admittedly know nothing about Tabarrok, but it seems that there are many put off by the prospect of space tourism because they can't admit/believe that the private sector can do everything the government can do - except better, faster, cheaper and safer.

""I thought SS1 was about 1000ms (Mach 3 ish), with (quick calc) orbital velocity for a 250km orbit with a period of 90 minutes around 7,800ms.

It's more like 7 times.""

Exactly, and Rand is the one worried about people not understanding the "technical issues"? Although correcting
his error actually helps his arguement, it's gems like these that
keep me reading.

D'oh!

You're right. I was thinking thousands of miles per hour (seventeen versus three plus), rather than Mach numbers. But as you point out, it actually strengthens the case, since there's an even bigger disparity between the two velocities.

Anyone familiar with Alex's work for the Independent Institute knows Alex is a classic "can't see the forest because of all the trees" scholar. He's a number cruncher instead of a visionary, the sort who can analyze what already exists but can't visualize anything new. He thinks stasis is the natural order of the universe.

This is an interesting discussion going... I have two points/questions...

1. The dV required for low Earth orbital insertion is about 9.3km/s or 21,000 mph (one must add the energy losses due to gravity, drag, and geometry to the 17,000 mph orbital velocity), The max velocity of SpaceShipOne was about 2,000 mph. Right there you have a ratio of about 10:1, but it's still not comparing apples to apples. Has anyone taken a stab at estimating the total dV of White Knight+SS1 so we can better estimate the increased energy requirements for going orbital? By the way, it should be kept in mind that these are all very rough numbers, and in any case, the argument just gets stronger and stronger...

2. It seems that reliability and safety are two concepts being used interchangably in these discussions. Can we really equate the two? If not, how does one translate reliability gains to safety?

Oh, there are a hundred arguments, but I wouldn't see much point in taking it further. Michael Mealling, in a comment over at the catallarchy.net is thinking very much along the same lines I am on this issue: If you want to take the anti suborbital flight position, the most you could possibly argue is that there is insufficient information to determine what the risk level will be. You can make arguments for different risk levels and pick data to support it, but ultimately, we'll have to wait and see.

It seems that reliability and safety are two concepts being used interchangably in these discussions. Can we really equate the two? If not, how does one translate reliability gains to safety?

No, we can't equate the two, and I try not to do so. When I say that the Shuttle is unsafe, I really mean it. Reliability is a sufficient condition for safety, but it's not a necessary one.

As I stated earlier, unmanned rockets either make it to orbit or become fish habitat.

Any toruism vehicle is going to have numerous abort and/or escape modes that do not apply to unmanned launchers or even necissairly the shuttle.

A failed launch and a launch disaster are not one in the same, just like a commerical airliner can abort due to a malfunction with a very high degree of sucess.

If you want to take the anti suborbital flight position, the most you could possibly argue is that there is insufficient information to determine what the risk level will be.

Perhaps not exactly. What you (meaning an anti-suborbital person) can argue is that there is insufficient information for you to determine what the risk level will be. Someone else (someone willing to take a ride) may not agree.

This is far from a trivial point of language. There's a deep divide between the point of view that says let every man judge the risk for himself and that which says we must achieve a single consensus judgment of the risk.

The former POV argues for a largely free market: let each entrepreneur decide for himself the risk to his capital, and invest or not as he chooses. Likewise let each passenger decide for himself the risk to his life, and take a ride or not as he chooses. I submit that your conclusion that we should just wait and see implicitly accepts this argument.

The latter POV argues we must, at some level, protect people from their own folly, or at least (in terms of innocent bystanders) from the folly of others. Now some might argue that many of the folks in this camp are just cynically protecting their turf, and up to a point I don't doubt that's true. But some of them at least believe they act from this altruistic motive.

I think it's worth thinking ahead to their reaction when stuff starts getting off the ground. The problem is, if it is a vibrant and daring business, which is its only hope of achieving efficiency and success, as has been pointed out, then there are going to be mistakes, serious mistakes, costly mistakes, mistakes that involve tragic and (in hindsight) wholly avoidable loss of life. Cute furry animals are going to die.

Now, this is what we want, right? NASA has been reorganized in the last 20 years around a core concept of No Loss Of Life, no mistakes. This is obviously connected to their plodding and expensive progress. So what we're asking for is the chance to make way more mistakes (and learn efficiency a lot faster). This should not be forgotten.

What that means is, think about how the folks who believe in protecting people from their mistakes are going to react when there's a doozy. Think carefully about stressing the safety and reliability of the new craft. You don't want that to come back and bite you when one of them blows up and takes a single slim attractive mother librarian author of childrens' books and volunteer at the animal hospital with it.

Perhaps there should be some emphasizing of the risk to some extent. You bet, Mr. Senator, this is very risky stuff, we need to make very sure people understand that. So let's have lots of warnings and disclosure forms and informed consent. Piles of paperwork to fill out. God-damn annoying to customer and a criminal waste of thin vendor resources. But also a big concession to the nanny-state people -- a quid for which perhaps a quo can be extracted -- and a down-payment on a future ability to shrug off accidents with 'Well, you were warned.'

Maybe the quo can be the right to set the terms of those warnings and paperwork. Properly worded and presented in the right way dire warnings have zero practical effect on determined customers while still giving vendors a lot of helpful cover ("The Surgeon General has determined...").

I don't know what the form of this kind of approach would be, or even if, practically speaking, it can fly. I am not a lawyer, as the saying goes, still less a politician. I'm only saying, consider not only how likely it is that we can defeat the nanny-state approach by frontal assault, but also whether, if we do, we may sow some seeds of significant future trouble. I think the experience of the nuclear power industry should serve as a warning: too much was promised in the beginning, and the backlash was vengeful.

In other words, a little political judo may be in order. . .

Any tourism vehicle is going to have numerous abort and/or escape modes that do not apply to unmanned launchers or even necessarily to the shuttle.

As an engineering amateur and conceivable customer I find this a very persuasive argument. I find it plausible because I contrast the Space Shuttle's "all at once" leap into orbit with the relatively leisurely flight of White Knight/SS1. Undoubtably I'm oversimplifying, but reassuring mostly correct oversimplifications of the engineering are essential in winning the political debate, 'cause the Senators and voters are not, in general, engineers and don't much think like one.