KENNEDY SPACE CENTER -- The crew of space shuttle Discovery is back in Houston after a few days of launch training and a practice countdown.

Now, shuttle program managers plan to hold a two-day flight readiness review on May 13 and 14, followed by an executive-level review May 19.

If all goes well, Commander Mark Kelly and his crew will fly back to KSC on May 28 for the start of their countdown to a May 31 launch.

Discovery will carry the heaviest payload ever to the International Space Station -- Japan's Kibo laboratory.

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