If you look at the Saturn V, Rocketdyne built both the F1 and J2 engines. IBM and Raytheon built the guidance computers. For the Space Shuttle, Rocketdyne bui

If you look at the Saturn V, Rocketdyne built both the F1 and J2 engines. IBM and Raytheon built the guidance computers. For the Space Shuttle, Rocketdyne built the RS-25, Thikol built the SRBs, and IBM built the AP-101S computer. I'm too lazy to see if NASA built the Saturn V fuel tanks or the Space Shuttle external tank, etc. themselves, but it has been a long time (if ever) since NASA could independently launch spacecraft into orbit. Sure, NASA used to act as the prime contractor, and now they're outsourcing that role, but the prime contracting capability isn't among the critical capabilities for space flight.