Fifty years ago, next week, Gemini XII astronauts Jim Lovell and Edwin “Buzz” Aldrin roared into orbit on a four-day mission which would demonstrate many of the capabilities that NASA needed to achieve the late President John F. Kennedy’s goal of landing a man on the Moon. In doing so, they also closed out a program which had seen a pair of unpiloted Gemini flights in April 1964 and January 1965 and, since March 1965, no fewer than 10 manned missions. Juxtaposed with tragedy, these missions had scored several remarkable national and empirical records: the first U.S. spacewalk, the longest single human space mission—set and re-set on two occasions in less than four months—and the first successful orbital rendezvous between piloted and unpiloted vehicles. With Gemini XII, Lovell and Aldrin would work to perfect these capabilities, as Project Apollo neared.
As outlined in yesterday’s AmericaSpace history article, the astronauts completed a flawless rendezvous and docking with their unmanned Agena target vehicle. Original plans, laid out before launch, had called for a reboost to high altitude, but this had to be abandoned eight minutes after the Agena launched, when its engine suffered a momentary decay in thrust chamber pressures and a drop in turbine speed. Instead, the astronauts were directed to turn their attention to solar eclipse photography; this task had been a scheduled part of their mission had they launched on the originally-scheduled 9 November 1966, but the two-day delay caused it to be dropped.
Now that the Agena reboost had been canceled, it was reinstated, thanks to the input of Gemini XII Experiments Advisory Officer James Bates. His recommendation marked a shift in operations, with the scientists’ representative—for the first time—being allowed to participate as a member of the flight control team in the main Mission Control room. Moreover, it was determined that the Agena’s secondary propulsion system had enough power to orient the spacecraft for an eight-second photographic pass at the proper time. At 10:51 p.m. EDT on 11 November, a little over seven hours into the Gemini XII mission, Lovell duly fired the target’s smaller engines to reduce their velocity by 42 feet/sec (13 meters/sec). The adjustment was successful and, after their first sleep period, the astronauts were advised to perform a second firing. Sixteen hours after launch, they reported seeing the eclipse “right on the money,” cutting a swath across South America from north of Lima down to the southern tip of Brazil.
At first, it had seemed to the disgruntled crew that the second Agena burn might throw out the remainder of their schedule and adversely affect the start of Aldrin’s first EVA. It did not, and at 11:15 a.m. on 12 November, some 20 minutes before orbital sunset, Aldrin cranked open his hatch and pushed his helmeted head outside. “The hatch rose easily,” he wrote in his memoir, Men from Earth, “and I rose with it, floating above my seat, secured to the spacecraft by short oxygen inflow and outflow umbilical hoses.” Years later, he would vividly describe the immensity of the Universe all around him and remember the absence of any sense of speed and the curvature of Earth.
Aldrin quickly set to work on his first task: dumping a small bag of used food pouches, which he watched slowly tumble away like a top, directly “above” him. Next, he attached cameras onto brackets to photograph star fields on ultraviolet film and retrieved a micrometeoroid package, which he passed to Lovell. Unlike his predecessors—fellow NASA spacewalkers Gene Cernan and Dick Gordon—Aldrin did not overheat, thanks partly to regularly scheduled rest breaks of two minutes apiece, and he returned inside Gemini XII at 1:44 p.m. after 2.5 hours.
His real work had yet to begin. The mission’s second period of EVA, which got underway at 10:34 a.m. on 13 November, required Aldrin to move away from the spacecraft on a 29.5-foot (9-meter) tether. He set up a movie camera to allow flight controllers to monitor his performance, then moved to Gemini XII’s nose and fixed a waist restraint strap to the docking adapter. Next, he removed a tether from the Agena’s nose and snapped it onto the Gemini, connecting the two vehicles for a “gravity-gradient” exercise scheduled for later in the mission. He then maneuvered himself to the rear of the spacecraft and slipped his boots into a pair of foot restraints nicknamed “golden slippers.” These, coupled with two small waist tethers, kept him anchored securely, and Aldrin was able to satisfactorily complete a number of tool-handling and dexterity tests.
