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Tuesday, September 11, 2012

The Very Short Version Of Pournelle On X-Programmes

  The full article on how government programmes rarely work, why X-Programmes are the exception and how to do them. Better yet - read the whole thing: The nominally military US organisation DARPA seems to be close to an X-Prize factory & has had remarkable successes. Britain has no equivalent. Instead we have hundreds of thousands of clerk in the MoD, who are worse than merely useless, they are in the way, and ensure any prohects we do are late and before they are completed we have to buy American stuff first.

We have institutions for nearly everything now, but we have lost the institutional means of long range planning. Who looks after our grandchildren? Surely not the politicians, who can hardly think past the next election, and are generally content to put problems off to be solved when the politician is safely out of office.
It isn’t strictly true that government always mucks things up, but it’s often enough so. A, if not the, major purpose of government is to extract money from non-government and use it to hire and pay government employees. This guarantees that government will always expand; and there inevitably comes a point at which the addition of people to a project has a negative impact. Almost all long-standing government agencies and projects have people; and the more conscientious they are about earning their pay the more they tend to get in the gears and bring progress to a halt.

It has certainly been that way in space R&;D and space operations. I needn’t give the history here. It can be summed up as early enthusiasm and success, expansion of the team, and then makework to keep the standing army busy or appearing to be busy.  New centers are then started in hopes of having a new cycle of enthusiasm and success, and that works for a while, but eventually the system is clogged with memoranda, policy directives, reviews, reviews of reviews, and the rest. Everyone is familiar with the process. Nothing can be done because nothing can be approved, and nothing can be approved because the only way to justify one’s importance is to ponder approvals, rewrite requirements statements, and require rewrites. And always to add complexities and more mission requirements.

X Programs: An Exception to the Rule

One of the most spectacularly successful government projects in technological history was the X-program. Beginning with the X-1 and going on through the X-15 and beyond, X programs were instrumental – indeed essential – in making the United States far and away the technological leader in aviation and space technology. One example should suffice: the X-3 Stiletto, the first airplane to take off from the ground, go supersonic, and land to be flown again. This airplane was useless for operations. It could hardly maneuver. However, the Stiletto led directly to the Lockheed F-104 Starfighter, and that airplane dominated military airspace for a very long time.

There were other such successes for the X programs; indeed, the program was cancelled not because of its failure, but due to its success. It generated so much new military technology that the arms control strategists were afraid of it. Whether or not arms control was a good strategy, one thing was clear, the X programs were not compatible with it; they had to go and they did.

Real X programs have certain characteristics, and while they are hardly all identical, we can tease out some common factors.

First, they are relatively small. They don’t have huge budgets. They don’t attract big attention and they are not good bait for large bureaucratic sharks or big companies. They are not profitable in the usual sense of the word. The payoff to a big company from participation in an X project is nearly all intangible: prestige at least within the profession, and some early technological advantages from having employed people who built and understood the new technologies identified or acquired by the project. Actual monetary gains are small and often negative.

Indeed, the payoff to everyone: sponsoring institution, contractors, the United States, and sometimes all mankind, is technology and experience and not much else.

Next, X-programs have limited goals, and are over and done with in a relatively short time. They are not intended for career building, and ideally there should not be any career opportunities in X-program management. One does the project and gets out. It’s over. There’s no empire to be built because the project doesn’t last long enough to allow that. This is key to X-success.

Finally, the best X-projects are based in out of the way places, generally unpleasant places. ...No one wants to build empires in the Mojave Desert.

The typical X project focused on a needed technology. Although the technique is applicable to many areas of technology, I’ll stay with aerospace for the moment. One designs the best ship possible given existing technology. There are to be few to no stretches or reaches: we are not looking for new technology, we are looking to see what the best we have can do – and thereby identify what’s needed next.

The ship is built. Typically there will be three vehicles (tail numbers in the jargon). The first is flown to find out its capabilities. Then those limits are tested, and tested again. Frequently tail number One is destroyed in the test process, although that’s not inevitable. Using what was learned from One, Two is modified and flown to its limits, and kept flying until there is no more to learn. Number Three makes a few token flights and goes to the Smithsonian.

