The SR-71 Blackbird was one of our greatest aeronautical achievements. A Mach 3+ spy plane, designed in the early '60s, gave the US a manned recon platform unequalled by anyone else in the world. The aircraft, though long retired by budget cuts, still holds many world speed and altitude records.
A program was initiated in the early '60s to use the SR-71 as a mothership/launch platform for the D-21 - a ramjet powered spy drone, that would extend the reach of the Blackbird well into Soviet territory (without endangering the crew). the D-21 looked much like a miniature Blackbird.
Although development was finished, and the D-21 used operationally for a few times, the program was not successful, and the D-21s were retired (long before the Blackbird).
Here is a video of the first test launch of a D-21, along with a fatal accident where the launch was not successful. It is narrated by Kelly Johnson, Lockheed'd genius aircraft designer and founder of the 'Skunkworks'. I can't embed the video directly, the person who posted it disabled the embedding feature. However, it can be reached via this link:
There is some amazing stuff out on Youtube!