It was acted and shot by a crew getting jerked around like bugs in a jar.
There are, as yet, only two ways to escape gravity. The first is to ride a rocket into space. The second is to ride NASA's KC-135, a plane used to introduce astronauts to the phenomenon before they get to space.
The plane achieves zero gravity the hard way. It flies steeply up to about 36,000 feet, then it screams earthward in a prolonged dive. The plane's parabolic motion creates enough centrifugal force to counter gravity at the top of the arc. As the KC-135 reverses direction, everyone and everything inside is gently released from the Earth's pull.
But it's only a 25-second taste. Because after the plane begins to plummet earthward, those seconds of float are punished by an equal dose of drag. Everything floating inside the plane is flung violently to the padded floor. On the way down and again on the way back up, those inside are pinned by double the normal pull of gravity. It's better than the most sadistic amusement park ride, and one that has separated more than a few hardened test pilots from their lunch - hence, the plane's nickname, the "Vomit Comet."
Hallowell and Apollo 13 director Ron Howard originally planned to depict weightlessness the way Hollywood always has, by faking it.
"We studied every film ever made where they recreated some sense of weightlessness," Hallowell said. "It's been done with varying degrees of success. We also studied NASA footage of the real thing, trying to figure out ways to make our own effects more realistic. With the special effects people we lined up, I have no doubt we could have matched or bettered anything done previously."
Special effects wizards take you most of the way there. They have ways of moving the camera, they can suspend astronauts in wire harnesses and float objects on threads invisible on screen. Each shot requires meticulous planning, because gravity is relentless. It has a way of sneaking into corners of the frame. It flawed even the most famous piece of weightless fakery in film history, Stanley Kubrick's space waltz in 2001: A Space Odyssey. A space traveler sucks food up a straw, only to have the food slide back down the straw when he takes it from his lips - in Zero G, that wouldn't happen.
When Hanks, Paxton and Bacon signed on to make the film, which tells the story of how NASA rescued astronauts Jim Lovell, Fred Haise and Jack Swigert on the ill-fated third moon-landing mission, the plan called for defeating gravity with cinematic smoke and mirrors. But to give the actors a taste of the real thing, they talked NASA into one ride out over the Gulf of Mexico on the Vomit Comet.
Hanks, a longtime space buff, was thrilled. Bacon, less so.
"I don't know if I need that much research," Bacon told Howard.
But when the director said both Hanks and Paxton were eager, Bacon caved in.
"I can't be the weenie," he said.
Dosed with motion-sickness pills, Hallowell, Howard, the three main actors, supporting actor Gary Sinise and three crew members paid a visit to Bob Williams, NASA's folksy test director for the Zero-G Aircraft Program. Williams wasn't all that happy about it.
"All we knew about Hollywood folks is what we read and see on TV," he said. "We were expecting a bunch of prima donna Hollywood types. But I can't tell you how impressed we were with this group. There wasn't an ounce of prima donna in any of them."
For Hallowell, it was the ride of a lifetime:
"First of all, you've got all this adrenaline pumping. You're going on the largest roller coaster ride in the solar system. They tell you to undo your seatbelt, and all of a sudden you look down and you are floating six or eight inches over the seat. It has this amazing, dreamlike quality to it, like something you've dreamed about many times but now you tell yourself, 'This is really happening!' "
Not everyone had the same reaction. Motion sickness made the ride miserable for actor Gary Sinise, who plays Ken Mattingly, the astronaut who was grounded by flight surgeons days before his scheduled ride on Apollo 13. In a recent interview, Hanks teased his costar:
"I always thought Gary looked nice in khaki, but not when the color is his face."
Fortunately for Sinise, his character stays on the ground.
Howard was so impressed with the experience he began thinking about how to actually shoot the weightless sequences inside the plane. They would build a mock-up of the interior of the Apollo capsule and lunar module inside the Vomit Comet. They would then break down every weightless scene into segments shorter than 25 seconds, and somehow stage the thing while being bounced around inside the plane.
NASA was reticent.
"After all, here we were making a movie out of what was, on its face, the biggest failure they ever had in space," said Hallowell. "But when they read the script and our formal proposal, their attitude started to change."
The film portrays the ill-fated Apollo 13 mission in the spring of 1970 as a triumph of will and ingenuity. An explosion on the outward leg of the moonshot shattered the smooth choreography of a typical NASA mission. Instead of another moon landing, the space agency found itself scrambling to cope with impending disaster. At stake were the lives of Lovell, Haise and Swigert, who might have ended up drifting through the universe as a macabre monument to an American space failure. Shedding their drone-like efficiency, NASA's engineers and pilots scrambled to improvise a rescue - and succeeded.
