Launch escape system

The LES is typically controlled by a combination of automatic rocket failure detection, and a manual activation for the crew commander's use.

As shown by Soyuz T-10a, a LES must be able to carry a crew compartment from the launch pad to a height sufficient for its parachutes to open.

The Space Shuttle was fitted with ejection seats for the two pilots in the initial test flights, but these were removed once the vehicle was deemed operational and carried additional crew members,[3] which could not be provided with escape hatches.

Following the 1986 Challenger disaster, all surviving orbiters were fitted to allow for crew evacuation through the main ingress/egress hatch (using a specially developed parachute system that could be worn over a spacesuit),[3] although only when the shuttle was in a controlled glide.

Although often referred to as a "pusher" arrangement since it lacks a tower, the Dragon 2 LAS removes both the capsule and its trunk together from the launch vehicle.

to sell the LAS it was building for the Orion spacecraft to future commercial crew vehicle providers in the wake of the cancellation of the Constellation project.

[12] During the Mercury-Redstone 1 mission on November 21, 1960, the escape system unintentionally blasted off from the Mercury spacecraft after the Redstone booster engine shut down just after ignition on the pad.

During the attempted launch, the booster switched from external to internal power as it normally would do, which then activated the abort sensing system.

Originally it was thought that the LES firing was triggered by a gantry arm that tilted the rocket past 7 degrees, meeting one of the defined in-flight abort conditions.

Reportedly, the capsule reached an altitude of 2,000 meters (6,600 ft) and landed 4 kilometers (2.5 mi) from the launch pad.