This mint self-adhesive stamp, issued on Oct. 14, 1997, pays tribute to the 50th anniversary of the historic 1947 flight at Edward's Air Force Base in which Chuck Yeager broke the sound barrier with a Bell X-1 rocket aircraft. This was the first time a piloted aircraft flew faster than Mach 1. This flight occurred during the first year of existence of the U.S. Department of the Air Force.

The above image is an enlargement; the actual size of this stamp is 26mm x 40mm.