It's a very situation-specific question. You may have inventions by NASA employees and then inventions by other entities (e.g., companies or non-profits) doing work under contracts and other arrangements with NASA. Patent rights may (or may not) go to the other entities for their inventions under a NASA contract or other arrangement, but there are several types of relationships that other entities can have with NASA - contracts, grants, cooperative agreements, etc. so it depends.

Aside from patents there are also rights in technical data and computer software that have their own regulations and terms & conditions.

Some NASA programs are intended to foster progress for wider application in industry so those may be set up with terms & conditions that reflect that goal. The LBFD description of later competing the production of an X-plane from the work under QueSST sound like NASA probably would have the right to provide the design details to competitors for the later phase, but you'd have to read the terms of the QueSST contract/agreement to really know the specifics.

NASA procurement and related regulations have changed since the initial space program, not sure what the arrangements were back then. Interestingly, Tang was actually invented independently before NASA happened to use it in the early space program, leading to its popularity.