Artemis: NASA’s Program to Return Humans to the Moon
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Updated February 8, 2024
Artemis: NASA’s Program to Return Humans to the Moon
Between 1969 and 1972, the Apollo program of the
Exploration Upper Stage to replace the Block 1 upper stage,
National Aeronautics and Space Administration (NASA)
which is known as the Interim Cryogenic Propulsion Stage.
landed 12 American men on the Moon and returned them
In December 2014, a partially complete Orion was
safely to Earth (see Figure 1). Since then, no human has
launched on a Delta IV Heavy rocket and orbited Earth
been farther from Earth than low-Earth orbit, a few hundred
twice before splashing down in the Pacific Ocean. This
miles up; the distance to the Moon is about 240,000 miles.
Artemis, named for Apollo’s twin sister in anc
uncrewed mission tested the crew module’s heat shield and
ient Greek
mythology, is NASA’s program for a return to the Moon by
parachutes, as well as other systems.
American astronauts—one of them a woman—in 2026.
The first launch of Orion on an SLS was in November
2022. During this mission, known as Artemis I, a complete
Figure 1. The Last Human Lunar Mission: Apollo 17
but uncrewed Orion orbited the Moon before returning to
Earth. The mission was designed to provide the data NASA
needs to certify safety for crewed flights.
Artemis II, the first crewed test of Orion and the SLS, is
expected in 2025. During this 10-day mission, Orion and its
crew of four are to fly around the Moon at an altitude of
about 4,000 miles before returning to Earth.
The Artemis III mission, planned for 2026, is to include the
first human Moon landing since 1972. Achieving that goal
would require the development of other systems, such as a
lunar lander.
Subsequent Artemis missions, with more lunar landings and
various additional capabilities, are planned approximately
Source: NASA, https://spaceflight.nasa.gov/gal ery/images/apollo/
every year starting in 2028.
apollo17/html/as17-134-20382.html.
Note: This image shows Apol o 17 astronaut Harrison Schmitt
Figure 2. Major Elements of SLS and Orion
standing on the surface of the Moon on December 13, 1972. Behind
him are the Lunar Module lander and the Lunar Roving Vehicle rover.
Orion and the Space Launch System
Artemis 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 then (see Figure 2).
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 the only
portion intended to return to Earth at the end of a mission; it
is designed to be reusable.
The SLS is an expendable rocket designed to carry Orion
into space and set it on its initial trajectory. The SLS could
also potentially be used for other missions involving heavy
payloads or requiring very high thrust. It is designed to be
Source: CRS il ustration based on NASA diagrams at
upgraded in stages (known as Block 1, Block 1B, and Block
https://www.nasa.gov/exploration/systems/sls/overview.html and
2) by substituting improved versions of its major elements.
https://oig.nasa.gov/docs/IG-20-018.pdf.
For example, for Block 1B, NASA is developing the
https://crsreports.congress.gov
Artemis: NASA’s Program to Return Humans to the Moon
Human Landing System
affect system reusability for subsequent NASA human
The Orion capsule is not designed to land on the Moon.
exploration missions.
Instead, for Artemis III and subsequent lunar surface
NASA’s schedule for Artemis III (and subsequent Artemis
missions, astronauts will need to transfer to a separate
missions) has since slipped several times, less due to these
spacecraft, known as a Human Landing System (HLS), for
policy debates than to development challenges. As of
lunar descent and ascent. In April 2021, NASA selected
January 2024, the estimated Artemis III launch date is
SpaceX to provide an HLS as a commercial service starting
September 2026.
with Artemis III. In May 2023, it awarded a second HLS
contract to Blue Origin to provide an alternative to the
Budget
SpaceX system starting with Artemis V (planned for 2029).
According to GAO, as of January 2024
Both systems are still in development.
NASA has not yet prepared an estimate of how
Gateway
much the Artemis III mission—or subsequent
To facilitate Artemis lunar landings and other missions,
Artemis missions—are likely to cost. Similarly, it
NASA is developing a modular platform, known as
does not plan to measure the production costs for
Gateway, to be placed in a permanent orbit around the
the SLS rockets that constitute a significant
Moon. The first two Gateway modules—the Power and
proportion of future Artemis-related costs.
