Acoustic testing begins on AA-2 Orion capsule at NASA Plum Brook Station
Michael Cole
August 23rd, 2018
The AA-2 Orion spacecraft test article is prepared for a series of acoustic stress tests in the Reverberant Acoustic Test Facility at NASA Plum Brook Station in Sandusky, Ohio. The acoustic tests are in preparation for the test article’s performance in an upcoming test of Orion’s launch abort system (LAS) at Cape Canaveral in April of 2019. The AA-2 (Ascent Abort 2) test will test the LAS by launching it to an altitude of 31,000 feet, where it will separate from the launch vehicle and performs its task, simulating a launch emergency during an ascent scenario. Photo Credit: SpaceFlight / Insider.
SANDUSKY, OH — The Orion crew capsule test article for the upcoming Abort Ascent-2 (AA-2) test has arrived at NASA’s Plum Brook Station testing facility in Sandusky, Ohio. The test article is being readied – to be blasted with sound.
A series of acoustic tests are part of the preparation for Orion’s AA-2 test, scheduled at Cape Canaveral in April of 2019. Engineers at Plum Brook have placed the Orion test article in Plum Brook’s Reverberant Acoustic Test Facility, where it will generate an important set of data as it undergoes a range of acoustic stress tests over the next two to three weeks.
Orbital ATK conducted a static test fire of the Launch Abort Motor that is planned for use on Lockheed Martin’s Orion spacecraft in Promontory, Utah on Thursday, June 15. Photo Credit: Jason Rhian / SpaceFlight Insider
“It’s a test facility that goes up to 163 decibels,” Nicole Smith, Plum Brook Station Orion Testing Project Manager, told Spaceflight Insider. “We will test this test article up to 155 decibels. We’re going to run a series of tests where we creep up on that really high level of 155. Basically we’re checking this thing out so we can send it down to the Cape and they can do a really successful test flight on it next April.”
Orion is NASA’s future spacecraft for crewed missions beyond Earth orbit. It is planned to be launched atop NASA’s giant Space Launch System (SLS) rocket on missions to cislunar space and beyond. Lockheed Martin is the prime contractor for the Orion spacecraft.
AA-2 is a test of the Orion spacecraft’s launch abort system (LAS). The LAS consists of a rocket-powered escape tower that would ignite and thrust the spacecraft away from the launch vehicle in the event of an emergency during launch or ascent. For the AA-2 test, the Orion spacecraft test article will be encapsulated in its fairing assembly and topped by the launch abort tower. A separation ring will attach the spacecraft to the launch vehicle, which for AA-2 will be an Orbital ATK SR-118 rocket motor, a surplus motor originally intended to be used as a first stage for the Peacekeeper Intercontinental Ballistic Missile (ICBM) program.
It will launch from Space Launch Complex 46 (SLC-46) at Cape Canaveral Air Force Station in Florida. The 3-minute test will launch the vehicle to an altitude of about 31,000 feet (9,448 meters) and to a speed of Mach 1.3 — the altitude and speed at which the vehicle will experience maximum aerodynamic pressure or Max Q.
At that point, 55 seconds into the launch, the Orbital ATK-built abort motor and attitude control motor on the LAS will ignite and thrust the spacecraft away from the launch vehicle. It is the ignition and firing of those motors, so close above the capsule, that necessitates the need to test the capsule acoustically to such high levels.
“If you can imagine a half a million pounds of thrust and the crew module is sitting right underneath it, that’s where we get the extremely high levels of sound,” Larry Price, Lockheed Martin’s Orion deputy program manager, told Spaceflight Insider. “That’s why we are testing at that level, to test margin even above what the spacecraft would see.”
In the AA-2 test, once the capsule test article is safely away from the launch vehicle, the LAS control motors will then reorient the test capsule in the proper attitude for a freefall. In an actual Orion mission emergency, the capsule would freefall and later deploy parachutes for splashdown in the Atlantic. For the AA-2 test, however, the capsule test article is not equipped with parachutes. After the escape tower separates, the test article will simply freefall, transmitting data and jettisoning twelve backup data recorders, until it impacts into the Ocean below. Only the floating backup data recorders will be recovered.
