Moving forward with some locations still open, some critical work on hold
The SLS workforce for Stages Element prime contractor Boeing is also under the same mandatory stay at home directives. “We applaud NASA’s decision to be a little bit early in the Louisiana and the Mississippi areas in closing the facilities and going to telework,” John Shannon, Boeing’s Vice President and Program Manager for SLS, said on April 10. “We initiated a process where we identified telework for all of our employees, that has gone extremely well.”
“It is activities like doing tabletop reviews of procedures so that we’re able to roll ‘red-lines’ into it for the next tests and processes. We’ve done a lot of our verification and validation of both software and test processes that we use on the vehicle.”
Credit: NASA Office of Inspector General.
(Photo Caption: High-level organizational chart of the SLS Program from a recent Inspector General report. The program is based at MSFC but includes offices at other centers and the prime contractors for hardware elements have assembly and production sites across the country. The impact from COVID-19 varies from region to region.
“We’ve been able to utilize this time when we’re teleworking to really catch up on paperwork, root cause corrective actions, processes,” Shannon added. “We’re also doing a lot of quality training for the team, we’re sending all the team at Michoud and at Stennis to something called ‘quality college,’ which is training for how to improve our quality processs, things that we would like to do but we were in such a developmental sense of urgency that these basic things that we wanted to get done we’re now having the opportunity to do.”
“For the majority of the workforce and the program that don’t have to do the touch labor we’re all in a virtual environment and continuing to make really good progress,” Honeycutt added.
The SLS Program is subdivided into several offices. In addition to offices for program operations, planning, and systems engineering and integration (SE&I), there are three hardware element offices that work with prime contractors and a payload integration office that works with other contractors.
Without a vaccine yet available different regions of the U.S. employ differing degrees of social distancing measures in an attempt to break the transmission chain of COVID-19, which has varying impacts on work locations around the country.
“For the Booster activities, those continue to go on out in Utah as well as at the Booster Fabrication Facility at KSC,” Honeycuttt said. “We’ve found a way to continue to support the work that’s going on at the Booster Fabrication Facility to minimize the impacts there primarily through social distancing and providing the touch labor workforce with the appropriate protective equipment to stay safe.”
“That said it’s a new operating model and we’re continuing to adjust that and fine-tune it.”
Credit: Philip Sloss for NSF.
(Photo Caption: SLS Booster assembly hardware in the Booster Fabrication Facility at KSC in November, 2018. In addition to the five solid rocket motor segments, each booster includes a forward and aft booster assembly that is prepared for integration in the BFF. With KSC in Stage 3 of the COVID-19 response framework, processing on the assemblies at the BFF is continuing.)
Northrop Grumman is the prime contractor for the SLS Booster Element. They produce the five-segment solid rocket motors (RSRMV) for the SLS Solid Rocket Boosters (SRB) at their Promontory facility north of Salt Lake City. Cases for a booster are assembled into five segments; inherited from the Space Shuttle Program after refurbishment the cases are lined with insulation, loaded with solid propellant, and outfitted with other booster hardware; the large nozzles for the booster are also built in Utah.
The motors will eventually be integrated with refurbished Space Shuttle SRB hardware that is being assembled by Northrop Grumman in the BFF at KSC. The forward assembly includes the nose cone and forward skirt that houses booster avionics and connects the boosters structurally and digitally to the Core Stage. The aft assembly includes the aft skirt that houses the booster thrust vector control (TVC) hardware that helps steer the whole vehicle by slewing the booster nozzles.
“Also out at Aerojet Rocketdyne, DeSoto and then the RL-10 work that we’re doing out at West Palm, those areas have pretty minimal impact and they’re working in the same kind of environment [as] the Booster element,” Honeycutt noted. Aerojet Rocketdyne is the prime contractor for the SLS Liquid Engines Element.
Their DeSoto facility in Canoga Park, California, produces most of the component hardware for the RS-25 engines that power the SLS Core Stage. Aerojet Rocketdyne’s West Palm Beach facility in Florida produces RL-10 engines that are used by multiple U.S. commercial and government customers, including SLS.
One RL-10 variant powers the upper stage for the SLS Block 1 vehicle, a derivative of United Launch Alliance (ULA)’s Delta 4 upper stage called the Interim Cryogenic Propulsion Stage (ICPS); another RL-10 variant is a part of the design for a higher-performance, in-house upper stage for the SLS Block 1B called the Exploration Upper Stage (EUS).
Credit: Aerojet Rocketdyne.
(Photo Caption: Four completed RL-10 engines for future SLS use at Aerojet Rocketdyne’s West Palm Beach facility. The company is currently contracted to produce a total of 10 engines that will power either SLS upper stage, the single-engine ICPS or the four-engine EUS.)
Another Aerojet Rocketdyne facility is located in the federal city at the Stennis Space Center, where final assembly and testing of engines including the RS-25 occurs. For now, Aerojet Rocketdyne spokesperson Mary Engola noted that facility is operating on a more limited basis.
“Our Stennis site remains open for mission-essential work supporting the Department of Defense,” she said in an email. “This includes work performed at our Engine Assembly Facility (Bldg 9101) and the B1 / RS-68 Test Stand.”
