Sunday, October 09, 2005
The broad outlines of the future for manned space exploration
The New Atlantic writes:- In Griffin’s testimony at his Senate confirmation hearing, he made clear his strong support for the new Vision for Space Exploration and candidly criticized the old NASA mentality. “It is time to recognize that we have squandered a once-insurmountable lead in the arts and sciences of spaceflight,” he said. “The best we can say for ourselves today is that our grounded space shuttle is much more sophisticated than the operational vehicles belonging to the two nations which have sent people into space since we have last done so.”
Gradually I've begun to see some coherent arguments around the idea of flying fuel and spacecraft separately on the HLV. The private spaceflight enthusiasists are going ape after the idea, yet not one has seriously suggested that we concentrate on getting resources into earth orbit from elsewhere in the solar system (e.g. NEOs). I guess I'm one of the few who still thinks it would be cheaper to get a grip on space that way.
In this matter, my views are congruent with the fuel depot crowd - if we can separate the propellant from the payload we can double (well, barring drag problems) the usable mass we send to orbit... and perhaps... one day... with this infrastructure in place... we could derive the propellant from outside earth's orbit. The technical problems in transferring cryogenics in space are severe, but they could be mastered - or we could settle on less difficult fuels (methane, alcohol, a variety of others).
Having a viable infrastructure for fuel delivery lowers risk and increases the size of the market for all those interested in seeing more competition in the space industry.
Consider this analogy about gas powered cars: If cars ran on Xenon, and could only refuel in Houston, would they have spread across the US and the world as fast as they did? No! Only by being able to make stops every few hundred miles are cars viable transport.
(Xenon is a popular, but very difficult to refine and rare propellant used in SEP powered spacecraft. It's a dead end fuel, suitable only for missions that can't refuel....)
In looking over the vision for space exploration I note that Zubrin slices NASA's problem in two:
- In the Apollo Mode, business is (or was) conducted as follows: First, a destination for human spaceflight is chosen. Then a plan is developed to achieve this objective. Following this, technologies and designs are developed to implement that plan. These designs are then built and the missions are flown.
The Shuttle Mode operates entirely differently. In this mode, technologies and hardware elements are developed in accord with the wishes of various technical communities. These projects are then justified by arguments that they might prove useful at some time in the future when grand flight projects are initiated.
Contrasting these two approaches, we see that the Apollo Mode is destination-driven, while the Shuttle Mode pretends to be technology-driven, but is actually constituency-driven. In the Apollo Mode, technology development is done for mission-directed reasons. In the Shuttle Mode, projects are undertaken on behalf of various pressure groups pushing their own favorite technologies and then defended using rationales. In the Apollo Mode, the space agency’s efforts are focused and directed. In the Shuttle Mode, NASA’s efforts are random and entropic.
To make this distinction completely clear, a mundane metaphor may be useful. Imagine two couples, each planning to build their own house. The first couple decides what kind of house they want, hires an architect to design it in detail, and then acquires the appropriate materials to build it. That is the Apollo Mode. The second couple polls their neighbors each month for different spare house-parts they would like to sell, and buys them all, hoping eventually to accumulate enough stuff to build a house. When their relatives inquire as to why they are accumulating so much junk, they hire an architect to compose a house design that employs all the knick-knacks they have purchased. The house is never built, but an excuse is generated to justify each purchase, thereby avoiding embarrassment. That is the Shuttle Mode.
I slice it in three - By the time that Apollo was hitting its stride the rot at NASA had already set in. For more details, read Chris Kraft's "Flight". I look to the upcoming moon program and especially the development of a specialized lander and return vehicle as a waste of money - we don't need specialized gear to land on an asteroid - just specialized gear to mine it - and the ability to refuel in orbit...
Labels: asteroids, fuel depots, nasa, space, space05
¶ 9:49 AM
