SPACE/COSMOS
Artemis: NASA’s Ambitious Program To Return Humans To The Moon – Analysis
Artist’s concept of an Artemis astronaut deploying an instrument on the lunar surface.
Credits: NASA
April 14, 2026
By Rachel Lindbergh
The Congressional Research Service (CRS)
Between 1969 and 1972, the Apollo program of the National Aeronautics and Space Administration (NASA) landed 12 American men on the Moon and returned them safely to Earth. Artemis, named for Apollo’s twin sister in ancient Greek mythology, is NASA’s program for a return to the Moon by American astronauts by 2028.
Orion and the Space Launch System
The Artemis program has evolved from plans initiated in the NASA Authorization Act of 2010 (P.L. 111-267). The act established a statutory goal of “expand[ing] permanent human presence beyond low-Earth orbit” and mandated the development of a crew capsule and a heavy-lift rocket to accomplish that goal. The capsule, now known as Orion, and the rocket, known as the Space Launch System (SLS), have been in development since that time.
Each Orion capsule consists of a crew module with room for four to six astronauts, as well as storage space and a docking port; a service module (contributed by the European Space Agency) to provide power and propulsion; and a launch abort system. The crew module is designed to be reusable and is the only portion intended to return to Earth at the end of a mission.
SLS is an expendable rocket designed to carry Orion into space and set it on an initial trajectory to the Moon. SLS could also be used for other missions involving heavy payloads or requiring very high thrust. As required by P.L. 111-267, SLS was designed to accommodate future upgrades in phases (known as Block 1, Block 1B, and Block 2) to increase its thrust capacity. Similarly, NASA planned to upgrade SLS’s upper stages (i.e., in-space propulsion) by developing what is known as the Exploration Upper Stage.
The first launch of Orion on an SLS was in November 2022. This mission, known as Artemis I, was an uncrewed test flight near the Moon to certify safety for crewed flights. Artemis II, the first crewed test of Orion and SLS, occurred in April 2026. Orion and its crew of four traveled near the Moon before returning to Earth.
In February 2026, the NASA Administrator announced that, after Artemis II, NASA will use a single version of SLS in a “near Block 1 configuration,” rather than upgrading to the Block 1B and Block 2 variants for future missions, in order to reduce complexity and accelerate manufacturing. Rather than developing the Exploration Upper Stage, NASA selected the United Launch Alliance’s Vulcan Centaur V Upper Stage in March 2026. The agency intends to award a sole-source contract, without competition, as NASA determined existing alternatives “fail to meet the performance requirements” or would require significant modifications or development.
Human Landing System
The Orion capsule is not designed to land on the Moon. Instead, astronauts are to transfer to a separate spacecraft, known as a Human Landing System (HLS), for lunar descent and ascent (see Figure 1). NASA selected two HLS providers: SpaceX, using a version of its Starship, and Blue Origin, using its Blue Moon lander. Both systems are still in development. Through committee reports and explanatory statements accompanying appropriations, Congress has repeatedly encouraged NASA to use more than one commercial provider in order to ensure redundancy and bolster competition.
In February 2026, the NASA Administrator announced that the Artemis III mission, to occur in mid-2027, will demonstrate one or both HLSs in low Earth orbit. Next, Artemis IV is to be the first human landing on the Moon since 1972 and is planned to occur by 2028.
In a March 2026 report, the NASA Office of Inspector General (OIG) reported that both HLS providers have faced schedule delays and technical challenges that “have the potential to further impact lander costs and delivery schedules,” particularly for a 2028 lunar landing. NASA is considering proposals from both providers to accelerate development in support of a 2028 lunar landing.
Other Elements
In addition to Orion, SLS, and HLS, NASA procures commercial space transportation services for small robotic missions through its Commercial Lunar Payload Services (CLPS) program; the purpose of these missions is to demonstrate new technologies, explore potential landing sites, and conduct research. Other efforts include commercial procurement of spacesuits and development of lunar surface systems such as rovers.
