(a) The use of customer-furnished payload specialists shall be subject to the approval of the NASA Administrator or the Administrator's designee.
(b) Customers with payloads whose Shuttle load factor is equal to or greater than 0.5 are entitled to request that a customer-selected payload specialist be flown with the customer's payload. Dedicated-flight customers are entitled to request the flight of two customer-selected payload specialists.
(c) NASA may approve the flight of a customer-selected payload specialist with payloads whose Shuttle load factor is less than 0.5 if, in NASA's judgment, there is sufficient scientific need to warrant such a flight.
(d) The standard Spacelab flight price is based on operation of the customer's payload by two NASA-furnished mission specialists. Accommodations for, and mission-independent training of, any payload specialists and backups required for the customer's mission shall be provided as optional services and shall be paid for by the customer. The price for this service shall be the same for both customer-furnished and NASA-furnished payload specialists.