In order to recover these scientific treasures, I had to master another crucial skill—spacewalking. I could operate the panoramic and mapping cameras from inside the command module, but to retrieve the film I needed to go outside. On the way back from the moon, I would recover the large cassettes from the SIM bay. It was an opportunity to do something historic: the first deep-space extravehicular activity, or EVA. I would float outside a spacecraft farther from Earth than anyone had ever done before. And if I didn’t get it right and bring the cassettes back inside the spacecraft, we’d lose priceless pictures.
I did much of my zero-G training in NASA’s Boeing KC-135 aircraft. Flying the aircraft in a shallow dive to gain speed, the pilots would then pull up in a climb. As the aircraft reached the top of the arc, the pilots would let it fall forward, eliminating all sensation of gravity inside the fuselage. We would briefly experience the feeling of weightlessness in the spacious interior, and the effect lasted long enough to perform some meaningful tests and training.
On a normal flight, we would fly fifty or sixty parabolas. One day, however, I asked if we could keep going. Dave Scott was also on that flight and kept asking if I was done. No, I wanted to try some more maneuvers. What Dave didn’t know is that I had asked Harry, the pilot, to smash the world record. And we did it—we flew an unprecedented 125 parabolas.
I trained underwater, too. I’d already passed the arduous training at the SCUBA underwater school in the Florida Keys, where the military underwater demolition teams honed their skills. It taught me what to do if I were training in a water tank in a spacesuit and something went wrong. It supplemented some water survival training we did out in the Gulf of Mexico. Our spacecraft would splash down in the ocean at the end of the mission, and we’d need to know the procedures if everything went correctly, but also if something bad happened. We floated around in a replica of the command module, and worked with our recovery crew to climb out into a rubber raft and wait for an airlift. The Navy SEALs we trained with also worked with us on our actual flight. They were professional, highly competent, and after my SCUBA training I had an extra appreciation for their toughness.
But I learned more in the KC-135 airplane than I ever did underwater. Our water tank was a good place to test some procedures, but not to practice moving objects around. The engineers tried to make our training equipment neutrally buoyant, and the right size and shape, so the objects felt right and wouldn’t float or sink. Nevertheless, anything we pulled through water was going to drag. We tried boring a large number of holes in the film canisters so the water passed through, but they still didn’t react the same way as they would in space. We didn’t have that problem on the parabolic flights.
The water tank could also be misleading, as NASA engineers discovered. They had already looked at and rejected a number of options for retrieving the film cassettes, such as a large robot arm to grab the canisters. By the time I started EVA training they had settled on a looping clothesline. I would place a pole in the open hatch. Then I’d float down to the other end of the SIM bay holding a second pole, and place it in a bracket. A looped line with clips would be strung between the two poles on pulleys; I was then supposed to clip the containers onto the line, and Jim would reel them into the spacecraft.
It worked fine underwater, but I wasn’t convinced it would work in space. Although the big film cassettes would be weightless, they still had mass. I doubted Jim, or anyone else, could pull that clothesline so smoothly that the film canisters would not whip sideways as they were pulled in.
I insisted we try the procedure in the KC-135; so we created a mock-up of the SIM bay, like a lengthwise slice of the command and service module, right up to the open spacecraft hatch. Once we were in a zero-G parabola, Jim delicately and precisely pulled on the clothesline. Sure enough, the film canisters began to sway—so much that one canister knocked a rocket thruster right off the side of the service module. The engineers agreed: we needed to find a better way.
Forget all the fancy stuff. The simplest and best way, I proposed, was to grab a handle on each canister and bring them back one by one, like carrying a briefcase. I thought I could do most of the EVA with one free hand. If I needed to let go of the handle for any reason, the canister would still be attached to my wrist with a short tether, a snap hook, and a pin. That container wouldn’t float away very far.
Even better, during the training, I found that the canister handle didn’t take up my whole glove, so I could still use both hands to guide myself. Hand rails on the outside of the service module would permit me to pull myself along. The motions seemed natural to me in training, and I anticipated few problems in space.
During the EVA, a long umbilical cord would supply me with oxygen and also pressurize my spacesuit. If there were a suit malfunction and the pressure dropped, a warning tone would sound in my helmet. Similarly, if the oxygen flowed too slowly through the umbilical and the supply was not refreshed fast enough, a warning tone would ring.
But would I hear it in space? It was such an even buzzing noise, easy to just disappear into the background. If I were losing pressure in the suit, there would be less oxygen to carry the noise and I might not even hear it. So I headed for a vacuum chamber in Houston, fully suited, to check it out.
With the technicians observing closely from the control room, we lowered the suit’s oxygen flow rate until the buzzing tone sounded, and then kept lowering the flow. We all soon mentally tuned out the buzz. Like living in a house next to a freeway, after a while you don’t notice the constant noise.
While I could still hear the buzzing, I stuck my finger in the spacesuit’s outflow valve and dropped the pressure. The tone almost disappeared, because there wasn’t enough oxygen left to carry it to my ears. After the tests, we changed the buzz to a loud, warbling tone like the siren on a French police car. It was impossible to ignore.
The original ideas for the film transfer and the buzz had looked good on paper, but did not work in practice. Throughout my training, I always tried to find the simplest, most practical way to carry out a task and then tested it thoroughly. It took extra time and effort, but I knew the experience might save my life, and the mission.
We trained hard right up to launch time, but also had to squeeze in some more personal duties. One was to name the spacecraft. Although NASA wasn’t keen on personal touches like spacecraft names, they recognized that when two spacecraft docked and undocked they needed distinct call signs, otherwise the mission could get hopelessly confusing.
Farouk El-Baz came up with our command module name. We believed that our flight was the first truly scientific voyage to the moon, and this concept made Farouk excited to help us find some names. At Washington National Airport one day, he spotted a children’s picture book about great explorers in history. Farouk bought it and gave it to me, and I shared it with Dave and Jim. As we turned the pages, we came to Captain James Cook and his pioneering scientific exploration of the Pacific two hundred years earlier. His first voyage took place in the sailing vessel Endeavour—Farouk particularly liked that name.
Dave, Jim, and I had often discussed spacecraft names, but every time we came up with an idea we found there was already a rocket or an air force program with the same name. So Farouk’s suggestion was most welcome. We agreed with him that Endeavour seemed a natural fit.
Although it has caused a few misspellings in history books over the years, we stuck with the English spelling Cook had used, with an extra u. If we used the name, we believed we needed to spell it right. Years later, I was delighted to see NASA name a space shuttle Endeavour, again with the original spelling.