Astronauts in zero gravity training onboard the KC-135,
affectionately known as the "Vomit Comet", get a unique perspective
of their environment during a zero gravity flight. Medical studies
and motion sickness experiments are also researched on these
flights. The NASA Reduced Gravity Program began in 1959 and the
KC-135 was the perfect aircraft. The Boeing four- engine turbojet
Stratotanker was originally designed for in-flight aircraft
refueling and later as a 707 for commercial flights.
Slide 6
The diagram above shows a flight plan for the KC-135 during
typical zero-g maneuvers. During a typical mission of 2 to 3 hours,
the aircraft will fly 30 to 40 parabolic arcs. During each
parabolic arc there are 20 to 25 seconds of "g" gravity when the
astronauts will experience how it feels to be in outer space.
Slide 7
Slide 8
How did they film the zero gravity scenes in the movie Apollo
13? Creating weightless scenes for the movie would have been no
problem if the crew could have filmed in space. But that would have
sent the movie's budget to the Moon! So instead, the actors did
what real astronauts in training do: they flew in NASA's
"zero-gravity" plane, nicknamed the Vomit Comet. The cast and crew
flew between 500 and 600 parabolic arcs in NASA's KC- 135 airplane
(nicknamed the "Vomit Comet") to achieve real weightlessness. Each
of the arcs got them 23 seconds of zero-gra vity. All of these
flights were completed in just 13 days. The plane climbs and dives,
coasting over the top of an invisible parabolic arc. When the Vomit
Comet reaches the bottom of its roller-coaster-like dive, the plane
slowly pulls out of its parabolic dive and the zero-gravity
environment disappears. As the plane climbs again, the cast and
crew hit the deck. When gravity took hold of the Apollo 13 cast,
says Hanks, the well-trained NASA crew would hold on to the actors
so they wouldn't crash on top of the cameras or each other.
Slide 9
Note: Assuming that the planes altitude was decreasing for half
of the 23 second zero-gravity experience, the plane and crew are
free-falling at around 250 miles per hour! Before climbing on board
the Vomit Comet, the cast and crew swallowed a potent medication
that astronauts take to keep them from losing their lunch. Then,
the film crew loaded mock-ups of the spacecraft, lights, cameras,
and other equipment needed to film the movie. Each Vomit Comet
zero-gravity arc lasts only 23 seconds, so the cast and crew had to
work fast. These are the scenes where actor Bill Paxton, as
astronaut Fred Haise, spins his sunglasses toward the camera, and
actor Kevin Bacon, as astronaut John Swigert, squirts orange juice
into the air. http://www.nasa.gov/missions/research/kc135.html