The Orion spacecraft for the Artemis II mission is nearing final assembly and testing at prime contractor Lockheed Martin’s Kennedy Space Center (KSC) production facility. After a final standalone test on the Orion crew module (CM), it is expected to be mated to the service module (SM) in mid-September. If there are no problems in the remaining months of testing, Lockheed Martin believes they can complete their work by the end of April next year.
NASA is planning Artemis II as a week-and-a-half long, lunar-flyby mission; it will be the first crewed test flight for Orion and the Space Launch System (SLS) and the four-person astronaut crew recently visited KSC together for the first time to see their spacecraft. With major hardware like Orion and the SLS Core Stage not yet completed, the space agency is retaining its late November 2024 launch forecast as a “work to” date, although the pace of work is currently “a number of weeks” behind that forecast.
Crew and service modules scheduled to be mated for flight in September
NASA and Lockheed Martin hosted a media event on Aug. 8 in the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Assembly and testing of Orion spacecraft are conducted in the high bay and low bay of the facility in what is called the industrial operations zone (IOZ).
As Lockheed Martin nears the final assembly of the Artemis II spacecraft, the assembly, test, and launch operations team are also simultaneously building spacecraft for the two missions that will follow. The crew module and crew module adapter (CMA) sets for both Artemis III and Artemis IV were also on display in workstations and test cells distributed throughout the IOZ floor.
The four-person Artemis II flight crew was announced in April and mission-specific training began in June. In fact, the media event ended up happening at almost the same time the four astronauts were visiting KSC together for the first time to get a first look at their lunar spacecraft. Artemis II is planned to be a 10-day long, lunar-flyby test flight and the first crewed mission for Orion and SLS.

The Artemis II crew outside the hatch of their crew module on Aug. 7, during their first look at their home for the mission. (Credit: NASA/Kim Shiflett)
The final major standalone test for the CM before it is ready to mate with the SM is a direct field acoustic test (DFAT). Lockheed Martin continues working around the clock, every day to get the Artemis II Orion completed, and the CM was moved down the IOZ floor to the test area a few hours before the media event.
“We’re doing everything in our power to keep the schedule the way that it needs to be but also make sure at the same time that we don’t sacrifice what needs to get done to build the spacecraft,” Sarah Malatesta, Systems Integration and Test Engineer for Lockheed Martin, said during the media event. “That’s very important as well, it’s not all about schedule, it’s about making sure that you’re making the right technical decisions along the way.”
The test simulates launch acoustics that the spacecraft will experience during the launch and mission, and the production team was ready to pick up work as soon as possible after the event. “We’re chomping at the bit to attach ground cables today as soon as media event is over,” Malatesta said. “We are waiting on standby to get the hatch opened up again so that we can get powered up and get into the testing.”
The Artemis II Orion is the third flight spacecraft built and is the first full-up implementation of the hardware and software to support a four-person crew for up to 21 days. Most of the CM life support and crew systems, such as crew displays and controls and systems for maintaining and supporting a habitable environment inside, are flying for the first time on Artemis II and this will be their first acoustic test.
“There are new components, the displays and controls, and the ECLSS (environmental control and life support system) components are new, and they have not been through a DFAT before, not at a vehicle level,” Debbie Korth, Orion Deputy Program Manager for NASA, said.
DFAT is expected to take a few days to execute and then the module will be moved back to the CM workstation while the test data is analyzed. “We’ll be running that for a couple of days and then once we’re complete with DFAT, we go back down to our regular workstation,” Malatesta said.
Back in the CM workstation, Malatesta said the spacecraft team will finish a little bit more outfitting, securely fasten outside panels, and run a few tests to make sure the module is ready to mate. “We’ll go back down to our regular workstation, checkout all of the subsystems that we can’t checkout while we’re down here, make sure those are still working great,” she said. “Once we’ve confirmed that, we’ll be ready to stack, and they’ll work that through September.”
