Amid the pantheon of Greek gods, few are more revered than Artemis, Goddess of the hunt, chastity, and the moon; Mistress of Animals, Daughter of Zeus and twin sister to Apollo. Famed for her pledge to never marry, feared from that time she turned the peeping Acteon into a stag and set his own hunting dogs upon him, Artemis has stood as a feminist icon for millenia. It seems only fitting then that NASA names after her a trailblazing mission that will see both the first woman and first person of color set foot on the moon, ahead of humanity’s first off-planet colony.

In fact, NASA has been naming its missions after Zeus’ progeny since the advent of spaceflight. There was the Mercury Program (the Roman spelling of Hermes) in 1958, then Gemini in ‘68 followed by Apollo in ‘73. NASA took a quick break on the naming convention during the Shuttle era but revived it when it formally established the Artemis program in 2017. Working with the European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA), Canadian Space Agency (CSA), and a slew of private corporations, NASA’s goal for Artemis is simple: to re-establish a human foothold on the moon for the first time since 1972, and stay there.

NASA is building a coalition of partnerships with industry, nations and academia that will help us get to the moon quickly and sustainably, together,” then-NASA director Jim Bridenstine said in 2020. “Our work to catalyze the US space economy with public-private partnerships has made it possible to accomplish more than ever before. The budget we need to achieve everything laid out in this plan represents bipartisan support from the Congress.”

“Under the Artemis program, humanity will explore regions of the moon never visited before, uniting people around the unknown, the never seen, and the once impossible,” he continued. “We will return to the moon robotically beginning next year, send astronauts to the surface within four years, and build a long-term presence on the Moon by the end of the decade.”

CAPE CANAVERAL, FLORIDA - NOVEMBER 16: NASA’s Artemis I Space Launch System (SLS) rocket, with the Orion capsule attached, launches at NASA's Kennedy Space Center on November 16, 2022 in Cape Canaveral, Florida. The Artemis I mission will send the uncrewed spacecraft around the moon to test the vehicle's propulsion, navigation and power systems as a precursor to later crewed mission to the lunar surface. (Photo by Red Huber/Getty Images)
Red Huber via Getty Images

Just as Artemis the Goddess grew out of earlier pre-Hellenistic mythology, Artemis the Program was born from the ashes of the earlier Constellation program from the early 2000s which sought to land on the moon by 2020 — specifically the Ares I, Ares V, and Orion Crew Exploration Vehicle that were developed as part of that effort. In 2010, then-President Barack Obama announced that the non-Orion bits of Constellation were being axed and simultaneously called for $6 billion in additional funding as well as the development of a new heavy lift rocket program with a goal of putting humans on Mars by the mid-2030s. This became the NASA Authorization Act of 2010 and formally kicked off development of the Space Launch System, the most powerful rocket NASA has built to date.

The Artemis program was helped further in December of 2017 when former President Donald Trump signed Space Policy Directive 1 (SPD 1). That policy change, “provides for a US-led, integrated program with private sector partners for a human return to the moon, followed by missions to Mars and beyond” and authorized the campaign that would become Artemis two years later. In 2019, then-Vice President Mike Pence announced that the program’s goals were accelerating, the moon landing goal pushed up four years to 2024 though its original goal of Mars in the 2030s remained unchanged.

“The directive I am signing today will refocus America’s space program on human exploration and discovery,” Trump said at the time. “It marks a first step in returning American astronauts to the moon for the first time since 1972, for long-term exploration and use. This time, we will not only plant our flag and leave our footprints — we will establish a foundation for an eventual mission to Mars, and perhaps someday, to many worlds beyond.”

Bang, zoom, straight to the moon

a diagram of how the Artemis missions will approach the moon
NASA

Now, we know NASA can put people on the moon — it’s the keeping them there, alive, that’s the issue. The moon, for all its tide-inducing benefits here on Earth, is generally inhospitable to life, what with its general lack of breathable atmosphere and liquid water, weak gravity, massive temperature swings and razor-sharp, statically-charged dust. The first colonists will need power, heat, atmosphere, potable water — all of which will have to either be brought from Earth or extracted locally from the surrounding regolith.

