Russian engineers will replace rocket engines on two Soyuz rockets assigned to send a batch of supplies and the next crew to the International Space Station after an investigation revealed foreign objects or a manufacturing defect led to the crash of a Progress cargo craft on launch in December, according to Russian media reports and a statement from the Russian space agency.

Boeing’s first Starliner spacecraft designed to fly to the International Space Station rolled out of a converted space shuttle hangar before dawn Thursday.

The four members of the SpaceX Crew-11 flight were previously set to fly on different missions before they ended up as a quartet on the Dragon Endeavour spacecraft. Liftoff of the Falcon 9 rocket from pad 39A at NASA’s Kennedy Space Center is scheduled for no earlier than Friday, Aug. 1, at 11:43 a.m. EDT (1543 UTC).