UPDATE: Success! The helicopter test flight was a success.

“We can now say that human beings have flown a rotorcraft on another planet,” said a delighted MiMi Aung, project manager for Ingenuity at Nasa’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

An unusual robot was ferried to Mars along with NASA’s Mars rover Perseverance: a helicopter. The helicopter will carry out its first flight today — the first flight by a man-made craft on an extraterrestrial body. It’s a 21st century ‘Wright brothers moment.’

“The moment our team has been waiting for is almost here,” Ingenuity project manager MiMi Aung said at a recent briefing at NASA’s Jet Propulsion Laboratory (JPL) near Los Angeles.

If everything goes according to plan, the 4-pound (1.8 kg) helicopter will slowly take off, fly 10 feet (3 meters) high, hover above the Martian surface for 30 seconds, then rotate and gently (very gently) land on all its four legs.

The debut is modest in scale, but pioneering moments usually are. The Wright Brothers’ first controlled flight of a motor-driven airplane in 1903 covered just 120 feet (37 meters) and lasted seconds. It was a small thing, but it demonstrated that it can be done — just like NASA wants to do now. It’s a groundbreaking moment for space exploration, Farah Alibay, from NASA’s Jet Propulsion Laboratory, told the BBC, adding that the flight felt “absolutely nuts”. 

“We’ve been flying on Earth for just over 100 years, and now we’re like, ‘yeah, we’re gonna go to another planet and fly’. It’s crazy. But that’s the beauty of exploration. That’s the beauty of engineering.”

Ingenuity’s, as the helicopter is named, will being its flight test around 3:30 a.m. Eastern Time on Monday (0730 GMT Monday), data confirming its outcome is not expected to reach JPL’s mission control until around 6:15 a.m. ET on Monday. NASA will have images and video of the flight, thanks to cameras aboard the helicopter, as well as cameras mounted on the Perseverance rover, which is currently 250 feet (76 meters) away from the flight one.

If the test succeeds, Ingenuity will carry out several longer flights in the weeks ahead, resting 4-5 days in between to recharge its batteries. NASA plans to proceed with extreme care, especially as the helicopter doesn’t have a self-righting system — one bad landing or an unexpected gust of wind could essentially end the mission.

Flying on Mars is notably different than flying on Earth, and not just because it’s so far and the commands don’t happen in real-time. The main difference is the lack of an atmosphere — well, Mars does have an atmosphere, but it’s much thinner and rarefied than that on Earth, about 100 times thinner. To compensate for this, Ingenuity features larger rotor blades that also turn faster than would be necessary on Earth. Ingenuity also features a pretty heavy solar panel which it uses to recharge power.

The helicopter was already tested on vacuum chambers on Earth and also passed an important test, surviving in the frigid temperatures of the Martian night using its solar chargers.

“The Ingenuity team has done everything to test the helicopter on Earth, and we are looking forward to flying our experiment in the real environment at Mars,” said MiMi Aung, Ingenuity’s project manager at JPL. “We’ll be learning all along the way, and it will be the ultimate reward for our team to be able to add another dimension to the way we explore other worlds in the future.”

Ingenuity is just a proof of concept mission. If it is successful, it could open up a new dimension for Martian exploration missions, adding aerial surveys to the arsenal of scientific observation