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On May 13, 2026, NASA published new details about the Artemis 3 mission and the changes were striking enough to warrant attention not for what they added, but for what they removed. The mission, originally planned as the first crewed lunar landing since Apollo 17, will now send four astronauts to low Earth orbit aboard the Space Launch System and have them dock with prototype lunar landers. No landing. No lunar surface. The Moon is gone from the mission.

The agency confirmed that Artemis 3 will launch from Kennedy Space Center’s Launch Complex 39B no earlier than late 2027, and that the SLS rocket will fly without its usual upper stage. Instead of the Interim Cryogenic Propulsion Stage, the upper stage that has carried Orion to the Moon on previous flights, NASA will install an inert structural spacer — essentially a hollow cylinder with the same mass, dimensions, and interface geometry as the ICPS. The spacer preserves the rocket’s aerodynamic and structural characteristics without consuming propellant that could be allocated elsewhere.

The reason for the change is straightforward: the lunar landers are not ready. SpaceX’s Starship Human Landing System and Blue Origin’s Blue Moon have both experienced development delays. A crewed lunar landing requires those vehicles to perform rendezvous and docking in lunar orbit, execute a descent to the surface, support a stay of variable duration, and then launch back to rendezvous with Orion. Each step involves systems that have not yet been demonstrated in the configuration needed for crewed operations. NASA, having learned hard lessons from the heat shield anomalies encountered on the Artemis 2 flight in April 2026, decided it would not also accept the risk of an unproven lander.

The restructured Artemis 3 instead serves as what the agency describes as a dress rehearsal — similar in concept to Apollo 9, which tested the lunar module in Earth orbit before the first Moon landing. Four astronauts will launch on the Block 1 SLS configuration, which consists of the core stage and twin solid rocket boosters. Orion will separate from the stack and the crew will spend extended time aboard the spacecraft, testing rendezvous and docking with one or both lander prototypes in the relatively safe environment of low Earth orbit, approximately 463 kilometers above Earth at a 33-degree inclination. The European Service Module that powers Orion will handle orbital raising and maneuvering, with the ICPS being preserved for Artemis 4.

The hollow spacer solution was driven in part by hardware availability. The supply of ICPS stages is limited, having been built for the first three Artemis missions, and transitioning to the Exploration Upper Stage on later Block 1B configurations is still years away. Using the final ICPS on Artemis 4 rather than consuming it on an Earth-orbit test mission makes sense from a launch vehicle economics perspective. The spacer, being fabricated at NASA’s Marshall Space Flight Center in Huntsville, Alabama, maintains the structural interface between the Orion stage adapter and the launch vehicle stage adapter while costing nothing in propellant mass.

Artemis 4 remains targeted as the first crewed lunar landing, currently scheduled for no earlier than 2028, and will use the first ICPS from the original batch. The lander situation will need to be resolved by then. SpaceX is expected to conduct an uncrewed Starship HLS test flight before committing a crewed variant. Blue Origin is targeting an end-of-2026 launch of its Blue Moon Pathfinder MK1, an uncrewed cargo mission to validate the BE-7 engine, precision landing systems, and surface operations. Both companies face continued schedule pressure, and the May 2026 grounding of Blue Origin’s New Glenn rocket following an April 19 second-stage failure adds a further complication for Blue Moon’s path to orbit.

The decision to strip the landing from Artemis 3 drew predictable criticism from observers who saw it as another in a long series of delays. But the engineering logic is sound. Artemis 2’s heat shield erosion, traced to an arc-jet test anomaly and now requiring a redesigned thermal protection system for the Orion capsule, consumed program schedule margin. Adding a lunar landing with unproven vehicles on top of a heat shield redesign would have compounded risk in a domain where the cost of failure is measured in human lives. Moving the landing to Artemis 4 preserves schedule integrity for the test flight while keeping the lunar surface objective alive.

