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Updated January 8, 2021
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 ancient Greek
uncrewed mission tested the crew module’s heat shield and
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 2024.
The first flight of Orion on an SLS is expected in
November 2021. During this mission, known as Artemis I,
Figure 1. The Last Human Lunar Mission: Apollo 17
a complete but uncrewed Orion is to orbit the Moon before
returning to Earth. The mission is intended 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 August 2023. During this 10-day mission,
Orion and its crew of 4 are to fly around the Moon at an
altitude of about 4,000 miles before returning to Earth.
The Artemis III mission, planned for 2024, 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. Detailed plans for Artemis III and subsequent
Artemis missions are not yet finalized.
Figure 2. Major Elements of SLS and Orion
Source: NASA, https://spaceflight.nasa.gov/gal ery/images/apollo/
apollo17/html/as17-134-20382.html.
Note: This image shows Apol o 17 astronaut Harrison Schmitt
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
Source: CRS il ustration based on NASA diagrams at
into space and set it on its initial trajectory. The SLS could
https://www.nasa.gov/exploration/systems/sls/overview.html and
also potentially be used for other missions involving heavy
https://oig.nasa.gov/docs/IG-20-018.pdf.
payloads or requiring very high thrust. It is designed to be
upgraded in stages (known as Block 1, Block 1B, and Block
2) by substituting improved versions of its major elements.
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
2024 landing might affect the availability of funding for
The Orion capsule is not designed to land on the Moon.
other NASA programs; how schedule pressure might
Instead, for Artemis III and subsequent lunar surface
influence safety decisions; and how design choices made to
missions, astronauts will need to transfer to a separate
meet the 2024 deadline might affect system reusability for
spacecraft, known as the Human Landing System (HLS),
subsequent NASA human exploration missions.
for lunar descent and ascent. In April 2020, NASA awarded
fixed-price contracts for the first phase of HLS design and
Cost and Schedule
development to three companies: Blue Origin, Dynetics,
Even among congressional supporters of the Artemis
and SpaceX. Not all companies will necessarily be selected
program and the 2024 goal, concerns remain about cost and
for subsequent development and demonstration contracts.
schedule. For example, in its report on FY2020 NASA
appropriations, the Senate Appropriations Committee
Gateway
wrote: “While there is support for the mission, it is difficult
To facilitate Artemis lunar landings and other missions,
to weigh the impacts of the accelerated mission on the
NASA is developing a modular platform, known as
overall budget of NASA” (S.Rept. 116-127). For FY2021,
Gateway, to be placed in a permanent orbit around the
NASA requested a budget increase of $2.6 billion (about
Moon. The first two Gateway modules—the Power and
12%); enacted FY2021 appropriations provided an increase
Propulsion Element (PPE) and the Habitation and Logistics
of $642 million (less than 3%), with funding for the HLS at
Outpost (HALO, a pressurized habitat for astronauts)—are
about 25% of the requested level. NASA notified Congress
currently in development, with launch planned in 2024.
in August 2020 that cost growth in the development of SLS
will exceed 30%, triggering a reauthorization requirement.
Gateway is intended to serve as a depot for storing supplies,
In addition, repeated slips in the launch dates for Artemis I
a platform for science experiments, a location where
and II—September 2018 and August 2021 in the baseline
subsystems launched separately can be assembled and
plan; currently November 2021 and August 2023—have
integrated, and a rendezvous point where astronauts can
made some policymakers doubt the credibility of the 2024
transfer between Orion and the HLS and potentially, at
schedule for Artemis III.
some point in the future, depart for other, more distant
destinations, such as Mars. NASA initially planned for
Moon or Mars?
Gateway to be the Orion-HLS transfer point for the Artemis
Is returning to the Moon the primary goal for human
III lunar landing in 2024. In March 2020, it announced that
exploration of space, or is it an interim step to gain
Gateway will no longer be essential for that mission, to
experience for future expeditions to Mars? While this
ensure that delays in Gateway development do not
distinction is to some extent a matter of emphasis, the
jeopardize the planned 2024 lunar landing. It did not
debate continues. For example, the NASA Authorization
immediately announce an alternative mission architecture.
Act of 2020 (H.R. 5666, 116th Congress) would have stated
Other Elements
that “the Nation’s human space exploration goal should be
to send humans to the surface of Mars,” although “reducing
In addition to Orion, SLS, HLS, and Gateway, NASA is
the risk and demonstrating the capabilities and operations
planning robotic precursor missions to explore potential
needed to support a human mission to Mars may require
landing sites, as well as developing technologies for lunar
human exploration of the cis-lunar vicinity [i.e., the region
surface power, in situ use of lunar resources such as water,
around the Moon and between Earth and the Moon] and
and other lunar surface systems such as rovers and habitats
lunar surface.” This debate may drive how Artemis
for missions after Artemis III. The detailed profiles of those
missions are planned, e.g., whether lunar habitats are
future missions are not yet fully developed.
designed to be permanent and whether potential reuse for
Issues for Congress
Mars missions is a major factor in technology choices for
lunar missions.
As Congress oversees the progress of the Artemis program
and acts on NASA authorization and appropriations
Role of the Commercial Space Sector
legislation, it may address issues such as the 2024 target
In recent years, NASA has placed growing emphasis on
date for the first landing, cost and schedule concerns, the
procuring services from the commercial space industry. For
relative exploration priority of the Moon versus Mars, and
example, where it used to use NASA-owned space shuttles
the role of the commercial space sector.
to carry cargo and crews to the International Space Station,
Why 2024?
it now buys cargo and crew transport as a commercial
service on commercially owned spacecraft.
As recently as early 2019, NASA was planning the first
post-Apollo human lunar landing for 2028. The acceleration
Orion and the SLS are being developed as NASA-owned
to 2024 was announced by Vice President Pence in March
systems under the traditional model, but NASA intends the
2019. Supporters of the 2024 goal argue that it instils a
HLS to be commercially owned and lunar surface descent
sense of urgency, focus, and motivation, and that the U.S.
and ascent to be a commercial service. Not all policymakers
space program is in competition with Russia and China.
support this approach. For example, H.R. 5666 would have
Opponents argue that the 2024 date is driven by political
directed that the U.S. government should retain “full
goals rather than by technical or scientific considerations.
ownership of the human landing system.”
As Congress considers the schedule for Artemis, it may
Daniel Morgan, Specialist in Science and Technology
examine what geopolitical or other benefits a 2024 landing
Policy
might bring; how providing the funding needed to achieve a
https://crsreports.congress.gov
Artemis: NASA’s Program to Return Humans to the Moon
IF11643
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