1. Safety issues and considerations concerning humans aboard commercial reusable launch vehicles
2. 4Anon. "Draft Guidelines for Commercial Suborbital Reusable Launch Vehicle Operations With Space Flight Participants," Office of Commercial SpaceTransportation[online database], URL:http://ast.faa.gov/, [cited 11Feb. 2005].
3. 5Anon. "DraftGuidelinesforCommercialSuborbitalReusableLaunchVehicleOperationsWithSpaceFlightCrew,"Office of CommercialSpaceTransportation[online database], URL:http://ast.faa.gov/ ,[cited 11Feb. 2005].