Will NASA’s lunar rover find enough ice it is looking for?

NASA plans to land its next lunar rover next to a crater, named Nobile, near the moon’s south pole, the agency said. But some scientists are wondering if the mission, which is slated to launch in 2023, will effectively find the moon ice it is looking for.

The mission, known as the Volatiles Investigating Polar Exploration Rover (VIPER), aims to study ice on the lunar surface that could serve as a resource, for example as a rocket fuel ingredient for future astronauts. The south pole of the Moon has so far not been visited by any spacecraft, but is scientifically very promising: it receives little sunlight, so it has reserves of ice containing information on the origin and the evolution of the solar system, preserved for billions of years. VIPER will chase ice in the lunar soil using a variety of methods, including drilling down to 1 meter deep.

Lunar exploration is intensifying on a global scale, with China, South Korea, India and Russia among the nations working on lunar missions. Amid these efforts, NASA aims to regain the glory of its crewed moon landing in 1969 by sending astronauts to the lunar surface somewhere near the South Pole. The goal is to do so by the end of 2024, but that deadline is likely to slip given budget and other constraints.

Before the astronaut lands, NASA will send a fleet of robotic spacecraft to the Moon. Among them, VIPER, which will be the very first mission to provide ground measurements of lunar polar ice. VIPER will cost NASA around US $ 433 million to build and operate. An additional $ 226 million will go to a private company, Astrobotic Technology in Pittsburgh, Pa., To deliver it to the surface of the moon. If all goes well, once the rover lands at its landing site near Nobile Crater, it will travel 25 kilometers or more over 100 days while mapping the ice and drilling into it in several places.

But some researchers are concerned that the landing site, announced on September 20, may not be guaranteed to have an abundance of ice. So far, scientists have only been able to estimate polar ice concentrations on the basis of data from orbiting spacecraft. According to this information, the Nobile crater has ice in and around it, including inside several permanently shaded regions that never see the sun’s rays.^1,2. “We have a lot of data indicating there’s water ice out there – we’re not going blind,” says Amy Fagan, a planetologist at Western Carolina University in Cullowhee, North Carolina .

But some point out that the lunar polar ice appears to be distributed in patches – with frost on the surface in some places and frozen ice deeper in others, inaccessible even to VIPER’s drill. “It’s not like water ice is everywhere,” says Bethany Ehlmann, a planet specialist at the California Institute of Technology in Pasadena. “Details matter when it comes to where we’re going. “

VIPER may not even encounter water, adds Clive Neal, a geoscientist at the University of Notre Dame in Indiana – although even this information may help future ice hunting missions find better target sites. .

Ice search

Since 2017, when then-President Donald Trump tasked NASA with returning astronauts to the moon, many lunar scientists have been working to identify areas around the South Pole where robotic spacecraft or astronauts might have the best chance of finding ice or other geologically interesting terrain. to explore³.

NASA chose Nobile Crater for VIPER in part because it offers a variety of locations where ice can be studied in lunar soil. Other factors in the decision included that VIPER could easily cross the terrain, that there was enough sunlight for the solar-powered rover to regularly recharge its batteries, and the crater to have a good line of sight to Earth. , so that engineers can communicate directly with the spacecraft.

The agency acknowledges that VIPER does not yet have a detailed map of the location of the ice around Nobile, named after an Italian explorer who developed airships for Arctic exploration. “That’s exactly why we’re going there,” says Anthony Colaprete, Project VIPER scientist at NASA’s Ames Research Center in Moffett Field, Calif. “Any new information is going to be illuminating beyond what we have at this time.”

But some scientists say VIPER would be better off if NASA first launched another planned spacecraft, a small $ 55 million satellite called the Lunar Trailblazer. Lunar Trailblazer’s mission is to map water on the Moon. Researchers say the VIPER team could use these maps to plot the parts of Nobile that the rover could effectively travel to as it searches for ice during its rapid 100-day mission. “Not launching Trailblazer at the same time or before VIPER is a missed opportunity,” says Neal.

NASA, however, plans to store the Lunar Trailblazer until 2025, when it is scheduled to travel to space alongside an unrelated spacecraft. Ehlmann, who is the principal investigator for Lunar Trailblazer, says it will be ready for launch in February 2023, well ahead of VIPER, and could make advanced maps for VIPER if NASA finds a launch opportunity sooner.

U.S. lunar scientists discussed the matter last month at a meeting of the Lunar Exploration Analysis Group, which provides information to NASA on lunar activities. They backed the launch of Lunar Trailblazer as soon as possible, but recognized that VIPER would still be successful without it, said Fagan, who is the group’s chairman.

NASA defends its choice to launch VIPER first. “We have absolutely enough knowledge to fly the VIPER mission” before Trailblazer, says Lori Glaze, director of NASA’s planetary science division in Washington DC. And Neal argues that the two missions should only be seen as the start of a long-term search for lunar polar water, in which NASA and space agencies in other countries can coordinate to map and mine the ice. as part of an ongoing space exploration program.

Despite the concerns, VIPER will provide scientists with the best glimpse yet of where the ice might be around the lunar south pole. The rover can detect very low levels of ice in the ground, less than a tenth of a percent by weight. Because of this sensitivity, says Kevin Cannon, a planetologist at the Colorado School of Mines in Golden, “I think there is a good chance of finding detectable ice.”