"The mission management team has decided to postponed another 24 hours a launch and come back tomorrow to work at this problem," said National Aeronautics and Space Administration spokesman Dean Acosta.
Earlier a NASA spokesman said that Atlantis's launch has been postponed until Thursday because one of the three fuel cells providing electricity to the shuttle had malfunctioned.
"This technical glitch could prevent a launch by Friday," the last day of the current launch window, said Allard Beutel, a NASA spokesman. "They will make a decision today (Wednesday)."
The Atlantis's launch on the first International Space Station (ISS) construction mission in nearly four years had been scheduled for 12:29 pm (1629 GMT).
Earlier, the fuelling of the shuttle's external tank was delayed for two hours when the technical glitch was detected.
It takes three hours to fill the tank with almost two million litres of liquid hydrogen and oxygen.
Complex mission
Inclement weather last week scuttled three attempts to launch Atlantis on its 11-day mission to the ISS.
Failing to launch this week could delay the Atlantis mission until late October.
NASA officials took the new launch delay in stride, even though they had been optimistic for an earlier launch after the weather service gave a favourable forecast.
The agency plans to undertake 16 shuttle missions to complete the complex assembly of the half-finished space station by 2010, when the three-shuttle fleet is set to retire.
Atlantis will carry a new 16-tonne segment with two huge solar panels that will double the station's ability to produce power from sunlight and ultimately provide a quarter of the completed ISS's power.
Three lengthy spacewalks are planned to install the solar arrays, which are 73 metres long when unfurled.
It will be the most complex work ever undertaken at the nearly eight-year-old space station and that the next few missions will only get harder.
During their 11-day mission, the six shuttle astronauts will also use a robotic arm to scan the orbiter's heat shield for potential damage from debris falling off the external fuel tank during liftoff.