The targeted launch dates in 2007 will be June 8 for Atlantis; Aug. 9 for Endeavour; Oct. 20 for Discovery and Dec. 6 for Atlantis.
NASA officials also announced dates for two of next year's flights, although more shuttle missions are expected in 2008, including one to repair the Hubble Space Telescope.
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Endeavour is scheduled to be launched on Valentine's Day in 2008 and Discovery is set to fly again on April 24, 2008.
NASA managers had hoped to squeeze five shuttle flights into 2007 at the beginning of the year, but a postponement in launching Atlantis made that impossible and created a domino-effect in launch delays for the rest of the year.
Golfball-sized hail left thousands of dents on the foam insulation on Atlantis' fuel tank as it sat on the launch pad in February.
The space shuttle was rolled off the launch pad and sent back for repairs, forcing NASA to miss the original March 15 launch date.
Four shuttle flights in 2007 is "certainly something that can be accommodated and it can work," said NASA spokesman Kyle Herring. "But if we run into something along the way, we're going to slow down and fly when we're ready to fly."
During an 11-day mission in June, Atlantis' crew will deliver a new pair of solar arrays to the space station and fold up an old pair of solar panels.