First, appearing at the Slate on-line magazine web site, is an article by the novelist Neal Stephenson, noted for such works as Cryptonomicon (marvelous!) and Anathem (merely quite good).
The piece, Space Stasis: What the strange persistence of rockets can teach us about innovation, explores the phenomena of path dependence and lock-in as they affect technological progress.
Path dependence refers to the way in which certain environmental factors, each in itself perhaps improbable, are nonetheless essential for a technology to have evolved to its present state. The phenomenon of lock-in is related. It refers to historical factors acting to impose rigid constraints on current implementations of a technology. One familiar illustration is the thesis that purports to show how the modern standard railroad gage is derived from the track width of Roman chariot wheels.
Stephenson's essay will give you a new way to think about space transportation issues, and a new perspective on the evolutionary potential of any incumbent technology. (For example, how have path dependence and lock-in affected transport-category aircraft?) I commend it to you. And after you've read it, you probably ought to read The Fountains of Paradise by the late Sir Arthur C. Clarke for a counterpoint.
The second essay I'd like to recommend appears as a guest post at Jim Fallows' blog. It's called Three Dimensional Visionaries and is written by Dr. Bruce J. Holmes, a retired NASA strategist (focused on the first "A", aeronautics) and current advocate for advancing aeronautical technologies.
In the piece, Dr. Holmes looks as far back as the time of Thomas Jefferson to discern the role of our national administrations in formulating strategic visions for what he calls the "mobility mandate" in our country. He notes that some administrations have been visionary while others have been caretakers - and he makes a passionate case for the need to return to visionary thinking. A part of his argument refers to the need to break out of the present state of technical path dependence and lock-in by empowering industry to exploit paradigm-shifting technologies.
Bruce Holmes' essay is a fine complement to Neal Stephenson's. Together they help to define an aspect of our problem and to illuminate a possible way forward.
Please read them both.