An Escape Tower, the original version officially known as the Aerial Capsule Emergency Separation Device, is the visible part of the Launch Escape System. It consists of a rocket and a frame attaching it to the top of the crew capsule. This was originally designed for the US Project Mercury program rockets, in 1958 and has since been built into the Apollo program, Soyuz and many other manned rocket series.
The idea of using a rocket to remove the capsule from a space vehicle was developed by Maxime Faget in 1958. The system, using the tower on the top of the space capsule to house rockets, was first used on a test of the Project Mercury capsule in March 1959.