The Moon is a treasure chest of science. The lunar samples returned during the Apollo program dramatically changed our view of the solar system, yet they just scratch the surface of what we know about the Moon — knowledge that can be acquired with a sustained human and robotic presence on the Moon. Although Americans first walked on its surface 50 years ago, footprints were left at only six sites during a total of 16 days on the surface. The next wave of lunar exploration will be fundamentally different.

Exploration of the Moon and Mars is intertwined. NASA’s sustainable Moon to Mars exploration approach is reusable and repeatable. It involves building an open exploration architecture with as many capabilities that can be replicated as possible for missions to Mars. The Moon is a testbed for Mars, providing an opportunity to demonstrate new technologies that could help build self-sustaining outposts off Earth.

The Artemis Program

Artemis is the twin sister of Apollo and goddess of the Moon in Greek mythology. Now, she personifies the next path to the Moon as the name of NASA’s program to return humans to the lunar surface by 2024. When they land, Artemis astronauts will set foot where no human has been before: the Moon’s South Pole.

NASA has selected 11 companies to conduct studies and produce prototypes of human landers for the Artemis lunar exploration program. Through Next Space Technologies for Exploration Partnerships (NextSTEP) contracts, the selected companies, over the next six months, will study and/or develop prototypes that reduce schedule risk for the descent, transfer, and refueling elements of a potential human landing system.

The Gateway orbital outpost with the Orion spacecraft docked. (NASA)

NASA’s proposed plan is to transport astronauts in a human landing system that includes a transfer element for the journey from the lunar Gateway to low-lunar orbit, a descent element to carry them to the surface, and an ascent element to return them to the Gateway. The agency also is looking at refueling capabilities to make these systems reusable.

The Gateway

To return to the Moon and prepare for Mars, NASA has designed the Gateway — an orbital outpost concept in the vicinity of the Moon — with U.S. industry and International Space Station partners (Canada is the first to sign on). The Gateway will be a small spaceship in orbit around the Moon for astronauts as well as science and technology demonstrations. Located about 250,000 miles from Earth, the Gateway will be a temporary home and office for astronauts, enable access to the entire surface of the Moon, and provide new opportunities in deep space for exploration.

“The Gateway will give us a strategic presence in cislunar space. It will drive our activity with commercial and international partners and help us explore the Moon and its resources,” said William Gerstenmaier, Associate Administrator, Human Exploration and Operations Mission Directorate, at NASA Headquarters in Washington. “We will ultimately translate that experience toward human missions to Mars.”

Even before the first trip to Mars, astronauts will use the Gateway to train for life far away from Earth, and practice moving a spaceship in different orbits in deep space. On the Gateway, NASA will study how living organisms react to the radiation and microgravity of a deep space environment over long periods. The Gateway will have living quarters, laboratories for science and research, docking ports (like doors) for visiting spacecraft, and more.

The power and propulsion element of the Gateway is a high-power, 50-kilowatt solar electric propulsion spacecraft — three times more powerful than current capabilities. (NASA)

Astronauts will visit the Gateway at least once a year but they won’t stay year-round like crews on the International Space Station (ISS). The Gateway is much smaller than the ISS — its interior is about the size of a studio apartment (the ISS is larger than a six-bedroom house). Once docked, astronauts can live and work aboard the spaceship for up to three months at a time, conduct science experiments, and take trips to the surface of the Moon. Even without crew present, cutting-edge robotics and computers will operate experiments inside and outside the spaceship, automatically returning data back to Earth.

NASA is looking at options for astronauts to use to shuttle between the Gateway and the Moon on reusable landers. Just like an airport, spacecraft bound for the lunar surface or for Mars can use the Gateway to refuel or replace parts and resupply things like food and oxygen without going home first. For months-long crew expeditions to the Gateway, this could allow multiple trips down to the lunar surface, and exploration of new locations across the Moon.

Concept image of the interior of a Gateway deep space habitat. (NASA)

NASA plans to launch elements of the Gateway on its Space Launch System (SLS) or commercial rockets for assembly in space. The Gateway will be built with just five or six launches (it took 34 launches to build the ISS). The power and propulsion element will be the initial component and is targeted to launch in 2022. Using high-power solar electric propulsion, the element will maintain the Gateway’s position and can move it between lunar orbits over its lifetime. The power and propulsion element will also provide high-rate and reliable communications for the Gateway including space-to-Earth and space-to-lunar uplinks and downlinks, spacecraft-to-spacecraft crosslinks, and support for spacewalk communications.

Concept image of Boeing’s prototype Gateway habitation module. (Boeing)

Adding an airlock to the Gateway in the future will enable crew to conduct space-walks, enable science activities, and accommodate docking of future elements. NASA is also planning to launch at least one logistics module to the Gateway that will enable cargo resupply deliveries, additional scientific research and technology demonstrations, and commercial use.

Drawing on the interests and capabilities of industry and international partners, NASA will develop progressively complex robotic missions to the surface of the Moon with scientific and exploration objectives in advance of a human return. Robotic lunar surface missions will begin as early as 2020 with a focus on scientific exploration of lunar resources, and preparing the lunar surface for a sustained human presence. By the late 2020s, a lunar lander capable of transporting crews and cargo will begin trips to the surface of the Moon. The sustainable, long-term lunar surface activities enabled by these efforts, in tandem with the Gateway, will expand and diversify over time, taking advantage of the Moon and near space for scientific exploration in the broadest sense.

Mobility platforms, such as rovers, will carry science instruments and look for and sample water-ice (volatile) deposits. Landing a rover in 2023 on the Moon will provide knowledge of how to use water-ice for fuel, oxygen, and drinking water for human exploration missions to the lunar surface.

Living There

NASA is conducting ground tests inside five full-size, deep space habitat prototypes. The mockups, constructed by five American companies, offer different perspectives on how astronauts will live and work on the Gateway. Rather than selecting one habitat, the tests will help NASA evaluate the design standards, common interfaces, and requirements for a future U.S. Gateway habitat module, while reducing risks for eventual flight systems.

Engineers and technicians will analyze habitat system capabilities and performance proposed by each prototype, while human factors teams consider layout and ergonomics to optimize efficiency and performance. During the tests, future Gateway flight operators at Johnson Space Center will collect actual live telemetry streams from each prototype. They will monitor habitat performance and support realistic mission activities as astronauts conduct “day-in-the-life” procedures within each prototype, providing their perspectives as potential crewmembers who may one day live and work on the Gateway.

In addition to the physical enclosure, each company has outfitted their prototype with the basic necessities to support humans during deep space expeditions including environmental control and life support systems, avionics, sleeping quarters, exercise equipment, and communal areas.


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