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 2023 to look for 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 has the goal to return humans to the moon by 2024.

It's quite amazing to think about how many rovers we have on Mars, and yet we have not sent one to the moon," says Tracy Gregg, University at Buffalo College's planetary volcanologist. That part was kind of overlooked. We sent landing craft, and then sent astronauts in a 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 rover.

VIPERs main purpose is to search for water

Remote sensing data has confirmed that frozen water is already present 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, something that scientists are not able to do remotely. Anthony Colaprete is the VIPERs project scientist at NASA's Ames Research Center. "To really get to the core of some of these questions we need to get up to the surface," he says. This is where the VIPER Rover comes 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 find water in the vicinity of where you are and avoid shipping it through the solar system, 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. The water will melt and you can then collect the water. It would be harder if the water was more chemically bound to lunar materials.

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

Colaprete says, "I don't know what I'm going to find yet." These things are worth exploring with open eyes because you will discover things that we didn't know.

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. Because the moon's axis is slightly tilted compared to Earth's, the sun does not rise as high above the horizon. This leaves craters and basins in permanent shadow. The moon's surface temperatures can reach as high as 225 degrees Fahrenheit during daylight because it lacks Earth's insulating atmosphere. The lunar surface is -400° Fahrenheit at night, and permanently shadowed places, so the polar craters of the moon are some of the coldest spots in the universe.

Thomas Watters, senior scientist at Smithsonian National Air and Space Museum, said 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 of crater basins. Although VIPER's components can withstand extreme temperatures and the rover will need to run heaters in order to keep warm enough to work in darkened areas, it must also be able to operate with heaters. VIPER, unlike Perseverance or other nuclear-powered robots will need to heat using only solar energy.

Colaprete says that when you go into the unknown, many unanswered questions will be answered. The moment 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 some time taking in the energy from the three solar panels and part of that time 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 will be going to a location that is different from anything we have ever explored before, according to Colaprete. The rover can cruise up to 15 degrees on a slope and then handle 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. Four independently controlled wheels, the solar panels, and the drill measuring a meter in length are part of the mobile robot. These will be used to cut samples from lunar soil for analysis by onboard spectrometers.

Colaprete explains that the neutron spectrometer works in a similar way to the bloodhound of a rover. The robot can detect neutrons that are leaking from the soil and can detect hydrogen atoms up to one meter deep, which could indicate water. Near-infrared spectrum can detect minute changes in color from lunar surface. This could reveal water or other volatile compounds. VIPERs mass-spectrometer measures the gas released from the moon's surface. This could be caused by the rover moving 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 safe location until the moon's south pole is visible, which occurs for two weeks each month.

These safe havens provide enough energy for the rover to survive long periods of darkness. VIPER must have regular sunlight access as it cannot survive 72 hours in darkness. Safe havens are areas that allow sunlight to reach the rover for as long as possible. Colaprete says that the majority of time, the rover will be parked in this location and just bask in the sun. The rover switches to hibernation when it gets dark and the temperature drops. This allows them to stay warm and afloat.

To maximize daylight hours, the mission will be carried out 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, unlike rovers on Mars, will be closer to Earth and allow for faster communication. VIPER's latency is only 6-10 seconds, whereas rovers on Mars took 20 minutes to send commands.

Gregg says that the travel time between Earth issuing commands and the rover receiving those commands is only a few seconds. Think of a slow cell phone call. It will be almost like playing video games, as you can drive the thing and respond almost instantly to data and what you see.

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 rovers cameras. NASA scientists can determine where to drill next in minutes after the lunar rover samples have been analyzed. Colaprete says that this allows us to plan, react, and optimize our observations in a way that is not possible with longer periods of observation like Mars rovers. This is a truly unique and exciting aspect to this mission.