By Eric J. Savitz, editor-in-chief, GM News
This video shows some of the capabilities of the Eagle Lunar Terrain Vehicle, including Crab Walk and zero-point turns.
By Eric J. Savitz, editor-in-chief, GM News
Imagine you could drive a GMC Hummer EV on the Moon.
How much fun would that be?
On the one hand, you’d get up to 1,000 horsepower, an estimated 367 miles of range on a full charge, and the ability to work through tight spaces with Crab Walk mode, tackle obstacles with extreme ground clearance. And on the other hand, you’d be doing that at one-sixth of Earth’s gravity.
Also, General Motors has no dealerships on the Moon, there aren’t any lunar charging stations, and the Hummer isn’t really designed to work in a place with almost no atmosphere and drastic temperature extremes. So, there would be complications.
But we’re working on a more than fair alternative by applying the offroad technology that makes the Hummer EV so capable on tricky terrain like the slickrock in Moab to lunar duty.
NASA is preparing for the first crewed exploration of the lunar surface in more than 50 years. As part of its Artemis program, NASA has chosen three teams to compete to develop a new Lunar Terrain Vehicle, which will be the successor to the Apollo program’s lunar rover. General Motors is working with a group led by Colorado-based Lunar Outpost on a proposed Moon vehicle. The Eagle Lunar Terrain Vehicle is informed by GM’s expertise in designing and producing rugged off-road vehicles – like the Hummer – while also leveraging GM’s strong market position in electric vehicles and advanced battery technology.
General Motors and Lunar Outpost will offer the public a rare chance to see the Eagle LTV later this month at the State Fair of Texas in Dallas, which runs from September 26 to October 19. On the opening weekend of the fair, we’ll be displaying the new rover alongside a Hummer EV, with which it has more in common than you might imagine. You’ll find the vehicles in the GMC display at the event.
As we’ve previously noted, the lunar vehicle prototype under development by the Lunar Outpost-led Lunar Dawn team includes GM-designed lithium-ion batteries with high-nickel cathodes, a technology often called NCMA, an acronym for nickel cobalt manganese aluminum oxide. Similar batteries can be found in the Hummer EV and other GM electric vehicles. NCMA batteries provide high energy density, long lifespan, high power output, and a wide operating temperature range, which as it turns out makes them an excellent choice for a lunar vehicle. Among other features, the vehicle has an estimated 10-year and 30,000 kilometer service life, nearly 1,000 times the distance travelled by the three original Apollo lunar rovers combined.
Engineered with the rugged capability of a Hummer, the Eagle would navigate the lunar surface with confidence — a reliable asset for astronauts executing complex mission tasks in extreme conditions.
Matt Nassoiy, program engineering manager for GM’s work on the lunar project, notes that there are more common features on the two vehicles than you might imagine. “GMC Hummer is a super truck, and this is a super truck for the Moon,” he says. “It has many of the features of the Hummer but adapted for a more extreme environment.”
Hummer EV mobility features like Crab Walk and King Crab mode are made possible by having three independent motors, one on each of the rear tires, and a third for the front wheels – that configuration allows the wheels to turn in same direction so the vehicle can drive laterally around objects. The Eagle LTV takes that idea a step further, with four independent motors, one on each wheel, providing extra flexibility to avoid and conquer lunar obstacles. The Moon is basically an off-roader’s heaven – there is no black top on the lunar surface. “There are no roads,” Nassoiy says. “We won’t know what we have to deal with until the vehicle is on the surface.” Those independent motors add considerable vehicle flexibility – the Hummer EV has a tighter turning radius than the far smaller Chevrolet Bolt, for instance.
Among other challenges, the lunar surface primarily consists of loosely packed dust, sand, rocks, and pebbles, which can pose traction issues. To state the obvious, you don’t want to get stuck if you are driving on the surface of the Moon – there is no one to come to the rescue. GM and Lunar Outpost are leveraging features found on the Hummer like traction control, anti-lock brakes and “torque vectoring,” which adjusts each of the four wheels to improve maneuverability and stability on challenging terrain.
