The X-15 rocket plane, shortly after being dropped from its B-52 mother ship, and the full engine burn to take it to the edge of space. Three X-15 planes flew 199 flights: 13 of which reached altitudes exceeding 50 miles, the USAF definition of space; two, exceeded 60 miles.

The X-15 rocket plane, shortly after being dropped from its B-52 mother ship, and the full engine burn to take it to the edge of space. Three X-15 planes flew 199 flights: 13 of which reached altitudes exceeding 50 miles, the USAF definition of space; two, exceeded 60 miles.


X-15 Flight 138 : Flown $1 Bill

Launch Date: June 29, 1965 | Top Speed: 3,431 mph | Altitude: 53.1 miles



About the Provenance

This 1963 series Federal Reserve one dollar note, serial number L48115031B belonged to the late Norman Foster, an executive with the David Clark Company, which manufactured high altitude space suits and hardware in support of the X-15, X-20, F-40, XB-70, and YF12/SR-71 programs. As a personal favor to Norman, this particular bill was carried in flight by future NASA astronaut Joe Engle on his USAF designated space flight on June 29, 1965. Engle signed and flight certified the bill for Foster, who kept it all his life as a memento. Upon his passing, his grandson, Patrick Fallon, inherited the bill, from whom we acquired it.

About the Bill

The X-15, built by North American Aviation, was a rocket-powered, winged aircraft operated jointly by the USAF and NASA. The X-15 established speed and altitude records in the 1960's -- and still holds the official world's speed record for a manned, powered aircraft at 4,520 m.p.h. Of 199 overall flights with three X-15 aircraft, 13 exceeded 50 miles in altitude -- the USAF definition of the edge of space in the 1960's -- and two of the 13 reached 60 miles, the standard international definition of the edge of space.

This particular bill flew aboard Flight 138 with USAF Captain Joe Engle on June 29, 1965, and reached an altitude of 53.1 miles (having entered the USAF's definition of space at 50 miles up), and reaching a top speed of 3,431 m.p.h. This is the only known, pilot certified flown dollar bill to appear on the market from the X-15 program, and certainly the only one from one of the thirteen X-15 USAF designated space flights.

In an emotional letter about the bill's history, Patrick writes: "My grandfather, Norman Foster, was very involved with the high altitude projects in the 50's and 60's. He became very good friends with all the pilots. At the time, he was the field representative for the David Clark Co., which were providing pressure suits & helmets for the projects. Their lives were in his hands, so to speak. The last few years of my grandfather's life, I would visit him and he would tell me stories of the times with the pilots, going out for drinks after a test flight to celebrate, and how he became good friends with people like Neil Armstrong, Pete Knight, Joe Engle, Al White -- really, all the guys from the X-15 project....so he used to tell me, 'When I die, you'll have all this.' So, when he passed, I inherited all kinds of stuff...(including) the dollar bill."




Test pilot Joe Engle in his David Clark Company pressure suit standing in front of the X-15 rocket plane.

Test pilot Joe Engle in his David Clark Company pressure suit standing in front of the X-15 rocket plane.

The original envelope this bill was stored in for decades.

The original envelope this bill was stored in for decades.


Restoration crews towed the X-15 into the new fourth building today. This is the first aircraft to move into the building, which will open to the public in June 2016. Retired NASA astronaut and the only surviving X-15 pilot, Maj. Gen. (Ret.) Joe Engle speaks about his experience in the X-15 program.