Excerpt from "An Unusual Memoir"

Gemini 8

by Ken Roy

I’m going to set the table for this story with a short history lesson.  It was the late 1950’s, Eisenhower was President and the USSR and US were deep in a decade long “Cold War”.  Following WWII both countries had extracted significant German rocket technology and engineers. These were the seeds of their own rocketry development.  It was 1958 when the Soviets launched a small earth satellite, “Sputnik”, and it was soon thereafter that the “Space Race” was underway.  JFK was elected president and within a year he had us headed for the Moon.  With this goal in mind the US undertook a sequence of three projects intended to develop the basic technology necessary for spaceflight.  The initial program was Mercury a single seat spacecraft whose goal was mainly to demonstrate that man could safely fly to and return from Earth orbit.  The Gemini program followed and it was a two seater spacecraft test bed for developing extra-vehicular activities, orbital rendezvous, and powered orbital maneuvers; the fundamental procedures required for the final phase; the Apollo three seater program and flights to the moon. 

Gemini 8 was a major milestone mission in America’s quest for lunar exploration.  It was nearly a disaster. First, imagine you’re in this spacecraft orbiting the Earth at well over 185 miles altitude and 17,000 mph.  You see the Earth slowly rotating beneath you and you give no thought to the fact of your velocity being more than ten times faster than a bullet.  (5 mi/sec; Beverly to Boston in 2 seconds)  Your objective is to catch up to a target vehicle in orbit going just as fast.  The cockpit of your craft is about as roomy as the front seat of a small car and is packed with all manner of gauges, switches, circuit breakers and flight controls.  There is one small window for external viewing.  When it’s time to eat you take out a bag filled with some roast beef paste, or something equally appetizing, and squeeze it into your mouth.  With the help of ground control and onboard radar tracking you manage to rendezvous with the target vehicle.  The objective, in technical terms, is to match both orbital planes and phase using minimal energy.  This involves tedious and precise maneuvering (The complexity of a rendezvous is perhaps illustrated by the fact that this was the subject a PhD thesis at M.I.T by Buzz Aldrin, the second man on the Moon).  Any collision in space could be a life-ending event.  You are now going to link your spacecraft to the target vehicle, fire up the target’s rocket engine and maneuver into a new orbit.  All goes well until your linked together and then this hybrid spacecraft goes wildly out of control and you have only a few seconds to regain control or the mission and your life will come to a violent spinning end.  Sound like fun?  All well beyond the average persons imagination. 

In the Gemini 8, where this scenario played out, two highly experienced test pilot astronauts were selected for the mission.  The mission objective was the first orbital rendezvous and docking with the Agena Target Vehicle (ATV); then powered flight into a higher orbit using the ATV rocket engine.  All phases of these procedures were intensely trained for in simulators at the Houston, Texas, Manned Spaceflight facility.  The following is a brief recap of the flight as reported in the book by Shepard and Slayton* 

After rendezvous the Gemini astronauts circled the twenty-six foot ATV to confirm its stability, then with consummate care nudged Gemini’s nose into the docking adapter mounted on the ATV.  Clamps, electric motors and connectors clicked home and the two craft were one, a first in space.  In moments the astronauts were thrust from a smooth flight into a struggle to survive.  The Gemini/ATV had literally become a twisting, turning bomb waiting for the first chance to turn into a searing fireball.  Faster than the two astronauts could believe, roll and yaw became the orbital equivalent of severe uncontrolled turbulence in flight.  They quickly managed to reduce the spin to the point where it was safe to disengage the vehicles.  As was later determined, the spin rate rose to 550 degrees/second; close to the point where they would lose consciousness.  They miraculously persisted, brought the Gemini under control and made a hasty and premature reentry to Earth.  Two dead astronauts in orbit, with no means for retrieval, would have been a historic disaster for America in the space race.  The cause was later determined to be a stuck thruster on the Gemini vehicle. 

Fortunately the future Gemini/ATV flights were successful.  Rendezvous and powered orbital flight were proven and we were on our way to the Moon.  By the way, the Command Pilot and a true hero, who saved Gemini 8, was Neil Armstrong, the first man on the Moon. 

It was 1961 and I was 3 years out of MIT when I got the urge for sunshine and a job in the space exploration business.  This took me to a position at the Lockheed Missile and Space Company in Sunnyvale, California.  My job was focused on various programs using the Agena space booster and eventually the Gemini/ATV.  The ATV attitude control system issues were my primary concern.  How much control gas to carry for the mission along with some serious stability control concerns when the Gemini and ATV were docked and then powered up in orbit?  Mainly, would fuel slosh in the ATV cause control instability.  With the help of excellent analysis support at Stanford University it seemed that the problem was slight but still marginal. The Agena had performed flawlessly thanks to the efforts of a great many dedicated and skilled people. 

* Moon Shot – The Inside Story of America’s Race to the Moon by Alan Shepard and Deke Slayton.  Turner Publishing 1994.