Those who follow the NOSSes will remember the Titan Launch Dispenser that was revealed early last year. (If you don't but are interested, see www.fas.org/spp/military/program/surveill/open.htm ) The TLD is mostly of interest in connection with the NOSS 2 A objects, which are a subset of secret satellites that do a disappearing act after a brief stay in LEO. Rumors blowing about have suggested that they go into a fairly high orbit, with apogee in the 5,000 to 10,000 kilometer range. Clearly, the TLD would play a role in getting them there, and so understanding the TLD is an important part of being able to analyze what the A objects might be like. In the January 1999 issue of the Smithsonian Air&Space magazine (ISSN 0886-2257), there's an interesting article on the TLD in its role as a backup to the ISS Service Module (Space Station Understudy, by Carl Posey, pp. 54-59). It's not terribly technical, but dropped in here and there in the text are some seemingly relevant facts. I'll simply quote the text below and not try to resolve any ambiguities or do any analysis. (ICM = Interim Control Module, the form of the TLD modified for ISS.) - "...the Titan Launch Dispenser, a powerful 12.5-ton upper stage..." - "The Dispenser ... [e]ven though it had been rejiggered to fly on the Titan launcher after the Challenger accident.. originally was designed to ride in a [Shuttle] orbiter." - "Around an oblong space at its center, four spherical tanks are arrayed -- two for the nitrogen tetroxide oxidizer and two for the monomethyl hydrazine fuel... Two smaller spheres in the frame contain helium, which provides an inert-gas pressure in the other tanks of 3,000 pounds per square inch. Altogether, the ICM can supply 11,500 pounds of propellant..." - "...the [TLD] was spin-stabilized..." - "... the rocket engine used for spy satellites produced 900 pounds of thrust, much more than what NASA needed for the space station job." - "We couldn't redo the tanks [in making the TLD -> ICM modifications]... Fifty-two-inch-diameter tanks are not on the shelf anywhere."