The scientific tourist #170 — the SR-71 blackbird

This week’s “scientific tourist” subject can be seen all over the place in the U.S. — fitting, for an aircraft that cruised at somewhere over Mach 3.

The SR-71 was a success originally born out of a failure — namely, the failure to reduce the radar cross-section of the U-2 spy plane in a CIA program called Project Rainbow in 1956 and 1957. So since engineers couldn’t make the U-2 invisible to radar (allowing it to spy on the Soviet Union without causing a diplomatic incident), the CIA and USAF attempted to make an aircraft invisible to radars of the day by cruising at Mach 3. At that speed, radar displays of the time couldn’t track an aircraft — or so it was thought.

A number of aircraft designs were experimented with and tested to succeed the U-2. Since the U-2’s program was “Angel,” this successor craft was designated “Archangel,” and the evolving designs were named Archangel-1, Archangel-2, and so on (later abbreviated to A-1, A-2, etc.). Eventually the design settled upon was the A-12 (I’ve talked a bit about a variant of it, the M-21, in an earlier scientific tourist post). Between 1962 and 1964, 12 A-12s were built for the CIA, all intended for missions overflying the Soviet Union — but it soon became apparent that while they could outrun defensive armaments, they couldn’t really outrun radar. As a result, missions flying over the USSR were no longer allowed except in case of emergency (and reconnaissance satellites were coming along well enough anyway).

Yet the A-12’s speed drew the U.S. Air Force’s interest, so in 1962 the USAF ordered up their own version of the A-12 — eventually to be dubbed the SR-71 (SR standing for Strategic Reconnaissance). Since an SR-71 would carry a crew of 2 (vs. the A-12’s 1), it couldn’t fly quite as fast or as high as the A-12 — but had upgraded avionics and reconnaissance systems. 32 SR-71s would eventually be built in 3 variants before the production tooling was destroyed by USAF instruction in 1968. Twelve were lost in a variety of accidents, another 18 retired by 1998, leaving just two still flying today — owned by NASA’s Dryden Flight Research Center.

The 18 retired SR-71s are on display in a variety of museums scattered across the U.S. Here’s one of the most photogenic displays, at the National Air and Space Museum’s Udvar-Hazy Center in Chantilly, Virginia:


The Pima Air Museum near Tucson, Arizona also has a copy on display outdoors (I believe this has since been moved to a hangar):

SR-71 up close & personal
SR-71 from a distance

The Museum of the USAF has its own copy, in a free but somewhat more difficult to photograph hangar in Dayton, Ohio:

This entry was posted in Sci / Tech Tourism, Technology and tagged , , . Bookmark the permalink.