SpaceX to try early Saturday launch of ISS cargo

CAPE CANAVERAL, Fla. — SpaceX will try again early Saturday to launch an International Space Station resupply mission from Cape Canaveral Air Force Station, according to NASA officials.

The instantaneous launch window is at 4:47 a.m., when there's an 80 percent chance of favorable weather at Launch Complex 40.

SpaceX had previously been targeting a 5:09 a.m. Friday launch, and no reason was given for the change.

Thursday, NASA said it was likely the company would replace a component responsible for scrubbing the mission's first launch attempt on Tuesday, but no decision had been made.

SpaceX said an actuator in the system that controls steering of a Falcon 9 rocket's upper-stage engine behaved strangely, resulting in the scrub with 1 minute and 21 seconds remaining in Tuesday's countdown to a planned 6:20 a.m. liftoff.

Atop the Falcon 9 is an unmanned Dragon spacecraft packed with more than 5,000 pounds of food, supplies and science experiments bound for the station and its six-person crew orbiting about 250 miles above the planet.

If it launches, the Dragon would be expected to arrive at the outpost around 6 a.m. Monday.

The mission is SpaceX's fifth of 12 planned under a $1.6 billion NASA resupply contract.

After the launch, SpaceX also plans to try to land the Falcon 9 rocket's first stage on an ocean platform, an experiment aimed at advancing development of reusable rockets.

If the mission does not launch Saturday, the next possible attempt would be at 3:36 a.m. next Tuesday.