During the 1966 Gemini 9A mission, astronaut Eugene Cernan performed a spacewalk in one of the first suits designed to function in the vacuum of space. In the stiff and overheated suit, Cernan’s visor completely fogged over and movement was extremely difficult. As Cernan began climbing back into the capsule, command pilot Thomas Stafford had to hold onto his partner’s legs and feared that he could not get him back inside. “We could have lost him and even myself,” Stafford told the attendees of the 2019 annual meeting of the National Academy of Engineering.
A combination of careful planning, unforeseen circumstances, improvisation, and pluck marked the entire Apollo program. “In the end,” said Stafford, “we were good, but we were lucky, too.”
The decision to send astronauts to the moon was made in a politically charged atmosphere, Stafford recounted. On May 5, 1961, Alan Shepard became the first American to fly into space aboard the Mercury spacecraft. But Soviet cosmonaut Yuri Gagarin had become the first person to fly into space three weeks before Shepard’s flight, and a few days after Gagarin’s flight the US-sponsored invasion of Cuba at the Bay of Pigs failed. “It was a dynamic time,” said Stafford.
President John Kennedy, inaugurated just four months earlier, saw the worldwide acclaim that both Shepard and Gagarin received. He directed his vice president, Lyndon Johnson, to figure out, over the following two weeks, what the United States could do in space that would produce scientific and economic benefits and demonstrate America’s superiority in science and technology. After consulting with NASA administrator James Webb, NASA engineers Robert Gilruth and Maxime Faget, rocket pioneer Wernher von Braun, and others, Johnson told Kennedy that the Soviet Union had a significant lead in being able to fly a spacecraft around the Moon and back to Earth. He also said that the United States had even chances of beating the Soviets to orbiting the Moon. But if Americans could land astronauts on the Moon and bring them back to Earth, the benefits would be substantial and the United States would clearly demonstrate its leadership in space.
Kennedy had also asked Johnson to determine the cost of a proposed program. The experts Johnson consulted estimated that a Moon landing would cost about $10 billion. But Webb had been the head of what is now the federal Office of Management and Budget, and he advised Johnson to double the estimate to $20 billion, Stafford said.
Kennedy discussed the idea with several congressional leaders. Then, during a special joint session of Congress on May 25, 1961, he announced the goal of sending Americans safely to the Moon before the end of the decade. “That’s how Apollo was started,” said Stafford. “There weren’t study groups and all that.”
Stafford cited three developments that made the Apollo program possible. The first was the development of the F-1 rocket engine starting in the 1950s, five of which would eventually power the first stage of the Saturn V rocket that launched the Apollo spacecraft into orbit. The second was the choice of liquid hydrogen as a fuel in the upper stages of the Saturn V, which made it possible to put much more weight into low Earth orbit than was possible with other fuels. The third was adoption
of the lunar-orbit rendezvous mission profile, an innovative idea that called for orbiting a combined command and service module and a lunar module around the Moon and then sending just the lunar module to the Moon’s surface, after which the astronauts would return to the command module on the lunar module’s ascent stage. Before settling on that mission profile, two others were in the running, both of which called for landing a powerful rocket on the Moon that could return astronauts directly to Earth. But at a crucial July 1962 meeting in Huntsville, Alabama, the decision was made to develop the new technology. “We would go with the lunar-orbit rendezvous,” said Stafford.
The mission profile chosen for the Apollo program required that two spacecraft be able to rendezvous and dock in space, a procedure that had never been attempted. In the fall of 1965, as part of the Gemini 6 mission, Stafford and Walter Schirra Jr. set out to show that it could be done.
They ran into problems even before leaving the launch pad. The original mission was for Stafford and Schirra to dock with an uncrewed Agena target vehicle launched by an Atlas rocket. However, as the two astronauts waited in the Gemini capsule for the target vehicle to launch, the Agena succumbed to a fundamental problem. “In rocket science, you always lead with fuel and follow with oxidizer,” said Stafford. “Von Braun learned that back in Germany in the 1940s as he blew up V2s.” But the Agena led with the oxidizer rather than the fuel, causing it to explode as it separated from the Atlas booster a few minutes after launch.
Stafford and Schirra were rescheduled to fly the renumbered Gemini 6A to rendezvous with the Gemini 7 spacecraft being flown by astronauts James Lovell and Frank Borman. But just as their Titan II launch rocket ignited, the engines abruptly shut down. Schirra made a snap decision not to activate the ejector seats, which could have injured or killed the two men and delayed the mission for months.
Finally, three days later, Stafford and Schirra made it into space. They flew their Gemini 6A around Gemini 7 for about six hours, approaching within a foot of the other spacecraft. The two could not dock because they did not have docking mechanisms, but the procedure
was like “flying formation airplanes, very easy,” said Stafford. “You can fly formation at 17,400 miles per hour. The main thing is to get there.”
