Watch a time-lapse of the Crew Dragon access arm installation (members only)

The 21 satellites from York Space Systems are the first in the SDA’s Tranche 1 Transport Layer satellite constellation. SpaceX launched from pad 4 East at Vandenberg Space Force Base at 7:12 a.m. PDT (10:12 a.m. EDT / 1412 UTC).

Delays have set up the possibility of up to three rocket launches this weekend from different pads along Florida’s Space Coast, including two SpaceX missions on Sunday that could set a company record for the shortest span between two Falcon 9 rocket launches. But in the world of ever-changing launch schedules, numerous factors such as weather and technical issues could thwart launch plans this weekend. 

A SpaceX-owned supply ship arrived at the International Space Station on Sunday with 2.4 tons of cargo, including space debris and solar energy monitors mounted in the Dragon spacecraft’s external payload bay and more than 3,400 pounds of gear inside its reused pressurized module.