Video: 4K video replay of SpaceX’s CRS-21 launch (members only)

SpaceX technicians at Cape Canaveral are readying for the first launch of an upgraded Falcon 9 rocket configuration next week, a mission that will debut changes to make the launcher safer for astronauts and make it easier — and less expensive — for the company to reuse first stage boosters.

The first pair of RD-181 rocket engines set to launch on Orbital ATK’s redesigned Antares rocket are in the final stages of acceptance testing in Russia ahead of their export to the United States in early July, officials said.

Following the same timeline as they will on launch day, NASA astronauts Doug Hurley and Bob Behnken put on their SpaceX flight suits and strapped inside SpaceX’s Crew Dragon spacecraft Saturday at the Kennedy Space Center in Florida.