Complicating matters, the Moon, at 230,000 miles away, is about a thousand times farther than the International Space Station, and getting a crew with everything they need to survive for more than a few days is going to require multiple trips — not just from Earth orbit to the moon but also from lunar orbit down to the surface and back. But high-risk, high-reward logistical nightmares are kind of NASA’s whole deal.

As such, the Artemis program is split between the SLS missions, which will eventually bring the human crew to the moon, and the support missions, which will bring everything else. That includes robotic rovers, the Human Landing System, as well as moonbase and Gateway components along with all of the logistical support and infrastructure that they will require.

Artemis SLS missions

The SLS missions are built around NASA’s new Deep Space Exploration System, which comprises the SLS super heavy-lift launch vehicle, the Orion Spacecraft and the Exploration Ground Systems at Kennedy Space Center (KSC).

Artemis 1 moon sequence
NASA

NASA’s deep space exploration system

The Space Launch System is the single most powerful rocket humanity has built and, given its modular, evolvable design, will likely continue to be for the foreseeable future. Its initial configuration, dubbed Block 1, consists of just the core stage with four RS-25 engines and two, five-segment solid rocket boosters. Once the SLS breaks atmosphere, its Interim Cryogenic Propulsion Stage takes over for in-space propulsion.

Those RS-25’s are the same engines that flew on the Space Shuttle. Aerojet Rocketdyne of Sacramento, California is updating and upgrading 16 of them for use in the modern era — bringing them up to standard for use with the SLS — with a new engine controller, new nozzle insulation, and 512,000 pounds of thrust. Altogether, the core stage will produce 8.8 million pounds of thrust and be capable of pushing 27 metric tons (22,000 sqft) of cargo out to the moon at speeds in excess of 24,500 miles per hour. The Artemis 1 mission that launched in November, as well as the next two Artemis missions, are slash will be powered by Block 1 rockets.

SLS Block builds
NASA

Block 1B rockets will include an Exploration Upper Stage (EUS) built by Boeing and composed of “four RL10C-3 engines that produce almost four times more thrust than the one RL10B-2 engine that powers the ICPS,” per NASA. That additional engine will enable the space agency to haul 38 tons of cargo out of Earth’s gravity well. This updated block will provide NASA a bit more flexibility in its launches. A 1B rocket can be configured to lift the Orion spacecraft or cargo loads into deep space as easily as it can be for hauling large cargoes to the moon or Mars. NASA plans to lift unwieldy portions of the moonbase and Gateway into space with it.

The SLS’ final form (for now) will be Block 2. Standing more than 30 stories tall, weighing the equivalent of 10 fully-loaded 747’s, the block 2 blasting 9.2 million pounds of thrust (20 percent more than the Saturn V) to push 46 metric tons of stuff (taking up as much as 54,000 square feet) into deep space. Once that configuration comes online, NASA expects it to take on much of the heavy lifting (sorry not sorry) in delivering crews and cargo to the moon.

Orion spacecraft

Riding atop the SLS’s multi-ton controlled explosions is the Orion Spacecraft, the first crew capsule designed for deep space exploration in more than a generation. Designed and built with help from the ESA, the Orion sandwiches a four-person crew cabin in between a services module that holds all of the important life support, navigation and propulsion systems, and a Launch Abort System (LAS) that will forcibly eject the crew capsule from the larger launch vehicle if a catastrophic failure occurs during takeoff.

The 50-foot tall LAS weighs 16,000 pounds and is designed to engage within milliseconds of a launch going sideways, lifting the crew cabin away from the rest of the SLS at Mach 1.2 using the 400,000 pounds of thrust produced by the abort motor. Its attitude control motor provides another 7,000 pounds of thrust to keep the capsule upright during escape while the jettison motor will separate the LAS from the cabin once clear, the latter deploying a parachute ahead of its upcoming water landing.

