U.S. Superiority In Space
In February 2005, an article Gray culled from a book manuscript was published in Air & Space Power Chronicles, the on-line adjunct to the Air Force's Air & Space Power Journal. Entitled, "U.S. Superiority In Space--Considering Propulsion And Power," the article examined what might be expected from advances in space propulsion and space power technologies.
One of the topics the article explored is the idea of multi-purpose rockets and payloads. Gray explained some of the difficulties in making this idea work:
The common launch vehicle will require a common adapter that fits multiple payloads. 'Fit,' however, requires more than just mating the two mechanical surfaces together. If the aim is to speed the build-up and launch process, the common adapter must provide standardized power (voltage, amperage, DC or AC), cooling (available in a range, but not an infinite range), and communications signals (for telemetry and commands prior to launch and during flight)--and all the satellites that would be fitted to the adapter must be built to similar power, telemetry, etc., standards. That is the rub: building different types of satellites that are all compatible with the common launch vehicle and adapter, and keeping both payloads and launch vehicles ready for call-up at a moment's notice. And even if the satellite interfaces are identical, that does not mean the mission requirements for different types of satellites--their orbital parameters, attitude, etc.--will ever be the same.
Gray was more forthright in criticizing the wishful thinking inherent in many acquisition programs.
Despite the promise of 'better, faster, cheaper,' experience (and a little forethought) shows that usually we can have only two out of the three, not all three at once. Better and faster usually will be more expensive; faster and cheaper usually does not turn out to be better; and so forth.
On the Air Chronicles site you can read the full article.
Or, if you prefer, you can read the article in Chinese -- as it was translated by the USAF in the Fall 2007 issue of the Chinese language edition of Air & Space Power Journal.