Propulsion Element (PPE) and the Habitation and Logistics
Outpost (HALO, a pressurized habitat for astronauts)—are
Absent more information on long-term costs, Congress
currently in development, with launch planned in 2026.
typically makes budget decisions on an annual basis. The
FY2024 request for Artemis systems is $8.0 billion.
Gateway is intended to serve as a depot for storing supplies,
a platform for science experiments, a location where
Moon or Mars?
subsystems launched separately can be assembled and
Is returning to the Moon the primary goal for human space
integrated, and a rendezvous point where astronauts can
exploration, or is it an interim step to gain experience for
transfer between Orion and the HLS and potentially, at
future expeditions to Mars? While this distinction is to
some point in the future, depart for Mars. NASA initially
some extent a matter of emphasis, the debate continues. For
planned for Gateway to be the Orion-HLS transfer point for
example, the NASA Authorization Act of 2020 (H.R. 5666,
the Artemis III lunar landing. It is no longer part of the
116th Congress) would have stated that “the Nation’s human
plans for Artemis III, but it is to be used for subsequent
space exploration goal should be to send humans to the
missions starting with Artemis IV (planned for 2028).
surface of Mars,” although “reducing the risk and
Other Elements
demonstrating the capabilities and operations needed to
support a human mission to Mars may require human
In addition to Orion, SLS, HLS, and Gateway, NASA is
exploration of the cis-lunar vicinity [i.e., the region around
planning robotic missions to demonstrate new technologies
the Moon and between Earth and the Moon] and lunar
and explore potential landing sites, developing new
surface.” This debate may drive how Artemis missions are
spacesuits, and developing technologies for lunar surface
planned, e.g., whether lunar habitats are designed to be
power, in situ use of lunar resources such as water, and
permanent and whether potential reuse for Mars missions is
other lunar surface systems such as rovers and habitats for
a major factor in technology choices for lunar missions.
missions after Artemis III.
Issues for Congress
Role of the Commercial Space Sector
In recent years, NASA has placed growing emphasis on
As Congress oversees the progress of the Artemis program
procuring services from the commercial space industry. For
and acts on NASA authorization and appropriations
example, where it used to use NASA-owned space shuttles
legislation, it may address issues such as the schedule for
to carry cargo and crews to the International Space Station,
the first landing, cost concerns for the program as a whole,
it now buys cargo and crew transport as a commercial
the relative exploration priority of the Moon versus Mars,
service on commercially owned spacecraft.
and the role of the commercial space sector.
Orion and the SLS are being developed as NASA-owned
Schedule
systems, but the HLS is to be provided as a commercial
As recently as early 2019, NASA was planning the first
service, and several Artemis-related robotic missions are
post-Apollo human lunar landing for 2028. An acceleration
being conducted through the Commercial Lunar Payload
to 2024 was announced by Vice President Pence in March
Services (CLPS) initiative. Not all stakeholders support the
2019. Supporters of the 2024 goal argued that it instilled a
commercial approach. For example, in January 2024,
sense of urgency, focus, and motivation, and that the U.S.
former NASA Administrator Michael D. Griffin testified
space program is in competition with Russia and China.
that the emphasis on commercial services is “the
Opponents argued that the 2024 date was driven by political
fundamental flaw in the Artemis acquisition approach.” The
goals rather than by technical or scientific considerations.
NASA Authorization Act of 2022 directed that Artemis
Congress deliberated questions such as what geopolitical or
human landing missions are to be “carried out solely by
other benefits a 2024 landing might bring; how providing
government astronauts” (P.L. 117-167, Section 10811).
the funding needed to achieve a 2024 landing might affect
the availability of funding for other NASA programs; how
Daniel Morgan, Specialist in Science and Technology
schedule pressure might influence safety decisions; and
Policy
how design choices made to meet the 2024 deadline might
https://crsreports.congress.gov
Artemis: NASA’s Program to Return Humans to the Moon
IF11643
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has
been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the
United States Government, are not subject to copyright protection in the United States. Any CRS Report may be
reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include
copyrighted images or material from a third party, you may need to obtain the permission of the copyright holder if you
wish to copy or otherwise use copyrighted material.