One complication with developing a vehicle intended for the lunar surface is how to test it under realistic conditions – such as in one-sixth gravity. For that reason, Nassoiy’s colleague Dave Robinson explains, GM relies on the same driver-in-the-loop simulator technology used to test a wide-range of potential road conditions in developing the Hummer and other GM vehicles. Robinson notes that simulators, which include lifelike wrap-around screens, can create dynamics similar to actual conditions on the lunar surface. Two NASA astronauts have already had a chance to drive the vehicle using GM’s simulator.
That testing is crucial – for both the vehicles, and for their eventual drivers. As Robinson notes, vehicle stability on the Moon is about 3x worse than on the Earth – driving 30 mph on the Moon feels like 90 mph on the Earth.
“Stability is the critical thing here,” he says. “The focus is on maximizing the ability to go over obstacles, and to maintain a low center of gravity. If it tips, that’s game over. We’re working through ‘suspension kinematics,’ to effectively envelop most obstacles.”
Another challenge: keeping operation of the lunar vehicle relatively simple for astronauts who have hundreds of other tasks – driving is not the primary reason they’re going to the Moon. “We try to keep the cognitive load as low as possible,” Robinson says. “It has to be easy to drive, and the vehicle has to be stable.” But the vehicle also needs the ability to travel on its own – for most of its 10-year service life, the lunar vehicle will operate autonomously, mapping the lunar surface and conducting science missions – the vehicle will have a full sensor suite, including LiDAR, radar, and high-resolution cameras.
Adding to the complexity of the mission for the lunar vehicle is the fact that NASA’s plans for Artemis include exploration of the lunar south pole, which has vast, permanently shadowed regions that could potentially include water ice, like the bottom of Shackleton Crater, which is 2.6 miles deep. Temperatures in those areas could drop as low as –382 degrees Fahrenheit, according to the Planetary Society, making them the coldest places in the Solar System – colder than Pluto. Other areas receive near-perpetual sunlight, making them ideal locations for solar power generation for more permanently space exploration in the future.
“Here men from the planet Earth first set foot upon the Moon," reads a plaque placed on the lunar surface by the crew of Apollo 11 in 1969. “We came in peace for all mankind.” Now, at long last, we’re getting ready to go back. Don’t forget the car keys.
Eric J. Savitz, a former reporter and columnist with Barron’s, Forbes, and other publications, is editor-in-chief at GM News. Reach him at news@gm.com.
Imagine you could drive a GMC Hummer EV on the Moon.
How much fun would that be?
On the one hand, you’d get up to 1,000 horsepower, an estimated 367 miles of range on a full charge, and the ability to work through tight spaces with Crab Walk mode, tackle obstacles with extreme ground clearance. And on the other hand, you’d be doing that at one-sixth of Earth’s gravity.
Also, General Motors has no dealerships on the Moon, there aren’t any lunar charging stations, and the Hummer isn’t really designed to work in a place with almost no atmosphere and drastic temperature extremes. So, there would be complications.
But we’re working on a more than fair alternative by applying the offroad technology that makes the Hummer EV so capable on tricky terrain like the slickrock in Moab to lunar duty.
NASA is preparing for the first crewed exploration of the lunar surface in more than 50 years. As part of its Artemis program, NASA has chosen three teams to compete to develop a new Lunar Terrain Vehicle, which will be the successor to the Apollo program’s lunar rover. General Motors is working with a group led by Colorado-based Lunar Outpost on a proposed Moon vehicle. The Eagle Lunar Terrain Vehicle is informed by GM’s expertise in designing and producing rugged off-road vehicles – like the Hummer – while also leveraging GM’s strong market position in electric vehicles and advanced battery technology.
General Motors and Lunar Outpost will offer the public a rare chance to see the Eagle LTV later this month at the State Fair of Texas in Dallas, which runs from September 26 to October 19. On the opening weekend of the fair, we’ll be displaying the new rover alongside a Hummer EV, with which it has more in common than you might imagine. You’ll find the vehicles in the GMC display at the event.
As we’ve previously noted, the lunar vehicle prototype under development by the Lunar Outpost-led Lunar Dawn team includes GM-designed lithium-ion batteries with high-nickel cathodes, a technology often called NCMA, an acronym for nickel cobalt manganese aluminum oxide. Similar batteries can be found in the Hummer EV and other GM electric vehicles. NCMA batteries provide high energy density, long lifespan, high power output, and a wide operating temperature range, which as it turns out makes them an excellent choice for a lunar vehicle. Among other features, the vehicle has an estimated 10-year and 30,000 kilometer service life, nearly 1,000 times the distance travelled by the three original Apollo lunar rovers combined.
