NASA said Friday it is now targeting February 2022 for the uncrewed lunar mission Artemis 1, the first step in America's plan to return humans to the Moon later this decade.

The space agency had initially wanted to launch the test flight by the end of this year, with astronauts on the ground by 2024 on Artemis 3, but the timeline has slipped back.

It achieved a major milestone Wednesday when it stacked the Orion crew capsule atop its Space Launch System megarocket, which now stands 322 feet (98 meters) tall inside the Vehicle Assembly Building at NASA Kennedy Space Center in Florida.

After further tests, it will be wheeled out to the launch pad for a final test known as the "wet dress rehearsal" in January, with the first window for launch opening in February, officials told reporters on a call.

University of California San Diego Physics Professor Tom Murphy is among five authors of an essay, appearing in the November 2021 issue of the journal Energy Research & Social Science, that cautions current levels of worldwide economic growth, energy use and resource consumption will overshoot Earth's finite limits.

The essay, "Modernity is Incompatible with Planetary Limits: Developing a PLAN for the Future," also announces the establishment of a network of scholars and researchers to promote the understanding of planetary limits, envision scenarios for humanity to thrive within planetary limits, better educate college students about these challenges and advise government officials and communities in developing effective responses.

"We all are a product of our times, where 'new,' 'shiny,' 'better' seem normal and 'more, more, more' seems good, but that is a reflection of the abnormal period of the last century or so," said Murphy. "If humanity keeps growing its impact on the planet, we will overshoot planetary limits, so we need to plan to power down while there's still time. Even the founders of economics recognized that Earth's resources are finite and growth is but a transient phase.