Meanwhile, the Soviet program to send men around the Moon and back to Earth was experiencing severe setbacks. In one unmanned mission, a rocket exploded a few hundred feet off the launch pad, producing one of the largest nonnuclear explosions in the world—perhaps a fourth the size of the Hiroshima atomic bomb explosion, Stafford said. Von Braun, in contrast to his Soviet counterparts, insisted that each rocket involved in the Apollo program be fired on test stands to ensure their reliability, which produced an unprecedented record of success. The Saturn V rocket, for example, made 13 launches without a failure.
Stafford was the commander of the Apollo 10 mission, which did everything the subsequent Moon landing would do except the landing. On that mission, he flew the lunar module to within 9 miles of the Moon’s surface, inspecting the future landing site for Apollo 11. For the astronauts and support personnel, the procedures were exactly the same as for a Moon landing—with the exception of the landing. That way, said Stafford, “when Apollo 11 came, it was like they’d been there before.”
The lunar module was a unique device, designed to fly only in the vacuum of space. The aluminum skin of the spacecraft “was so thin between the frames that, unpressurized, you could take your thumb and push and the aluminum would bow out,” Stafford said. When the lunar module was pressurized with 5 pounds per square inch of pure oxygen, the door, machined out of an aluminum slab, also would bow out. “It wasn’t meant to be used commercially,” Stafford quipped.
By this time Stafford had been to space twice and he knew that seeing the Earth from space could make a powerful impression. He became convinced that the view should be shown on color television, even though existing color cameras were too heavy and delicate to take into space. He advocated in NASA for the creation of a lens with the proper characteristics for space and a camera based on an older and simpler technology: It would spin a wheel with red, yellow, and blue filters in front of the camera lens, producing images in each color that could then be recombined. “We got a small motor slightly bigger than your finger off a Minuteman missile, spun that, and they had Westinghouse build it for us…. It worked! We put it on the spacecraft one week before launch.”
“You never forget your first Earthrise,” said Stafford. From the distance of the Moon, the Earth is about the size of an orange. “And with color TV, people here on the Earth saw it within a second and a half after we saw it.”
As the three astronauts were taking the first color television images of the Earth from space, Stafford suggested to ground control that they call the British Flat Earth Society in London and tell its members that “you can see on live color TV that the Earth is round.” The next day the president of the society sent a message back to Stafford: “Yes, the Earth is round, but it’s a flat disk.”
Two weeks after Apollo 10 returned to Earth, Stafford got a call from the National Academy of Television Arts and Sciences in New York saying that he had been awarded an Emmy for his space telecasts. “I said, ‘What about John Young and Gene Cernan?’ They said, ‘Well, it was your idea, and you did all the pushing.’ I said, ‘That’s true, but on board the spacecraft I was busy coordinating things as commander. Cernan did about 50 percent of the work, John Young did 40, and I may have done 10.’ I said, ‘Either they get Emmys, or I refuse to take it.”
Finally, the National Academy of Television Arts and Sciences agreed. “Always keep your people out in front,” said Stafford.
Stafford went on to achieve many other firsts. He commanded the Apollo-Soyuz mission, which culminated in the historic first meeting in space between US astronauts and Soviet cosmonauts, on July 17, 1975. He helped the Space Shuttle return to flight after the 2003 Columbia accident. Over the course of his career, he flew four types of spacecraft and more than a hundred types of aircraft.
Those missions yielded lessons that proved invaluable. During the launch of Apollo 10, the spacecraft began vibrating like a pogo stick, so much so that Stafford could no longer read the instrument panel. “I thought the thing was going to blow apart.” He had the choice to abort but realized how much it would delay the program. “This is why you have test pilots as commanders. I said, ‘If it blows, it blows.’” Von Braun later apologized to him personally. A tank pressurization valve was too close to a vent valve, causing the two to resonate, and a stabilizing bar had not been disconnected before launch. “We fixed that one real easy,” Stafford recounted. “Two people check it now.”
A near disaster during Apollo 13 was an important reminder of a lesson that “you learn back in high school chemistry,” Stafford said. “When you mix acid and water, you always pour acid into water. You do not pour water into acid, because you have some bad results.” During the Apollo 13 mission, a carbon-containing combustible material was in a tank that also contained liquid oxygen. “You have all probably seen the pictures. It blew that double wall of steel tank to pieces, and also a square of the service module.” Getting the Apollo 13 spacecraft back to Earth was one of the program’s best days, Stafford said.
The famous author Arthur C. Clarke once wrote that a thousand years from now, when historians look back on the 20th century, they will note that the leading nations of the time fought two major wars among themselves. “But the one item that they will note most of all,” said Stafford, “was Project Apollo and the lunar landings.”
The other plenary speaker, former astronaut and NASA administrator Charles Bolden (whose presentation is summarized later in this report), made a point on which all the speakers at the meeting agreed: The Apollo program inspired a half-century of engineering creativity and achievement, and it continues to point the way into space. “Get excited about your space program and Mars,” he said, “because we’re going.”