The Artemis program has always been aæ…¢ exercise in managed ambition. The original Constellation program was canceled in 2010. The SLS was ordered to replace shuttle hardware that did not exist. The lunar landing has been pushed back repeatedly as funding, politics, and engineering complexity have collided. Stripping Artemis 3 to an Earth-orbit test is not a sign of weakness. It is a sign that the program has decided, perhaps for the first time, to let engineering reality set the schedule rather than politics.

Mea AI adiutor dicit:

When NASA’s Space Launch System (SLS) powers into the sky, it must contend with some of the most extreme and complex aerodynamic conditions ever attempted. The ascent phase—especially during transonic and supersonic transitions and through maximum aerodynamic stress—is a crucible for design and engineering. Rather than rely solely on wind tunnels, NASA has increasingly turned to supercomputer-based computational fluid dynamics (CFD) simulations to model the flows around the twin solid rocket boosters, the core stage, and plume interactions. These simulations feed into aerodynamic databases used across vehicle design, structural loads, control algorithms, and safety margins.

The challenge in modeling the flow around SLS boosters is immense. As the vehicle accelerates, shock waves form, flow separation regions emerge, boundary layers evolve, and the rocket plumes themselves strongly interact with the surrounding airstream. Moreover, during events like booster separation, multiple plumes fire simultaneously—up to 22 different exhaust sources in some analyses, combining output from the core engines, boosters, and separation motors. Resolving those off-body interactions, transient flow features, and the coupling between vehicle aerodynamics and plume dynamics demands very high fidelity simulations. The NASA team has used solvers such as OVERFLOW, FUN3D, and Cart3D to explore a wide envelope of flight conditions.

Running these simulations requires massive computational resources. Each case can consume thousands to tens of thousands of core-hours, depending on flow complexity, grid resolution, and the number of interacting plumes. To build a full aerodynamic database that spans multiple Mach numbers, angles of attack, mass fractions, and thrust conditions, NASA runs hundreds to thousands of individual cases. The supercomputers at the NASA Advanced Supercomputing (NAS) facility, including Pleiades, Electra, and others, serve as the backbone of these efforts. Through careful meshing strategies, solver optimizations, and parallel computing techniques, engineers map out pressure distributions, shear stresses, and load profiles for every relevant component of the booster-core assembly.

These simulation results are not academic exercises—they directly inform the safety and performance of SLS missions. The aerodynamics databases are used by structural engineers to assess bending loads, by guidance and control teams to refine trajectory models, and by separation system designers to ensure that boosters detach cleanly without risking collision with the core. When flight data come in, the models themselves can be validated and refined, closing the loop between simulation and real world performance. As SLS evolves—especially with future variants and heavier payloads—the simulation infrastructure will scale accordingly, enabling continuous improvements in confidence, margin, and mission success.

Video credit: NASA/NAS/Gerrit-Daniel Stich, Michael Barad, Timothy Sandstrom, Derek Dalle

NASA dicit:

​Technicians use massive cranes inside the Vehicle Assembly Building at NASA Kennedy’s Space Center in Florida to lift the fully assembled SLS (Space Launch System) core stage vertically 225-feet above the ground from High Bay 2 to a horizontal position in the facility’s transfer aisle. In the transfer aisle, technicians conducted final preparations of the core stage before it was integrated with the completed twin solid rocket booster segments. NASA is implementing a more efficient stacking process to support future missions to the Moon beginning with the Artemis II test flight.

Video credit: NASA

Wikipedia dicit:

The Space Launch System (SLS) is an American super heavy-lift expendable launch vehicle used by NASA. As the primary launch vehicle of the Artemis Moon landing program, SLS is designed to launch the crewed Orion spacecraft on a trans-lunar trajectory. The first (and so far only) SLS launch was the uncrewed Artemis I, which took place on 16 November 2022.

Development of SLS began in 2011 as a replacement for the retiring Space Shuttle as well as the canceled Ares I and Ares V launch vehicles. SLS was built using existing Shuttle technology, including solid rocket boosters and RS-25 engines. The rocket has been criticized for its political motivations, seen as a way to preserve jobs and contracts for aerospace companies involved in the Shuttle program at great expense to NASA. The project has faced significant challenges, including mismanagement, substantial budget overruns, and significant delays. The first Congressionally mandated launch in late 2016 was delayed by nearly six years.

