Dictionary of Space Concepts

NASA. (1965, June). Apollo Pad Abort Test #2. Retrieved from https://upload.wikimedia.org/wikipedia/commons/1/17/Apollo_Pad_Abort_Test_-2.jpg

Short Definition:

Launch escape system (LES) or launch abort system (LAS) is a system in rockets that will separate a capsule with crew and move it away from the rocket in case of emergency such as pending rocket explosion. This is a safety measure necessary to evacuate the crew when their presence in the rocket is life-threatening.

Detailed Definition:

LES is attached to the capsule and usually has thrusters and a little fuel. It is just enough to propel it for a short time and send the capsule away from the rocket. It can be placed above capsule as a tower (as in Apollo) or be a part of capsule (as in Crew Dragon). LES doesn't have to be detachable from the capsule with crew, but if it is (as towers), it will be separated as soon as it runs out of fuel or when it is no longer needed. When LES finished working, capsule can land or splash with its own parachutes. Nowadays all crewed missions are equipped with some kind of launch escape system.

Etymology:

Launch – from Old French lancier– to fling, hurl, throw, castEscape – Old French eschaper– free oneself from confinementSystem – from Late Latin or Greek systema– an arrangement, organized whole, a whole compounded of parts

Sample Sentences:

The launch escape system provided a critical safety measure for astronauts in case of a rocket malfunction.

Translations:

References:

McHale, S. (2014, February). Soyuz launch escape system. Retrieved from https://web.archive.org/web/20140221212224/http://suzymchale.com/ruspace/soyescape.html

Clark, S. (2010, February). Orbital sees bright future for Orion launch abort system. Retrieved from https://spaceflightnow.com/news/n1002/18orionlas/