The two modules will be attached in the final assembly and systems testing (FAST) cell, adjacent to where the DFAT equipment was set up. The Artemis II SM has already been mated to the Spacecraft Adapter cone and that assembly had already made one trip into the cell. After the CM DFAT is complete, it will be moved back into the cell for mating.
The Orion SM, which consists of the European Service Module and CMA, has already gone through its standalone assembly, test, and checkout and is essentially ready for the next phase of spacecraft integration and testing. “It is more or less ready, so what we are currently doing here is we have handed over the vehicle already to ESA (European Space Agency) and NASA,” Kai Bergemann, European Service Module Deputy Programme Manager for Airbus, said.

The Artemis II Orion service module and Spacecraft Adapter in the O&C Building on Aug. 8. (Credit: Max Evans for NSF)
“It’s no [longer] under the ownership of Airbus but the next steps are to finalize some sensor integration on the top and we will close the thermal protection on the aft side, so the MLI (multi-layer insulation) will be attached in the next weeks and then following that we are really ready to accommodate the crew module.”
Mid-September is when the multi-month process of integrating the two modules is planned to begin. The modules are physically bolted together and there’s also an umbilical that connects all the electrical, data, and fluid lines. After those are connected, all the functions of the mated spacecraft need to be checked out.
“You have to make sure that all of the components and interfaces between the crew module and the service module are working the way that they are supposed to,” Malatesta explained. “We fly the majority of the mission stacked, so we need to make sure that the crew module is talking to the service module appropriately and the way that we need it to.”
“We do full-scale mission testing, simulations and phasing simulations to make sure that the correct thrusters are firing when you get the correct sensor input, all of that kind of stuff.”
The final, major standalone checkout of the mated crew and service modules (CSM), along with the Spacecraft Adapter, is a vacuum test that will be performed in a newly renovated chamber inside the O&C Building. Korth said the Orion is projected to be ready to start the test sometime early in 2024 after integrated testing of the mated spacecraft is complete.
“If I look at the schedule I want to say the mate takes about three to four months to get all of the vehicle mated, so it’s early next year,” she said. Korth said that the vacuum test is expected to take a number of weeks; however, the vacuum testing process should still take less time than the testing done on the Artemis I Orion at the Neil Armstrong Test Facility (formerly known as Plum Brook Station) in Ohio.

The Artemis II crew module is seen positioned in a test cell for the direct field acoustic test (DFAT) that was planned shortly after the Aug. 8 media event. (Credit: Max Evans for NSF)
“The major difference between the Plum Brook vacuum testing and this one is the Plum Brook testing was actually a thermal-vac test, this is going to be vacuum only,” Malatesta noted. “This is a much shorter test because we don’t have to go through a thermal profile throughout.”
“I don’t think we have final timelines, so I don’t have an exact number of days or anything like that, but we are working on the finalization of all that, what do the timelines look like, how long does it take to get it into the chamber, all that. It’s a brand-new chamber for us to use, obviously it’s been used during Apollo, but it’s been retrofitted for Orion, so I’m excited.”
Following the vacuum test, at a high level, the spacecraft team will again double-check that Orion remains fully functional after removal from the vacuum chamber before beginning final work before handing over to Exploration Ground Systems (EGS) for launch processing. EGS will move the Orion “short stack” of the CSM and Spacecraft Adapter to the Multi-Payload Processing Facility (MPPF).
“When we come out we make sure everything is still working the same way that it was before we went through a vacuum environment, install the solar arrays, and we’re pretty much there,” Malatesta said. “It will go back into the FAST cell [first]. We do a little bit there, bring it back up here so you can attach solar arrays and then send it on its way down the road to the MPPF.”
NASA leaves the launch target date as-is, but work is currently weeks behind
NASA also held an Artemis update media briefing at the KSC Press Site later in the day on Aug. 8, the first since the late November 2024 target date for launch was announced in early March. NASA Exploration Systems Development Mission Directorate Associate Administrator Jim Free said in the briefing that the target date still remains unchanged, although work was “a number of weeks” behind.
