Flying the Gusmobile
It didn't look remotely like a fighter plane. So why did astronauts who flew the Gemini spacecraft compare it to one?
- By D.C. Agle
- Air & Space magazine, September 1998
(Page 3 of 6)
The Gemini astronauts had achieved history's first rendezvous in space--although their competition saw things differently. "Around that time," Schirra explains, "the Russians flew two spacecraft within three miles of each other and said they performed the world's first rendezvous. No way was that rendezvous! It was a passing glance--the equivalent of a male walking down a busy main street with plenty of traffic whizzing by and he spots a cute girl walking on the other side. He's going "Hey wait' but she's gone. That's a passing glance, not a rendezvous." He adds: "Now if that same male can cut across all that traffic and nibble on that girl's ear, now that's a rendezvous!"
Gemini's usual target was an unmanned Agena-D. Launched by its own Atlas rocket 100 minutes prior to the crew's launch via Titan, the Agena was a combination docking target and booster rocket. At one end it had a gimbal-mounted, turbopump-fed 16,000-pound-thrust rocket engine and plenty of fuel. At the other was a Gemini-compatible docking target replete with radar transponder, flashing xenon lights, shock absorbers, and mooring latches. For the world's most proficient test pilots, the Agena was a piece of cake.
"Docking in space is cool," says Dick Gordon, who was a Navy test pilot before he flew Gemini and Apollo missions. "As a young aviator I'd done my fair share of air-to-air refueling and that was what docking with the Agena was like. You get yourself lined up, maybe five to ten feet out. And if everything looks all right and you look lined up with the docking cone, all you do is add a little thrust with the translational controller. And if it looks like you're going too fast you take a little off with the translational controller. And just like flying an aerial refueling, you did all this with just the old Mark-VIII eyeball. There was no optical sight on board like I had for docking the [Apollo] command module with the lunar module. It was all feel."
The actual encounter occurred at a walking pace: half a foot per second. Gordon calls it "little more than a bump in the road and hardly felt." The Gemini's index bar--a vertical bar on the end of Gemini's nose--slid into a V-shaped notch at the top of the Agena's docking cone. At the point of contact three clamps inside the Agena grabbed hold and pulled the spacecraft closer, and electrical cables connected, enabling the astronauts to control the Agena-Gemini stack.
"I had the ability to maneuver the Agena from the right side of the Gemini's cockpit," Gordon says. "There was this little coder--the "Orphan Annie coder,' as I called it, because it looked like one of those little ring decoders kids used to get. By working the coder's rings and hitting "send' by moving a lever to either "0' or "1,' you could transmit signals to the Agena. You could do everything from tell the Agena what direction it should point, to fire its big engine."
During the Gemini 10 and 11 missions they did just that. The right-seaters on those missions (Michael Collins on Gemini 10 and Dick Gordon on Gemini 11) ended one of their long digital conversations with the Agena by sending the sequence 041-571-450-521-501, the command to fire the engine. After an 84-second pre-fire routine, John Young and Collins on Gemini 10 and, later, Pete Conrad and Gordon on Gemini 11 became spectators at an out-of-this-world fireworks display.
"At first, the sensation I got was that there was a pop, then there was a big explosion and a clang," John Young said at a mission debriefing following Gemini 10. "We were thrown forward in the seats. Fire and sparks started coming out of the back end of that rascal. The light was something fierce and the acceleration was pretty good. The shutdown on the PPS [Primary Propulsion System] was just as unbelievable. It was a quick jolt and the tailoff I never saw anything like that before, sparks and fire and smoke and lights."
On September 14, 1965, 25 seconds' worth of sparks, fire, smoke, and lights lofted Gemini 11 to a new Earth orbit and an altitude record of 853 miles. Conrad and Gordon became the first humans to witness the planet in true spherical splendor.