Use wechat scan QR code < / P > < p > to share with friends and circle of friends < / P > < p > <-- On April 23, NASA (< a target = "_ blank" href=" https://news.163.com/news/search?keyword=NASA "> NASA < / a >) engineers not long ago in < a target ="_ blank" href=" https://news.163.com/news/search?keyword=%E7%81%AB%E6%98%9F "> Mars < / a > made history, using the smart < a target ="_ blank" href=" https://news.163.com/news/search?keyword=%E7%9B%B4%E5%8D%87%E6%9C%BA "> helicopter < / a > made its first controlled powered flight in Mars' thin atmosphere for 39.1 seconds. On Thursday, U.S. local time, wit completed its second test flight to Mars, this time flying higher, farther and staying in the air longer < p > the second test flight was conducted at 5:33 a.m. on Thursday, and the location is still in the yezelo crater. The smart once again lifted off automatically from the red surface of Mars, and raised a large amount of dust in the process of rising. This time, the smart flew over 4 meters, tilted 5 degrees, moved about 2 meters horizontally, circled and turned around, aimed the camera in multiple directions, and then returned to the starting point_ blank" href=" https://news.163.com/news/search?keyword=%E7%9D%80%E9%99%86 "> landing < / a >. The flight lasted 59.1 seconds NASA's willpower rover has seen all the operations of the smart at 210 feet (64 meters). Then, this six round < a target = "_ blank" href=" https://news.163.com/news/search?keyword=%E6%8E%A2%E6%B5%8B%E5%99%A8 "> the probe < / a > began to transmit images and other data captured by it back to the earth < p > the chief pilot of the wit, H å "It sounds simple, but there are a lot of unknowns about how to fly a helicopter on Mars," he said. But that's why we're testing the smart, making these unknowns public The smart spacecraft shows a new exploration method that NASA may use in the next few years, and it will become an important supplement to the extraterrestrial ground probes. Although the cost of the small rotorcraft (US $85 million) is only a fraction of NASA's current mission, it carries complex computer hardware and software. The project requires NASA engineers to design solutions to major engineering problems < p > the most difficult part is how to make the helicopter fly over Mars with an atmospheric density of only 1% of the earth. NASA's JPL team overcame these problems with ultra light materials at about 2400 revolutions per minute In its first test flight to Mars on Monday, the smart took off to an altitude of 3 meters, then rotated 90 degrees and finally landed at its starting position. The attempt is the first time a device such as an airplane or helicopter has powered a flight on another planet and has expanded NASA's lead < p > this may also inspire engineers on earth to explore the potential of other unconventional spacecraft, such as robotic soft airships that study Venus clouds, or submarines and UAVs that dive into icy satellite oceans such as Europa At present, NASA has no plan to deploy a second helicopter on Mars, but Bob Balaram, the chief engineer of the project, said that he and his colleagues have started to design a larger Mars helicopter, which can carry about 4.5kg of scientific equipment < p > to complete all the test plans, the smart mission team has little spare time. NASA has allocated only 30 Mars days (about 31 Earth days), allowing them to make up to five test flights. Then, the willpower rover, which is connected to the earth, will set out on its main mission, which is to search for signs of life in the dry river delta at the edge of the crater < p > after the first flight, the remaining flight of the smart will start to carry out limit test. Mimi Aung, project manager of the smart, said she hoped the helicopter would eventually reach about 2300 feet (700 meters) from its starting point（ Small) < / P > < p > <-- EndFragment-->