Orion Service Module getting world’s hardest shake-up at NASA’s Plum Brook Station
SANDUSKY, Ohio — NASA’s Orion service module is getting a serious shake-up, thanks to the engineers and technicians at NASA’s Plum Brook Station testing facility in Sandusky, Ohio. Inside Plum Brook’s giant Space Power Facility, the service module is currently undergoing a rigorous series of vibration tests atop the facility’s new vibration table, the most powerful such apparatus in the world.
The machine, called the Mechanical Vibration Facility (MVF), is designed to simulate the vibration that Orion will experience during the different phases of its liftoff aboard the Space Launch System (SLS) rocket, which NASA is developing as the launch vehicle for Orion. Although the MVF is the most powerful machine of its kind in the world, the engineers at Plum Brook do not shake the Orion service module to its full capacity right away.
“We sort of creep up on it,” Space Power Facility Manager, Jerry Carek, told Spaceflight Insider. “We do several test runs at 20 percent test levels. Then we’ll go to 40 percent, and then we’ll go to 60 percent. We’re now at 80 percent, and 100 percent will happen within the next week or so.”
The engineers then will do tests in the horizontal axis, going in the machine’s orientation directions of both left and right and then front and back.
“It will take a good part of the rest of the summer to complete this phase of the testing,” Carek said.
Following completion of the acoustic tests, the service module test article was moved onto the MVF earlier this summer. At the conclusion of the vibration tests, it will be towed over to the facility’s assembly bay where engineers will conduct a series of pyro-shock tests. In those, engineers will put the service module back into its special stand and fire the pyrotechnics that will be used during a mission to separate the service module from the launch vehicle adapter. Engineers will measure the dynamics of the shock due to that pyrotechnic event.
After the pyro-shock tests, the service module will perform another solar array deployment test – a repeat of tests they conducted this past spring.
“The purpose is to find out if all that shaking breaks the mechanisms or causes damage that will prevent us from deploying the solar arrays,” Carek said. “We need to repeat that test and demonstrate another full deployment on the solar arrays.”
After the solar array deployment comes a series of pyro-shock tests. In those, engineers will put the service module back into its special stand and fire the pyrotechnics that will be used during a mission to separate the service module from the launch vehicle adapter. Engineers will measure the dynamics of the shock due to that pyrotechnic event.
The Orion service module is provided by the European Space Agency (ESA) and built by Airbus Defence and Space. Coupled to the crew module built by Lockheed Martin, the service module will power, propel, and cool the vehicle; it will also provide Orion with air and power. Orion is currently scheduled for its next uncrewed test flight, its first atop the SLS launch vehicle, sometime in 2018.
“What we have here now is a structural test article,” Plum Brook Station’s Orion Testing Project Manager, Nicole Smith, told Spaceflight Insider. “The service module that was on the Dec. 2014 (EFT-1, Exploration Flight Test 1) flight was sort of a dummy service module. It didn’t have all the capabilities of what the full-service module would, and it was built by Lockheed Martin. Shortly before that flight, we brought the Europeans in as international partners and so they are committed to building a pretty major part of the service module. This round of tests is really qualifying the structure of that new service module. The testing that is going on here now is all structurally-based.”
Once the test article is done at Plum Brook, it will go back to KSC and be integrated with the current test version of the Orion crew capsule and then both will be transported to the Lockheed Martin facility in Denver for additional testing.
Sometime late next year, the EM-1 flight hardware will arrive at Plum Brook for testing. The service module and the crew capsule will arrive at the facility fully integrated.
“We will have over two months of testing in the thermal vacuum chamber,” Smith said, referring to the 100-foot (30-meter) wide by 122-foot (37-meter) tall aluminum-lined vacuum chamber at Plum Brook, the largest such chamber in the world.
The assembled spacecraft will go through thermal vacuum and EMI (Electromagnetic Interference) testing – all in the thermal vacuum chamber. There is some possibility that it will be in the acoustic chamber as well, but the flight hardware will not repeat tests on the vibration table.
“We will do thermal soaks, then thermal balancing,” Smith said. “We’ll hit it with cold and then hit it with hot and simulate it being on orbit for a really long time, try to give it a lot of the extremes. And then the EMI we will do in the chamber. We do a reverberant test where we soak it with frequencies and then make sure that everything still works.”
Smith said the testing on the Orion flight hardware at Plum Brook will begin sometime in late 2017, and will continue into 2018. That final round of testing should take about five months, after which it will be shipped down to Kennedy Space Center for integration and assembly with the launch vehicle, and ultimately the launch of EM-1.
This article was updated at 12:20 p.m. EDT July 28, 2016, to correct an error regarding the order of tests on the service module.
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.”