IIRC according to a biography of the Skunk Works by Ben Rich a former head
of said Plant, it is. The drone was not actually an SR-71 but small scale
version which incorporated many of the SR-71s features including its
shape. It was launched by piggy backing off an SR-71 however and crashed
over Communist East Asia (I forget where and don't have the book to hand
at the moment) and part of the skin was given to an American delegation by
a Russian delegation who thought it was the current level of Stealth
technology at the time.

(If this answer came through twice, my apologies. I posted my first answer
using "Google Groups" which -- even in its latest incarnation -- is the
worst piece of sh*t I've ever used... But I digress.)

According to Bill:

This story is not true. No D-21 drones were ever lost over enemy territory,
despite the fact that they routinely crossed hostile countries. The drone
would be launched at altitudes of 70+ thousand feet, and would fly using its
ramjet at speeds of over Mach 3.5. Incredibly, it had a range of over
2200 miles.

When it got back over "friendly" territory (usually the Sea of Japan) it
would "kick out" its payload -- a 6' x 4' x 3' box -- which would float down
under three parachutes. The payload would then be snagged by a C-130, and
the D-21 would be destroyed remotely, blown into a million pieces.

The only accident Bill reported was when one of the three 'chutes failed to
open, and the payload dropped much faster than expected. The C-130 missed
catching it, and it impacted the sea. Two American destroyers in the area
began a search, with one finally putting a tow-line on the payload.
Amazingly, while under tow, the OTHER destroyer managed to cross the
towline, breaking it, sending the payload to the bottom.

The D-21 program was axed by Kelly Johnson after a fatal accident about 50
miles off the coast of California. Apparently the D-21 experienced an
"unstart" at release, causing it to settle back down on top of the mother
ship, breaking the SR-71 in two. One of the pilots was killed when he broke
his arm while ejecting, which tore his flight/space suit, which then filled
with water after he landed in the water, drowning him.

From that point on, D-21s were only launched from B-52s. They were attached
to a missile to accelerate them to speeds where their ramjet could ignite,
not unlike the recent NASA scramjet test -- although much slower. (If Mach
3+ can be called "slow"...)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"