Two more Service Module tests
As NASA Orion Program Manager Mark Kirasich put it when the ESM arrived at KSC in November, “What we’re going to do now and what we’ll keep doing for the next several months is ‘integrate and test’ and ‘integrate and test’ to make sure that these vehicles function well together.”
More specifically Schneider said: “We basically build the vehicle up to a level that matches the next test configuration.” “There’s a lot of internal components tanks and avionics boxes and things that are inside the CMA, inside the outer mold line of the Service Module,” Wilson added. “I think for the most part we’re done.”
Once functional testing is complete, the Service Module will have two more standalone tests. The first is a thermal cycle test.
In addition to all the operational wiring and sensors packing into the spacecraft, this first working Service Module has a significant amount of development flight instrumentation (DFI) installed. “DFI is probably one of the biggest challenges we have, there’s so much of it,” Schneider said.
A qualification model solar array wing is test deployed while attached to the Service Module structural test article (STA) in February, 2016, at the Space Power Facility (SPF) at NASA Glenn’s Plum Brook Station in Ohio. Credit: NASA.
“I forget how many data acquisition units we have on the spacecraft, but I think it’s somewhere between six and eight, maybe even more and you need all that because there’s so much information being gathered by the instrumentation that you can only get like a fraction of it in the telemetry during the flight. The rest of it is all going to data acquisition units and stored onboard the CM and after the CM is recovered all that data is downloaded, pulled off those data acquisition units.”
“One of the other challenges with DFI is you usually don’t quite know where to put it until all the other systems are fully designed so it’s typically one of the last things to be designed and so that’s always a challenge you know when you’re trying to put those systems in, and kind of find the right places for them in the end,” Wilson added.
There’s even more instrumentation for ground tests like the thermal cycle test. “So you have GTI, which is ground test instrumentation, which is instrumentation that you need to get data during these tests. It’s not going to fly, so most of it comes off before we fly but some of the GTI is buried so you can’t get it off,” Schneider noted.
“So you have to put it on as if it were going to fly and then you just abandon it after you get the data from the test.”
“Once we get out of all the initial power up and the functional tests we’ll go into [an] oven basically,” Wilson added. “We’ll cook and cool it and that GTI is what tells us how it’s performing during those tests.”
The EM-1 Orion spacecraft adapter cone in August, 2018, at the Michoud Assembly Facility in New Orleans. The adapter will be temporarily installed on the bottom of the Service Module for the upcoming direct field acoustic test (DFAT). It will be reinstalled in the O&C by Lockheed Martin before the spacecraft is handed over to Exploration Ground Systems for launch processing next year. Credit: Philip Sloss for NSF/L2.
Following the thermal cycle test, the Service Module will be reconfigured for a direct field acoustic test (DFAT). For this ‘integrate and test’ cycle, most of the remaining, large appendages will be attached including the four solar array wings.
“I think the biggest scope yet to go with the ESM is the solar array integration, that’s a huge amount of work and they’re not on yet,” Schneider said.
“The Dutch Airbus guys show up, you know those are the guys that build it, they do a manual deploy just to check for damage during shipment and we do a soft-mate to the Service Module and do a deployment that way, driven by the spacecraft, and then we actually physically install them after we do that second deployment test.”
In addition, the nozzle for the OMS-E engine and the spacecraft adapter (SA) will be installed at the base of the ESM for the DFAT. The test will validate that the working, integrated module handles high-noise levels within requirements and remains healthy.
The solar array wings and the spacecraft adapter are then removed and the Service Module is prepared for mating to the Crew Module. The OMS nozzle will remain on the spacecraft.
Crew Module status
While the Service Module integration and test activities were going on, a couple of remaining major components for the EM-1 Crew Module arrived recently and were installed. At the time the ESM arrived at KSC in November, a few of the CM avionics boxes were still being reworked and the first working side hatch was due from its vendor.
The EM-1 Crew Module in the O&C Building in November, 2018, prior to installation of the side hatch. The EM-1 vehicle will fly the first working hatch versus one bolted into place. Credit: NASA/Rad Sinyak.
“All the avionics are back in, we’ve actually done all of the regression testing associated with putting them back in, we’re finished with that,” Schneider noted. “We’re integrating the hatch as we speak, the side hatch integration should be complete next week,” he added.
The Crew Module was largely outfitted with those exceptions. Functional testing and a thermal cycle test were completed by the end of 2017 over a year ago and the heatshield was installed last summer. While waiting for ESM arrival and Service Module integration, issues with a few systems such as a few avionics boxes were addressed.
Now that all of the components are on-site, the Crew Module is being prepared for its last standalone test. “The Crew Module goes through a direct field acoustic test as well, it’s already been through its thermal cycle test,” Schneider noted.
The EFT-1 Crew Module inside a portable acoustic test configuration in a Lockheed Martin lab in Waterton, Colorado. A similar set up will be used for direct field acoustic tests (DFAT) of the Crew and Service Modules in the O&C Building at KSC. Credit: Dusty Volkel/Lockheed Martin.
