The extremes of light and dark found on the moon are prompting NASA to install the first-ever lighting system on the VIPER rover that will hunt for water on the moon.

Shadowed and lit areas are in such high contrast on the moon that VIPER’s rover drivers will rely on a system of rover-mounted lights and cameras to steer clear of boulders, descend steep declines into craters and avoid other mission-fatal dangers.

NASA’s VIPER team is testing prototypes in a high-fidelity recreation of a lunar landscape at NASA’s Ames Research Center in California’s Silicon Valley.

“We face similar challenges as any car designer,” said Uland Wong, VIPER’s navigation hardware lead and a computer scientist at Ames. “Whether it’s on a rover or the next model of sedan, a bad lighting design means a driver can’t see details in the landscape. We have to pay extra attention to these challenges on the Moon because once VIPER gets there, there’s no coming back.”

Other lights do exist in space such as single light emitting diodes (LEDs) inside microscopes on Mars rovers and lights that help spacecraft dock on the International Space Station. However, the harsh environment of the moon combined with VIPER’s goal to find water in deep, dark places make this the first rover to require car-like floodlights.

Sunlight typically allow rovers to operate in sunlit areas, however VIPER’s solar-powered mission will venture into spots that never receive direct sunlight, due to the moon’s tilt and the low angle of the sun at the South Pole.

Bright lights

The lights that will be installed on the VIPER rover will be an array of LEDs and will offer the same flexibility of a car’s high beams and parking lights. Mounted on a mast, two of these arrays will cast a narrow, long-distance beam. On the base of the rover, six lights will illuminate a broad area less intensely and can be turned on and off individually.

NASA tested several LED candidates to see which offered the best performance or reflection of light back in the direction of where they came from. This is an issue because the moon’s surface is covered in a powdery dust that reflects a lot of light that could potentially blind VIPER’s cameras.

In testing, NASA sculpted out a simulated lunar soil and surface and lit the terrain as it would appear in different areas of the moon’s poles, mimicking the low-angle illumination of the sun, or in total darkness. The team then tested the light candidates and took photos to compare the quality of the images.

The results will be sent to the VIPER development team at NASA’s Johnson Space Center in Houston where the lights will eventually be built.