Lunar Base
In December 2025, President Trump issued Executive Order (E.O.) 14369, “Ensuring American Space Superiority.” The priorities outlined in E.O. 14369 include “establishing initial elements of a permanent lunar outpost by 2030,” as well as developing a nuclear reactor for use on the lunar surface.
In March 2026, the NASA Administrator released the agency’s plan to fulfill E.O. 14369. To establish a lunar base, the agency intends to use a phased approach. Initially, an increased cadence of CLPS missions would deliver initial elements and support research and technology development. In the next phases, the agency intends to progress from recurring lunar astronaut operations to continuous human presence.
As part of this shift, the agency intends to pause development of the Gateway, a modular platform designed to operate in a permanent orbit around the Moon. Gateway was intended to serve as a depot for storing supplies, a platform for science experiments, a location where subsystems launched separately could be assembled and integrated, and a rendezvous point where astronauts could transfer between Orion and HLS. The space agencies of countries such as Canada and Japan had planned to contribute components. In its shift from Gateway to a lunar base, NASA intends to “repurpose applicable equipment and leverage international partner commitments.”
Issues for Congress
As Congress oversees the progress of the Artemis program and acts on NASA authorization and appropriations legislation, it may consider issues such as the architecture of the program, the planned schedule for a 2028 Moon landing, cost concerns for the program as a whole, and the role of the commercial space sector. Congress may consider the potential effects of recently announced changes.
Budget
For FY2027, NASA requested $8.5 billion for Artemis systems, an increase of $731 million compared with FY2026 appropriations. In addition to regular appropriations, Congress provided $6.7 billion for Orion, Gateway, and SLS through the FY2025 reconciliation law (P.L. 119-21), available through FY2032.
Congress may continue to consider the budget of (1) the overall Artemis program, (2) the individual Artemis missions, and (3) the various projects and components within the program. For example, the Government Accountability Office (GAO) estimated in a 2025 report that cost overruns for three major Artemis projects total $6.8 billion. GAO further noted that “growing complexity and scope of future Artemis projects” could negatively impact the agency’s future cost performance, particularly as these projects are interdependent and complex. Thus, Congress may contemplate whether adjustments to the provided funding levels may be necessary (e.g., shift funds from Gateway to the proposed lunar base) or whether to keep funding levels as they are.
Moon to Mars Architecture
Per the NASA Authorization Acts of 2022 and 2017 (P.L. 117-167, Title VII; P.L. 115-10), the Artemis program is a stepping stone for future Mars missions. P.L. 117-167directed the agency to establish a Moon to Mars Office to oversee that approach. Policymakers continue to discuss NASA’s Moon to Mars architecture. Topics of debate include whether the United States should pursue a sustained presence on the Moon; whether future Artemis missions should use SLS and Orion or whether the private sector could provide an alternative; the viability of the agency’s various Artemis components, particularly HLS and SLS; and NASA’s overarching Moon to Mars strategy and its implementation. Congress may also assess the Trump Administration’s announced changes to this architecture.
During the 119th Congress, both the House and Senate have considered NASA authorization bills with differing perspectives on the Artemis architecture. In the House, H.R. 7273, as ordered to be reported, would direct the agency to continue developing major Artemis components and would reemphasize existing statutory requirements. (The markup of H.R. 7273 predated the Administrator’s February 2026 announcement.) In the Senate, S. 933, as ordered to be reported, would permit the Administrator greater flexibility in changing the Artemis architecture.
Role of the Commercial Space Sector
In recent years, NASA has placed growing emphasis on procuring services from the commercial space industry. HLS, CLPS, and other Artemis elements are to be provided as a commercial service. The Trump Administration has supported expanding such efforts in future missions, such as by replacing SLS with commercial transportation services after Artemis V, as proposed in the President’s FY2027 budget request.
