Manned re-entry vehicles, past, present and future.

Ten things you should know about the Evolution of the Launch Abort System

Primary Objective: Keeping the crew safe

We are sending astronauts to the Moon by 2024. To keep astronauts safe on their missions, NASA has high safety standards and prepares to keep them safe in many potential mission scenarios. In the event of a complication during launch, measures such as Orion’s Launch Abort System ensure their safety and are a critical part of making the Artemis Program a reality.

Designing an escape system for a spaceship

Several different types of crew escape systems have been developed over the years. NASA scientists developed ejection seats to protect astronauts on Gemini missions. The space shuttle had the Emergency Exit System, which was a series of baskets the astronauts could climb in and ride down a cable to safety, in the event of a complication on the pad before launch. NASA’s Commercial Crew Program partners, Boeing and SpaceX, have both developed systems beneath the crew module that push the capsules away from a failing rocket if necessary.

Orion’s launch abort system has a tower-like structure on top of the crew module designed to pull the crew module away from the rocket if needed. A similar tower design was also used during Mercury and Apollo missions.

Mercury Launch Escape System: the first iteration

The first Launch Escape System (LES) was used in the Mercury program and was designed to carry a capsule weighing about 3,200 lbs. to safety to protect the solitary crewmember inside, if necessary. These capabilities were tested on what is known as Little Joe, a rocket booster designed to simulate conditions similar to the Atlas rocket. Little Joe 1 launched five times in 1959 and 1960 to test the ability of Mercury’s escape system.

Gemini Launch Escape System: a new leap forward

Unlike NASA’s other early crewed missions, Project Gemini used ejection seats to be ready to propel the crew to safety should the need arise. This feature had the ability to simultaneously jettison the two crewmembers.  The ejection seats could provide an escape for the crew either directly before the launch while the capsule was below 60,000 feet, or upon an unforeseen paraglider failure at reentry.

Launch Abort Success

NASA and its commercial crew partners are not the only agency designing and implementing launch abort systems. The escape system used on the Russian Soyuz, called the Spacecraft Abort System, has been called into action twice. In 1983, the abort system was initiated on the launch pad when an issue with the rocket arose. In October 2018, the abort system initiated on the Soyuz MS-10’s climb to space while   American astronaut Nick Hague and Russian cosmonaut Alexey Ovchinin were en route to the International Space Station.

The Launch Abort System of Orion: safety for a new century

Orion’s LAS is highly capable and technologically advanced. It can activate within milliseconds and pull the 22,000 pound Orion crew module away from the Space Launch System rocket at a speed of 1020 mph to keep the crew out of any potential danger. Unlike its predecessors, Orion’s LAS will only be tested twice, once from the launch pad in 2010, and once during ascent in July 2019.

Pad Abort-1: the first test

During Orion’s Pad Abort-1 tests in 2010, the LAS’s ability to take a crew module to safety in the event of a problem on the launch pad was verified.

Ascent Abort-2: our next destination

Ascent Abort-2, currently scheduled for July 2, will test the LAS in flight-like conditions while the spacecraft is under the highest aerodynamic loads it will experience during a rapid climb into space. AA-2 provides the only opportunity to test a fully active launch abort system during ascent before flying crew, so verifying that it works as predicted in the event of an emergency is a critical step forward for deep space exploration.

Abort Scenarios

Orion’s launch abort system can be used if there is a problem on the launch pad or a complication during initial ascent. After Orion reaches a certain altitude, the abort system is jettisoned and Orion must use other methods to keep the crew safe. The spacecraft can use its service module to send the crew back to Earth or abort to orbit. During an Untargeted Abort Splashdown, service module engines would fire to separate Orion from the SLS for a landing in the Atlantic Ocean. If Orion were to reach orbit, but then needed to return prematurely, service module engines would be used to help it deorbit and return to Earth. Other scenarios the Orion is equipped to handle include complications further into the mission, involving aborts from both Low Earth Orbit and High Earth Orbit.

Cosmonauts Aleksei Gubarev and Vladimir Remek train for the Soyuz 28 mission, circa 1978.