Engineered with the rugged capability of a Hummer, the Eagle would navigate the lunar surface with confidence — a reliable asset for astronauts executing complex mission tasks in extreme conditions.
Matt Nassoiy, program engineering manager for GM’s work on the lunar project, notes that there are more common features on the two vehicles than you might imagine. “GMC Hummer is a super truck, and this is a super truck for the Moon,” he says. “It has many of the features of the Hummer but adapted for a more extreme environment.”
Hummer EV mobility features like Crab Walk and King Crab mode are made possible by having three independent motors, one on each of the rear tires, and a third for the front wheels – that configuration allows the wheels to turn in same direction so the vehicle can drive laterally around objects. The Eagle LTV takes that idea a step further, with four independent motors, one on each wheel, providing extra flexibility to avoid and conquer lunar obstacles. The Moon is basically an off-roader’s heaven – there is no black top on the lunar surface. “There are no roads,” Nassoiy says. “We won’t know what we have to deal with until the vehicle is on the surface.” Those independent motors add considerable vehicle flexibility – the Hummer EV has a tighter turning radius than the far smaller Chevrolet Bolt, for instance.
Among other challenges, the lunar surface primarily consists of loosely packed dust, sand, rocks, and pebbles, which can pose traction issues. To state the obvious, you don’t want to get stuck if you are driving on the surface of the Moon – there is no one to come to the rescue. GM and Lunar Outpost are leveraging features found on the Hummer like traction control, anti-lock brakes and “torque vectoring,” which adjusts each of the four wheels to improve maneuverability and stability on challenging terrain.
One complication with developing a vehicle intended for the lunar surface is how to test it under realistic conditions – such as in one-sixth gravity. For that reason, Nassoiy’s colleague Dave Robinson explains, GM relies on the same driver-in-the-loop simulator technology used to test a wide-range of potential road conditions in developing the Hummer and other GM vehicles. Robinson notes that simulators, which include lifelike wrap-around screens, can create dynamics similar to actual conditions on the lunar surface. Two NASA astronauts have already had a chance to drive the vehicle using GM’s simulator.
That testing is crucial – for both the vehicles, and for their eventual drivers. As Robinson notes, vehicle stability on the Moon is about 3x worse than on the Earth – driving 30 mph on the Moon feels like 90 mph on the Earth.
A short video showing testing of the Eagle Lunar Terrain Vehicle in a GM simulator.
“Stability is the critical thing here,” he says. “The focus is on maximizing the ability to go over obstacles, and to maintain a low center of gravity. If it tips, that’s game over. We’re working through ‘suspension kinematics,’ to effectively envelop most obstacles.”
Another challenge: keeping operation of the lunar vehicle relatively simple for astronauts who have hundreds of other tasks – driving is not the primary reason they’re going to the Moon. “We try to keep the cognitive load as low as possible,” Robinson says. “It has to be easy to drive, and the vehicle has to be stable.” But the vehicle also needs the ability to travel on its own – for most of its 10-year service life, the lunar vehicle will operate autonomously, mapping the lunar surface and conducting science missions – the vehicle will have a full sensor suite, including LiDAR, radar, and high-resolution cameras.
Adding to the complexity of the mission for the lunar vehicle is the fact that NASA’s plans for Artemis include exploration of the lunar south pole, which has vast, permanently shadowed regions that could potentially include water ice, like the bottom of Shackleton Crater, which is 2.6 miles deep. Temperatures in those areas could drop as low as –382 degrees Fahrenheit, according to the Planetary Society, making them the coldest places in the Solar System – colder than Pluto. Other areas receive near-perpetual sunlight, making them ideal locations for solar power generation for more permanently space exploration in the future.
“Here men from the planet Earth first set foot upon the Moon," reads a plaque placed on the lunar surface by the crew of Apollo 11 in 1969. “We came in peace for all mankind.” Now, at long last, we’re getting ready to go back. Don’t forget the car keys.
Eric J. Savitz, a former reporter and columnist with Barron’s, Forbes, and other publications, is editor-in-chief at GM News. Reach him at news@gm.com.