Yesterday at 21:00 Australian Oriental standard time, the Ingenuity helicopter – which landed on Mars with the Perseverance Rover in February – took off from the Martian surface. More importantly, it hovered for about 30 seconds, three feet above the surface and came back again.
It may not sound like a great achievement, but it does. Ingenuity’s flight is the first powered flight of an airplane on another planet. This is a milestone in the story of human space exploration.
While the Apollo 11 spacecraft made the Moon famous, at the new launch it simply had to leave the gravity of the Moon and return to Earth. However, maintaining flight within the environment of a world without atmosphere is a different story.
The now historic Ingenuity helicopter took six years to make. We can understand why, once we understand the complexity of the requirement.
Today I watched the history. Now you can too. You are watching the video of the #MarsHelicopter‘s first flight – a true “Wright brothers” moment.
See how it all unfolds:
ā Spin-up
Ascension
About Hover
ā Turn
LandingRead more: https://t.co/FIsf5RfHGjpic.twitter.com/hucsBY2RDE
– NASA’s Perseverance Mars Rover (@NASAPersevere) 19 April 2021
Why local flights on Mars are a big problem
There are several technological challenges to flying a helicopter flight to another world. First, and most importantly, helicopters need an atmosphere to fly.
The blades or rotors of a helicopter must rotate fast enough to generate a force called lift. But elevator can only be generated in the presence of an atmosphere. While Mars does have an atmosphere, it is much, much thinner than Earth’s – in fact about 100 times thinner.
Flying ingenuity in Mars’ atmosphere is thus the equivalent of a helicopter on Earth at an altitude of 100,000 feet. For reference, commercial aircraft fly between 30,000-40,000 feet above the earth’s surface and the highest we have ever been in a helicopter on earth is 42,000 feet.
To test the vessels on Earth, a room under pressure was needed, from which much air would be extracted to emulate the atmosphere of Mars.
Then there is the Martian gravity to consider, which is about one-third of the gravity on Earth. It actually gives us a slight advantage. If Mars had the same atmosphere as Earth, it would mean less gravity that we would be able to absorb the ingenuity with less force than would be necessary here.
But while Mars’ gravity works to our advantage, it’s compensated by the lack of atmosphere.
Ingenuity’s success is the first time that even a flight outside the earth has been attempted. And the reason for this may be simple that this task, as outlined above, is very, very difficult.
Read more: ‘7 minutes scared’: a look at technology Perseverance will need to land on Mars
Advanced manufacturing
There are two ways in which Ingenuity was able to overcome the obstacles in Mars’ atmosphere. First, to generate charge, the two rotors (made of carbon fiber) had to rotate much faster than any helicopter on earth.
On Earth, most helicopters and drones have rotors that rotate at about 400-500 revolutions per minute. The Ingenuity’s rotor rotated at about 2400 rpm.
It also has a clear relationship between aircraft and wing span. While Ingenuity’s body is about the size of a tissue, the blades are 1.2 m from point to point.
Even sending the signal for the start of the flight required advanced technology. Although it only takes minutes for radio signals to travel between Earth and Mars, there were still a few hours of delay to reach the helicopter.
It makes sense when you consider the journey that these signals must take – from a computer on earth, to a satellite dish, to the Mars Reconnaissance Orbiter, to the Perseverance Rover and then, finally, to the helicopter.
Remote flight on Mars
Ingenuity is what we call a ‘technology demonstrator’. Simple, its sole purpose is to prove that it can complete a series of simple missions. In the next few weeks, the helicopter will undertake three or four more flights, the most adventurous of which will take off and travel about 300 meters from Perseverance.
Data obtained from the flights will be analyzed and used as important input for future designs of more sophisticated aircraft. Once this technology is applied, its potential will be huge.
Drones and helicopters operating on Mars can act as scouts and check the land in front of a rover to confirm whether it is safe to travel there. Such aircraft can even help with the search for water and life on the Martian surface.
And in 2035, the first humans are expected to land on Mars. There is a good chance that this crew will be trained to operate aircraft locally and in real time and locate the land for obstacles and dangerous sites that could damage people, or pack, damage aircraft or robbers.
Tribute to the past, with the future in sight
As a moving tribute to the first flight on Earth, scientists from the NASA Jet Propulsion Laboratory added a historic artifact to the Mars helicopter. Attached to a cable under one of its solar panels was a small wing of the 1903 Wright brothers.
This item of flight history is the second piece of an earth-plane that enters space; a similar piece of wing was taken to the Moon during the Apollo missions.
Missions are already placing the obstacles of powered flight to other worlds. In particular, it is planned that the Dragonfly helicopter will fly above the surface of Titan, one of Saturn’s moons, with the arrival for 2034.
Perhaps it will also take with it a piece of Earth’s history as we continue our worldwide exploration of other planetary bodies. 
“We’ve been talking for so long about our Wright brothers moment. And here it is.”
MiMi Aung, #MarsHelicopter Project Manager, take a moment to @NASAJPL team following the news of the successful Ingenuity test flight: pic.twitter.com/qeoQnOdXiK
– NASA (@NASA) 19 April 2021
This article by Gail Iles, senior lecturer in physics, RMIT University, was published from The Conversation under a Creative Commons license. Read the original article.