In its continued oversight, Congress may assess NASA’s acquisition approaches and the status of these commercial programs, particularly for HLS, which is a key component for future lunar landings. In its 2025 annual report, the Aerospace Safety Advisory Panel (ASAP)—an independent panel that reports to NASA and Congress on the agency’s safety and management—expressed concern that HLS’s complexity and delays “cast doubt” on the timeline and feasibility of the Artemis crewed lunar landing mission.
More broadly, Congress may assess NASA’s use of commercial programs. NASA posits that the use of commercial services will encourage innovation, support the U.S. space industry, and reduce costs for the agency, assuming that commercial providers are able to attract non-NASA investment and customers. Other stakeholders have contended that limited or uncertain markets may hinder the effectiveness of such programs or of certain acquisition approaches. For instance, in its 2024 assessment of CLPS, the NASA OIG found that the agency relied on “overly optimistic” market assessments in selecting contracting approaches and schedules, leading to “cost increases and schedule delays” due to technical difficulties and “continuing market uncertainty.”
Source: This article was published by the Congressional Research Service (CRS)
The Congressional Research Service (CRS) works exclusively for the United States Congress, providing policy and legal analysis to committees and Members of both the House and Senate, regardless of party affiliation. As a legislative branch agency within the Library of Congress, CRS has been a valued and respected resource on Capitol Hill for nearly a century.
Starquakes and the archaeology of stellar magnetism
ISTA team presents theoretical evidence for ‘fossilized’ magnetism in stars
image:
How the evolution of a star changes the shape of a magnetic field. Rather than being centered at one point, the ISTA team’s simulations suggest that magnetic fields can form shell‑like structures (pink field lines).
view moreCredit: © Lukas Einramhof | ISTA
New theoretical models, published in Astronomy & Astrophysics, connect, for the first time, the magnetism at the surface of long-dead stellar remnants (white dwarfs) with recent evidence of magnetism at the cores of their dying progenitors (red giants). The team, led by astrophysicists at the Institute of Science and Technology Austria (ISTA), argues that these magnetic fields might originate early in the stars’ lives, and survive their entire evolution, emerging as ‘fossil fields’ at the surfaces of older remnants. A better understanding of these processes can also help to better understand our own Sun’s future.
For thousands of years, human civilizations have looked to the stars with a blend of curiosity and reverence. From a human perspective, these twinkling dots in the sky seem to shine eternally. However, while stars live for billions of years, their evolution is also marked by major events. While some die in a spectacular display of cosmic fireworks called supernovae, others retreat and cool down quietly, leaving behind a dead remnant called a white dwarf.
Using a theoretical model, an international team—led by PhD student Lukas Einramhof and Assistant Professor Lisa Bugnet at the Institute of Science and Technology Austria (ISTA)—links independent observations collected at different stages of stellar evolution. For the first time, they connect the evidence of magnetic fields reaching the surface of older white dwarfs to recent findings of magnetism in the cores of red giants—the dying progenitors of those remnants. Central to their model is the idea that magnetic fields formed early in a star’s life can persist through all later stages, emerging at the surfaces of white dwarfs as “fossil fields” billions of years later. By incorporating recent asteroseismic data—measurements of stellar oscillations or “starquakes”—the team revisits the fossil field theory as a possible explanation for stellar magnetism.
Long-dead, and suddenly magnetic?
Magnetic fields at the surface of white dwarfs provide astrophysicists with valuable information about the remnants’ past. “The magnetic field in a star is important for how the star works on the inside and how long it lives and evolves. Generally, more of the older white dwarfs tend to be more magnetic than younger white dwarfs,” says Einramhof. Therefore, to explain where the magnetic fields at the surface of older white dwarfs—dead several million years earlier—come from, scientists must dig deeper into the remnants’ past lives.
So far, several teams of researchers have been examining the magnetic fields of stars at different points of their stellar evolution. The ISTA team now seeks to connect these dots to clarify the processes underlying the evolution of the stars and their remnants. “As a theoretical astrophysics group, we develop theories to explain observations,” Bugnet underlines.
