Nissan has announced that it and the Japan Aerospace Exploration Agency (JAXA) are working together to develop a new prototype rover that could one day explore the surface of the moon. Nissan has been working with JAXA to improve driving controllability since January 2020. Lunar rovers face significant challenges when tasked with exploring the moon’s surface.
One of the major challenges is the regolith that covers the surface of the moon. The material is very powdery and has a tendency to cling to anything it touches, accelerating component wear and sometimes damaging the sensors. The lunar surface also features boulders and hilly terrain that require a sufficiently controllable, powerful, and rugged rover to survive and work.
Nissan’s work on the rover prototype focuses on the engine control technology that was developed for the LEAF electric vehicle and its e-4ORCE integral control technology used on the new Ariya electric crossover. Nissan claims that its e-4ORCE technology is an important component for the JAXA rover that helps improve performance on difficult terrain.
Nissan’s technology helps improve vehicle wheel control over a variety of terrains, especially in sandy and harsh conditions. Lunar Regolith is not sand like we would see on a beach, but it does offer some of the same challenges to wheeled vehicles trying to explore the lunar surface. When a car is driven in sand, the wheels spin, causing them to sink into the surface, leaving the vehicle stuck.
On Earth, if you get stuck, you can be removed. On the moon’s surface, roadside assistance is not available. So if a lunar rover gets stuck while exploring the surface, its mission is accomplished. To prevent the rover prototype from getting stuck in lunar regolith, Nissan has developed prime mover controls that minimize wheel slip depending on surface conditions.
Nissan and JAXA jointly research and share technologies developed for the automotive market, while JAXA shares expertise in rover design and research. JAXA works with many companies, universities and research institutes on various projects and aims to apply its research to future space exploration. The research goal for Nissan is to apply what is learned in research to future high-performance lunar rovers.
Nissan says that through its work with JAXA, it hopes to bring innovations to its vehicles that will benefit customers in the long run. The e-4ORCE technology that Nissan uses for the lunar rover was originally developed for its new Ariya electric crossover. The technology makes it possible to individually control the torque of each electric motor to improve traction during acceleration.
Traction can be a challenge for electric vehicles because all of the torque created by the electric motor is instantly available. Cars using combustion engines need to generate torque, so less is available when cranking, which helps minimize wheel slip. Nissan’s e-4ORCE technology can also control the amount of regeneration individually for the front and rear motors during deceleration and the technology minimizes nose-down and body shaking during braking. While the technology was originally developed to help drivers on Earth navigate road conditions, including rain and snow, it also has benefits for exploring the moon’s surface.
Nissan plans to sell its Ariya e-4ORCE model in Japan in the summer of 2022. Nissan started accepting reservations for the Ariya 2023 last month. The vehicle starts at $ 45,950, presumably before destination and handling. The base model has 238 horsepower and 221 pound-feet of torque. Upgrading to the version with e-4ORCE technology starts at $ 58,950. This version produces 389 horsepower and 442 pound-feet of torque and has a range of 265 miles. The lunar rover that JAXA and Nissan are working on does not have a launch date.
Other lunar rovers
Other lunar rovers are currently exploring the surface of the moon. China has placed a lunar rover on the far side of the moon. In October 2020, the Yutu-2 rover traveled the lunar surface for more than 565 meters. It had to go into standby mode during the long lunar night but performed flawlessly for its first 23 lunar days.
The days on the lunar surface are significantly longer than on Earth. A lunar day spans 14 days on Earth, while a lunar night lasts 14 nights on Earth. The Chinese lander and rover had survived 660 Earth days on the far side of the moon as of October 2020. Earlier this year, the rover discovered a strange rock on the moon’s surface that Chinese scientists were investigating. The rock would have been ejected from a nearby crater during an impact.
While Nissan and JAXA are working on their lunar rover, NASA is also working on moon rovers for future missions. One of these rovers is the VIPER rover designed to search for water on the lunar surface. VIPER stands for Volatiles Investigating Polar Exploration Rover and is approximately the size of a golf cart. NASA believes it will be the first rover to sample water ice at the lunar South Pole, where NASA plans to send astronauts on future Artemis program missions.