As for the technical hurdles of shooting a film inside the Vomit Comet, NASA's Williams was convinced it could work.
"We've always taken cameras up," he said, "and we've even made some documentary films. And these guys were real pros. It wasn't going to be easy. It was going to be OJT (on-the-job training) every step of the way."
When permission was granted, Hallowell's production crew built sets that could fit inside the KC-135. The cast and crew then undertook a grueling shooting schedule that eventually compiled 612 flight parabolas, for a total of nearly four hours of weightlessness - more than most astronauts get before reaching space.
Howard and his staff broke down the scenes they wanted to shoot into short segments - he has likened them to football plays. Hanks, Paxton and Bacon had to put themselves in position, say a few lines or perform a highly scripted maneuver, then scramble to avoid hurting themselves as the plane pulled out of its dive - all in 25 seconds.
Early efforts were frustrating.
"The actors were floating, the cameras were floating, the cameramen were floating, the director was floating," said Williams. "Actors and things kept drifting in and out of the shot. We thought, anybody watching this thing is going to get motion sickness."
"There were plenty of bumps and bruises, but nothing serious," said Hallowell. "People would land on the hard edges of things, or come down wrong, things like that."
Bacon complained that if the plane crashed, his popular costar would get top billing: "The headline will read: 'TOM HANKS KILLED IN PLANE CRASH, turn to Page 6 to see who else was aboard.' "
Superstar Hanks got cocky after a few flights free of motion sickness, so he decided to skip his pills one morning.
"I wanted to see if I could handle it because the people who do this all the time don't use drugs," Hanks recalled. "Well, my . . . Oh, it was bad. I'll tell you, I've never felt that sick."
Inside the plane during those first flights it was, as Hallowell puts it, ''a mad scramble." Cameramen discovered that, when weightless, the small motors running inside the cameras tended to pull them to the right. The KC-135 engines screamed so loudly during the parabolic maneuver that none of the dialogue recorded in flight was usable.
But, gradually, the crew began to master the task.
"Right from the start, even with the trouble, we were more encouraged than discouraged," said Hallowell. "Because everybody learned so fast. When you're that excited, time slows down. Once you know what you're doing, 25 seconds begins to feel like a long time. With proper advance planning, we were amazed by how much we could get done in that period of time."
The crew made two flights a day.
"We would do about 30 or 40 (parabolas) on each flight," recalled Bacon. ''That's about all you can do. Then we'd come back, land . . . and have lunch. I'd call my wife and tell her I was back on the ground. Then we'd go back up and do an afternoon flight."
Camera operators learned to brace themselves with one hand and foot. Howard watched a monitor suspended from a bungee cord, shouting instructions like a quarterback at the line of scrimmage. NASA's Williams recalled the most difficult shot was one where Paxton (as Haise) spins a small tape recorder toward the camera:
"It kept spinning right out of the shot. Or the camera would drift. They had to shoot it over and over and over again," Williams said. "But you know what? When I saw that scene in the finished film, in the background you can see Paxton bobbing his head in time to the music. Well, there wasn't any sound up there when they shot it. I don't know how that boy managed that."
Ultimately, the only space scenes shot on the ground were those showing the three astronauts waiting it out on their return to Earth inside the frigid capsule and lunar module. NASA technicians ordered the astronauts to shut down most electrical systems, including heaters, in both crafts in order to preserve energy to get them home. For those scenes, the production company built a refrigerated set in Hollywood, where the special effects wizards performed their tricks while the actors simulated weightlessness by gently rocking on seesaws.
"These guys got so good at being weightless, they learned how to mimic its effects with the way they moved their bodies and hands, how every little motion you make forward tends to create a stronger backward motion," said Hallowell. "When we were editing the film, it got so we couldn't tell which scenes were really weightless and which were faked."
In the movie, when you can see the astronauts' breath, the scene was shot on the ground. Some of the scenes are composites, shots of weightless cavorting interspersed with the actors perched on their seesaws. The end result is an effect matched only by pictures sent home by the real astronauts - only this one has better dialogue and a more dramatic plot.
All of the living Apollo astronauts were invited to a sneak preview of the film in Houston several months ago, and many of them came. Hallowell said he was anxious about their reactions until the theater exploded with applause when the movie ended.
"As they were leaving, one man walked up and shook my hand," Hallowell said. "He told me, 'You guys really got it right. You really nailed it.' "
It was Buzz Aldrin, the second man to walk on the moon.