SpaceX has pushed back the launch of its next robotic resupply mission to the International Space Station (ISS) by four days, to April 30.
The California-based company's Dragon cargo capsule is now scheduled to lift off atop a Falcon 9 rocket at 4:22 a.m. EDT (0822 GMT) on April 30 from Florida's Cape Canaveral Air Force Station, NASA officials announced today (April 19).
"SpaceX will take advantage of the additional time to perform a static fire test and pre-flight checkouts," NASA officials wrote in an update. "Falcon 9 and Dragon are on track to be flight-ready for an earlier launch attempt; however, April 30 is the most viable date for both NASA and SpaceX due to station and orbital mechanics constraints."
Related: How SpaceX's Dragon Space Capsule Works (Infographic)
The upcoming mission will be the 17th flown by SpaceX under its Commercial Resupply Services contract with NASA. SpaceX also holds a commercial-crew deal with the space agency, the terms of which the company will fulfill using the Falcon 9 and a crewed variant of Dragon.
Crew Dragon flew its first test mission to the ISS last month. The successful six-day flight, known as Demo-1, was uncrewed. But Demo-2 will carry two NASA astronauts, and that mission could lift off as early as this summer. Operational contracted missions to the orbiting lab will follow, perhaps by the end of the year.
Boeing also holds a NASA commercial-crew contract. The aerospace giant is targeting August for the debut mission of its CST-100 Starliner capsule to the ISS. That first flight will be uncrewed.
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There's already a privately built cargo spacecraft docked to the ISS — Northrop Grumman's Cygnus, which arrived at the orbiting lab early this morning. Like SpaceX, Northrop Grumman holds a NASA resupply deal.
NASA will host a news conference Monday (April 22) at 11 a.m. EDT (1500 GMT) to discuss the science payloads that Dragon will carry to the ISS on the upcoming cargo mission. You can watch it live here at Space.com, courtesy of NASA TV.
- In Photos: SpaceX's Dragon CRS-16 Cargo Launch and Rocket 'Water Landing'
- SpaceX's Historic Crew Dragon Demo-1 Mission in Pictures
- SpaceX's Falcon 9: Rocket for the Dragon
Mike Wall's book about the search for alien life, "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), is out now. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.
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Michael Wall is a Senior Space Writer with Space.com and joined the team in 2010. He primarily covers exoplanets, spaceflight and military space, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.