The plane spotters website amcaronline has noted that the FAA Office of Commercial Space Transportation reserved has booked sixty aircraft registration numbers begining with ”N” ready for commercial space travel.
The first suborbital SpaceShipTwo rocket plane of Virgin Galactic dubbed VSS Enterprise has the tail number N339SS. The WhiteKnightTwo carrier aircraft VMS Eve has N348MS as its tail code.
NASA’s Boeing 747-100 aircraft used to ferry the Space Shuttle Orbiters both carried N-registations: N905NA and N911NA. The Space Shuttle Orbiter’s however had OV numbers representing “Orbiter Vehicle” (e.g. Space Shuttle Endeavour OV-105) but these were not painted onto the orbites. Nor were the Space Shuttle mission STS numbers.
Post script: A thank you to Gaz Ibberson for spotting this one.