According to NASA computer models, the Ares I rocket intended to replace the space shuttle could crash into its own launch pad as a result of excessive "liftoff drift," which occurs when engine ignition causes a rocket to jump sideways. The models show a moderate southeast breeze could be enough to push the vessel into its launch tower, causing expensive repairs or even the destruction of the rocket, according to unnamed sources. "I get the impression that things are quickly going from bad to worse to unrecoverable," said a NASA contractor quoted in the Orlando Sentinel. But an official with the space agency denied the problems were insurmountable. "We have a lot of data and understanding of what it's going to take to build this," said program manager Jeff Hanley.