CAPE CANAVERAL—Characterized as a challenge high in risk, NASA's Artemis I flight test will open a new era in human space exploration, one intended to provide global dividends across the science, economic and global leadership spectrums, agency leaders said as the mission's two-day launch countdown got underway.

Liftoff of the 322-ft. Space Launch System (SLS) rocket to send an uncrewed Orion capsule on a 42-day mission around the Moon and back—designed to assess the hardware and operations for human missions to follow—was set for April 29 at  8:33 a.m. EDT at the opening of a 2-hr. launch window before it was scrubbed due to technical issues.

Officially, the agency is targeting a late-2025 launch for Artemis III, which is expected to become the first post-Apollo mission to deliver astronauts to the surface of the Moon, with landing planned for the unexplored south pole.

Follow-on efforts to establish a sustained lunar presence with international and commercial partners are aiming to vault humanity to Mars in the late 2030s or early 2040s, according to NASA Administrator Bill Nelson.

“This mission goes with a lot of hopes and dreams of a lot of people,” Nelson told reporters on Aug. 27. “It's no longer the Apollo generation; it's the Artemis generation.”

Under the 1969-72 Apollo program, NASA staged six crewed landings in the Moon's equatorial region and brought back lunar regolith samples for scientific analysis. The Cold War-era initiative was halted by former U.S. President Richard Nixon.

Nelson credited the administrations of former presidents Barack Obama and Donald Trump and the current administration of President Joe Biden with restarting and backing a human deep-space exploration program that is built around a sustained human presence on the Moon, with the long-term goal of sending astronauts to Mars.

“Through our human exploration efforts, we seek to imagine and create first-ever missions and approaches that showcase American ingenuity, pioneer new science and technology, improve long-term affordability, reinforce U.S. preeminence, improve life on Earth and address critical national challenges,” Bhavya Lal, NASA's associate administrator for technology, policy, and strategy, told reporters.

“What we are starting with the [Artemis I] launch on Monday is not a near-term sprint but a long-term marathon to bring the Solar System and beyond into our sphere,” she said.

As currently being implemented, NASA's goals of establishing a permanent human lunar presence to prepare for human expeditions to Mars are influenced by external as well as internal factors, according to Lal. They include:

• Capabilities offered by international and commercial partnerships forged in part by the assembly and operation of the 15-nation International Space Station (ISS).
• Geopolitical competition, cited by Nelson as evident in Russia's military invasion of Ukraine, as well as in a surge in Chinese space capabilities, including rocket technologies and the assembly and initial staffing of the Tiangong space station.
• A fiscal environment that is driving optimization of resources and workforce capabilities as well as funding and timelines. “NASA is working hard to establish a technically and politically resilient architecture for our long-term exploration efforts,” Lal said.

To mitigate the chance of cancellation, NASA is in the process of establishing a new Moon to Mars Program Office within the agency's Exploration Systems Development Mission Directorate, Nelson explained. Other top agency leaders joined Nelson for the news briefings, including Jim Free, Exploration Systems Development Mission Directorate associate administrator; Kathy Lueders, Space Operations Mission Directorate associate administrator; Thomas Zurbuchen, Science Mission Directorate associate administrator; and Prasun Desai, Space Technology Mission Directorate deputy associate administrator.

The Moon/Mars mission architecture forged by the new joint program office will feature four interrelated components, according to Lal. They are:

• Habitation and transportation that includes a space nuclear-propulsion element devoted to faster, more distant robotic as well as human space exploration, plus surface habitation, spacesuit and surface mobility elements, including pressurized rovers for lengthy lunar sorties.
• An infrastructure for lunar utilization by international and U.S. industrial partners able to maintain a continuous robotic and human presence on the lunar surface, with NASA as one of multiple users, while the agency prepares the technologies and science strategies needed for Mars.
• Operations that employ a gradual-buildup approach to the demonstration of technologies for living and working on planetary surfaces beyond the Earth.
• Integrated human and robotic capabilities for addressing high-priority space science objectives.

“That long-term presence, economic benefit and thirst for science is what makes Artemis different,” Exploration Systems Development Mission Directorate Associate Administrator Free said. “We have put science in from the beginning, and science will be central to our architecture in the future.”

Artemis I, for example, includes a secondary payload of 10 small satellites that will further assess the lunar surface for the presence of water ice, a potential human life-support resource and the raw material for production of liquid hydrogen and oxygen rocket propellants.

The Orion capsule is equipped with sensors to assess the cislunar radiation environment as well as the launch and reentry forces that astronauts will experience as NASA prepares for Artemis II, a second Orion mission around the Moon with four astronauts aboard, targeted for mid-2024.

The same year, NASA plans to kick off the assembly of the Gateway, a human-tended outpost in orbit around the Moon equipped for internal and external science activities that will also serve as a waypoint for astronauts arriving from Earth and descending and returning from the lunar surface.

The Gateway will provide support for a planned base at the lunar south pole and serve as a staging outpost to test Mars mission technologies. "NASA's astronaut corps has been involved in every step of the way, embedded in the programs and directorates,” veteran NASA astronaut Randy Bresnik said.

“We are there to share our spaceflight experiences and expertise in the design and development of the spacecraft because ultimately, we represent the humans who will be on those vehicles that will be on those missions to the Moon and ultimately on to Mars,” he said.

Bresnik noted the professional and social diversity of NASA's current astronaut corps, which includes 43 men and women eligible for mission assignments and 10 astronaut candidates in training.

When it comes to Mars, Free said the top technical challenges are:

• Development of environmental control and life support capabilities, which are now being assessed and advanced aboard the ISS.
• Assessing and addressing the deep-space radiation threat to humans.
• Developing strategies to soft-land a 20-ton payload on the Martian surface—20 times more than what NASA has accomplished to date.

“Everyone mentions propulsion, but those three things have to be solved as well,” Free noted.

Nelson acknowledged the cost and schedule challenges NASA faces as it pivots its human-exploration focus from the ISS to deep space. “Space is hard,” Nelson said. "You are developing new systems and new technologies. It takes money and it takes time.

“What we are doing in the future to try to stop some of these cost overruns is simplifying the system,” he added, citing implementation of the new Moon to Mars Program Office. “The proof will be in the pudding, but right now we are on the cusp of something that is pretty great.”