NASA is working with SpaceX to develop its Starship human landing system (HLS) for use during the Artemis III and Artemis IV missions to land American astronauts near the South Pole of the Moon. The Starship HLS will be powered by two variants of the company’s Raptor engines—one optimized to operate in atmospheric pressure at sea-level and one optimized to operate in space, or in a vacuum, where there is no atmosphere.
Last month, SpaceX demonstrated a vacuum-optimized Raptor’s performance through a test that successfully confirmed the engine can be started in the extreme cold conditions resulting from extended time in space. One challenge that differentiates Artemis missions from those in low Earth orbit is that the landers may sit in space without firing for an extended period of time, causing the temperature of the hardware to drop to a level below what they would experience on a much shorter low Earth orbit mission.
One of the first testing milestones SpaceX completed under its Artemis III contract in Nov. 2021 was also an engine test, demonstrating Raptor’s capability to perform a critical phase of landing on the Moon. In a 281-second-long test firing, Raptor demonstrated the powered descent portion of the mission, when the Starship HLS leaves its orbit over the lunar surface and begins its descent to the Moon’s surface to land. The test had two goals: to show Raptor’s ability to change the level of engine power over time, known as its throttle profile, and for the engine to burn the full length of time of the powered descent phase. The successful test provided NASA with early confidence in the company’s engine development.
The 281-second throttle test demonstrated the engine’s ability to meet the demands of a descent burn to the lunar surface. Credit: SpaceX
Testing critical technologies and hardware under simulated and actual flight conditions is key for the development of Artemis Moon landers. These tests provide early and mission-like validation of the systems necessary for carrying astronauts to and from the lunar surface. Data reviews following these tests provide NASA with continually increasing confidence in U.S. industry’s readiness for the mission. SpaceX’s Raptor engines will next be put to the test during the company’s second integrated flight test of Starship and Super Heavy.
With the success of NASA’s Artemis I launch, the previously unexplored shadowy regions near the lunar South Pole where Artemis astronauts will land in 2025, are more within our reach than ever before.
One instrument that will support these future lunar exploration efforts is a hypersensitive optical camera called ShadowCam. ShadowCam is one of six instruments on board the Korea Aerospace Research Institute (KARI)’s Korea Pathfinder Lunar Orbiter, known as Danuri, which launched in August 2022 and entered lunar orbit last December.
Previous cameras in lunar orbit were designed to acquire images of sunlit surfaces. Developed by Malin Space Science Systems and Arizona State University, ShadowCam’s primary function is to collect images within permanently shadowed regions near the lunar poles. These areas never receive direct sunlight and are thought to contain water ice – a significant resource for exploration that can be used as fuel or oxygen and for other habitation applications.
Building on cameras developed for NASA’s Lunar Reconnaissance Orbiter, ShadowCam is 200 times more light-sensitive and is therefore able to capture detailed images within permanently shadowed regions – even in the absence of direct light – by using the light that is reflected off nearby geologic features such as mountains or the walls of craters.
Images of the permanently shadowed wall and floor of Shackleton Crater captured by Lunar Reconnaissance Orbiter Camera (LROC) (left) and ShadowCam (right). Each panel shows an area that is 5,906 feet (1,800 meters) wide and 7,218 feet (2,200 meters) tall. Image Credit: NASA/KARI/ASU
In addition to mapping the light reflected by permanently shadowed regions to search for evidence of ice deposits, ShadowCam will also observe seasonal changes and measure the terrain inside the craters, all in service of science and future lunar exploration efforts. The high-resolution images could help scientists learn more about how the Moon has evolved, how water is trapped and preserved in permanently shadowed regions, and could help inform site selection and exploration planning for Artemis missions.
Since Danuri entered lunar orbit, ShadowCam has been in an operational checkout period, during which it has been collecting dozens of images of the lunar polar regions, including an image of Shackleton Crater, to calibrate and test its functionality. Following this checkout period, which will conclude later this month, ShadowCam will start its campaign to capture images of shadowed terrain as Danuri routinely passes over them during the planned mission of 11 months.
NASA’s Artemis program has sparked excitement around the world and catalyzed new interest in exploring the Moon as the agency prepares to land the first woman and next man on the lunar South Pole in 2024. After that, NASA and its growing list of global partners will establish sustainable exploration by the end of the decade.
NASA will build on the momentum of that human return mission in four years and plans to send crew to the Moon about once per year thereafter. To give astronauts a place to live and work on the Moon, the agency’s Artemis Base Camp concept includes a modern lunar cabin, a rover and even a mobile home. Early missions will include short surface stays, but as the base camp evolves, the goal is to allow crew to stay at the lunar surface for up to two months at a time.
“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,” said Kathy Lueders, associate administrator for human spaceflight at NASA Headquarters in Washington. “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.”
Where to stay
Crew will return to the lunar surface for the first time this century beginning with the Artemis III mission. From lunar orbit, two astronauts will take the first new ride to the surface of the Moon, landing where no humans have ever been: the lunar South Pole. This is the ideal location for a future base camp given its potential access to ice and other mineral resources.