From that process we learn what we can do, and what more we need to know.

There comes a time when you must fly something if you hope to learn more. We need data for those simulations. We are at that stage now in a critical area of space technology.

First and most obvious, the real cost of space is access. We over-build satellites because they have to last a long time, and they have to last a long time because it costs too much to replace them. Technology outstrips us every time: by the time a satellite or other spacecraft is launched it is generally obsolete, sometimes hopelessly so, as Moore’s Law takes another run along the exponential curve.

Ideally we would build satellites to last for a few years, then replace them with smaller, more powerful, and cheaper spacecraft; but we don’t do that. Instead we lock in electronics that are outdated before the design is completed, and design those systems to last a long time. This only makes sense if the launch costs are enormous. But of course they are.

The real key to space exploration is developing cheap and reliable ways of getting there. It’s pointless to speculate on whether we need humans in space when the costs are so high. My own view is that if access to the Moon cost anything like what access to the South Pole costs, we’d be there like a shot: we certainly have not been content to explore Antarctica with robots. But until the costs come a long way down, we have to be content with robots, and getting them to orbit and beyond is all but prohibitively expensive.

Airline operations cost a small multiple (typically 3 to 5) of fuel costs. It costs about the same in fuel costs to fly a pound to Sydney, Australia from the United States as it does to put that pound in orbit. It shouldn’t cost more in dollars, either. Of course the airline doesn’t roll the airplane into the sea after it gets to Sydney.
Although fuel cost drives airline operations costs, there’s another driver for space ops. A typical airline will have about 110 employees per airplane, but half of those sell tickets. Sixty in operations and maintenance is more likely. Now divide the number of NASA civil servants and contractor employees working on Shuttle by the number of Shuttles, and you will get some idea of why Shuttle flights are about a billion dollars a flight instead of the hundred million or so an airliner would charge. Understand I am not accusing NASA of featherbedding Shuttle: all those people are needed, but that’s just the problem. Shuttle was in some respects designed to need them. When your goal is to employ a standing army, you will reach that goal one way or another.

Operations driven designs are the key to our future in space.

That brings us to what I call the SSX. We sold this concept to the National Space Council in 1989, but alas it was only partially implemented before X-33 came to dominate space development.

SSX is a Vertical Takeoff Vertical Landing Single Stage to Orbit rocket with multiple rocket engines.

SSX-1 will probably have a negative payload to orbit: that is, it won’t get there. We will and should overbuild it. Flight safety and recoverability are more important than shaving the mass fraction.

Remember. X programs have no payloads, nor do they have mission requirements. The purpose of an X program is to learn how to build ships that do have payloads and can fulfill mission requirement...

 when it’s done we’ll have numbers to input: we’ll have a much better idea of what the mass fraction, and thus the payload, of an SSTO VTOL ship will be. We will know what size the ship must be to make orbit. Perhaps we need much better engines, or to go to some kind of Two Stage to Orbit (with recoverable first or zero stage). But we will know these things, not merely guess at them.

More likely we will find the stress points, bore holes in the structure to remove needless strength and weight, and come close to orbit with this ship. My guess is that we may never make orbit but we can scare it to death.

Because we don’t have to make orbit or come close to fly the ship and bring it home we can experiment with different arrangements and tricks: extensible bells, dynamic aerospike geometries, and so forth.

And finally, we’ll relearn what X projects are all about, and that will be the best payoff of all.

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Instead of an X project they went with the X-33 which had three major technical leaps to make. Linear Arospike Engine, Conformal Cryogenic Fuel Tanks and Advanced Thermal Protection System. But instead of working on these three things before they built the X-33 or a little at a time, they worked on them all at the same time while trying to make a big leap while building one vehicle so any problems or changes would mean having to redesign and rebuild the X-33 they were already building.

An X project would have had several vehicles which they would first get flying and then they would add new technology to improve the performance instead of taking a flying leap using multiple examples of brand new tech in one vehicle.

The Space Shuttle is an example of a bit more successful effort in trying to make it in one leap and it still was over budget and under performance with little political support to do the improvements which could have made it more reliable and cheaper to operate.
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