Orion spacecraft about to be put through its paces at Glenn
Preliminary testing has begun on the Orion crew module adapter at NASA Glenn Research Center’s Plum Brook Station in Sandusky, Ohio. There, with a test version of Orion’s European Space Agency (ESA)-provided service module, also due to arrive in a few weeks, personnel have prepared their giant Space Power Facility for a series of tests that should prove Orion’s readiness for future missions beyond low-Earth orbit (LEO), and possible missions to Mars.
“This testing equipment is so unique. Nobody has ever built anything like this before,” said Jerry Carek, manager of the Space Power Facility, the testing destination for all components of the Orion spacecraft.
It is the destination for good reason – no other facility in the world can so thoroughly test Orion for launch into space. Indeed, after a $130 million upgrade, the newly-revamped Space Power Facility is ready to present Orion with a formidable triple-threat of simulated launch stresses and space environment tests.
With its mammoth Space Environment Simulation Vacuum chamber, its Reverberant Acoustic Test Facility (RATF), and the new Mechanical Vibration Facility (MVF), it is a one-stop-shop in terms of simulating the rigors stresses of space flight.
First tests on the crew module adapter began late last week. The crew module adapter, designed by Orion’s prime contractor, Lockheed Martin, was built at NASA’s Kennedy Space Center and delivered to Plum Brook Station in June. The adapter will connect the Orion crew module, also built by Lockheed Martin, to the ESA service module.
When the service module arrives this October, the crew module adapter will be stacked atop and they will then be rolled into the Space Power Facility’s central structure for tests in the giant Vacuum Chamber. The 100 foot (30 meter) wide by 122 foot (37 meter) tall aluminum-lined chamber is the largest chamber of its type in the world. Its mechanical and cryogenic pumps are capable of pumping down the vast chamber to a vacuum of 2×10–6 torr, simulating the vacuum environment Orion will experience in LEO.
To simulate the hot and cold temperatures Orion will endure, the Vacuum Chamber uses large cryogenic shrouds that are deployed around the spacecraft. The shrouds use a recirculating gaseous nitrogen system capable of surrounding the spacecraft components with a low-temperature environment of –240 °F (–151 °C), and a warm temperature up to 140 °F (60 °C).
Although Orion is often described as a larger, souped-up version of the Apollo spacecraft, the differences in the two crafts are numerous and major.
“There are fairings that go around the service module that eject, as opposed to Apollo, where there were no fairings involved,” Carek told SpaceFlight Insider. “So the fairings are needed to protect the service module hardware. And the launch of this thing is a lot more severe and intense than Apollo.”
Orion will launch atop NASA’s Space Launch System (SLS) rocket, and it will be attached to the rocket by a launch adapter module. The protective fairing will enclose the service module, while the emergency launch escape system covering will protect the crew module. The launch escape system will jettison from the crew module, and the fairings will separate from the service module only moments apart during the later phases of launch.
The enormous size of the Space Power Facility’s Vacuum Chamber will allow NASA to conduct these critical fairing separation tests on the fully stacked Orion spacecraft assembly in a simulated vacuum environment. Those tests on that version of Orion should occur sometime in 2017. They will be some of the final tests on Orion, just before it is flown directly from Plum Brook Station to Kennedy Space Center for the launch of Exploration Mission 1 – the first flight of SLS and Orion.
Orion will also be subjected to Plum Brook Station’s newest addition – a 22-foot (7 meter) wide, 55,000-pound (24,948 kg) aluminum vibration table called the Mechanical Vibration Facility (MVF). Located in the testing bay on the west side of the Vacuum Chamber, the $8 million MVF is an intimidating structure. Its 16 horizontal and four vertical high-powered servo-hydraulic actuators provide a 3-axis base-shake vibration system to simulate the vibration of launch.
“It is probably the most complicated aluminum welded structure that anybody has ever built,” Carek told SpaceFlight Insider. “The idea is you want something extremely light yet extremely stiff.”
The appearance of the MVF, with its large, roughly circular shape, and numerous mechanisms and hoses protruding at all angles from beneath, gives the vague suggestion of a Millennium Falcon from hell – which, in a way, it is. It will give Orion a wickedly violent ride, simulating conditions up to and beyond the vibratory stresses it will experience during liftoff aboard its SLS launch vehicle. The MVF will have no trouble providing that ride, as it can support up to 75,000 pounds (≈34,000 kg) of spacecraft weight.
“With this table in this bay,” Carek said, “we can have the service module, the crew module, and the launch abort system on there and stacked all the way to the ceiling.”
Once attached to the MVF, the entire spacecraft assembly will be at the mercy of the MVF’s powerful hydraulic cylinder actuators, subjecting the spacecraft to controlled vertical and horizontal sine vibration.
The third part of the Orion testing hat-trick at Plum Brook Station is the Reverberant Acoustic Test Facility (RATF). With a 57-foot (17 meter) tall wall mounted with dozens of powerful horns, and capable of filling the chamber with an overall acoustic sound pressure level (OASPL) of 163 decibels, it is the most powerful acoustic chamber in the world. This world-class acoustic assault will simulate the horrendous sound pressures Orion will experience during the deafening launch atop the SLS rocket, as well as some of the stresses and effects the spacecraft will endure during max-Q – the phase of maximum aerodynamic pressure during launch.
“Most acoustic chambers will have eight or maybe ten of these horns,” Carek pointed out. “This one has 36. This is more powerful than the next most powerful acoustic chamber by a factor of ten.”
The horns Carek refers to are no ordinary horns. “Nitrogen gas comes through these horns, and it’s turned on and off at a very high rate of speed,” Carek told SpaceFlight Insider, referring to the hydraulic actuators that move rapidly back and forth, turning the gas flow on and off. “So it’s similar to a guy blowing on a tuba or a trumpet and he’s using his mouth and lips to start and stop the air moving through. But with the nitrogen gas we’re doing it a whole lot faster.”
Carek is among those at Plum Brook Station who have been planning and preparing for the Orion testing program for nine years. “It’s been a long time coming,” he said, “and after all that planning and building, and creating the vibroacoustic facility… we’re finally about to see the culmination of that, and about to see the testing happen.”
All of these facilities will make Orion the most rigorously, thoroughly, and exhaustively tested manned spacecraft ever to fly. Plum Brook Station has tested countless space hardware over the years for everything from ISS components to the Mars Pathfinder airbags. But anytime the testing is on hardware for human spaceflight, the feeling is a little different.
“Yeah, I think we feel that even with the ESA service module,” said Rick Sorge, Space Power Facility Test Manager. “It’s a step closer to flight. And anytime you start touching flight hardware it gets pretty exciting.”
That feeling was evident throughout the personnel testing the Orion hardware at the Space Power Facility.
“All of your processes and procedures are checked that much more closely,” Sorge told SpaceFlight Insider. “Everybody knows where it’s headed. We know that it’s going down to the Cape.”
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.”