Five Things to Know About NASA’s Lunar Rover ‘VIPER’

Corryn Wetzel Daily Correspondent
VIPER, the Volatiles Investigating Polar Exploration Rover, is heading to the moon's South Pole in late 2023 in search of resources that can sustain future human settlements. NASA's rover will explore lunar surfaces that have not seen sunlight in order to analyze and map the concentrations of water-ice in real time. NASA's Artemis program could be affected by changes in water availability and distribution. It aims to return humans to the moon by 2024.

Tracy Gregg, University at Buffalo College's planetary volcanologist, says that it's quite amazing to think of the fact that there are rovers on Mars, but we haven't sent one to the moon. "We kind of skipped that part--we sent landingers, then we sent astronauts with an dune buggy."

NASA announced in September that VIPER would land just west of Nobile. This is a crater close to the moon's south pole, chosen for its potential to host water and its terrain. Here are five facts about NASA's first lunar probe:

VIPER's main purpose is to search for water

Remote sensing data has confirmed that scientists already know that frozen water can be found at the moon's south Pole. Lunar Crater Observation and Sensing Satellite confirmed that water ice was present at the moon's South Pole in 2009. It remains to be determined where and how that water got there. The drill, measuring a meter in length, will provide a detailed look at lunar soil that scientists are unable to remotely assess. Anthony Colaprete (VIPER's VIPER project scientist at NASA’s Ames Research Center) says, "To really get to the heart of some questions, we have to get to the surface." "That's where VIPER rover steps in."

Water is an essential resource, not only for human consumption but also for space exploration. Water can protect humans from radiation, and can also be used to make rocket fuel or breathable oxygen. Gregg says that if there is a way to save shipping water through the sun and instead find water in the vicinity, space travel becomes possible and humans can spend extended periods on the moon. It is possible to launch a Mars-bound rocket by launching it from the moon, rather than from Earth. However, this would be more expensive than if there was enough water on the moon.

NASA believes that the moon's soils may contain hundreds of million of gallons frozen water based on remote sensing data. Scientists believe it is unlikely that the rover will discover water ice in large pieces or sheets similar to those on Earth. It is likely that water will be found in smaller pieces within lunar dust. Gregg says that water can be easily accessed if it is frozen on the outer surface of the lunar dust particles. You just need to put it in a heater and let the water melt. Then you can collect the water and dirt. It would be harder if the water was more chemically bound with the lunar materials. Then it's not just an oven matter, then you have to actually do chemistry.

VIPER's primary purpose is to determine what resources the moon has for future missions. However, the characteristics of VIPER's polar waters could provide clues into whether there is water elsewhere in the solar system and on Earth. The samples from the rover could be used to identify the source of the moon's water. It may have been trapped in icy shadows or landed on an asteroid.

Colaprete says, "I don’t know what we’re going to discover yet." "We try to see these things with open eyes because we'll learn things that we didn't anticipate," Colaprete says.

VIPER can survive in some of the coldest places in the universe

The rover will search for frozen water ice where there is no sun. The tilt of the moon's axis is only slightly different to Earth's. This means that the sun does not rise as high above the horizon, and leaves basins of debris in shadow. The moon's surface temperatures can reach a scorching 225° Fahrenheit during the day, despite not having an insulating atmosphere like Earth. The lunar surface is -400° Fahrenheit at night, and permanently shadowed places, so the polar craters are some of the coldest spots in the universe.

Thomas Watters, senior scientist at Smithsonian National Air and Space Museum, says that if the ice exists, and in any amount, it is likely you will find it. For example, any water that was deposited on the moon from an asteroid impact would have evaporated immediately in the sun. These cold traps could only be used by water that has settled in sunless basins. VIPER's components can withstand extreme temperatures. However, the heaters must be used by the rover to keep it warm enough to work in dark areas. VIPER, unlike Perseverance or other nuclear-powered robots will need to heat using only solar energy.

Colaprete says, "Going into unknown for the first-time, so many unknown question will be answered." "That moment when we enter that dark crater which has never seen daylight for 3 billion years or more...that's what I am most excited about."

VIPER has custom-made tools for the moon

VIPER will spend part its time taking in the energy from the three solar panels and part using its headlights to navigate through the craters at the south pole. The rover must have enough power to travel into dark craters, and return to sunlight before it goes to sleep.

VIPER is "going somewhere that is unlike any we've ever explored before," Colaprete says. The rover's unique design makes it difficult for the golf-cart-sized vehicle to navigate a slope up to 15 degrees, and can handle slopes of 25 to 30 degrees when required. VIPER's onboard cameras can help rover operators avoid rocks, other hazards, and capture images of the lunar surface. There are four independent control wheels for the mobile robot, as well as those solar panels and the drill measuring a meter long that will be used to cut samples of lunar soil that can then be analyzed using onboard spectrometers.

Colaprete says that the neutron spectrometer "is kind of like the bloodhound of the rover." The robot can detect neutrons that are leaking from the soil and can pick up hydrogen atoms down to one meter. This could indicate water. Near-infrared spectrum can detect minute changes in color from lunar surface. This could reveal water or other volatile compounds. VIPER's mass-spectrometer measures the gas released from the moon's surface. This could be caused by the rover's movement of the top layer of soil.

VIPER Will Hibernate in Survival

VIPER requires a direct-to Earth radio link because there are no satellites capable of relaying communications to Earth orbiting the Moon. The rover must avoid high mountains and steep crater walls, which could block the signal. The rover must also wait in a designated "safe haven" area until communication is reestablished after the moon's south pole moves away from view for at least two weeks each month.

These safe havens provide enough energy for the rover to survive long periods of darkness. VIPER requires regular sunlight as it cannot survive longer than 50 hours in darkness. Safe havens are areas that allow sunlight to reach the rover for as long as possible. Colaprete says that the rover will spend most of its time parked in this type of location basking in the sun or just relaxing. The rover switches to hibernation when it gets dark and the temperatures drop. This allows them to stay warm and afloat.

To maximize the amount of daylight that can be provided to life, the mission will take place during the summer season at the moon's South Pole. NASA expects to complete the mission in 100 days, which will run from November 2023 to March 2024. As the summer winds down on the moon, the darkness will get longer and longer until VIPER is unable to generate enough power to sustain itself.

VIPER Will Rove in Near Real-Time

VIPER will be closer to Earth than rovers on Mars missions. This allows for faster communication. VIPER will operate close to Earth and send commands faster than rovers on Mars. VIPER's latency is only 6-10 seconds.

Gregg says that the travel time between sending commands to Earth and receiving them is only a few seconds. It's like a slow cell phone call. It's almost like a videogame, Gregg says, as you can drive the thing and respond almost instantly to data and what you see on top.

Mars rovers perform a series pre-planned commands on the surface of Mars. VIPER operators stop and move the rover every fifteen feet depending on what they see through the cameras. NASA scientists can quickly decide where to drill next after the lunar rover samples have been analyzed in an area. "It allows me to plan, react and optimize my observations in ways we wouldn't normally learn much from other rovers like Mars rovers," Colaprete says. This mission has a truly unique and exciting aspect.

Editor's Note, October 14, 2021. This article has been updated by NASA with new information that indicates VIPER cannot survive longer than 50 continuous darkness hours.