Stormy weather thwarted SpaceX's effort Thursday to launch its first recycled cargo ship to the International Space Station.
A lightning strike within 11 miles of the pad violated launch weather rules. Moments later, SpaceX halted the countdown at Florida's Kennedy Space Center with just 25 minutes remaining. The company will try again Saturday, but more storms are expected.
Atop the unmanned Falcon rocket is a Dragon capsule that flew to the space station nearly three years ago. It's making a comeback after a few modifications and much testing.
The first-stage booster for this flight is new, but as is now the custom, will attempt to return to Cape Canaveral following liftoff. It's all part of the company's long-term effort to save time and money through reusability, a pursuit that NASA considers worthy. SpaceX launched its first reused rocket booster in March.
Besides the usual NASA supplies, the 6,000-pound shipment includes mice and flies for research, a new kind of roll-up solar panel and a neutron star detector.
Two of the space station's five crew members head back to Earth on Friday. Russian Oleg Novitskiy and Frenchman Thomas Pesquet will aim for the steppes of Kazakhstan in their Soyuz spacecraft, ending a 5 1/2 -month mission.
"Love this crew! Sorry to leave you tomorrow," Pesquet said via Twitter to the astronauts staying behind. "Enjoy the extra space, hope I packed everything :)"