Why NASA will send two more helicopters to Mars

Why NASA will send two more helicopters to Mars

NASA’s Perseverance rover is currently collecting rock and soil samples from Mars’ Jezero crater that will one day be returned to Earth. According to the current plan, the rover should deliver the sample tubes itself to a Mars lander for return home in 2030. But if anything goes wrong, two small helicopters will be ready to fly in, NASA’s Mars Sample Return team announced in late July.

When this occurs, the Sample Recovery Helicopters will be the second and third rotorcraft ever to fly to another planet. And their inclusion on the Mars Sample Return mission, a joint effort by NASA and the European Space Agency, could herald the beginning of a new chapter in Mars exploration – one in which small, light helicopters will regularly orbit the red planet.

The news that helicopters have been added to the Mars Sample Return mission comes just over a year after the first aircraft in history made a powered flight to another planet when NASA’s Ingenuity helicopter entered the Martian skies in April 2021 rise. Since then, the experimental rotorcraft has deployed 28 more flights, far exceeding expectations.

“The whole point of Ingenuity was to be the Wright Brothers moment that leads to a future in the wider aerial exploration of Mars,” says Teddy Tzanetos, Ingenuity Mars Helicopter team leader at NASA’s Jet Propulsion Laboratory. “The goal of Ingenuity was to make flying boring…Now we can just keep doing boring flights and doing exciting things with boring flights.”

Originally, the Mars Sample Return mission concept included a so-called fetch rover: a robot that can collect the samples that have already been temporarily stored in tubes by the Perseverance rover. The Fetch rover would have taken them several hundred meters above the Martian surface to a lander near Jezero Crater, where the sample tubes would be transferred to the Mars ascent vehicle. The rocket-powered ascent vehicle would then launch the container containing the sample tubes into orbit, where a spacecraft bound for returning to Earth would be waiting.

But, says Ann Devereaux, Mars’ deputy program manager for sample return, “getting a rover big enough and capable enough to collect decent samples was problematic.” It would be costly to ship such a rover along with Mars Design and ship Ascent Vehicle.

The team was exploring other concepts when Ingenuity made its first test flights. After the rotorcraft proved a success, engineers began investigating whether helicopters might be the best option for retrieving Perseverance’s cached samples.

[Related: This sailplane could cruise Mars for months on only wind]

Helicopters are smaller, lighter and more maneuverable than rovers in many situations, Devereaux says. Although the planes need a safe place to land, they don’t have to worry about crossing dunes on heavy tires.

The designs for the pattern retrieval helicopters will not differ significantly from Ingenuity. “When it comes to robots in space, legacy is extremely important,” says Tzanetos. “We want to stay as close to the Ingenuity design as possible because we know it’s reliable and robust.”

Because Martian air is so thin – about 1 percent of Earth’s density – any aircraft on Mars must be extremely light and have large, rapidly spinning rotor blades to provide sufficient lift, he explains. Ingenuity’s repeated flights confirmed that NASA’s aerodynamic simulations were accurate – so much so that the models will help engineers build the new pair of flying robots.

“Now we can just keep doing boring flights and doing exciting things with boring flights.”

Teddy Tzanetos

However, the sample recovery helicopters will not be an exact replica of Ingenuity. The team needs to make some adjustments, Tzanetos says, because these two rotorcraft need to be able to do more than just fly. You have to travel about 700 meters from the lander to the cache depot location, take a tube, fly back to the lander and drop it off at a designated drop-off point — and then repeat that cycle 15 times, he says.

And that means the helicopters have to carry more weight than the 4-pound Ingenuity. The current concept design for the sampling helicopters requires additional tools, like arms to pick up samples and wheels to maneuver around the cache depot and drop sites, which Tzanetos says could add another pound to the robots.

“We did the calculations and found that we could make certain changes to the rotor system to make it lift more mass,” he says. After the Mars Sample Return mission leaders decided to move forward with the helicopter pickup concept, Tzanetos and his team are focused on making those optimizations.

One of their first steps is to determine how far they can continue to push Ingenuity’s original rotor system. Just in case the Martian environment was more challenging than the team’s models predicted, engineers designed the test helicopter to have more lift than was deemed necessary.

“We start by figuring out what the sweet spot is where you weigh all these different mass applications,” he says. “We can turn the blades a little faster, we can challenge more from the rotor system, for example, and we can carry a heavier aircraft that we can use to complete the mission.”

In the end, however, the helicopters might not be needed at all. They are flown to Mars just in case the Perseverance rover fails to deliver samples or the robot dies before the salvage is complete.

But the future of helicopters on Mars may already be predicted by the success of Ingenuity.

“This helicopter was phenomenal,” says Devereaux, describing how Ingenuity proved it could fly in front of the Perseverance rover and look ahead for the rover’s ground detection. Helicopters give us an additional perspective on our neighboring planet, she adds. Perhaps one day a drone-like rotorcraft could zoom through canyons like the Valles Marineris, revealing the red planet’s geological strata up close where rovers can’t reach.

For exploring Mars, “rovers have become commonplace,” says Tzanetos. “We understand how to build rovers, we understand how to operate rovers. I hope we’ll say the same thing about helicopters in the coming decades.” Perhaps, he says, fleets of airplanes with wings like airplanes or helicopter-like rotor blades will one day fill the Martian skies.

Leave a Comment

Your email address will not be published.