The LAS actually predates Orion by four years. The LAS was first integrated into a Delta IV and flown at the White Sands test facility in New Mexico in 2010 while the (uncrewed) Orion Exploration Flight Test-1 didn’t take off for its four-hour, two orbit jaunt until 2014.

The Orion main cabin is just under 16 feet tall and just over 16 feet in diameter. Its four wing solar array produces 11kW of power and the attached service module holds enough air and water to keep the crew alive, if a bit panicked and sir-crazy, for up to three weeks.

Exploration ground systems

CAPE CANAVERAL, FL - NOVEMBER 3: In this handout photo provided by NASA, NASAs Space Launch System (SLS) rocket with the Orion spacecraft aboard is seen atop the mobile launcher as Crawler Transporter-2 (CT-2) begins to climb the ramp at Launch Pad 39B at NASAs Kennedy Space Center on November 3, 2022 in Cape Canaveral, Florida. NASA's Artemis I mission is the first integrated test of the agency's deep space exploration systems: the Orion spacecraft, SLS rocket, and supporting ground systems. Launch of the uncrewed flight test is targeted for November 14 at 12:07 a.m. EST. (Photo by Joel Kowsky/NASA via Getty Images)
Handout via Getty Images

Located at the Kennedy Space Center in Florida, the Artemis program’s Exploration Ground Systems (EGS) is tasked with developing and enacting the facilities and operations necessary to conduct SLS missions. That includes the Vehicle Assembly Building, the Launch Control Center, the Firing Rooms, Mobile Launchers 1 and 2, the Crawlers that haul rockets out to the launchpads, and also the launchpads — specifically Launch Pad 39B. Teams have been working to modernize many of those facilities and NASA notes that it, “has successfully upgraded its processes, facilities, and ground support equipment to safely handle rockets and spacecraft during assembly, transport, and launch.”

NASA already has five main Artemis launches scheduled. The uncrewed Artemis I, again, successfully launched in November. Artemis II, which will carry four live astronauts for the first time but only loop around the moon, launches in 2024. Artemis III will go up in 2025 and is expected to be the first to actually set down on the moon. Artemis IV is slated for 2027 and will deliver half of the lunar Gateway (as well as debut the EUS) while Artemis V is set to deliver the other half of the Gateway in 2028. From there, NASA has some thoughts on Artemis missions VI (2029) through X (2033) but has not finalized any details as of yet.

Artemis support missions

“We need several years in orbit and on the surface of the moon to build operational confidence for conducting long-term work and supporting life away from Earth before we can embark on the first multi-year human mission to Mars,” Bridenstine said in 2020. “The sooner we get to the moon, the sooner we get American astronauts to Mars.”

the capstone cubesat flying over the moon with the sun in the distance
NASA

But before we can build confidence in our ability to survive on Mars, we need to build confidence in our ability to survive on the moon. The Artemis support missions will do just that. The Capstone Mission (“Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment”), for example, successfully launched a 55-pound cubesat in June to confirm NASA’s math for the much larger Gateway’s future orbital path. While in orbit, the Capstone will communicate and coordinate some of its maneuvers with the Lunar Reconnaissance Orbiter which has been circling the moon since 2009.

In 2023, NASA also plans to launch the VIPER robotic rover to the moon’s South Pole where it will search the lowest, darkest, coldest craters for accessible water ice. Finding a source for H2O is of paramount importance to the long-term viability of the colony. In space, water isn’t just for drinking and bathing — it can be split into its component atoms and used to fuel our oxidizing rockets, potentially turning the Moon into an orbital gas station as we push farther out from Earth. The rover, and others like it, will be delivered to the surface as part of NASA’s Commercial Lunar Payload Services (CLPS) program.

It wasn’t until the mid 1990s that NASA even confirmed the presence of water ice on the moon and only two years ago did they discovered ice accessible from the moon’s surface. “We had indications that H2O – the familiar water we know – might be present on the sunlit side of the moon,” Paul Hertz, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters, said at the time. “Now we know it is there. This discovery challenges our understanding of the lunar surface and raises intriguing questions about resources relevant for deep space exploration.”

