Five Seconds of Fury: Orbital ATK conducts test fire of Launch Abort Motor
PROMONTORY, Utah — With a brief flash of highly controlled power, Dulles, Virginia-based Orbital ATK, along with NASA and Lockheed Martin, successfully conducted a test of a system designed to increase safety and to save lives on Thursday, June 15, 2017.
“We at Orbital ATK are very proud to work with NASA and Lockheed Martin on the Orion Launch Abort System, and to provide a motor that is so integral to astronaut safety,” said Charlie Precourt, Vice President and General Manager of Orbital ATK’s Propulsion Systems Division and former NASA astronaut via a company issued release. “The importance of our crews’ safety and well-being can’t be stressed enough.”
The Launch Abort Motor – the primary motor of the Orion spacecraft’s Launch Abort System (LAS) – would, in an emergency event, pull Orion’s Command Module off its Service Module and the Space Launch System (SLS) super-heavy-lift booster that is currently being developed to send astronauts to deep space destinations, such as the Moon, asteroids, and Mars.
NASA and Orbital ATK carried out this test to qualify an array of elements that are a part of the Launch Abort Motor’s design. Some of these include the thrust profile reduction, or “TPR”, grain design to verify the motor-manifold joint and manifold-nozzle joint performance. This test also served to qualify the motor under high-temperature limits (100 degrees Fahrenheit / 38 degrees Celsius) and to distinguish abort motor induced environments.
The test accomplished all of that – in the scant five seconds that the motor was active for. It also sent exhaust plumes 100 feet (30 meters) in height thundering into the blue skies above Utah. The motor was designed in such a way as to use most of its propellant within the first three seconds of the test.
Thursday’s static test fire saw the Launch Abort Motor firmly attached to the test stand at Promontory’s T-97 facility. During firing, the Launch Abort Motor exerted an estimated 400,000 pounds-force (1,780 kN) of thrust – in just an eighth of a second. The extreme capabilities that this system is capable of bringing to bear is important given its role.
In the event of an emergency during an SLS launch, either on the pad at Kennedy Space Center’s Launch Complex 39B in Florida or while ascending, the Launch Abort Motor would go from zero to an estimated 400–500 miles per hour – in just two seconds. With an acceleration greater than that of a drag racer, the Launch Abort Motor places some 10Gs on those on board – pulling them from whatever had gone “off-nominal”.
Given its abilities, it should come as little surprise that the Launch Abort Motor burns its solid fuel some 3–4 times faster than a typical motor of this size (according to a statement issued by Orbital ATK).
The Launch Abort Motor measures approximately 17 feet (5.2 meters) in length and about three feet (0.9 meters) in diameter.
While this Qualification Motor 1 (QM-1) test is viewed as a key milestone in allowing NASA to regain the ability to send astronauts beyond low-Earth orbit (LEO), it is not the system’s first test. In November 2008, ATK (this test was conducted before Orbital Sciences Corporation and ATK had merged in 2014) conducted the ST-1 Static Test. This was followed by a Pad Abort Launch in May 2010 and Exploration Flight Test 1 (EFT-1) in December 2014 (on EFT-1 the Launch Abort Motor was inert).
Lessons learned on ST-1, helped shape certain aspects of the Launch Abort Motor’s design as was noted by one member of the motor’s development team.
“There [are] a few things that we learned on ST-1; one is that one of our acoustic gauges got saturated, so the acoustic loads were higher than we had anticipated,” Steve Sara, Orbital ATK’s Launch Abort Program Manager, told SpaceFlight Insider. “We also learned about these joints; the joints survived fine on ST-1, but that was a steel manifold, this is a titanium manifold. So we changed materials for the reason of weight savings. Years ago, even before ST-1, we decided to move to a lighter weight manifold so that we could save about 1,300 pounds (590 kilograms).”
If everything continues to go as currently planned, the Motor’s QM-2 test should take place late next year (2018). One member of NASA’s astronaut corps, Rex Walheim, who was a part of the crew of the final flight of the Shuttle Program, STS-135, spoke with SpaceFlight Insider about what it was like to watch the test first hand.
“I was amazed at just how powerful it was, you expect it to be powerful but, you know, it’s quite a ways down the hill from us and you see those flames come up (laughs) and I was thinking, ‘this is going to be loud when it gets to me’ and then BAM it hits you – it’s pretty impressive,” Walheim said.
Walheim also noted that the importance of the test simply could not be overstated, as it could one day save the lives who fly on the SLS and Orion.
“We want to test all of the hardware at the ends of the extremes, especially this hardware which is a part of the essential Launch Abort System for us. Whenever you build a new rocket, you try to take into account all of the things that could go wrong and have ways to fix all the failures, but, you want to have something that can get you off the rocket if you have a really bad day – and that’s our launch abort system. That’s what this abort motor we tested today is for; it pulls us off the Space Launch System if we have a bad day and need to get off the pad or rocket.”
As Walheim noted, the test regimen is designed to validate the design under both the high and low end of what the Launch Abort Motor is expected to encounter. The next step is to test the design in lower temps (approximately 30 degrees Fahrenheit / -1 degree Celsius).
In about 18 months, the three organizations are planning to conduct the QM-2 Launch Abort Motor (this will also take place in Utah); this will be followed by the Ascent Abort-2 Flight Test (AA-2) currently slated to take place at Cape Canaveral Air Force Station, Florida, in 2019.
Video courtesy of SpaceFlight Insider
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.