“So we have to get it configured for the direct field test, which means we have to install the backshell panels temporarily and the forward bay cover. After we put the hatch on, we’re basically we’ve got a few ‘cats and dogs’ things to clean up but then mainly what we’re doing is getting it configured for the acoustics test.”
Another one of those cats and dogs is to install the docking hatch plate. After the DFAT is complete, the Crew Module will be prepared for mating to the Service Module.
A silicone-oxide coated aluminum kapton tape to prevent electrostatic discharge will be applied to the thermal protection system tiles on the backshell panels. For the EFT-1 flight, the tape covered the heatshield but not the backshell tiles.
One panel was recently taped to verify the first-time application procedures, but the remainder will be covered after the DFAT.
CM-SM mate
Once the remaining standalone tests are complete, the modules will be mated at the far end of the O&C Building. “The cell in the building that we do that work in we call the FAST (Final Assembly System Test) cell and the schedule has us in there for about eight weeks doing the CM to SM mate, but it’s not just the mate,” Schneider said.
The Service Module will be moved into the cell and then the Crew Module will be brought over and lifted on top on to join the two. “By the way, it’s the same exact location that the Apollo program used to stack the Command Module and their Service Module and a couple of the other elements that they used,” he noted.
The EFT-1 Service Module simulator loaded in the FAST cell in June, 2014. The EM-1 Service Module will be moved here for mating to the Crew Module after completing its standalone testing. Credit: NASA/Glenn Benson.
As Schneider observed earlier, the spacecraft is often being configured for its next set of tests, which will be a series at Plum Brook Station in Ohio later this year. In this case, getting the combined Crew and Service Module (CSM) ready for the space environment tests at Plum Brook will also configure some parts of the spacecraft for launch.
“The schedule has us in there for about eight weeks doing the CM to SM mate, but it’s not just the mate,” he explained. “The umbilical that runs between the CM and SM, you can’t put that on until you have a CM and an SM together, so again it’s bunch of that kind of stuff.”
“We put the backshell panels on I believe for flight in there, which means we have to do all the thermal barrier closeouts,” he added. “A lot of thermal barrier, MLI closeouts happen in that eight weeks because you’re really getting the vehicle buttoned up for flight.”
The EFT-1 Crew Module shortly after mate to the simulated Service Module structure in June, 2014, in the FAST cell. The EM-1 modules will be mated and closed out in the same cell for a trip to Plum Brook Station for thermal vacuum and EMI testing later this year. Credit: NASA/Kim Shiflett.
Schneider noted that all the functional testing on the Crew Module and Service Module before they are joined limits the testing necessary post-mate. “We try and test as much as we can at the module level and so by the time we get to the FAST cell the only things that we really need to test are the new interfaces,” he said.
“So anything that crosses the CM-SM interface we would test there, but we don’t do a lot of retesting of all the stuff that we tested at the module level, we just test the stuff across the interface, so umbilical tests or anything running across the umbilical or CM-SM R&R (Retention and Release) mechanism, those kinds of things are what we would test in the FAST cell.”
“We’ll do a high-level, general functional test prior to shipment to Plum Brook and then we’ll do the same thing after receive up there,” Wilson added.
Plum Brook testing later in the year
The combined Crew and Service Module (CSM) will be transported to Plum Brook for thermal vacuum (TVAC) and electromagnetic interference/compatibility (EMI/EMC) testing. The spacecraft will be powered for the tests.
“One of the things you want to do in the first thermal vacuum cycle we call it a thermal balance test and the idea is to figure out the equilibrium point of the spacecraft thermally and then you’re going to run the spacecraft itself because it’s both generating heat and radiating it at the same time so you want to make sure those systems are working,” Wilson explained.
Animation depicting the EM-1 Orion spacecraft after receiving in the Assembly High Bay at the Space Environment Complex at Plum Brook Station. The spacecraft is oriented horizontally transport to Ohio, then rotated to vertical for testing. Credit: NASA Glenn Research Center.
Without its solar array wings, the spacecraft’s power distribution system will get its power generation from the EGSE used at Kennedy. “That same ground support equipment that we use at KSC in the O&C to simulate the solar arrays like the way we are during the power-on testing right now, we’ll use that same rack of equipment up there and it basically simulates the power generation of the solar arrays and feeds it into the same connections on the spacecraft,” Wilson said.
“We have to run the active thermal control loops while we’re in there so all that stuff that we have here, we move to Plum Brook with the vehicle,” Schneider also noted.
Final steps before launch preparations
Orion and its associated ground support hardware will be transported back to KSC after the Plum Brook tests, where Lockheed Martin will install the remainder of the CSM hardware and closeout the spacecraft for launch.
In addition to the solar array wings and spacecraft adapter, the Service Module launch fairings will be installed. “They’re one of the last things we do because you’re closing out the access to the Service Module,” Schneider said. “So after the solar arrays get put back on after Plum Brook for flight, the last time, then we put the fairings on that encapsulate the Service Module.”
Lockheed Martin will then turn the spacecraft over in the O&C Building to EGS for launch processing.