For the last couple of months I've been studying the Titan-II's reentry vehicle, the Mk-6. It so happens the geometry of the Mark 6 maybe useful for nonmilitary applications. The Titan 4 mentioned in Raoul's post was descended from the Titan 3, which came from the Titan 2 that originated with the Titan 1 (there's an old Titan 1 parked in front of my daughter's day care center). The Titan 3 was the only "man rated" ELV ever made in the United States that never actually carried people (The Ariane V was originally intended to be man rated for Hermes but never made the grade). The Titan 3 was designed to serve as the booster for the Manned Orbiting Laboratory (MOL). The MOL was the American equivalent of the Soviet Salyut space station. Like Salyut, MOL was intended to function as a manned spy satellite. MOL was also called "KH-10". Before MOL went operational, some clever guy invented CCD arrays for the US Air Force (the same technology used in your digital camera). With CCD arrays there was no need for a manned spy satellite or returning photographic film spools from orbit like they did for KH-1 through KH-9 satellites. So they built the unmanned KH-11 instead and sent all the MOL hardware off to the Air Force Museum. Many San Francisco Bay Area residents have no doubt noticed a building called the "Blue Cube" off of Highway 101 near Moffett Field. The Blue Cube was intended to be the mission control center for the KH-10. The Blue Cube was latter used for unmanned recon. satellite mission operations. Now that the Cold War is over, the Blue Cube is an idle building surrounded by obsolete and useless hardware.

Getting back to the Titan 2 and the Mk-6: The Mk-6 was the biggest operational military RV ever made by the United States. It had a nose radius of 0.5677 meters, base radius of 1.143 meters, a cone half angle of 12.5 degress and a length of 3.1 meters. The Mk-6 was the most terrible weapon ever created by the United States. Inside the Mk-6 was the W-53 thermonuclear warhead which weighed 8850 lb. and had a yield of 9 megatons. Supposably the Soviets had operational warheads even bigger than the W-53, which is pretty hard to believe. The W-53 could have wiped out a city the size of San Francisco in a single flash. I find it incomprehensible that human beings could have been so stupid as to actually build and deploy something like Mk-6/W-53. The Mk-6 was developed back in the early 1960s and cost the American tax payer hundreds of millions of dollars. Originally everything about the Mk-6 was highly classified. However most of those classified documents were automatically declassified due to their age and are now available to aeronautical engineers. They make fascinating reading (I'm hoping some good can be salvaged from the Mk-6). Antonio Ferri (the inventor of the scramjet) was involved in developing the Mk-6 (his company did the aerodynamic studies of the Mk-6). The Mk-6 was built by General Electric. Most of the design philolosphy used on the MK-6 was reused on the Pioneer Venus entry probes and the Galileo Probe used to explore Jupiter. Hall marks of General Electric entry vehicles are the 2:1 base radius to nose radius ratio, the use of carbon-phenolic as the thermal protection material and RTV adhesives to attach the thermal protection material to the entry vehicle's metal structure. That General Electric RTV adhesive that you buy at the hardware store to seal your bath tub was developed courtesy of the United States Air Force (GE still makes a profit selling ballistic missile spinoff technology as consumer products). Another fun tidbit is the story about teflon. NASA did NOT develop teflon. The USAF through the Dupont Corp. was responsible for developing teflon as a thermal protection material. Apparently teflon was used as the thermal protection material for decoys deployed by the Mk-6. The decoys were intended to confuse Soviet anti-ballistic missiles.

The ICBM version of the Titan 2 was fueld by a hypergolic room temperature storable propellant. This sort of propellant is almost as toxic as mustard gas. Converting the Titan 2 over to a more reasonable propellant is a very expensive proposition. I suspect this was "a" reason why so few Titan-2 ICBM were converted over to nonmilitary use. Of course, the main reason why they haven't been converted is because the American military industrial complex is greedy and corrupt. Why the hell should they only charge 10 cents on the dollar converting old ICBMs when they can build nice shiney new ones? However that's another story.

Gary