(a) A rendezvous mission involves the rendezvous of the Space Shuttle orbiter with an orbiting spacecraft for one or more of the following purposes:
(1) Retrieval and return to Earth of the orbiting spacecraft (or part thereof), including a spacecraft deployed earlier on the same Space Shuttle flight.
(2) Exchange of a spacecraft (or part thereof) delivered to orbit on a particular Space Shuttle mission for an already orbiting spacecraft (or part thereof) and return of already orbiting spacecraft to Earth.
(3) Revisit of an orbiting spacecraft for purposes such as resupply, repair, reboost or inspection.
(b) Mission operational requirements and associated optional service charges and conditions for both dedicated and shared flight rendezvous services will be negotiated on a case-by-case basis.