Under FAA regulations crew is defined as:
"any employee or independent contractor of a licensee, transferee, or permittee, or of a contractor or subcontractor of a licensee, tansferee, or permittee, who performs activities in the course of that employment or contract directly relating to the launch, reentry, or other operation of or in a launch vehicle or reentry vehicle that carries human beings. A crew consists of flight crew and any remote operator."
Flight crew is defined as:
"crew that is on board a vehicle during a launch or reentry"
The FAA requires that each flight crew member be trained on how to fulfill his or her role on board or on the ground so that the vehicle will not harm the public, and train for his or her role in nominal and non-nominal conditions. They also require that each member of a flight crew demonstrate an ability to withstand the stresses of space flight, which may include high acceleration and/or deceleration, microgravity, and vibration, and be in sufficient condition to safely carry out his or her duties so that the vehicle will not harm the public.