Perseverance: a helicopter on Mars
To our near planetary neighbour, Mars! And Adam Murphy looked at the newest addition to the Martian landscape: the Perseverance rover, and its travelling companion, the helicopter Ingenuity…
Adam - On the 18th of February, the population of Mars increased by one robot.
The NASA rover Perseverance touched down in the Jezero Crater after a nail biting 7 minutes where it had to land itself safely. Perseverance is just beginning its mission, trundling around in what’s thought to be an ancient lake bed looking for indications of life, and there are some amazing photos to go with it. And, for the first time, some sounds.
That is the martian wind. The breeze on another planet, millions of miles away. And it’s going to pose an interesting challenge to Perseverance’s friend. Usually we send the rovers up alone. But this time, it’s got a buddy, a little helicopter called Ingenuity. Ingenuity is a solar powered drone that hitched a ride on the belly of Perseverance. Drones are becoming common annoyances here on Earth, but making something fly on another planet is a real challenge. The martian atmosphere is very, very thin. The atmospheric pressure on the surface of mars is less than 1% of what it is here on Earth. And it’s much colder than here. The average surface temperature is -63 degrees c.
Both of those pose a big challenge for a helicopter. To take off, a helicopter needs to generate lift. When a wing (or a rotor) whips through the air, it pushes against it. And since as Newton said, every action has an equal and opposite reaction, the air pushes back. If you’ve shaped and angled that wing just right, the push back is upward. But if there’s less air, there’s a lot less to push back against. Like trying to swim in air, instead of water. Which I don’t recommend. It looks very silly. So the rover is super light, its rotors are quite long, and they spin much, much faster than a traditional helicopter, nearly five times faster, to get as much lift as possible.
This is all a proof of concept for a Mars helicopter. It’s to show that it can be done. Nothing is certain in space exploration, but the plan is for it to take a few 90 second flights above the Martian surface over the course of the next month or so, and take some incredible photographs. A view of Mars we’ve never seen. If it can, it opens a lot of avenues for exploration. A rover can’t go everywhere, but a little helicopter buddy could scout ahead, could visit nearby locations the rover couldn’t. Even help the humans who make it to Mars. Which is a lot of pressure on the shoulders of such a little robot. Although not air pressure of course.