On the first few missions, the human landing system will double as lunar lodging, offering life support systems to support a short crew stay on the Moon. In the future, NASA envisions a fixed habitat at the Artemis Base Camp that can house up to four astronauts for a month-long stay.
Since 2016, NASA has worked with several companies on their habitation systems and designs, assessing internal layouts, environmental control and life support systems, and outer structure options, including rigid shells, expandable designs, and hybrid concepts. The agency is currently working with industry to refine ideas for a combination home and office in orbit, recently testing full-size prototypes.
What to wear
Even with minimal surface support in place on early missions, astronauts will embark on at least a week-long expedition on the Moon. Crew will work by day in their modern spacesuits – using new tools to collect samples and setting up a variety of experiments.
These next generation spacesuits will provide increased mobility, modern communications and a more robust life support system than its Apollo predecessors. With improved functionality and movement, crew can conduct more complex experiments and collect more unique geologic samples.
NASA is building the new suits for the initial lunar landing and will transition the design and manufacturing to Industry for follow-on production.
Traveling in style
NASA has proposed two lunar surface transportation systems: a lunar terrain vehicle (LTV) and a mobile home and office referred to as a habitable mobility platform.
The LTV will be an unpressurized, or open-top vehicle, that astronauts can drive in their spacesuits for more than 12 miles from a camp site. Earlier this year, NASA asked American companies to send ideas to develop an LTV that handle the rough surface of the Moon as well as push the boundaries of power generation and energy storage. The agency is evaluating those responses and hopes to leverage innovations in commercial all-terrain vehicles, military rovers and more. Such a vehicle may also be autonomous and capable of driving on pre-programmed paths or could be operated remotely from Earth to conduct additional science and exploration activities.
In addition to the LTV, a pressurized rover will greatly expand lunar surface exploration capabilities to the next level. Pressurization means that astronauts can be in the vehicle in their regular clothing as opposed to wearing their spacesuit inside too. This will provide more comfort to work as they cross the lunar terrain in their mobile habitat and explore large areas. When they’re ready to go outside to collect samples or set up experiments, they would need to put their spacesuits on again.
NASA is in the early idea stage for a pressurized rover – formulating concepts and evaluating potential science and exploration rover missions around the South Pole.
What to do
Breakthrough discoveries from the Lunar Reconnaissance Orbiter and Lunar CRater Observation and Sensing Satellite have shown the Moon is rich with resources, such as ice and greater than average access to light, which could support Artemis explorers and provide new opportunities for scientific discoveries and commercial enterprising activities. The unexplored south polar region provides unique opportunities to unlock scientific secrets about the history and evolution of the Earth and Moon, as well as our solar system.
Harvesting lunar resources could lead to safer, more efficient operations with less dependence on supplies delivered from Earth. NASA plans to send the Volatiles Investigating Polar Exploration Rover (VIPER) to the lunar South Pole before crew. Arriving via a commercial Moon delivery, mobile robot will get a close-up view of the distribution and concentration of ice that could eventually be harvested to support human exploration farther into the solar system. We will learn how to spend more time on the lunar surface as well as prepare to future trips to Mars by conducting life science research and learning to mitigate hazards associated with space exploration.
What to know
The Sun hovers over the lunar South Pole horizon continuously throughout the day and year, providing a near-constant source of energy for solar power opportunities. There is no single location, however, that avoids periods of darkness. This means NASA must plan for early Artemis systems to survive the extremely cold environment without power, to build in the capability to store power for up to eight days.
For longer-term work trips to the Artemis Base Camp, NASA’s Lunar Surface Innovation Initiative is working with the U.S. Departments of Energy and Defense to develop a nuclear fission surface power unit that can continuously provide 10 kW of power – the average annual power consumption of a home here on Earth. This small power plant will be able to power and recharge the other basic elements of the Artemis Base Camp and allow greater flexibility for mission planning by easing the requirement for continuous access to sunlight in a distinct location during a specific timeframe.
What to pack
While NASA will need to bring or send ahead all the supplies it needs for early Artemis missions, the agency wants to know what others would pack for their trips to the Moon. It’s not too late to submit photos of your #NASAMoonKit online.
This decade, the Artemis program will lay the foundation for a sustained long-term presence on the lunar surface. As our lunar presence grows with the help of commercial and international partners, someday the Moon could be the ultimate destination for all to explore.
Illustration of NASA astronauts on the lunar South Pole. Credit: NASA
Following a series of critical contract awards and hardware milestones, an update on NASA’s Artemis program is now available, including the latest Phase 1 plans to land the first woman and the next man on the surface of the Moon in 2024.
In the 18 months since NASA accepted a bold challenge to accelerate its exploration plans by more than four years and establish sustainable exploration by the end of the decade, the agency has continued to gain momentum toward sending humans to the Moon again for the first time since the last Apollo mission in 1972.
The document captures Artemis progress to date, identifying the key science, technology and human missions as well as the commercial and international partnerships that will ensure we continue to lead in exploration and achieve our ambitious goal to land astronauts on the Moon.
