Riding the Titan II
Riding the tip of a 100-foot burning cylinder whose useful life is less than your average Marlboro is something you don't forget, even after three and a half decades.
- By D.C.Agle
- Air & Space magazine, September 1998
Once the Gemini's hatches were closed and locked just before launch, the busy throng that readied the spacecraft for orbit diminished dramatically--to two men and a machine that smelled slightly of plastic, sitting on top of a 150-ton intercontinental ballistic missile.
Recalling the launcher that powered all 10 manned Gemini spacecraft into orbit, two-time Gemini astronaut Pete Conrad says: "The thing about the Titan that I remember was somewhere in the count, like at T-minus-30 seconds, they open the oxidizer pre-valves. The oxidizer was all the way up in the tank, and that line runs all the way down through the fuel tank down to the base. So when they opened that thing up, you are sitting on top of this thing--you are not that far away--and you can hear it going glah-glah-glah-glah.
"The Saturn V was a great big hulk, you know," he says of the enormous launcher behind the Apollo moon missions, "and the engines are 365 feet away and you don't hear a lot of things happening. But the Titan wasn't that big. You can even feel it sway a little bit in the wind. I'll always remember that oxidizer pre-valve at 30 seconds. When you heard that you knew they were serious about sending you somewhere."
At the time it was chosen for Gemini duty, the Titan II was the most powerful rocket in America's inventory. An improved version of the Air Force's Titan I, it first flew successfully in March 1962. Unlike Project Mercury's Redstones and Atlases, as well as the later Saturn Vs, the Titan used room-temperature propellants called hypergolics, which ignite on contact. At T-minus-0, an electrical signal set things in motion by igniting two small cartridges in the Titan's two first-stage Aerojet engines. The gas from the cartridges started the Titan's turbopumps spinning, which in turn forced both fuel and oxidizer into the engine's combustion chambers. When combined, the hypergolics emitted only a relatively small white flame and a rosy cloud rather than the burst of orange flame and billowing smoke of Mercury and Apollo launches. Four seconds later, if all systems remained go, the bolts that anchored the Titan to the launch pad exploded and the Titan was on its way.
"A light came on in the spacecraft saying we had liftoff," Schirra says. "I heard from the blockhouse that the clock had started, which means we had lifted off. But I knew we had not lifted off. It was a gut feeling. Stafford didn't know what was going on but I had the experience of a Mercury flight and my butt told me we hadn't left the pad."
Schirra's butt was right. A small electrical connector had vibrated loose a split-second before launch, sending a spurious shutdown signal to the Titan's first-stage engines. Had the Titan actually left the pad before engine cutoff, the missile would have toppled over, engulfing Schirra and Stafford in flames. If so, their only chance at survival would have been the Gemini's untried ejection seats.