American rockets are launching more frequently than ever, yet getting a ride to orbit is becoming harder.

SpaceX broke the record for the shortest interval between two orbital launches in August, sending two Falcon 9 rockets into orbit only 38 minutes apart. But companies trying to put their own satellites into space are struggling to get a ride on Falcon 9 or its competitors. Reportedly, Falcon 9 is fully booked until 2028 or 2029.