EGS synchronizing Artemis 1 Orion, SLS Booster preps with Core Stage schedule

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NASA Spaceflight.com by Philip Sloss March 27, 2021

https://www.nasaspaceflight.com/2021/03/egs-aligns-artemis-1-schedule/

NASA’s Exploration Ground Systems (EGS) program and prime test and operations contractor (TOSC) Jacobs are working at the Kennedy Space Center (KSC) to position Artemis 1 Orion and Space Launch System (SLS) hardware to be ready for final assembly ahead of the arrival of the SLS Core Stage in the late-April time-frame. With the final major Core Stage test completed, the SLS Boosters are stacked in the Vehicle Assembly Building (VAB) and fueling of the Orion spacecraft was expected to begin.

EGS and Jacobs are also working to align the schedules of cubesat payloads and the Interim Cryogenic Propulsion Stage (ICPS) so they can be ready for vehicle integration when their turn arrives for stacking. EGS is looking at ten months of work to get ready for Artemis 1 once the Core Stage arrives, which would put the current launch forecast towards the end of the first quarter of 2022.

Orion, ICPS preparing for propellant loading

Now that the major SLS Core Stage Green Run tests are finally complete, more attention is turning to KSC in Florida where EGS and Jacobs are already processing the rest of the Artemis 1 vehicle for the first flight of all the Exploration Systems Development (ESD) division programs. While an Orion crew module flew the Exploration Flight Test-1 mission in late 2014 on a Delta IV Heavy launch vehicle, all the other ground and vehicle elements from the Mobile Launcher to the Orion Service Module to SLS will make their debut on Artemis 1.

The Core Stage Hot-Fire on March 18 at the Stennis Space Center was the final major standalone development test; now that it has been performed, stage prime contractor Boeing and RS-25 engine prime contractor Aerojet Rocketdyne are performing inspections and refurbishment required before transportation from Stennis to the Kennedy Space Center launch site. About 30 days was planned after the test-firing to get the Core Stage ready to depart Stennis, and NASA is hoping to see it on dock at the Launch Complex 39 Turn Basin around April 27.

Once the Core Stage is at KSC, what remains to get ready for Artemis 1 is the first-time full assembly and integration with the launch infrastructure there. There’s still some uncertainty when Artemis 1 will be ready to go.

“We know the flow once we get the Core Stage but at this point there is still work to be defined, traveled work, that will have to be performed,” Cliff Lanham, NASA Senior Vehicle Operations manager for EGS at KSC, said. “So what I would tell you is that from that standpoint we fully expect it to take, once the Core Stage arrives on dock, ten months to get everything completed and to get the vehicle to launch ready.”

The testing-heavy schedule will be periodically refined, and NASA has not officially ruled out a launch in 2021, but a late-April, early-May arrival of the Core Stage at KSC and a 10 month estimate from there to Artemis 1 launch readiness projects out to the February-March, 2022 timeframe.

All the other major Artemis 1 hardware elements are already at KSC and have been formally turned over to EGS for launch processing. Both the Orion spacecraft that will orbit the Moon on Artemis 1 and the SLS Boosters have started that work.

After Lockheed Martin delivered the Artemis 1 Orion to EGS, the spacecraft was transferred from the Armstrong Operations & Checkout (O&C) Building at KSC to the Multi-Payload Processing Facility (MPPF) on January 16. Work on the spacecraft to load its flight commodities was juggled due to delays in the Core Stage Green Run schedule, and the sequence is now ordered so that the most life-limited items are serviced at the end.

“For example, the CM (Crew Module) helium tanks have a limited life of a little over a year,” Marcos Pena, NASA Spacecraft Element Operations manager for EGS at KSC, said. “So given that the Core Stage is completing its testing at Stennis, we don’t want to go ahead and start those clocks prematurely, so we have switched the operations such that we’re servicing the commodities that don’t have limited life associated with them [first].”

Pena noted that so far the Service Module (SM) helium and nitrogen tanks in Orion have been loaded; Lockheed Martin did the SM nitrogen servicing in the O&C Building before the handover to EGS. The test team then serviced the CM ammonia to do a functional check of the thermal control system; after the test, the ammonia was then drained from the system.

“There’s an ammonia functional check – which, basically, we load it to the flight level, it’s about 80 pounds, and then we power up all the systems on the CM and the SM and verify that we can reach these various [temperature] set points,” Pena explained.

The team is also performing fit checks of equipment inside the Crew Module. “We’ve been trying to take advantage of when we’re not doing a hazardous operation in the MPPF and we have the hatch open, we’re trying to do fit checks,” Pena said. The equipment cage of one experiment has already been fit checked, and in April the plan is to do a test install of a crew seat with a suited mannequin.

“One of the payloads that we’re flying on Artemis 1 is a suited mannequin with radiation dosimeters, and the Orion suit that the Artemis 2 crew would wear,” Pena noted. “We’re going to plan on doing a fit check while we’re at the MPPF not doing hazardous ops. That fit check is going to be done some time in the early to mid-April time-frame.”

The mannequin will be strapped to a seat that will be removed once Orion lands at the completion of Artemis 1 and readied to carry a human passenger on the Artemis 2 mission.

“Actually today we’re in the middle of fit checking the lightning monitoring system inside the Crew Module,” Pena said during the March 16 interview. “We need that lightning monitoring system when we go out to the pad. That will help us have ground truth on whether the vehicle has had any lightning strikes or anything like that.”

In the days before the critical Core Stage test on March 18, the spacecraft offline operations team got ready to start loading the hypergolic propellant commodities onboard the SM. “What we’re going to get into next here between now and mid-May is first is the SM oxidizer loading. There’s about 12,000 pounds of nitrogen tetroxide that we’re going to be loading,” Pena said.

At the time of the interview on March 16, Pena noted that the offline operations team was getting set up to begin the hazardous hypergolic loading. “Today, we’re actually working on the connections to the vehicle between our oxidizer servicing GSE (Ground Support Equipment) and the flight interfaces on the CMA (Crew Module Adapter). And the plan is to do all those connections here in the next few days and be ready to perform the actual flight load next week,” he said.