Similarly, any habitat established on the surface will need an ample supply of electricity to remain online. Solar charging is one obvious choice (that lack of atmosphere is finally coming in handy) but NASA has never been one to underprepare and has already selected three aerospace companies to develop nuclear power sources for potential deployment.

Gateway

Gateway components blowup
NASA

In addition to a surface installation, NASA plans on putting a full-fledged space station, dubbed the Lunar Gateway, into orbit around the moon where it will serve much the same purpose as the ISS does today. Visiting researchers will stay aboard the pressurized Habitation and Logistics Outpost (HALO) module where they’ll have access to research facilities, remote rover controls and docking for both Orion capsules from Earth and HLS (Human Landing System) landers to the moon’s surface. A 60kW solar plant will provide power to the station, which also serves as a communications relay hub with the planet. The station’s position around the moon will also provide a unique astronomical perspective for future research.

The Gateway will very much be an international operation. As NASA points out, Canada’s CSA is providing “advanced robotics” for use upon the station, the ESA is supplying a second living module called the International Habitat (IHab) as well as the ESPRIT communications module and an array of research cubesats. Japan’s JAXA will kick in additional habitat components and assist with resupply logistics.

Human Landing System and rovers

From the Gateway, astronauts and researchers will ferry down to the moon’s surface to collect samples, run experiments and conduct observations aboard the Human Landing System, a reusable lunar lander program currently being operated out of Marshall Space Flight Center in Huntsville, Alabama.

NASA selected SpaceX’s Starship for its initial landing system in April 2021, awarding the company $2.9 billion to further the vehicle’s development. The agency then awarded SpaceX with another $1.15 billion this past November as part of the Option B contract modification. The extra money will help fund planned upgrades to the spacecraft, which is being modified from the base Starship design for use on and around the moon’s surface.

“Continuing our collaborative efforts with SpaceX through Option B furthers our resilient plans for regular crewed transportation to the lunar surface and establishing a long-term human presence under Artemis,” Lisa Watson-Morgan, NASA HLS program manager, said in November. “This critical work will help us focus on the development of sustainable, service-based lunar landers anchored to NASA’s requirements for regularly recurring missions to the lunar surface.”

Researchers, however, will not be content to travel nearly a quarter million miles just to set down on the moon and look out the lander’s windows. Instead, they’ll be free to wander around the surface safely ensconced in spacewalk equipment supplied by Axiom Space and Collins Aerospace.

“With these awards, NASA and our partners will develop advanced, reliable spacesuits that allow humans to explore the cosmos unlike ever before,” said Vanessa Wyche, director of NASA’s Johnson Space Center in Houston, said in June. “By partnering with industry, we are efficiently advancing the necessary technology to keep Americans on a path of successful discovery on the International Space Station and as we set our sights on exploring the lunar surface.”

Those researchers won’t be on foot either. Just as the Apollo astronauts famously bounced around on NASA’s first-gen lunar rovers, the Artemis missions will use new Lunar Terrain Vehicles. The unpressurized buggies are currently still in development but NASA expects to have a finalized proposal ready by next year and have the LTVs ready for surface service by 2028.

The Artemis Base Camp

When not in use, the LTVs will be parked at NASA’s Artemis Base Camp at the lunar South Pole, alongside a pressurized version designed for longer-duration expeditions. The surface habitat itself will be able to support up to four residents at a time and provide communications, equipment storage, power and, most importantly, robust radiation shielding (and there’s the downside of not having an atmosphere). A site hasn’t yet been officially selected, though mission planners are looking for areas near the region’s permanently shadowed craters where water ice is expected to be most easily accessible (aside from the negative 280 degree temperatures and perpetual darkness).

“On each new trip, astronauts are going to have an increasing level of comfort with the capabilities to explore and study more of the moon than ever before,” Kathy Lueders, associate administrator for human spaceflight at NASA Headquarters, said in 2020. “With more demand for access to the moon, we are developing the technologies to achieve an unprecedented human and robotic presence 240,000 miles from home. Our experience on the moon this decade will prepare us for an even greater adventure in the universe — human exploration of Mars.”