This undated SpaceX photo obtained January 5, 2015 from NASA shows the Dragon spacecraft and its Falcon 9 rocket, both made by SpaceX. (AFP)
SpaceX on Saturday will try again to launch its Falcon 9 rocket, propelling the Dragon cargo ship toward the International Space Station and then attempting its first landing on an ocean platform.
The landmark bid in the California-based company's mission to make rockets as re-usable as airplanes was delayed at the last minute Tuesday due to a problem with the rocket's second stage.
The launch from the Cape Canaveral Air Force Station in Florida is now scheduled for 4:47 am (0947 GMT) Saturday Eastern time.
"A launch on Saturday would result in Dragon arriving at the station for its grapple on Monday, Jan. 12 at approximately 6 am Eastern time (1100 GMT)," NASA said.
Minutes after blast off, when the unmanned cargo vessel is on its way to orbit, the landing experiment will begin.
Instead of plummeting into the ocean, the rocket's first stage engines should refire three times, guiding the 14-story tall portion of the Falcon 9 to land upright on a floating platform in the Atlantic Ocean, some 200 miles (322 kilometers) off the coast of northern Florida.
If Saturday doesn't work out, the next attempt could be Tuesday, January 13 at approximately 3:36 am (0836 GMT).
The launch was initially scheduled in December 2014 but was pushed back due to a technical problem during a launchpad test fire.
The stakes for SpaceX are particularly high because Orbital Sciences, the only other US company capable of sending cargo to low-Earth orbit, suffered a catastrophic rocket failure in October, forcing an end to its NASA-contracted supply missions until further notice.