NASA actually kind of has a reputation for using old air frames such as the S-3 Viking and even the U-2 but the B-57 is one of if not the oldest airframes they use its also just an interesting story.
The Martin B-57 Canberra is an American-built, twin-engined tactical bomber and reconnaissance aircraft that entered service with the United States Air Force (USAF) in 1953. The B-57 is a license-built version of the British English Electric Canberra, manufactured by the Glenn L. Martin Company.
Initial Martin-built models were virtually identical to their British-built twinjet counterparts; Martin later modified the design to incorporate larger quantities of US-sourced components and produced the aircraft in several different variants.
The B-57 Canberra holds the distinction of being the first jet bomber in U.S. service to drop bombs during combat. The Canberra was used extensively during the Vietnam War in a bombing capacity; dedicated versions of the type were also produced and served as high-altitude aerial reconnaissance platforms (the Martin RB-57D Canberra), and as electronic warfare aircraft. The B-57 Canberra was also sold to export customers abroad; further combat use was seen by the Pakistani Air Force during the Indo-Pakistani War of 1965 and the Indo-Pakistani War of 1971.
In 1983, the USAF opted to retire the type; the B-57 Canberra’s retirement marked the ending of the era of the tactical bomber. The three remaining flightworthy WB-57Fs are technically assigned to the NASA Johnson Space Center, next to Ellington Field in Houston, as high-altitude scientific research aircraft, but have also been used for testing and electronic communications in the U.S. and Afghanistan.
Sources: YouTube; Wikipedia