Rand Simberg’s article of today brings a fresh perspective to those of us who’ve fretted over the seeming decline of America’s space technologies. Please read the whole thing, as the facts it presents are likely to diverge quite a distance from your current preconceptions.
But along with providing a pleasant attitudinal contrast with the common malaise about “America’s retreat from space,” it got me thinking about the challenges of space travel once again, for the first time in several years. Despite the inevitable association with government (ugh), it makes for a pleasant change of subject from politics.
The first question is always the most important one: What is our purpose in developing technologies for the exploration of space? What actual ends do we seek?
The least disagreeable aim would be to increase our knowledge: of the other bodies in our solar system, and of the laws that govern the universe. Virtually everyone would accept that those are desirable ends, though there would be some dispute over whether space travel is the best way to pursue them. Granted that you can’t prove that the Moon isn’t made of cheese except by going there, still there are other ways to probe the nature of our satellite than by sending men to have a personal look. However, there are aspects of nature that can only be tested in conditions that cannot be maintained on Earth’s surface.
Other purposes elicit much more controversy: to gain a purchase on the strategic “high ground;” to establish off-Earth outposts for experimentation and colonization; to exploit the resources available elsewhere in the Solar System; to safeguard Mankind against extinction; to “build a bridge to the stars;” and so forth. Each of these things is at least one step removed from the bedrock desideratum it’s founded on...and that desideratum could be even more controversial than space exploration itself.
The degree of disagreement over both the ends in view and space exploration as a means toward them guarantees that there will be no end to the political wrangles over whether the federal government should fund or otherwise encourage the development of space technologies, much less operate a space-exploration R&D organ such as NASA. However, what governments can do, private persons and voluntary associations thereof can do – and typically, can do it better. Moreover, they’re doing it, as SpaceX, Orbital Sciences Corporation, and Virgin Galactic are demonstrating even now.
Once a primary purpose has been selected, other questions, such as the question of the best means, must be addressed. But what about secondary purposes, and how they might be combined with the primary one?
Have a little wisdom from Herbert Spencer:
A blade which is designed both to shave and to carve, will certainly not shave so well as a razor or carve so well as a carving-knife. An academy of painting, which should also be a bank, would in all probability exhibit very bad pictures and discount very bad bills. A gas company, which should also be an infant-school society, would, we apprehend, light the streets ill and teach the children ill. -- Herbert Spencer, "Over-Legislation"
Spencer was, of course, principally concerned with the aggressiveness of government (and its boosters) in taking up an endless series of purposes to the detriment of the ones for which it was founded. But the same observations hold true for any sort of organization: to serve two purposes is to serve neither one as well as we might. The risks inherent in assigning many purposes to a single organization are great – particularly so when one or more of those purposes involves manned travel through space.
It’s always most effective to have a single aim, and to refuse to compromise it for any other end. But that hasn’t been the history of space technologies development. The proliferation of space-oriented companies reduces the probability that any one of them will be tempted to take the whole gamut of space-oriented purposes as its mission...but there’s no guarantee that it will be so, especially once the government gets involved.
A brief digression onto a related subject of importance: Certain possible objectives for space travel inherently demand exclusivity. For example, if our aim is orbital hegemony, then preventing other powers from acquiring a foothold in low Earth orbit is as important as getting there ourselves. Similarly, if our aim is to annex the Moon to the United States, it’s necessary not merely to get there, but to garrison it against incursions by other powers.
In such cases, politics, especially geopolitics, is the dominant consideration to be served. As long as space technology remains an involvement of the State, such considerations will remain “on the table.” Yet while the State possesses a de facto monopoly, the degree of conflict over such ends will remain low. It would rise as private competition with the State’s space travel organ rises...which suggests that such companies had better be aware of the ugly possibilities involved.
Finally for this brief screed, past experiences must be mined for the lessons inherent in them. The two Space Shuttle disasters ought to have taught us the folly of using delicate, thermally sensitive solid-fuel rockets to achieve orbital velocity, and of using bodily friction against the Earth’s atmosphere as the preferred way of shedding that velocity for re-entry. The Shuttle development program itself was a case study in technological hubris. (Look into the history of its “success by design” philosophy and the major fires that resulted.) Ponder the compromises that resulted from using the same vehicle both for manned missions and for missions that need no human component, thus serving neither aim with maximum effectiveness. To perpetuate the attitudes and approaches that led to those results would be inexcusable.
I’m a space junkie of long standing. I’m passionate about the importance of the space technologies. I’m an advocate for getting Man firmly established, not merely as a space traveler, but as a space dweller. For those reasons and others, the recent semi-privatization of American efforts in space cheers me greatly: privatization leads to competition, which leads to greater breadth of experimentation and, ultimately, to greater knowledge. But there are clouds on the horizon, in particular, the prospect of a renationalization of space exploration and technology, which grows more likely as Washington becomes more aware of the unpleasant possibilities inherent in unfriendly nations’ advances into space.