Free also noted that Orion is still the primary critical path to reaching launch readiness for Artemis II. A combination of budget factors and likely also COVID industry impacts in the 2020-2021 time frame led the agency to reaffirm the decision to reuse several avionics components from the Artemis I crew module on Artemis II; this meant that assembly and test of the Artemis II Orion had to wait until early in 2023 after Artemis I was successfully completed to receive those components.
The post-flight assessment review for Artemis I was recently completed and Free said that open items from the mission are continuing to be analyzed. “We looked at a number of things that are open, the heatshield, an electronics box on the service module, and some of the release and retention bolts,” he said. “I think we have plans forward with all of those. We still have to get to the root cause before we get to flight rationale.”

The Artemis I crew module in San Diego on Dec. 13, a few days after splashdown to successfully complete the first Artemis mission to the Moon. (Credit: Jack Beyer for NSF)
In March at the time the late November 2024 target date was announced, the forecast was for the crew module and service module to be ready to be mated in June; however, NASA and Lockheed Martin still hope to complete the spacecraft and formally hand over to EGS by the end of April.
“It’s an aggressive schedule, but that’s the goal and we still have a path to get there,” Korth said. “It’s a green light [schedule], things are going to have to go well for all these tests.” If the tests are executed on time and nothing needs to be redone, the vacuum tests would take a number of weeks to conduct early next year, with the final stretch of work for Lockheed Martin running from February through April.
“We have a weight and CG (center of gravity) test and a final proof and leak test, so there’s other tests that happen after [vacuum testing],” Korth noted. “There’s a bunch of little things that happen between the February to April time frame.”
Preliminary schedules projected that EGS would need to receive Orion around eight months before they would be ready to launch, which provides the time needed to complete launch preparations. That includes a few months to load all the flight commodities on the spacecraft in the MPPF and a couple of months to stack the Launch Abort System (LAS) on top of the spacecraft.
On that timeline, if EGS were to move Orion into the MPPF in late April/early May, they would be looking to have Orion ready to stack on top of SLS in the Vehicle Assembly Building (VAB) in the Fall of 2024 for launch readiness at the end of 2024.
Other major deliverables necessary before Artemis II launch processing can begin include upgrades to Mobile Launcher-1 and completion of Core Stage-2.
After it weathered the Artemis I launch and returned to the VAB in December, Mobile Launcher-1 (ML-1) was moved to the West Park Site on the north side of the Vehicle Assembly Building in January. Post-launch repairs and refurbishment of the Mobile Launcher (ML) were completed in parallel with modifications to install and upgrade systems that will be needed for crewed launches of Artemis II and III.
Upgrades and modifications were made both at Launch Pad 39B and to the ML for an emergency egress system that can be used by astronauts and personnel to quickly get away from the ML umbilical tower at the pad in case of a hazardous situation with the ML and/or vehicle.
Once all of the work that can be accomplished at the West Park Site is completed, the ML-1 will be picked up by CT-2 and rolled out to Pad 39B for verification and validation of the systems upgrades. Free said that the rollout to the pad was currently projected for Aug. 16.

Mobile Launcher-1 undergoes refurbishment and modifications at KSC’s Launch Complex 39 West Park Site, as seen during a July NSF flyover. (Credit: Max Evans for NSF)
The other flight hardware element still in major assembly is the SLS core stage. In March, Core Stage-2 completion was expected by July but assembly of the stage at the Michoud Assembly Facility (MAF) in New Orleans still hasn’t reached the point where the four RS-25 engines can be installed. By May, engine installation wasn’t forecast to start until July and completion of the stage was projected in late Fall.
One of the issues Mr. Free has noted recently was with parts that are assembled into the long, large-diameter liquid oxygen feedlines (also called “downcomers”). Mr. Free called the problem “minor” and said that the stage would probably ship from the MAF to KSC in the November timeframe.
NASA spokesperson Corinne Beckinger provided an update on engine installation from the SLS Program in an email: “The four RS-25 engines for the Artemis II mission will begin installation onto the Space Launch System core stage in early September at NASA’s Michoud Assembly Facility in New Orleans.”
