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
(Page 2 of 3)
Recalling the final Gemini mission, Gemini 12, Buzz Aldrin says, "There was no doubt in Jim Lovell's and my mind when we lifted off. Our bodies knew it. We could feel the acceleration straight off. The Saturn V was different. It had a much lower thrust-to-weight ratio and it didn't accelerate as well. When we came back from Apollo  and debriefed, we all agreed that we couldn't identify liftoff except for the instruments and the audio transmissions. But on Gemini we knew."
"Saturn V is an old man's ride," says Dick Gordon, who flew on both Gemini and Apollo missions. "There is a lot more shake-rattle-and-roll going on with the Saturn V because it is so much longer. And it's got three stages and is more flexible in its longitudinal axis. As opposed to the two [stages] on the Titan--which was a young fighter pilot's ride. It's faster. It's dynamic. The forces involved are greater."
Both Schirra and Gemini 5 astronaut Gordon Cooper agreed it was a smoother ride than the liftoff on their previous Mercury flights, which had been launched by Atlas rockets. "The Titan had a thicker skin than the Atlas," Cooper says. "The Atlas was literally a gas bag. Its skin was so thin it had to be pressurized to hold its shape. I remember going up the gantry for my Mercury flight and seeing the skin of the [Atlas] flexing. When you take that flexible skin and you launch it you get more oscillations, kind of like being on the end of a Slinky."
What sticks out in Frank Borman's mind about his ride aboard the Titan that launched him on Gemini 7 was the sound. "The Gemini simulators we trained on were extremely realistic and prepared us for all the sensations of liftoff--except the noise," he says. "Even in our insulated cabin, over 100 feet away from the engines, the sound was almost deafening. It started right off the bat at liftoff and sounded like a large jet in afterburner or a large freight train bearing down on you."
Two and a half minutes after launch, the Gemini-Titan stack was 50 miles high, traveling 6,700 mph, and, with its two first-stage engines gulping 1,600 pounds of propellant every second, had already shed over three-quarters of its launch weight. The crew members were being pressed into their ejection seats by nearly six times the force of gravity when suddenly the acceleration dropped off.
"Staging is really something," says John Young, who flew on Gemini 3 and 10. "It's called "fire in the hole' because you fire the second-stage engine before you get rid of the first stage. [It] blew out everything and fire came all around the vehicle and you could see it. That was a surprise to me. But it is only momentary, and with the second stage firing you get right out of there."
"That second stage surprised me," Dick Gordon says. "On Apollo, the third stage of the Saturn V got to altitude and then chug-chug-chug at about half a G until it got the right velocity and shut down. Well, on Titan both were done simultan-eously. And near the end, you've got 100,000 pounds of thrust pushing an almost empty stage and a lightweight Gemini spacecraft. It was startling how fast the G-forces built up. I said Man, how long is this sucker gonna keep a-running? I tell you I was ready for the second stage to quit about the time it did. And cutoff was a great transition. I mean, you're going from 7 Gs to zero Gs just like that. Soon as that engine cuts you are thrown up against the straps just like on a carrier landing."
At SECO, or Second Stage Cut Off, the Gemini was 100 miles high and 531 miles downrange. Twenty seconds and 90 miles later, the command pilot reached a now-weightless hand toward the left side of the center panel and pressed a button marked SEP SPCFT. In an instant, mini-guillotines fired, severing electrical connections between the Gemini and its booster, while two rings of a flexible charge encircling the base of Gemini's white adapter section detonated, literally ripping the two machines apart.