This uncirculated two dollar bill (Serial No. 115894612 A) was flown on-board SpaceShipOne on its X Prize winning flights into space. The first flight (X1) was piloted by Mike Melvill; the second and last flight of SpaceShipOne (X2) was with Brian Binnie at the controls. The bill was signed and dated by both civilian astronauts. Certifying the bill as flown is a signed letter printed on stationery that also flew into space on X2. The bill is identified as no. 8 of 10 flown.