NASA scores successful Orion solar array deployment test
NASA took another important step in testing the Orion crewed spacecraft yesterday with the successful completion of a solar array deployment test inside the Space Power Facility (SPF) at NASA’s Plum Brook Station in Sandusky, Ohio.
The test demonstrated the successful unfurling of the 24-foot wing qualification model of the solar array, built by Airbus Defence and Space, the primary contractor for Orion’s service module, which will provide power, propulsion, air, and water for the Orion spacecraft. The test was the first of two Orion solar array deployment tests that will be conducted at Plum Brook Station this year.
“Today’s deployment kicked off our test campaign and set a baseline for the second array test,” said Meg Nazario, NASA Glenn Test and Transportation project manager. “It proved that everything was shipped and installed correctly and that the array is functional. The second [test] will show that it withstood the launch environment. That is when everyone will be holding their breath.”
That second test, coming sometime this fall, is when the solar array and its deployment mechanism will prove if they have survived the simulated launch stresses they will be subjected to at Plum Brook Station’s SPF.
SPF’s intimidating gauntlet of test facilities includes the largest vacuum chamber in the world (to simulate the vacuum and chilling temperatures of space), the most violent mechanical vibration table in the world (to simulate the extreme vibration during launch and max-Q), and the most powerful acoustic chamber in the world (to simulate the effect of tremendous sound vibrations during launch).
The testing is in preparation for Orion’s first launch atop the mighty Space Launch System (SLS) rocket, on an unmanned mission known as Exploration Mission-1, or EM-1. That mission will take Orion on a test flight far beyond the Moon and back to Earth.
Yesterday’s test came after months of preparations, as the service module and other test articles arrived from across Europe and the United States. The European Space Agency (ESA) has provided the service module. It was stacked together with structural representations of the Lockheed Martin-built crew module adapter, which will connect the service module to the crew module, and the spacecraft adapter, which will connect the service module to the SLS rocket.
On Feb. 20, engineers carefully tilted the assembled test article to a 90-degree angle to position it for the deployment test. Last week they attached the solar array test wing, as well as mass simulators to represent the other wings.
The test wing was held in a stowed position by four Kevlar straps. When an Airbus Netherlands test engineer issued the command for the wing to deploy, thermal knives cut the straps to release the array wing. After the successful deployment, engineers performed what they called a “glow test” to make sure the thermal knives heated as they should and activated simultaneously.
“The test was successful, and the solar array deployed exactly as planned,” SPF Facility Manager Jerry Carek told SpaceFlight Insider. “After we get done with all the vibration and acoustic testing, we’re going to come back sometime in the early fall and repeat this test and ensure that it still deploys properly after the experience of the launch environment. So we’ll be going through acoustic testing this spring, and mechanical vibration testing throughout the summer. By fall, we should be mostly completed with that testing, and then do another test on the solar array deployment. That next test will be done in the high bay at ambient conditions, replicating the same conditions as the earlier test.”
Carek explained that the current round of tests will only expose the test articles to simulated launch conditions, not the simulated space environment of the SPF’s giant vacuum chamber.
“The whole purpose of this portion of testing that we’re doing here this year is to simulate launch loads only,” Carek said. “Once we get into the EM-1 test program, and that’s starting up in mid to late 2017, we will then be doing more of the vacuum simulation for Orion. It will then be a different test article. It will be more flight-like. The service module here now is more of a structural test article. When we get into the EM-1 testing, then we will really be dealing with more finalized flight-like hardware. However, the solar arrays we have here now are flight units. These particular units won’t fly, but they are flight units.”
The solar arrays are based on the ESA Automated Transfer Vehicle’s X-shaped array of four panels. Together the four panels will generate 11 kW of power and span 63 feet when extended.
With the solar array deployment test a success, engineers are already preparing for the next test.
“The next step is to put together the service module with its fairings,” Carek said. “We will then attach its launch abort and crew module mass simulators, and then the whole assembly will be put into the acoustic chamber for acoustic testing.”
The current testing is the first time engineers have integrated NASA and Lockheed Martin hardware with hardware from the ESA.
“We are proving out our planning, assembly, and integration together,” said Ben Van Lear, NASA Glenn assembly and integration lead for the test campaign. “It is really a pathfinder for the EM-1 flight.”
Video courtesy of Airbus Defence and Space
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.”