A stowaway helicopter on NASA’s Mars Rover will attempt the first flight in another world

When NASA’s last Mars rover, Perseverance, launches this week, the robot will have a small stowaway on board: a small box-shaped helicopter. If the helicopter manages to successfully fly over Martian terrain, it will be the first time that a man-made vehicle has flown in another world, and it could open up a new way to explore the Solar System in the future.

The helicopter, called Ingenio, is not the main focus of the rover. The greatest goal of perseverance is to search for signs of life on Mars and unearth samples of earth that could one day be returned to Earth for study. But the engineers managed to find space under the vehicle’s belly to store the small helicopter. At some point during the Perseverance journey, the rover will deploy Ingenuity on the surface of Mars, where it will spin its rotor and attempt to take off.

This interplanetary experiment hopes to provide a new point of view to explore Mars, beyond the current limited options. Mars orbiters cannot obtain the high-resolution images that a spacecraft can obtain close to the ground. Landers can only get information from a fixed location, while rovers can only move to a limited extent, with limited information on what’s ahead. But a helicopter can act as an explorer, doing reconnaissance for other spacecraft or reaching hard-to-reach areas.

That ability to explore could be super useful if humans ever reach the Martian surface. “Really flying forward and then getting high definition images to inform humans and rovers for tours will really advance world exploration,” says MiMi Aung, project manager for the Mars helicopter at the Jet Propulsion Laboratory at The NASA. “Being able to fly will add a whole new dimension to exploration.”

There is still a major obstacle to flying on Mars: the atmosphere. The air that surrounds the planet is only 1 percent as thick as Earth’s atmosphere. With so little air to move, achieving elevation on Mars will be very difficult. Low gravity on the surface of Mars helps; it is about 38 percent of Earth’s gravity. But even with that help, a vehicle still can’t fly on Mars with the same technologies we use to fly on our planet.

For something to take off in that environment, it has to be super light and the propellers have to move incredibly fast. But they can’t go too fast, or things start to get dangerous. “You can’t keep going faster and faster, because what happens is that the tips of your blades start to get closer to Mach one,” says Bob Balaram, chief engineer of the Mars helicopter at JPL. The edge. “They start to want to become supersonic, and you don’t even want to make them transonic because you get much more turbulent effects.”

With these limitations in mind, a team of NASA JPL engineers set out to invent the first Martian helicopter. The team behind Perseverance established the dimensions of the helicopter, determining that the rover could accommodate a small helicopter with blades that were approximately 1.2 meters, or approximately 4 feet wide. That ultimately determined the weight the helicopter could be, putting it at just 1.8 kilograms, or about 4 pounds. Creating such a small vehicle full of electronics is just something that could have happened today, says Aung. “A few decades ago, light electronics technology (computers, sensors, cameras, gyros) was not available,” he says.

The final design of the helicopter looks like a long-legged spider with an intricate helmet. Ingenuity’s main body is a box with four protruding limbs that keep the vehicle upright on the ground. Four carbon fiber blades are mounted on top, as well as a solar panel to generate power. Those blades are designed to rotate up to 2,400 revolutions per minute, or 40 times per second. The blades of a typical land helicopter rotate at around 450 to 500 revolutions per minute. However, the Ingenuity blades should not exceed the speed of sound, reaching less than 0.7 Mach.

However, building ingenuity was only half the battle. The team had to make sure that the helicopter could fly into another world. “Parallel to the invention of the helicopter is also: ‘How do you prove it?'” Says Aung. “Because it has never been done before.”

Fortunately, NASA’s Jet Propulsion Laboratory is equipped with giant test rooms that could be used for the job. A large camera called Space Simulator in JPL can recreate a total vacuum and manipulate all the extreme temperatures a spacecraft could experience after leaving Earth. To test ingenuity, the engineering team converted the camera into a Mars-like environment. “Basically we take that chamber, we pump it to almost vacuum and fill it with carbon dioxide, so the room now contains an atmospheric density similar to that of Mars,” says Aung.

Another test challenge remained: getting rid of Earth’s heavy gravity. To simulate the lower gravity of Mars, engineers placed a light strap on the prototypes of ingenuity each time they flew in the test chamber. Called the Gravity Unloading System, the tether strap provided a constant upward tug on the spacecraft, making it feel as if the vehicle was in 38 percent of Earth’s gravity.

That test helped shape Ingenuity’s final design. During the first couple of flight tests, the team found that the blades of the test helicopters flapped up and down. The tendency to flap also occurs with helicopters on Earth, since the blades are long and thin. But the thick atmosphere cushions that effect. The thin Martian atmosphere, on the other hand, does not reduce that flutter.

“That was a bit of a discovery for us when we made the first flights,” says Balaram, adding that the flapping could have interfered with the helicopter’s controls. The solution? Engineers made the blades stiffer, much stiffer than a normal helicopter of a similar size on Earth would be.

The team made dozens of test flights in various extreme conditions, including deep cold to simulate Martian nights that can reach -130 degrees Fahrenheit or -90 degrees Celsius. Now, after all that hard work, it’s time for Ingenuity to embark on her journey. To reach Mars, the helicopter will travel folded at the bottom of Perseverance, covered by a shield for your protection. When the rover reaches Mars and finds the right place, Ingenuity will do a complicated gymnastics, spreading out into its final form with its paws pointing towards the ground. Then it will fall to the surface, when Perseverance walks away and leaves it behind.

The team received only 30 Martian days to operate Ingenuity, which is approximately 31 Earth days. The first flight will be simple: the helicopter will attempt to take off and climb to a height of approximately 10 feet, or 3 meters, floating there for 30 seconds or so. It will be brief, but it will determine whether all the hard work from the engineers was worth it. “I think I will feel like: finally, our son, so to speak, is in the environment that has developed over all these years,” says Aung.

The mill will make up to four short flights, pushing the envelope with each progressive takeoff. No flight will last more than approximately 90 seconds. But the mill could reach up to about 15 feet or 5 meters in height and travel horizontally for about 160 feet or 50 meters.

All these flights will have to be autonomous, thanks to the long delay in communication between Earth and Mars. The team will send a list of commands to Ingenuity and perform all the steps on their own. The plan is for the helicopter to capture images when it flies, and Perseverance may also be able to take some distant images of Wit floating in midair.

At the end of the day, Ingenuity is a technology demo, so your flights should be short and direct. But it could prove that flying machines can be valuable for future missions to Mars. Engineers are already working on designs for larger helicopters weighing up to 44 pounds or 20 kilograms. Larger helicopters could carry much more significant science payloads and nicer cameras than Ingenuity now has.

But before you can walk, you first have to crawl. And that’s what ingenuity is all about. “I hope we have what I like to call our ‘Wright Brothers moment,'” says Balaram. “But it is a controlled flight on another planet.”