Image Credit: NASA
The structural test capsule was built at NASA’s Langley Research Center in Hampton, Virginia, and shipped to NASA Johnson Space Center (JSC) earlier this spring. At JSC, the capsule was outfitted with all the components, sensors, wiring, mass simulators, and other instrumentation needed to run the AA-2 test, currently scheduled for April 2019.
NASA had earlier considered re-using the Orion spacecraft that was flown into space on the Exploration Flight Test 1 (EFT-1) mission in 2014 as the test spacecraft for the AA-2 test. But many of the components and systems aboard that spacecraft that were necessary for its previous orbital mission to space were not necessary for the purposes of the AA-2 test. It was decided that building a test article dedicated to just the AA-2 test was a better and more cost-effective plan than modifying the EFT-1 Orion with sensors and instruments for the test. The decision helped accelerate the agency-wide effort to keep Orion’s next unmanned test flight, Exploration Mission 1 (EM-1), moving toward its launch, currently targeted for the middle of 2020.
Image Credit: NASA
“There is a lot of effort going on to get EM-1 accomplished on time,” Jon Olansen, NASA Johnson Space Center Orion Flight Test manager, told Spaceflight Insider. “Bringing the development of the crew (test) module to separate as a NASA in-house build afforded us the opportunity to work on those systems, focused specifically on this flight test. We were able to do design and development work. All the components in this vehicle are targeted just for this flight test. It doesn’t have all of the extra or necessary components that you need for spaceflight. So we were able to reduce the cost associated with it. And we could actually accelerate when we could accomplish the mission because we reduced the scope of our development work to just this test. We were first targeting December of 2019, but we were actually able to accelerate that 8 months, through the design and development cycle. So we are able to do the test 8 months earlier than we originally planned.”
Both the AA-2 test and the preliminary acoustic testing at Plum Brook Station — essentially the testing for a test — are not just about observing whether or not the structure and components of the spacecraft are designed with the tolerances for the expected stresses. Although that is part of it, the testing is overall intended to accumulate a wealth of important data sets that engineers can use to model how the spacecraft will tolerate a range of possible stresses or perform in a range of different conditions.
“The demonstration is an important piece,” Olansen said. “But really it is all about getting the data. This vehicle itself has 223 sensors. There are 450 on the LAS itself. Overall there are over 800 sensors that we are collecting data from. So it is a significant amount of data that it is important to us to get as a result of this test.
It’s really about building models from the data and characterizing how the structure will respond.”
A previous test, called Pad Abort-1, was conducted in 2010, when the Orion spacecraft was part of the previous Constellation program. That test, conducted at the White Sands Missile Range in New Mexico, tested the abort scenario from the standstill position on a launch pad. AA-2 will be the final test of the fully active launch abort system before the EM-1 flight, scheduled for 2020, and the crewed missions that will follow.
At the completion of the acoustic testing at Plum Brook Station, the Orion test article will be shipped back to JSC, where engineers are currently outfitting the separation ring which will attach the test article to the launch vehicle. Once the separation ring is completed and mated to the Orion test article, they will be shipped to Cape Canaveral sometime before December.
Upon arrival at the SLC-46 launch site, all elements of the vehicle will be connected, and undergo integrated systems testing leading up to its launch in April of 2019.
Tagged: AA-2 Glenn Research Center Lead Stories NASA Orion
Michael Cole is a life-long space flight enthusiast and author of some 36 educational books on space flight and astronomy for Enslow Publishers. He lives in Findlay, Ohio, not far from Neil Armstrong’s birthplace of Wapakoneta. His interest in space, and his background in journalism and public relations suit him for his focus on research and development activities at NASA Glenn Research Center, and its Plum Brook Station testing facility, both in northeastern Ohio. Cole reached out to SpaceFlight Insider and asked to join SFI as the first member of the organization’s “Team Glenn.”
Wow the development of the vehicle is so long. I know it was delayed, but it’s incredible drawn out. I’m glad their showing progress. I do wonder how useful it will be overall, the vehicle SLS largely expensive disposable rocket.