“I think it’s entirely feasible,” Peck, now a professor of aerospace engineering at Cornell University, told Live Science. The project might sound like science fiction, but former NASA chief technologist Mason Peck said the idea isn’t entirely off the wall, and the challenge is more a question of engineering than fundamental science. If funded, the feasibility study would run for five years and have a budget of 15 million yuan ($2.3 million). The foundation wants scientists to conduct research into new, lightweight design methods that could limit the amount of construction material that has to be lofted into orbit, and new techniques for safely assembling such massive structures in space. A research outline posted on the foundation’s website described such enormous spaceships as “major strategic aerospace equipment for the future use of space resources, exploration of the mysteries of the universe, and long-term living in orbit.” The project is part of a wider call for research proposals from the National Natural Science Foundation of China, a funding agency managed by the country’s Ministry of Science and Technology. But how feasible is the idea, and what would be the use of such a massive spacecraft? SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.China is investigating how to build ultra-large spacecraft that are up to 0.6 mile (1 kilometer) long. The colors in the left image are assigned to different frequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted, horizontally received green is L-band, horizontally transmitted, vertically received blue is C-band, horizontally transmitted, vertically received. The left image shows an area 25 kilometers by 75 kilometers (15.5 miles by 45.5 miles), and the right images show an area 3.1 kilometers by 2.2 kilometers (1.9 miles by 1.4 miles). The left image is centered at 37.7 degrees north latitude and 107.5 degrees east longitude. The images were acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on April 10, 1994. In some areas, the Sui wall is buried by sand that has been blown across the desert. ![]() Detection of the remnant Sui Dynasty wall by radar is allowing Chinese researchers to trace the former location of the wall across vast and remote areas. The wall is easily detected from space by radar because its steep, smooth sides provide a prominent surface for reflection of the radar beam. The entire wall is about 3,000 kilometers (1,864 miles) long, but only a 75-kilometer (45.5-mile) long segment is shown in this image. The Ming Dynasty wall is between 5 meters and 8 meters high (16 feet to 26 feet) in these areas. Orchards and other trees lining a road parallel to the wall show up as bright rectangles on the these two images because the L and C channels are sensitive to complex vegetation structure. The two generations of the wall are seen less distinctly in the L-band image (horizontally transmitted, vertically received) and C-band image (6 cm wavelength, horizontally transmitted, horizontally received). Immediately to the right of this wall is a bright discontinuous line that is the remnant of an older version of the wall, built during the Sui Dynasty, about 1500 years ago. The bright continuous line running from top to bottom in this image is the younger wall, built during the Ming Dynasty about 600 years ago. The L-band image (24 cm wavelength, horizontally transmitted and horizontally received polarizations) provides the clearest image of the two wall segments. Each channel is sensitive to different aspects of the terrain, including two generations of the Great Wall. The black and white images on the right correspond to the area outlined by the box and represent the four radar channels of the Spaceborne Imaging Radar-C (SIR-C). ![]() The wall appears as a thin orange band, running from the top to the bottom of the color image on the left. ![]() These spaceborne radar images show a segment of the Great Wall of China in a desert region of north-central China, about 700 kilometers (434 miles) west of Beijing.
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