The Ingenuity helicopter has successfully completed its historic flight on Mars and safely landed back on the surface, according to NASA.
The first powered, controlled flight on another planet took place at 3:34 a.m. ET.
Unlike when the helicopter's fellow traveller, the Perseverance rover, landed on Mars on February 18, there was a bit of wait to know how the helicopter fared in its attempt.
The helicopter team was in mission control at NASA's Jet Propulsion Laboratory in Pasadena, California, early Monday morning local time to receive and analyse the first data from Ingenuity's flight attempt.
Confirmation of the flight's success came at 6:46 a.m.
The flight was originally scheduled for April 11, but plans shifted after a command-sequence issue was discovered when the helicopter went through a system of pre-flight checks with its software. The Ingenuity team received data on April 16 showing that the helicopter successfully completed its rapid spin test after they had made a tweak to the command sequence.
The chopper autonomously flew through the thin Martian atmosphere, with no help from its teams on Earth.
"We can now say that human beings have flown a rotorcraft on another planet," said MiMi Aung, Ingenuity project manager at JPL. "We've been talking about our Wright brothers moment on another planet for so long. And now, here it is."
Images, in addition to the data, also helped the team confirm that the flight was successful.
A lower-resolution black-and-white image from the helicopter's navigation camera appeared first.
The Perseverance rover has already returned several images it captured of the helicopter.
The rover will continue to send back more images and video from several of its cameras. The team has already shared the full video of Ingenuity's flight, which was captured by Perseverance.
"Ingenuity is the latest in a long and storied tradition of NASA projects achieving a space exploration goal once thought impossible," said acting NASA Administrator Steve Jurczyk in a statement. "The X-15 was a pathfinder for the space shuttle. Mars Pathfinder and its Sojourner rover did the same for three generations of Mars rovers. We don't know exactly where Ingenuity will lead us, but today's results indicate the sky -- at least on Mars -- may not be the limit."
Ingenuity, which is a technology demonstration, flew for about 40 seconds total on Monday. The 4-pound helicopter spun up its two 4-foot blades, rose up three metres in the air, hovered, made a turn, took a photo, and touched back down on Mars.
Ingenuity could fly up to four more times over the coming weeks.
"Mars is hard not only when you land, but when you try to take off from it and fly around, too," Aung said. "It has significantly less gravity, but less than 1% the pressure of our atmosphere at its surface. Put those things together, and you have a vehicle that demands every input be right."
The Perseverance rover helps the helicopter and its mission team on Earth communicate with each other. It received the flight instructions from JPL and sent those plans on to the helicopter. Perseverance is parked at an overlook 215 feet (65 meters) away from the helicopter so it could safely watch the flight and capture images and videos.
During the helicopter's hover, it captured images 30 times per second to feed into the navigation computer. This made sure Ingenuity remained level and in the middle of its 10-by-10-metre air field.
Ingenuity used a second higher-resolution camera pointing toward the horizon to capture images while the helicopter was aloft.
Once the helicopter landed on Mars, it sent back data through the rover to Earth.
Havard Grip, NASA's chief pilot for the Ingenuity helicopter, said this morning's helicopter flight was perfect.
"It was a flawless flight," he said. "It stuck the landing right in the place where it was supposed to go."
That first black-and-white image from the helicopter's navigation camera is key because "that wi...