50th anniversary of the Gemini 8 mission

March 16, 2016, marks the 50th anniversary of the Gemini 8 mission, the sixth manned spaceflight conducted during NASA’s Project Gemini Program. Gemini 8 was the program’s second rendezvous mission and the first docking mission, a critical component in putting a man on the moon.

The primary objec­tives of the planned three-day mission, as established in the Mission Directive, were:

• Rendezvous and dock with the Gemini Agena Target Vehicle
• Conduct extra-vehicular activity (EVA) lasting one and a half revolutions (roughly two hours and 40 minutes)

At 10:00:03 a.m. EST, on March 16, 2016, the Gemini 8 Agena Target Vehicle launched from Cape Canaveral’s Launch Complex 14 (LC-14). One hour and 41 minutes later, astronauts Neil Armstrong, command pilot, and David Scott, pilot, lifted off from LC-19 atop a Titan II GLV (Gemini Launch Vehicle).

It would be just under 6 hours before Gemini 8 would radio in that it was “Stationkeeping [on the Agena] at about 150 feet.”

With one objective completed, the astronauts were now in history-making mode.

* On this day 90 years ago, Dr. Robert Goddard, considered the father of modern rocket propulsion, launched the world’s first liquid-fueled rocket in Auburn, Massachusetts.

Closer view of the Agena Target Docking Vehicle, docking with this would be the Holy Grail of the mission.

All smiles for the Gemini 8 prime crew of Neil Armstrong and David Scott, on their way to a photo shoot at Kennedy Space Center.

Neil Armstrong and David Scott during water egress training in the Gulf of Mexico (left); Scott training with the “zip gun” aboard the “vomit comet” (right).

Ain’t no thang! David Scott (left) and Neil Armstrong, in the white room during countdown simulation, less than one week before launch.

Buckling in for a wild ride! Neil Armstrong (left) and David Scott (right) just prior to liftoff.

Close-up view of David Scott making final adjustments during the prelaunch countdown.

Liftoff of the Gemini Agena Target Vehicle (left) on at 10:00:03 A.M. EST, and of the Titan II Gemini Launch Vehicle (right) one hour and 41 minutes later.

View inside Mission Control, radio callsign Houston, at the Manned Space Center (Johnson Space Center) in Houston, Texas, during the Gemini 8 mission on March 16, 1966.

The Agena Target Docking vehicle, approximately 210 feet away from the nose of the Gemini 8 spacecraft (lower left).

Closer view of the Agena Target Docking vehicle seen from the Gemini 8 spacecraft during rendezvous.

GEMINI VIII VOICE COMMUNICATIONS

• 05:53:01 Armstrong: That’s just unbelievable! Unbelievable!
• 05:53:08 Armstrong: I can’t believe it!
• 05:53:10 Scott: Yes, I can’t either. Outstanding job, Coach!
• 05:53:13 Armstrong: Way to go, Partner!
• 05:53:16 Scott: You did it, boy! You did a good job!
• 05:53:17 Armstrong: It takes two to tango.

• 05:53:56 Scott: Boy! Look at that sucker!
• 05:54:06 Scott: That’s beautiful!
• 05:54:07 Armstrong: See the dipole?
• 05:54:08 Scott: Do I ever! I’ll say I see everything on that fellow!
• 05:54:17 Scott: I’ve got 18 pictures.
• 05:54:18 Scott: I don’t have the range sight on. Hope I’m hitting them.

Seen from the Gemini 8 spacecraft, the instrument panel on the Agena Target Docking vehicle is slightly out of focus (center).

• 06:33:52 Armstrong: Flight, we are docked!
• 06:33:58 Armstrong: Yes. It’s a — really a smoothie.
• 06:34:01 CAPCOM: Roger. Hey, congratulations! This is real good.
• 06:34:07 Scott: You couldn’t have the thrill down there that have up here.
• 06:34:10 CAPCOM: Ha! Ha! Ha!

Jim Lovell (foreground), serving as Houston CAPCOM (Capsule Communicator), watches the launch of Gemini 8 at Johnson Space Center in Houston, Texas.

For about 30 minutes, relations between the docked vehicles were perfect. Beginning around 07:02:08 ground elapsed time, Gemini would experience a radio blackout with the ground, and in the moments before this, Houston CAPCOM would relay a prescient message:

• 06:55:38 CAPCOM: If you run into trouble and the Attitude Control System in the Agena goes wild, just send in Command 400 to turn it off and take control with the Spacecraft.
• 06:55:58 Scott: Roger. We understand.
• 07:02:08 CAPCOM: Tananarive has LOS (Loss of Signal).
• 07:17:12 CAPCOM: Gemini VIII, CSQ CAPCOM. Com Check. How do you read?
• 07:17:15 Scott: We have serious problems here. We’re tumbling end over end up here. We’re disengaged from the Agena.
• 07:18:33 Scott: We have a violent left roll here at the present time and we can’t turn the RCS’s off, and we can’t fire it, and we certainly have a roll. … stuck hand control.
• 07:20:05 Scott: Okay. We’re regaining control of the Spacecraft slowly, in RCS Direct.

Regaining control of Gemini required the crew to undock from the Agena, though the spacecraft continued to roll, tumbling through space. David Scott, in his book, Two Sides of the Moon, recalled:

“This spinning roll was going on far too long. The chances of recovering from such a high rate of spin in space were very remote. Both Neil and I were beginning to feel dizzy.”

The firing of the ship’s Re-entry Control System (RCS) thrusters to stop the spin meant that per NASA’s mission rules, once the RCS had been fired, the spaceflight was over. Gemini had just 25% of its reentry maneuvering fuel remaining, and plans were immediately set in motion to have the crew splashdown at the secondary landing site in the Pacific Ocean off the coast of Japan.

David Scott (left) and Neil Armstrong (right) awaiting the arrival of the recovery ship, the USS Leonard F. Mason, after splashdown some 497 miles east of Okinawa, on March 17, 1966.

The Gemini 8 spacecraft, with Armstrong and Scott still strapped in, is hoisted aboard the recovery ship U.S.S. Leonard F. Mason.

American armed services personnel at the Naha, Okinawa military installation welcoming the astronauts.

Astronauts Neil Armstrong (center) and David Scott arrive at Hickam Field, Hawaii on their way from Naha, Okinawa, to Cape Kennedy, Florida, on March 18, 1966. Fellow astronaut Wally Schirra is at extreme left.

It was determined at the time that Orbit Attitude and Maneuvering System (OAMS) thruster Number 8 had “failed OPEN,” likely causing the spin that had put the mission in jeopardy.

10 hours, 41 minutes, 26 seconds after launching from Florida, Armstrong and Scott had returned safely to earth.

Though the mission ended prematurely, the successful docking of the two vehicles was a critical component of NASA’s plan to complete a successful lunar landing.

It would be three years before the Soviets, fierce competitors in the ongoing Space Race, would manage their own successful manned docking.

Armstrong would go on to fly his second, and last space mission, aboard Apollo 11, going down in history as the first man to walk on the moon. Scott would fly again on Apollo 9 and later command the Apollo 15 lunar mission.

All photographs courtesy of NASA.