Starquakes uncover buried magnetic fields
With asteroseismology—the study of starquakes—astronomers have only recently been able to probe the depths of red giants, the progenitors of white dwarfs. Similar to earthquakes, starquakes are natural phenomena that allow scientists to obtain measurements of the insides of stars.
The observations, carried out independently by different groups, show contrasting pictures. On the one hand, magnetic fields have been detected at the surface of older white dwarfs, suggesting that these might eventually reach the surface from within as the remnant evolves. On the other hand, observations on the ‘dying’ red giants using asteroseismology have provided evidence of the presence of magnetic fields at the cores of these progenitors of white dwarfs, several million years earlier in a star’s evolutionary path. Using these observations to constrain their theoretical model, the ISTA team demonstrates that these two time points in a star’s lifetime can be connected using a theory that had fallen out of fashion over the past decade in the white dwarf community: the fossil field scenario.
Einramhof explains, “Because a white dwarf is the exposed core of a red giant that has shed its outer layers, these different observations essentially examine the same region of a star’s interior at different evolutionary stages.” Therefore, after a red giant sheds its outer layers, its white dwarf remnant will display distinctive properties at its surface.
He adds, “If the magnetic field observed during the red giant phase is the same as the one that evolves to be observed at the surface of the white dwarf, then the fossil field theory can explain and connect the observations.” However, the team argues that this magnetic field must originate even earlier, before the red giant phase.
Magneto-archaeology: digging into the stars’ past
By revisiting the fossil field scenario with new insights, the team made several key findings about the archaeology of magnetism in stars. First, they showed that the extent of magnetism within the core of the red giant progenitor is key. “To connect the magnetic fields observed at the surface of older white dwarfs with the ones found at the core of their red giant progenitors, a larger fraction of the star must be magnetized,” says Einramhof. “However, this doesn’t mean the stars are more strongly magnetized, only that the magnetic fields must already reach a larger portion of their core.”
Furthermore, their methodology allowed them to uncover how the evolution of a star changes the shape of a magnetic field. Rather than being centered at one point, their simulations suggest that magnetic fields can form shell‑like structures—resembling the surface of a basketball—where the field is strongest near the shell rather than at the core.
Blind at the core: what if the Sun’s core is also magnetic?
Ultimately, the team’s goal is to better understand how the Sun will evolve. As a 4.6-billion-year-old main-sequence star, the Sun is midway through its expected lifetime in this phase before evolving into a red giant and likely engulfing Earth. “We still don’t know whether the Sun’s core is magnetic. Even though it’s our own star, we’re practically blind to what happens at its center,” says Einramhof. “Current predictions assume that the Sun’s core is not magnetic. But if it turns out to be, this information would change everything we know and all the models we’ve based our work on.”
During their longest-lived phase, called the main sequence, stars remain stable until they run out of core hydrogen ‘fuel’ and can no longer sustain the fusion process. When this internal mechanism fails, they puff up and evolve into red giants. “If the Sun can somehow bring hydrogen from its outer layers into its core, it would be able to live longer. One way to do this would be through strong magnetic fields,” says Einramhof. However, the magnetic fields might also lead to a very different outcome. “We know that magnetic fields can significantly affect a star’s evolution. But we still don’t know exactly how they influence stellar evolution or how strong their effects are.”
The ISTA team’s findings help reestablish the fossil field theory as a plausible mechanism for the evolution of stellar magnetic fields. However, other questions remain unanswered. “Given how little we know at this stage, our work suggests that stars are most likely all magnetic. But we can’t always detect this magnetism,” Einramhof concludes.
Journal
Astronomy and Astrophysics
Method of Research
Computational simulation/modeling
Subject of Research
Not applicable
Article Title
Magneto-Archeology of White Dwarfs. Revisiting the fossil field scenario with observational constraints during the red giant branch.
