eksath From United States of America, joined Aug 2004, 1213 posts, RR: 27 Reply 6, posted (11 months 2 weeks 5 days 10 hours ago) and read 3418 times:
AIRLINERS.NET CREW ARTICLE EDITOR
Quoting DTWPurserBoy (Thread starter): Has anyone heard what the plans are for the two modified 747's that were used to carry the shuttle? Hopefuly, they will be going to a museum.
N911NA - parts donor for SOFIA 747SP. Gate guard for the rest of the hulk at Palmdale.
N905NA - At Ellington Airfield in Houston. Current options are gate guard at EFD or another use for either NASA or outside entity. Engines will be shipped back to Palmdale via land for SOFIA 747SP, if that is the final result. She did take another training sortie from EFD. Things may change i.e. some other use or interested purchase.
More detailed info on the history of these aircraft are here:
“NASA Shuttle Carrier Aircraft – the Titans of the Space Shuttle Program”