NASA will attempt to launch a $500 million pair of unmanned spacecraft on Saturday that will use gravity tools to map the Moon's inner core for the first time.
The launch team said early Friday it needed more time to review technical data following the de-tanking operation of the Delta II rocket carrying NASA's Gravity Recovery and Interior Laboratory (GRAIL).
"The postponement will allow the launch team additional time to review the data," NASA said in a statement.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Saturday's two launch windows open at 8:29 am (1229 GMT) and 9:08 am (1308 GMT) at Cape Canaveral Air Force Station in Florida.
High winds delayed the first attempt moments before takeoff on Thursday.
The weather forecast for Saturday is 60 percent favorable for launch, up from 40 percent on Thursday and Friday, the US space agency said.
Scientists hope the satellites will help them understand how the Moon formed and whether there was once another Moon that melded with it, forming lunar mountains.
