This United States one dollar bill holds the signatures of the three Apollo 7 astronauts (Walter M. Schirra, Jr., Donn F. Eisele, and Walter Cunningham), all on the front of the bill. This memento of the first human flight of the Apollo program in October 1968 was part of the official process of certifying the flight.
Before human spaceflights, the National Aeronautic Association (NAA) had the astronauts autograph dollar bills, witnessed by the NAA official for the flight (who sometimes also signed the bill). The bills were then placed aboard the spacecraft. After the mission, recovering the identifiable bills served "as the basis for certification of the identity of the astronauts on each of the flights."
The NASA Johnson Space Center transferred this bill to the National Air and Space Museum in 1976.
Transferred from NASA - Johnson Space Center