The decision to launch the space shuttle Discovery next month came down to whether six months was too long to wait for repairs.
NASA's chief engineer says he wanted the extra time to fix the shuttle's fuel tank foam problem.
He was overridden by those wanting the international space station built on time.
Chief Engineer Christopher Scolese estimates the job would take six months, which he called "a reasonably short amount of time."
The head of spaceflight for NASA says the repair plans are not ready and could take a long time, although he used the same six-month estimate.
Those in favor of a July first liftoff worried that a six-month delay would prevent completion of the international space station by 2010.
Foam flying off the external fuel tank punched a hole in shuttle Columbia's protective skin in 2003, killing seven astronauts.