All Space Launch System flights are to be launched from Launch Complex 39B at the Kennedy Space Center in Florida. The first three SLS flights are expected to use the Block 1 configuration, comprising a core stage, extended Space Shuttle boosters developed for Ares I and the Interim Cryogenic Propulsion Stage (ICPS) upper stage. The improved Block 1B configuration, with the powerful and purpose-built Exploration Upper Stage (EUS), is planned to be introduced on the fourth flight; a further improved Block 2 configuration with new solid rocket boosters is planned for the ninth flight. After the launch of Artemis IV, NASA plans to transfer production and launch operations of SLS to Deep Space Transport LLC, a joint venture between Boeing and Northrop Grumman.

Video credit: NASA

Wikipedia dicit:

The Space Launch System core stage, or simply core stage, is the main stage of the American Space Launch System (SLS) rocket, built by The Boeing Company in the NASA Michoud Assembly Facility. At 65 m (212 ft) tall and 8.4 m (27.6 ft) in diameter, the core stage contains approximately 987 t (2,177,000 lb) of its liquid hydrogen and liquid oxygen cryogenic propellants. Propelled by 4 RS-25 engines, the stage generates approximately 7.44 MN (1,670,000 lbf) of thrust, about 25% of the Space Launch System’s thrust at liftoff, for approximately 500 seconds, propelling the stage alone for the last 375 seconds of flight. The stage lifts the rocket to an altitude of approximately 162 km (531,380 ft) before separating, reentering the atmosphere over the Pacific Ocean.

The core stage originated in 2011, when the architecture of the Space Launch System as a whole was defined. In the aftermath of the end of the Space Shuttle program and the cancellation of its prospective replacement the Constellation program, the SLS emerged, a super-heavy lift launch vehicle intended for human spaceflight to the Moon. The core stage is the first newly-developed stage of the SLS; the ICPS (Interim Cryogenic Propulsion Stage) and five-segment boosters are adaptations of existing hardware, to be replaced by the Exploration Upper Stage and BOLE boosters respectively.

Production of core stages began by 2014, but was beset by numerous difficulties in production and testing which delayed the readiness of the first core stage by several years. The core stage first flew on November 16, 2022, on the Artemis 1 mission, in which it performed successfully. As of 2024, the second core stage is completed, with the third and fourth core stages in production and while work has begun for the fifth and sixth, their production pending the transfer of SLS operations to Deep Space Transport, the vehicle’s future operator.

Video credit: NASA’s Marshall Space Flight Center

Wikipedia dicit:

The Space Launch System (SLS) is an American super heavy-lift expendable launch vehicle used by NASA. As the primary launch vehicle of the Artemis Moon landing program, SLS is designed to launch the crewed Orion spacecraft on a trans-lunar trajectory. The first SLS launch was the uncrewed Artemis 1, which took place on 16 November 2022.

Development of SLS began in 2011, as a replacement for the retired Space Shuttle as well as the cancelled Ares I and Ares V launch vehicles. As a Shuttle-derived vehicle, the SLS reuses hardware from the Shuttle program, including the solid rocket boosters and RS-25 first stage engines. A Congressionally mandated late 2016 launch was delayed by nearly 6 years.

All Space Launch System flights are launched from Launch Complex 39B at the Kennedy Space Center in Florida. The first three SLS flights use the Block 1 configuration, comprising a core stage, extended Space Shuttle boosters developed for Ares I and the ICPS upper stage. An improved Block 1B configuration, with the Exploration Upper Stage, is planned to debut on the fourth flight; a further improved Block 2 configuration featuring new solid rocket boosters is planned to debut on the ninth flight. After the launch of Artemis 4, NASA plans to transfer production and launch operations of SLS to Deep Space Transport LLC, a joint venture between Boeing and Northrop Grumman.

Video credit: NASA’s Marshall Space Flight Center