SpaceX’s next two missions will revert to launching older versions of the company’s Starlink internet satellites, instead of new second-generation Starlink platforms as originally planned, while ground teams work out unspecified problems with the first batch of upgraded Starlinks launched in February.

The adjustment of the launch manifest is in line with NASA’s desire to have a direct handover between its two long-duration crews on the International Space Station.

Follow the Delta 4 rocket’s ascent into orbit from Cape Canaveral’s Complex 37 launch pad to deploy the Wideband Global SATCOM 9 communications satellite. Liftoff is scheduled for Friday at 7:44 p.m. EDT (2344 GMT).