Sunday, July 31, 2016

50 Years Ago: Gemini 10 Docks in Space

Gemini 10 lifts off from Cape Kennedy.

Fifty years ago on July 18, 1966, astronauts John Young and Michael Collins took off for another NASA attempt at docking with the Agena target vehicle. On two prior missions, there had been problems with the Agena docking vehicles, sometimes due to errors in launch, and recently when the payload shroud failed to separate from the target dock. On this flight, things went much better. The Agena was blasted into space more than an hour before the Gemini-Titan rocket took off. It successfully deployed in orbit and awaited the Gemini capsule.
Agena Target Vehicle in view from the Gemini capsule.

Gemini 10 took off from Launch Complex 19 at about 3 in the afternoon into clear skies. During launch, it seems that one of the umbilical hoses from the launch tower came loose and clung to the Titan's second stage. It appeared to pose no trouble during the remaining flight. The capsule reached an altitude of 159 miles. Their first goal was to reach the Gemini 10 Agena target. Using fuel in the service module, they made up the 970 miles separating them, and docked with the Agena the next day (July 19th). For the first EVA of the mission, Collins opened his hatch and began photography experiments. One item pictured was a color patch on the capsule, which engineers would use to resolve color imaging issues for space photography. He also made some ultraviolet images of the Milky Way. The EVA was cut short when both astronauts experienced severe eye irritation. Some lithium hydroxide had leaked into their ventilation system. After closing the hatch the air system was purged and the problem solved.
Closing in for docking.
They next used the fuel in the Agena to boost their orbit higher, until they had reached more than 40 miles higher. This was the highest altitude reached by astronauts so far. Their goal was to reach another space vehicle - this time the Gemini 8 Agena target, which had lost power and was floating dead in in space. It was the original Agena that had been involved in the first docking in space on Gemini 8, just moments before a malfunction in the Gemini 8 thruster system caused the two docked vehicles to spin dangerously. To save their lives, Neil Armstrong and Dave Scott had forced an emergency separation from the Agena and then completed gaining control of their capsule and landing early in the Pacific Ocean. Now, Young and Collins found the Agena orbiting in a stable position and ready for the second part of the mission. For this rendezvous, they jettisoned the original Agena and approached the Agena (8) with their own thruster system.

Artist's idea of the Collins EVA to Agena 8. (If I could read the artist's name I would give credit.)
Collins performed the second EVA, exiting the Gemini capsule and floating the short distance to the Agena vehicle, where he retrieved a micrometeorite collection shield. The hand-held maneuvering unit helped him orient himself, but there were no handholds on the Agena in those days, so working around the Agena was difficult. After returning to the capsule, there were problems with the umbilical cord and so before closing the hatch, it was jettisoned along with the EVA chestpack. Ten other science experiments were performed by the astronauts during the mission. On July 21st, they deorbited and re-entered the atmosphere, landing 3 miles from the recovery ship USS Guadalcanal.

Helicopter view of John Young being hoisted up to safety.
For Command Pilot John Young, this was his second spaceflight, having originally flown with Gus Grissom on the first Gemini manned flight. He would go on to ave the longest career of any astronaut, and eventually became the only person to fly four different spacecraft type: Gemini, Apollo Command Module, Apollo Lunar Module, and the Space Shuttle. This was Michael Collins' first space mission, and he would go on to fly on the historic Apollo 11 mission. For a time, the capsule of Gemini 10 was on display in Norway, but is now home in the USA at the Kansas Cosmosphere and Space Center.

John Young on the left, Michael Collins on the right.


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