The planned launch Friday of NASA's twin moon mappers aboard a United Launch Alliance Delta II Heavy has been postponed until Saturday so engineers can review propulsion system data gathered during the draining of propellants from the rocket after an scrubbed initial attempt Thursday.
The 12-story rocket and NASA's lunar gravity field mappers now are scheduled to blast off at 8:29 a.m. Saturday. A second opportunity would come at 9:08 a.m. that day if need be.
The forecast for Saturday calls for a 60 percent chance conditions will be acceptable for launch.
The exact nature of the propulsion system problem was not clear when NASA and United Launch Alliance announced the postponement late today. However, the rocket's onboard tanks were drained of all propellant after a launch attempt was scrubbed Thursday due to higher-than-allowable upper-altitude winds.