<P> The real Mission Control Center consisted of two control rooms located on the second and third floors of Building 30 at the Johnson Space Center in Houston, Texas . NASA offered the use of the control room for filming, but Howard declined, opting instead to make his own replica from scratch . Production designer Michael Corenblith and set decorator Merideth Boswell were in charge of the construction of the Mission Control set at Universal Studios . The set was equipped with giant rear - screen projection capabilities and a complex set of computers with individual video feeds to all the flight controller stations . The actors playing the flight controllers were able to communicate with each other on a private audio loop . The Mission Control room built for the film was on the ground floor . One NASA employee, who was a consultant for the film, said that the set was so realistic that he would leave at the end of the day and look for the elevator before remembering he was not in Mission Control . By the time the film was made, the USS Iwo Jima had been scrapped, so her sister ship, the USS New Orleans, was used as the recovery ship instead . </P> <P>--Tom Hanks </P> <P> Howard anticipated difficulty in portraying weightlessness in a realistic manner . He discussed this with Steven Spielberg, who suggested using a KC - 135 airplane, which can be flown in such a way as to create about 23 seconds of weightlessness, a method NASA has always used to train its astronauts for space flight . Howard obtained NASA's permission and assistance in filming in the realistic conditions aboard multiple KC - 135 flights . </P> <P> In Los Angeles, Ed Harris and all the actors portraying flight controllers enrolled in a Flight Controller School led by Gerry Griffin, an Apollo 13 flight director, and flight controller Jerry Bostick . The actors studied audiotapes from the mission, reviewed hundreds of pages of NASA transcripts, and attended a crash course in physics . Astronaut Dave Scott was impressed with their efforts, stating that each actor was determined to make every scene technically correct, word for word . </P>

How did they do zero gravity in apollo 13