https://crsreports.congress.gov | IF11643 · VERSION 10 · UPDATED
Updated February 8, 2024
Artemis: NASA’s Program to Return Humans to the Moon
Between 1969 and 1972, the Apollo program of the
Exploration Upper Stage to replace the Block 1 upper stage,
National Aeronautics and Space Administration (NASA)
which is known as the Interim Cryogenic Propulsion Stage.
landed 12 American men on the Moon and returned them
In December 2014, a partially complete Orion was
safely to Earth (see Figure 1). Since then, no human has
launched on a Delta IV Heavy rocket and orbited Earth
been farther from Earth than low-Earth orbit, a few hundred
twice before splashing down in the Pacific Ocean. This
miles up; the distance to the Moon is about 240,000 miles.
Artemis, named for Apollo’s twin sister in anc
uncrewed mission tested the crew module’s heat shield and
ient Greek
mythology, is NASA’s program for a return to the Moon by
parachutes, as well as other systems.
American astronauts—one of them a woman—in 2026.
The first launch of Orion on an SLS was in November
2022. During this mission, known as Artemis I, a complete
Figure 1. The Last Human Lunar Mission: Apollo 17
but uncrewed Orion orbited the Moon before returning to
Earth. The mission was designed to provide the data NASA
needs to certify safety for crewed flights.
Artemis II, the first crewed test of Orion and the SLS, is
expected in 2025. During this 10-day mission, Orion and its
crew of four are to fly around the Moon at an altitude of
about 4,000 miles before returning to Earth.
The Artemis III mission, planned for 2026, is to include the
first human Moon landing since 1972. Achieving that goal
would require the development of other systems, such as a
lunar lander.
Subsequent Artemis missions, with more lunar landings and
various additional capabilities, are planned approximately
Source: NASA, https://spaceflight.nasa.gov/gal ery/images/apollo/
every year starting in 2028.
apollo17/html/as17-134-20382.html.
Note: This image shows Apol o 17 astronaut Harrison Schmitt
Figure 2. Major Elements of SLS and Orion
standing on the surface of the Moon on December 13, 1972. Behind
him are the Lunar Module lander and the Lunar Roving Vehicle rover.
Orion and the Space Launch System
Artemis 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 then (see Figure 2).
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 the only
portion intended to return to Earth at the end of a mission; it
is designed to be reusable.
The SLS is an expendable rocket designed to carry Orion
into space and set it on its initial trajectory. The SLS could
also potentially be used for other missions involving heavy
payloads or requiring very high thrust. It is designed to be
Source: CRS il ustration based on NASA diagrams at
upgraded in stages (known as Block 1, Block 1B, and Block
https://www.nasa.gov/exploration/systems/sls/overview.html and
2) by substituting improved versions of its major elements.
https://oig.nasa.gov/docs/IG-20-018.pdf.
For example, for Block 1B, NASA is developing the
https://crsreports.congress.gov
Artemis: NASA’s Program to Return Humans to the Moon
Human Landing System
affect system reusability for subsequent NASA human
The Orion capsule is not designed to land on the Moon.
exploration missions.
Instead, for Artemis III and subsequent lunar surface
NASA’s schedule for Artemis III (and subsequent Artemis
missions, astronauts will need to transfer to a separate
missions) has since slipped several times, less due to these
spacecraft, known as a Human Landing System (HLS), for
policy debates than to development challenges. As of
lunar descent and ascent. In April 2021, NASA selected
January 2024, the estimated Artemis III launch date is
SpaceX to provide an HLS as a commercial service starting
September 2026.
with Artemis III. In May 2023, it awarded a second HLS
contract to Blue Origin to provide an alternative to the
Budget
SpaceX system starting with Artemis V (planned for 2029).
According to GAO, as of January 2024
Both systems are still in development.
NASA has not yet prepared an estimate of how
Gateway
much the Artemis III mission—or subsequent
To facilitate Artemis lunar landings and other missions,
Artemis missions—are likely to cost. Similarly, it
NASA is developing a modular platform, known as
does not plan to measure the production costs for
Gateway, to be placed in a permanent orbit around the
the SLS rockets that constitute a significant
Moon. The first two Gateway modules—the Power and
proportion of future Artemis-related costs.
