Next month, almost a half-century since the United States last landed a spacecraft on the moon, NASA is expected to announce plans for a return. But the agency will just be along for the ride. Rather than unveiling plans for its own spacecraft, NASA will name the private companies it will pay to carry science experiments to the moon on small robotic landers.
Under a program called Commercial Lunar Payload Services (CLPS), NASA would buy space aboard a couple of launches a year, starting in 2021. The effort is similar to an agency program that paid private space companies such as Elon Musk's SpaceX to deliver cargo to the International Space Station (ISS). "This a new way of doing business," says Sarah Noble, a planetary scientist at NASA headquarters in Washington, D.C., who is leading the science side of NASA's lunar plans.
Scientists are lining up for a ride. "It really feels like the future of lunar exploration," says Erica Jawin, a planetary scientist at the Smithsonian Institution's National Museum of Natural History in Washington, D.C. She and other attendees at the annual meeting of the Lunar Exploration Analysis Group in Columbia, Maryland, last week were eager to show NASA why their small experiments would be worthy hitchhikers on the landers.
Several companies, including Astrobotic, Moon Express, and iSpace, are vying to establish a commercial moon market. Buying rides to the moon from launch providers like Rocket Lab, each firm hopes to become the go-to carrier for other companies seeking to prospect the moon for rocket fuel ingredients, or to gather rocks to sell for study. But a contract with NASA is the real prize. Moon Express, for example, has designed the MX-1, a lander roughly the size and shape of Star Wars's R2-D2. But, "We won't pull the trigger until we know we have a CLPS award," says Moon Express CEO Robert Richards in Cape Canaveral, Florida.
The companies selected for CLPS must deliver at least 10 kilograms of payload by the end of 2021, NASA says. It is scrambling to find instruments that are ready to fly. "What do you have sitting on shelf now that you can throw onto the mission immediately?" Noble says. "We're looking for flight spares, engineering models, student-built projects. It's a little bit of a weird call for us." The agency is planning to pay up to $36 million to adapt eight to 12 existing scientific instruments to the initial small landers; by the middle of next decade it aims to build a pipeline of instruments for bigger landers that might also carry rovers.
The first small commercial landers will pale in capability next to traditional NASA missions. Some will likely fail, as NASA's science chief, Thomas Zurbuchen, has repeatedly warned. They will not survive the lunar night, 2 weeks when surface temperatures drop to −173°C. They may not be capable of landing in a specific spot. But scientists are still excited to get cameras and other instruments back to the surface of the moon, says Clive Neal, a lunar scientist at the University of Notre Dame in South Bend, Indiana. "It's a great start."
NASA is still working out destinations for the commercial landers. Earlier this year, lunar scientists compiled a list of 16 sites key to testing an emerging picture of the moon as more active volcanically and richer in water than was thought. For example, 4 years ago scientists studying the Ina caldera, a collection of smooth, small volcanic mounds on the moon's nearside, noticed it was relatively free of craters. The observation suggested that instead of ending a billion years ago, volcanism—a sign of interior heat—persisted until a few million years ago, smoothing the landscape. If true—and some dispute the finding—it would upend theories of how the moon, and potentially the rocky planets, cool over time.
At the 2-kilometer-tall Aristarchus plateau, scientists want to study abundant volcanic ash deposits, which were created in explosive, gas-driven eruptions, a rarity on the moon. Thanks to its fine granularity, the ash could also make an excellent building block for human habitats. Samples from Marius Hills, a shield volcano that likely erupted for a substantial time, could shed light on how the moon's endowment of water, carbon monoxide, and other volatiles evolved over time. And a look inside permanently shadowed craters at the moon's poles could confirm whether some of its water is frozen there, says Brett Denevi, a planetary geologist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
The first small landers allow only small steps toward these science goals. But the agency could eventually support commercial robotic sample return missions, which Astrobotic and Moon Express hope to offer. "They could say, ‘I want 2 kilograms of lunar regolith from such and such location,’" says John Thornton, CEO of Astrobotic in Pittsburgh, Pennsylvania. Returned samples could help researchers with a perennial goal: dating the moon's old and young craters, which dictate age estimates for surfaces across the solar system.
NASA also wants to fly people back to the vicinity of the moon—but in its own spacecraft. It is building the Gateway, a small outpost, that, by 2024, would host astronauts for a couple of months at a time in a pressurized volume one-tenth the size of the ISS. The Gateway, which will cost NASA at least $3 billion for its first few sections, would not orbit the moon but, rather, would follow a weeklong loop around a distant gravitational balance point—a poor vantage for lunar observations. "We're not 100% sure of its value for lunar science," says Ryan Watkins, a lunar scientist at the Planetary Science Institute in St. Louis, Missouri. Noble acknowledges that the Gateway may be more valuable for studying the sun or the rest of the universe.
Ben Bussey, NASA's chief scientist for human exploration, says the agency is trying to accommodate scientists' concerns. For example, it will prioritize equipping the station with a robotic arm, needed for mounting experiments on its exterior. And it is investigating the possibility of a reusable "tug" spacecraft that could ferry landers, samples, and instruments between the Gateway and low lunar orbit, Bussey says.
Looming over these lunar plans is the fear that they will change. Republicans in Congress proposed a moon return under former President George W. Bush, only to have the administration of former President Barack Obama emphasize a visit to an asteroid in deep space, as a stepping stone to Mars. So far, the Republican-led Congress has fully funded the agency's moon plans: Draft 2019 spending bills contain $500 million for the Gateway and more than $200 million for NASA's initial lander and science plans. Now, lunar scientists need to convey their support to newly empowered Democrats, Neal says. If NASA funds a couple of small landers and the program changes again, Denevi adds, "that's just going to be another wasted decade."