Article Publication Date
14-Apr-2026
Rice researchers find sulfur-rich Mercury magmas behave differently than Earth’s
Sulfur reshapes interior evolution and crust formation on Mercury
image:
A sample of Mercury rock created in the lab
view moreCredit: Jared Jones/Rice University
Mercury is a small, rocky planet about which researchers know relatively little. Two missions, taking readings as they passed over the planet, have revealed that Mercury is covered by an iron-poor and sulfur-rich crust. It is also reduced, a chemical state in which the substances have gained electrons. In fact, it’s the most reduced planet in the solar system.
“Mercury’s surface looks completely different than Earth’s,” said Rajdeep Dasgupta, the Maurice Ewing Professor in Earth Systems Science and director of the Rice Space Institute Center for Planetary Origins to Habitability. “We couldn’t study its magmatic evolution using assumptions built off our understanding of Earth, and missions data are difficult to interpret. We had to find ways to bring the planet closer to our lab — specifically, through the meteorite Indarch.”
Indarch, a meteorite that landed in Azerbaijan in 1891, looks very similar to the chemical makeup of Mercury. The researchers realized they could use Indarch to study how Mercury’s unique chemical makeup had shaped the planet, sharing their results in a recent publication.
“Indarch chemically is as reduced as rocks on Mercury,” said Yishen Zhang, a postdoctoral researcher in Dasgupta’s lab and first author on the paper. “It is believed to be a possible building block of the planet,”
Zhang used a model melt composition of Indarch to cook his own Mercury rocks in a high-pressure, high-temperature facility. The process was fairly simple: mix Indarch’s chemical ingredients together in a small glass vial, change the settings in the facility to match the conditions on Mercury, add in the chemicals and cook.
“This process of cooking a rock can show us what happened chemically inside of Mercury,” Zhang said. “By using the temperature, pressure and chemical constraints derived from spacecraft observations and models, we recreate Mercurylike conditions to understand how magmas form and evolve there — even without direct samples from the planet.”
What Zhang found is that sulfur lowers the temperature at which these reduced melted rocks begin to crystallize. That means sulfur-rich magmas on Mercury may stay molten at lower temperatures than similar magmas on Earth. The reason for this significantly decreased crystallization temperature, Zhang found, is because of Mercury’s unique chemical composition: low iron, high sulfur and the chemically reduced state.
Sulfur is a promiscuous element — it likes to be bound to other elements, usually iron. Iron-rich planets like Mars and Earth have most of their sulfur bound to iron. Mercury’s low iron content, however, meant that its sulfur was looking for new binding partners. Specifically, it could bind to major rock-forming elements like magnesium and calcium.
On Earth, these rock-forming elements would typically bind to oxygen, resulting in a stable structure called a silicate network made up of silicon, oxygen and rock-forming elements. When sulfur replaces oxygen, however, that network becomes weaker and crystalizes at a lower temperature.
“As Indarch may represent Mercury’s proto-planet state,” Zhang said, “these experiments show that Mercury likely formed with sulfur occupying a structural position that on Earth belongs to oxygen. This fundamentally changes how the planet’s mantle solidified.”
“This is a fascinating glimpse of how Mercury may have evolved as a planet to its unique current-day surface chemistry,” Dasgupta said. “More importantly, it provides a way for us to think about planets not based on how Earth was formed, but based on their own unique chemistry and magmatic processes under vastly different conditions. What water or carbon does to magmatic evolution of Earth, sulfur does on Mercury.”
This work was supported by NASA grants (80NSSC18K0828 and 80NSSC24K0988) and by the Rice Space Institute Center for Planetary Origins to Habitability.
The chemical mixture cooked to create Mercury rocks
Credit
Jared Jones/Rice University
Journal
Geochimica et Cosmochimica Acta
Method of Research
Experimental study
Article Title
The effects of sulfur on near-liquidus phase relations of highly reduced basaltic melts with implications for magmatism in Mercury
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