When humans return to the Moon or land on Mars for the first time, they will likely use oxygen extracted from planetary rock. They'll build shelters from 3D-printed blocks composed of locally mined metals. They may even transport equipment via an interplanetary tether known as a space elevator. These are some of the essential tools for sustainable space exploration.
Sending humans into space is difficult, expensive and resource-exhaustive. NASA's Artemis program, which intends to land humans on the Moon in 2024, is the agency's "most ambitious and costly activity," according to NASA's Office of Inspector General. The OIG estimates that NASA will spend $93 billion by 2025, before Artemis heads to Mars.
Little wonder, then, that sustainability is embedded within NASA's Artemis Plan. The first chapter, "Setting Humanity on a Sustainable Course to the Moon," serves not only as an outline of the plan but also as a North Star to our ride to the stars. The opportunity afforded by sustainable space exploration strengthens our capability of touching the deep cosmos without sacrificing the resources of our home planet. It can enable us to go there while protecting what's here.
In the 2015 movie "The Martian," Matt Damon's character farmed potatoes on Mars. Far-fetched? Not anymore. In our return to space, here are four ways we can do so sustainably.
1. Greener Fuels
Rocket launches generate 200-300 tons of carbon dioxide, one researcher estimates, a volume that doesn't compete with air travel but will accumulate as citizen space travel expands. More launches will generate more emissions and more toxic residue, harming the atmosphere and likely prompting stricter launch regulations. Greener fuels can help.
NASA is reducing the use of the toxic fuel hydrazine through its Green Propellant Infusion Mission. The initiative employs a less-toxic propellant, blending hydroxyl ammonium nitrate fuel with an oxidizer that is safer to store and handle, delivers more thrust, increases performance and lowers costs. NASA's GPIM testing proved successful, and the agency expects the propellant to be a viable option in commercial spaceflight.
Reuse will be critical to sustainable space exploration as well. Nearly every component of Blue Origin's New Shepard rocket is reusable, including its booster, landing gear and parachutes. New Shepard also uses a fuel combination of liquid oxygen and hydrogen. The result generates no carbon emissions, unlike rockets that use the kerosene-based RP-1 fuel.
2. Space Elevators
Imagine transporting cargo, equipment and even people through space elevators rising 100,000 kilometers above Earth. Or traveling through space using solar-power sails. Both technologies are on the horizon.
The International Space Elevator Consortium (IPEC) calls space elevators the "transportation story of the 21st century," essential to continued exploration. The elevator calls for a fixed base structure on Earth (or perhaps the Moon) attached via cable to a counterweight in space. Using Earth's centrifugal force, the apparatus generates the tension and strength required to support and act as an elevator. This TED-Ed video offers a great overview.
Space elevators have the power to reduce, and perhaps even eliminate, the need for expensive, carbon-intensive rocket launches. They are estimated to be capable of lowering the costs of carrying payloads to space by more than 90%. And ISEC expects space elevators to have no carbon footprint. The group calls them "the green road to space."
ISEC further suggests that space elevators will allow us to mobilize solar power and solar shade to improve Earth's environment, dispose of nuclear waste in space and travel to Mars in 61 days. The Japanese company Obayashi plans to build a space elevator by 2050.
3. Solar Sails
Meanwhile, NASA is developing a solar-sail concept that can harness sunlight similar to the way sailboats harness wind. Solar sails convert light into energy, just as photovoltaic cells do in solar panels. Theoretically, this technology could send a spacecraft across our solar system using only sunlight as fuel.
NASA's Diffractive Solar Sailing Project is studying the project's viability, which the agency says dramatically could reduce the need for spacecraft to carry heavy, expensive and potentially toxic fuels.
4. In-Situ Resource Utilization
Past lunar missions required astronauts to bring a lot of luggage from Earth. When we return, advancements are underway that can enable us to make oxygen, water and building materials from Moon rock. It's called "in-situ resource utilization" (ISRU) and will be essential to the Artemis program.
In-situ (Latin for "on-site") refers to using local resources. The Moon and Mars, for example, are covered in a powdered rock called regolith. This residue of planetary evolution might contain oxygen, water and methane: All resources that we can use to power equipment and build bases.
The European Space Agency has awarded a company called Space Applications Services, a contract to develop devices that produce oxygen from Lunar soil. Such a station on the Moon would require spacecraft to carry less oxygen from Earth and could serve as a "refueling" stop on the way to Mars.
Space Applications also is developing systems to synthesize water from regolith and fabricate building materials from regolith through a 3D printing process.
Using ISRU as its guide, NASA plans to build Artemis Base Camp with the infrastructure necessary to support a crew of four on the Moon for 30-45 days. NASA also is developing the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE), capable of producing oxygen from the planet's carbon-dioxide atmosphere.
The Future Of Sustainable Space Exploration
The future of sustainability requires purpose of mission. The Apollo program's 1960s mission was simple: Win the Space Race, even with an unsustainable program.
Traveling 140 million miles to Mars requires a plan that, as NASA says, is both sustainable and extensible.
Space still captivates us. The first images from the James Webb Space Telescope provoked awe. And a 2021 YouGov poll found that 52% of U.S. adults support returning astronauts to the moon—and 53% want to explore Mars.
Imagine establishing a Moon base camp, harvesting lunar resources and using them to land on Mars. Such advancements can be pivotal to achieving sustainable space exploration.
Uncommon Knowledge
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