The change to the timeline, pushing back the start of engine installs, was attributed to a different issue, retesting of a liquid oxygen prevalve. “NASA and its partners continue to work toward a late fall delivery date of the Artemis II core stage to NASA’s Kennedy Space Center,” the SLS Program statement added.
Most of the other vehicle hardware is either complete or nearing completion and will be delivered to KSC this year or early next year. The 10 motor segments for the Solid Rocket Boosters (SRB) have been complete and in storage for years in Utah, the Interim Cryogenic Propulsion Stage for Artemis II is back in storage at Cape Canaveral Space Force Station after completing its test and checkout, and the Launch Vehicle Stage Adapter is complete and ready to ship from Marshall Space Flight Center to KSC early next year.
Final outfitting of the Orion Stage Adapter at Marshall and final test and checkout of the SRB aft skirts and forward assemblies at KSC should also be completed well before they are needed for stacking sometime next year.
The schedule announced in March projected ML-1 to be ready for Artemis II stacking by the end of 2023 and the SRB motor segments and exit cones would be transported to KSC ahead of that. Vehicle stacking for launch begins with the boosters, and that is still planned to start in February.

NASA Artemis launch director Charlie Blackwell-Thompson views the engine section of Core Stage-2 on June 30 at the Michoud Assembly Facility in New Orleans. Previously scheduled for July, the stage is now forecast to be ready to receive its four RS-25 engines in September. (Credit: NASA/Michael DeMocker)
Several “limited operational life items” are associated with preparing and stacking the vehicle, so the target date for planning might not need to be updated until stacking begins next year. Or it may be left unchanged until later.
In the media briefing, Mr. Free explained the rationale for maintaining the November 2024 target date: “It’s this balance of pushing hard but maintaining the right philosophy of not pushing too hard, if that makes sense to you,” he said.
“But I think to us up here it does, because we still need to press and get our missions on a cadence where we’re doing the exploration around the Moon and on the surface. This is a great first step for us but we do need to be vigilant and care about the people going on these missions.”
Given that the schedule to late November 2024 already has not just zero margin, but some weeks of negative margin, launch readiness is still likely to move into the 2025 calendar year.
Artemis I crew module will complete abort qualification for Orion ahead of Artemis II
Artemis II will mark Orion’s initial operating capability following the Exploration Flight Test-1 mission in late 2014 and Artemis I in late 2022. In parallel with preparations of flight and ground systems for Artemis, the Artemis I crew module is being reconfigured in the MPPF at KSC from its lunar mission to an environment test article that will be used to help certify Orion for Artemis II.
“We flew Artemis I without full abort qualification because we knew we wouldn’t abort Artemis I and we’re using that vehicle to close out abort qualification for Artemis II,” Korth explained. “It’s over there [in the MPPF] now, it’s getting ready to do its initial power-on (IPO).”
“[Following Artemis I] first we had to de-service it, we took the avionics out that we wanted to refly on Artemis II, then they have to clean all of the propellant out of it and get it to where people can be around it and then there was some hardware installations to do. That’s been done and I don’t know exactly when initial power-on testing is happening, but IPO is imminent in getting ready to ship it to the Armstrong Test Facility in November.”
The Artemis I spacecraft will spend a few months in Ohio undergoing those tests and then eventually come back to KSC.
“Ideally the plan is to ship it there in November, the testing starts in around January, and then wraps up [in the] March time-frame [and] it comes back to Kennedy Space Center for the post environmental testing prop testing,” Korth said. The spacecraft goes through a set of functional tests after the environmental testing, and due to the toxicity of Orion’s propellants, those functional tests will be performed after the spacecraft returns to the MPPF at KSC.
“We want to be able to cycle the prop valves before and after all this environmental testing, so most of the functionals after the test are done at ATF and then it comes back to the MPPF to do the final post-test functionals to prove that everything worked.”
(Lead image: The Artemis II flight crew in front of their Orion crew module at KSC. Credit: Max Evans for NSF)