Interestingly, Space Tourism seems to be much less regulated than commercial airline operations (121 being related to the operation of an air carrier, and not the actual airplane).
For example: 460.45 3 (b) calls out:
Link to regulations:
eCFR — Code of Federal Regulations
Reusable Launch Vehicles are covered under
Title 14 → Chapter III → Subchapter C → Part 431
Reentry Sites:
Title 14 → Chapter III → Subchapter C → Part 433
People transport:
Title 14 → Chapter III → Subchapter C → Part 460
For example: 460.45 3 (b) calls out:
An operator must inform each space flight participant that the United States Government has not certified the launch vehicle and any reentry vehicle as safe for carrying crew or space flight participants.
Link to regulations:
eCFR — Code of Federal Regulations
Reusable Launch Vehicles are covered under
Title 14 → Chapter III → Subchapter C → Part 431
Reentry Sites:
Title 14 → Chapter III → Subchapter C → Part 433
People transport:
Title 14 → Chapter III → Subchapter C → Part 460