Orion Launch Abort System Passes Full-Stress Flight Test

Ascent Abort-2 lifts off from Space Launch Complex 46. (Image courtesy: NASA)

The Orion spacecraft – the spacecraft integral to NASA ’s Artemis  program – passed through another milestone in preparation for flight. Researchers from NASA and Jacobs Engineering Group Inc.  successfully completed a crucial full-stress flight test of Orion’s launch abort system (LAS). The system is designed to lift the crew module off the launch vehicle’s engine stack in case of an emergency and steer it away from danger. According to NASA coverage, engineers have confirmed that the LAS can “outrun a speeding rocket.”

Ascent Abort-2 lifts off from Space Launch Complex 46. (Image courtesy: NASA)

For the “Ascent Abort-2” flight test, the LAS and a 22,000-pound test version of the Orion crew module launched atop a modified Peacekeeper missile from Space Launch Complex 46 at Cape Canaveral Air Force Station in Florida. The Northrop Grumman-built missile carried the LAS and crew module to an altitude of 31,000 feet at a speed of Mach 1.3 (over 1,000 miles per hour). At that height and speed, the LAS experienced high-stress aerodynamic conditions expected during ascent on a NASA Space Launch System (SLS).

Ascent Abort-2 lifts off from Space Launch Complex 46. (Image courtesy: NASA)

The abort sequence was triggered and within milliseconds the LAS fired, pulling the crew module away from the Peacekeeper. LAS attitude control motors flipped the module to achieve the proper escape orientation and then its jettison motor fires, releasing the crew module for splashdown in the Atlantic Ocean.

NASA engineers will analyze the flight data gathered by 12 flight recorders that launched with the LAS to better understand the abort system’s performance.

Orion Ascent Abort-2 full test article assembly and pad roll out (Image courtesy: NASA)

“We're building the most powerful rocket in the world to send astronauts to the Moon in the Orion spacecraft for Artemis missions,” says Bill Hill, deputy associate administrator for Exploration Systems Development at NASA Headquarters in Washington. “With this exploration system designed to safely carry humans farther into space than ever before, we'll also have an equally powerful launch abort system that will pull the crew away if there is a problem with the rocket during the early portion of ascent.”

The tower-like LAS structure consists of two parts: the fairing assembly, which is a shell composed of a lightweight composite material that protects the capsule from the heat, air flow, and acoustics of the launch, ascent, and abort environments; and the launch abort tower, which includes the abort motor, attitude control motor, and jettison motor. The system is built specifically for deep space missions and the SLS rocket.

“Launching into space is one of the most difficult and dangerous parts of going to the Moon,” says Mark Kirasich, Orion program manager at Johnson Space Center in Houston. “This test mimicked some of the most challenging conditions Orion will ever face should an emergency develop during the ascent phase of flight. Today, the team demonstrated our abort capabilities under these demanding conditions and put us one huge step closer to the first Artemis flight carrying people to the Moon.”

NASA was able to accelerate the test schedule and lower costs by simplifying the test spacecraft and eliminating parachutes and related systems. NASA already qualified the parachute system for crewed flights through an extensive series of 17 developmental tests and eight qualification tests completed at the end of 2018.

The successful Ascent Abort-2 test will pave the way for NASA's Artemis 1 mission, the first uncrewed flight of the Orion crew capsule atop SLS, which will travel thousands of miles past the Moon.

The agency recently reached major milestones for the SLS rocket, assembling four of the five parts that make up the massive core stage that will launch Artemis 1. When completed, the entire core stage will be the largest rocket stage NASA has built since manufacturing the Saturn V stages for NASA's Apollo lunar missions in the 1960s.

William Kucinski  is content editor at SAE International, Aerospace Products Group in Warrendale, Pa. Previously, he worked as a writer at the NASA Safety Center in Cleveland, Ohio and was responsible for writing the agency’s System Failure Case Studies. His interests include literally anything that has to do with space, past and present military aircraft, and propulsion technology.

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