With respect to SLS activities at Stennis, preparations to resume single-engine RS-25 development tests there to certify the restart of modernized production are on hold like the Core Stage Green Run activities, including work on both the development engine and refurbishing the A-1 test stand infrastructure.
In addition to the Stages Element work at MAF and Stennis, structural qualification testing at Marshall that was nearing completion is also on hold. “We had one additional test case that we needed to run on that LOX (liquid oxygen) tank per the plan and then we were going to have a discussion relative to a similar type final test where we do the test at a higher load,” Honeycutt said.
A structural test article (STA) for the Core Stage LOX tank was the final of four STAs to be subjected to a series of load cases in test stands at MSFC to verify that the structure had at least a factor of safety of 1.4 as required.
Credit: NASA/Tyler Martin.
(Photo Caption: The Core Stage LOX tank structural test article (STA) is lifted into Test Stand 4697 at MSFC in July, 2019. The LOX STA was the last of four test articles going through testing prior to the program’s first launch. The baseline set of test cases for the LOX STA was almost complete when work was suspended as a part of MSFC moving to Stage 4 in late March.)
Under the SE&I Office, development of the NASA flight software for the vehicle is largely designed, developed, and tested in labs at Marshall.
Integrated avionics and software development and testing between computer hardware and software is typically done on site at Marshall and Honeycutt noted that some development work was initially suspended by the COVID-19 stand down. “We’ve shut down the activities in the Software Integration Lab and the System Integration Test Facility (SIL/SITF) as well as the Software Development [Facility] Lab,” he said.
“And so the software development folks they’ve moved along, they’ve been able to make some good progress in this virtual environment and we’ve worked with our Safety and Mission Assurance (S&MA) folks who provide our quality support for all the inspections that we need to do and we have those verification activities that the quality folks do in parallel with the software developers and the testing that they do and so we’ve been able to work through that and find ways to do that verification quality oversight work in a virtual environment.”
Other activities in the SIL/SITF are still on hold. In addition to integrating device-level software and hardware, such as the NASA-developed SLS flight software that runs on flight computers supplied by Boeing for the Core Stage avionics subsystem, verification and validation of system integration between independently developed computer systems is also done at Marshall.
The flight computer/avionics system that runs on the SLS vehicle also has to operate with separate flight computer systems for the ICPS and the Orion spacecraft that are managed by separate programs. It also has to interoperate with ground launch and ground test systems. In particular, testing critical to the Green Run between the Core Stage computer system and the Boeing Stage Controller computer system that manages B-2 Test Stand infrastructure and preparations at Stennis, was going on in the SIL/SITF.
“Stage Controller work is done in two locations,” Shannon explained. “All of the qualification testing is done at the lab in Florida, they are still working and making good progress. The verification work is performed at Marshall and that work has been stopped although we are able to go in.”
Credit: NASA/Tyler Martin.
(Photo Caption: The development ring of the SIL/SITF at MSFC as configured with Core Stage avionics for integrated avionics and software verification and validation testing. With MSFC in Stage 4, most of these activities are on hold.)
The ICPS is under the Spacecraft/Payload Integration and Evolution Office because the ULA product is largely a commercial, off-the-shelf (COTS) upper stage and so more like a payload than the in-house EUS under development by the Stages Element. ULA production activities at their final assembly factory in Decatur, Alabama, continue; although mostly concentrating on their commercial Delta, Atlas, and Vulcan launch vehicles, production of the Delta-derived ICPS is a smaller part of the ongoing work there.
Work at home also continues on long-term evolution of the launch vehicle, in particular two future configurations: Block 1B crew and cargo configurations that would employ EUS, and a Block 1 cargo configuration that would be used to fulfill the Congressional mandate that SLS launch the Europa Clipper spacecraft.
“They are teleworking but since this is a development activity we really haven’t changed any of our expectations on dates or productivity and that team so far is just knocking it out of the park on just staying on track with their planning and their development work,” Shannon said regarding EUS development. Prior to the closure of MSFC, the SLS Program co-located its NASA EUS team with Boeing’s at the contractor’s office just offsite from the center.
Resuming work at closed locations will be a process, timing uncertain
The question no one can answer clearly yet is when parts of the workforce can start the journey back to a new normal. “As we move through this we don’t really know when we’re going to roll out of this,” Honeycutt said. “The things that we’re doing with the program and working with the prime contractors across the program is as we move through our day-to-day activities we’re doing the planning that is associated with looking forward to what the future looks like eventually when we do get back to work.”
“I don’t think it’s going to be a step function where we just all show up back to work and things go back to normal,” he noted. “There’s going to be some startup periods and things that we have to do to continue to protect the workforce as we potentially move from a Phase Four environment to a Three and then back to a Two. We’re working diligently with the center and the agency to continue to plan those efforts and then also tracking the impacts that we have.”
“Even in this new operating model that we’re living in today that we’re making progress every day and we’ll be ready to hit the ground running when things start to transition back to normal,” Honeycutt added. “I think all the prime contractors are going to be ready to make that transition.”
“Mr. Shannon and his team have been impacted the most on Green Run and at MAF but I see the things they’re doing to better position us to be able to hit the ground running and move quicker and be more efficient as we roll out of this. I think the team, the contractor team and the government team across the whole program, are really doing a phenomenal job in working through the COVID-19 situation.”