“Back in the buoyancy pool,” he wrote later, “I had torqued bolts and cut metal dozens of times—what I used to call ‘chimpanzee work’—and I had no problem with these chores in space. Someone even put a bright yellow paper Chiquita Banana sticker at my busy box.” He was even able to wipe Lovell’s window before returning to the cabin after two hours outside. (Lovell even asked him to change the oil, too.) Back on Earth, Aldrin would claim that he had personally solved many of the problems of EVA, arousing criticism among the other astronauts, including Cernan, who felt that his tasks were nowhere near as difficult as theirs. “Quite frankly,” Cernan wrote in his memoir, The Last Man on the Moon, “we said he was only working a monkey board. Draw your own conclusions.”
Shortly after Aldrin’s return inside Gemini XII, the men completed their evaluation of the tether by undocking from the Agena. The tether tended to remain slack, although they believed that slow gravity gradient stabilization was achieved. “Within minutes,” wrote Aldrin in Men From Earth, “the two vehicles had stabilized without the aid of thrusters.” After two full orbits connected in this fashion, they finally fired an explosive squib to jettison the tether at 7:37 p.m. on 13 November.
Aldrin’s record-breaking 5.5 hours of cumulative EVA experience concluded the following day, 14 November, when he ventured outside at 9:52 a.m. for a second stand-up period, lasting 55 minutes. He dumped unneeded equipment overboard, together with a sack containing his umbilical tether and two rubbish bags, and took one last lingering look at Earth below him: the vast land mass of Indochina … and thought of his friend, Sam Johnson, with whom he had undergone flight training and who was at that very moment a prisoner of war somewhere in North Vietnam.
Lovell and Aldrin’s four-day mission had brought Project Gemini to a spectacular ending and demonstrated rendezvous, docking, gravity gradient tethered operations, and the ability of skilled human pilots to calculate a rendezvous with sextants and charts and a slide rule and pencil. Such human skills, using, in Aldrin’s own words, the “Mark One Cranium Computer,” had relaxed managers’ concerns about the viability of astronauts being able to perform a manual rendezvous, if necessary, in orbit around the Moon.
A re-entry controlled completely by the computers brought Gemini XII into the Atlantic, barely 2.9 miles (4.8 km) from its target impact point, at 2:21 p.m. on 15 November. Within 30 minutes of splashdown, Lovell and Aldrin were safely aboard the aircraft carrier U.S.S. Wasp. The only unexpected event during re-entry had come at the onset of peak G loads, when a pouch containing books, filters, and equipment broke free from the sidewall and landed on Lovell’s lap. By this time, both men had unstowed the D-rings for their ejection seats and Lovell fought the urge to catch the pouch, lest he accidentally grab and pull the ring. “I didn’t want to see myself punching out right at this high heating area,” he said later.
With the safe return of Lovell and Aldrin to Earth, many of the procedures needed to get to the Moon and back had been thoroughly tested. EVA suits had been used for extended periods, and five astronauts had completed useful tasks outside. Unlike Alexei Leonov’s swim in the void 20 months earlier, Lovell and Aldrin had actually begun to demonstrate an astronaut’s ability to really work in space. It provided the closest analogue yet attained of what working on the lunar surface might be like. Rendezvous, despite its complexity, had been completed with seemingly effortless ease by six Gemini crews … and Lovell and Aldrin’s work had shown it could be done without the aid of radar.
In a very real sense, Gemini XII helped lay the final cornerstone for the work which Apollo crews would one day need in their voyages to the Moon. With a little more than three years remaining before the late President John F. Kennedy’s deadline of boots in the lunar dust by 1970, the heat was cranking up for NASA to get started on Project Apollo, with the first mission into Earth orbit planned for early 1967. Those next few years would begin with the hideous tragedy of Apollo 1, but NASA and its remarkable workforce would respond with magnificent resilience to achieve their exalted goal.
This is part of a series of history articles, which will appear each weekend, barring any major news stories. Next week’s article will focus on the 35th anniversary of STS-2, the first occasion that a piloted orbital spacecraft had completed a second mission and the inaugural voyage of Canada’s Remote Manipulator System (RMS) mechanical arm.