All the same, for those of us with one eye on the sky, the best is yet to come.
Around 1973 or -4, ANALOG magazine published two fascinating articles about the possibilities in manufacturing of materials in space. Not only are there the obvious microgravity condition and the availability of solar energy and hard vacuum, high levels of radiation are useful for some chemical processes. All this presumes the availability of the materials to be processed, i.e. mining of the Moon and the asteroids, as you mentioned. These furnish another reason to go into space.
ReplyDeleteIn the early eighties, ANALOG had another science-fact article describing possibilities for transferring momentum to spacebound craft from returning spacecraft, though most of those did not stick in my memory as very feasible.
One that did sound attractive, though presently infeasible, was a pair of decks (imagine aircraft carrier decks, without most of the aircraft carrier hull attached), tethered to each other many miles apart and rotating about each other (to be more precise, rotating about their common center of mass) in a vertical plane as they orbit. Suppose the center of mass of the decks is orbiting the earth in the clockwise direction from your point of view; the spin of the tethered decks is also clockwise, so that the deck in the higher location is moving quickly and the one in the lower location is moving slowly. A returning spacecraft would land on a deck, call it Deck A, as it passed through the higher part of its orbit and be braked by some arrangement on Deck A, thereby transferring its momentum to Deck A and simultaneously, via the tether, to Deck B. When Deck A rotates about Deck B to its low-altitude, the returning spacecraft leaves the deck to enter the atmosphere, but at a much lower speed relative to the atmosphere than before. An orbit-bound spacecraft would do the same process in reverse, lifting off and landing on a deck at the "low" altitude and then leaving it when the deck is at high altitude. The tethers would have to be made of currently unknown, extremely strong, material.
I'd be curious to hear your suggestions, Francis, about how to shed orbital velocity without using bodily friction.
There is one advantage to government getting back into space exploration-funding.
ReplyDeletebecause of the $$$ available the government,presumably through NASA can afford to hire the top scientists and engineers in the fields required.
There are simply not enough companies and/or individuals pursuing advances in space travel,and humans living and working in space. The ISS is a start,but we need much,much more investment in launch/re-entry technologies,and in building "housing" and expanding laboratories from just labs into manufacturing facilities.
We do need to be able to extract resources from meteors and asteroids,as well as planets and moons,if we reach that capability,then we can put people into space for long-term living,rather than the current fairly short "missions" on the ISS.
Another thing we have to do is get kids interested in math,physics,and the engineering fields.
Way back when I was in high school-there was an after school program called explorers or something similar that was funded by NASA,and we went to area manufacturing facilities that made things for the space program.
That was in the 70's,when NASA was going strong-plus the NASA-Lewis Research Center was nearby,and we went there often as part of the program.
There's a good chance that if we brought back similar programs-we would have a lot of kids entering engineering fields-that's what happened to most of us kids who were part of that after school program.There were 24 kids from area high schools who were accepted into the program-18 of them are now engineers,the remaining 6 of us work or worked in skilled trades,like tool and die maker,CNC machinist etc.
Education is one of the most important things we need to get the space program going again,and more importantly,to get private companies back into design and testing of the equipment needed.
Private companies always do a better job than any .gov agency ever has-or ever will.
Absolutely. The entire Shuttle program was exactly what was wrong with NASA.
ReplyDelete''It will be reusable and therefore cost less''
Nope, each mission cost more to fly than each Apollo mission.
''Many of them will have Military use''
Nope, only four missions were military related. Most military launches (such as GPS) were done with conventional rockets.
''Many will be science related''
HA! The Hubble and the INS both of which could have been done with Saturn V rockets.
What were the majority of the Shuttle's missions?
PR, nothing more. Such as The Congressman in Space. Including the two that ended in tragedy. The Challenger was ''The Schoolteacher in Space'' mission - and yes, it was supposed to be timed so it would be in orbit during Reagan's State of The Union Address. There were many that were literally ''high school science fair in Space'' missions such as the final Columbia one.
Fran,
ReplyDeleteExcellent article, but I have a minor quibble:
"...[folly] of using bodily friction against the Earth’s atmosphere as the preferred way of shedding that velocity for re-entry."
In fact, there is no better method of re-entry from orbit, as it uses no fuel, and provides good control of entry interface. Where the space shuttle got it wrong was in the shape of the body. Decades of missile re-entry research, as well as the Mercury, Gemini, Apollo, and Skylab programs, as well as the Russian programs, showed that a blunt conical body is the best shape for re-entry. An "airplane" is not, as hot spots will appear that can cause burn-through, ala the 2003 disaster.