Propulsion Element (PPE) and the Habitation and Logistics
Outpost (HALO, a pressurized habitat for astronauts)—are
Absent more information on long-term costs, Congress
currently in development, with launch planned in 2026.
typically makes budget decisions on an annual basis. The
FY2024 request for Artemis systems is $8.0 billion.
Gateway is intended to serve as a depot for storing supplies,
a platform for science experiments, a location where
Moon or Mars?
subsystems launched separately can be assembled and
Is returning to the Moon the primary goal for human space
integrated, and a rendezvous point where astronauts can
exploration, or is it an interim step to gain experience for
transfer between Orion and the HLS and potentially, at
future expeditions to Mars? While this distinction is to
some point in the future, depart for Mars. NASA initially
some extent a matter of emphasis, the debate continues. For
planned for Gateway to be the Orion-HLS transfer point for
example, the NASA Authorization Act of 2020 (H.R. 5666,
the Artemis III lunar landing. It is no longer part of the
116th Congress) would have stated that “the Nation’s human
plans for Artemis III, but it is to be used for subsequent
space exploration goal should be to send humans to the
missions starting with Artemis IV (planned for 2028).
surface of Mars,” although “reducing the risk and
Other Elements
demonstrating the capabilities and operations needed to
support a human mission to Mars may require human
In addition to Orion, SLS, HLS, and Gateway, NASA is
exploration of the cis-lunar vicinity [i.e., the region around
planning robotic missions to demonstrate new technologies
the Moon and between Earth and the Moon] and lunar
and explore potential landing sites, developing new
surface.” This debate may drive how Artemis missions are
spacesuits, and developing technologies for lunar surface
planned, e.g., whether lunar habitats are designed to be
power, in situ use of lunar resources such as water, and
permanent and whether potential reuse for Mars missions is
other lunar surface systems such as rovers and habitats for
a major factor in technology choices for lunar missions.
missions after Artemis III.
Issues for Congress
Role of the Commercial Space Sector
In recent years, NASA has placed growing emphasis on
As Congress oversees the progress of the Artemis program
procuring services from the commercial space industry. For
and acts on NASA authorization and appropriations
example, where it used to use NASA-owned space shuttles
legislation, it may address issues such as the schedule for
to carry cargo and crews to the International Space Station,
the first landing, cost concerns for the program as a whole,
it now buys cargo and crew transport as a commercial
the relative exploration priority of the Moon versus Mars,
service on commercially owned spacecraft.
and the role of the commercial space sector.
Orion and the SLS are being developed as NASA-owned
Schedule
systems, but the HLS is to be provided as a commercial
As recently as early 2019, NASA was planning the first
service, and several Artemis-related robotic missions are
post-Apollo human lunar landing for 2028. An acceleration
being conducted through the Commercial Lunar Payload
to 2024 was announced by Vice President Pence in March
Services (CLPS) initiative. Not all stakeholders support the
2019. Supporters of the 2024 goal argued that it instilled a
commercial approach. For example, in January 2024,
sense of urgency, focus, and motivation, and that the U.S.
former NASA Administrator Michael D. Griffin testified
space program is in competition with Russia and China.
that the emphasis on commercial services is “the
Opponents argued that the 2024 date was driven by political
fundamental flaw in the Artemis acquisition approach.” The
goals rather than by technical or scientific considerations.
NASA Authorization Act of 2022 directed that Artemis
Congress deliberated questions such as what geopolitical or
human landing missions are to be “carried out solely by
other benefits a 2024 landing might bring; how providing
government astronauts” (P.L. 117-167, Section 10811).
the funding needed to achieve a 2024 landing might affect
the availability of funding for other NASA programs; how
Daniel Morgan, Specialist in Science and Technology
schedule pressure might influence safety decisions; and
Policy
how design choices made to meet the 2024 deadline might
https://crsreports.congress.gov
Artemis: NASA’s Program to Return Humans to the Moon
IF11643
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has
been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the
United States Government, are not subject to copyright protection in the United States. Any CRS Report may be
reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include
copyrighted images or material from a third party, you may need to obtain the permission of the copyright holder if you
wish to copy or otherwise use copyrighted material.
https://crsreports.congress.gov | IF11643 · VERSION 10 · UPDATED