China is investigating how to build a super-sized spacecraft up to 0.6 miles (1 kilometer) long. But how feasible the idea is and what is the use of such a huge spacecraft?
This project is part of a broad call for research proposals from the National Natural Science Foundation of China, a funding agency managed by the Ministry of Science and Technology of China. NS research summary The giant spacecraft, posted on the Foundation’s website, is described as “a major strategic aerospace device for future use of space resources, exploration of space mysteries, and long-term life in orbit.” I am.
The Foundation is urging scientists to research new lightweight design methods that can limit the amount of construction materials that must be put into orbit, and new technologies for safely assembling such huge structures in space. I want it. If funded, the feasibility study will be conducted for five years and the budget will be 15 million yuan ($ 2.3 million).
The project may sound like a science fiction novel, but former NASA chief technologist Mason Peck said the idea wasn’t completely off the wall and the challenge was more engineering than basic science. Said it was a problem.
“I think it’s perfectly feasible,” Peck, now a professor of aerospace engineering at Cornell University, told Live Science. “I will explain the problem here as a matter of scale, not as an insurmountable obstacle.”
According to Peck, launching objects and materials into space can be very expensive, so the biggest challenge to date is the price tag. The International Space Station (ISS) is only 361 feet (110 meters) wide at its widest point. According to NASA Building 10 times larger will cost even the most generous national space budget, as it costs about $ 100 billion to build, Peck said.
But it depends a lot on what kind of structure China builds. The ISS is packed with equipment and is designed to accommodate humans, resulting in a significant increase in mass. “If you’re just talking about something that’s long and not heavy, that’s another story,” Peck said.
Construction technology can also reduce the cost of bringing a huge spacecraft into space. Whereas the traditional approach was to build components on Earth and assemble them in orbit like Lego, 3D printing technology can turn compact raw materials into structural components of much larger dimensions in space. There is sex.
An even more attractive option is to procure raw materials from Moon According to Peck, the lower gravity than Earth makes it much easier to launch matter from the surface into space. Still, it’s not an option in the short term, as it initially requires a lunar launch infrastructure.
Big spaceship, big problem
The structure of such large proportions will also face unique problems. Peck says that whenever a spacecraft receives force, whether it’s maneuvering in orbit or docking with other vehicles, its movements energize the spacecraft’s structure, causing it to vibrate and bend. , Explained. With such a large structure, it takes a long time for these vibrations to subside, so the spacecraft is likely to require shock absorbers or active controls to counteract these vibrations, he said.
Designers also need to make careful trade-offs when deciding what altitude a spacecraft should orbit, according to Peck. At lower altitudes, dragging from the outside air slows the vehicle and requires constant boosting to return to a stable track. Peck pointed out that this is already a problem for the ISS, but for much larger structures where greater drag acts and requires more fuel to return to its original position, it becomes a major concern. Become.
On the contrary, launching to higher altitudes is much more expensive and radiation Levels increase rapidly as objects move away from the Earth’s atmosphere. This is a problem when the spacecraft contains humans.
However, while it may be technically feasible to build such a structure, it is not feasible in a practical sense, a professor of aerospace engineering at the University of Illinois at Urbana Champaign, a government and commercial space program. I have been working on both.
“It’s like we’re talking about building a Starship Enterprise,” he told Live Science. “Thinking is fantastic, not feasible, and fun, but not very realistic at our technical level,” he said.
Given the low budget for research projects, it is likely that outlining the very early stages of such projects and identifying technical gaps is only a small academic study, Lembeck said. Stated. For comparison, the budget for making capsules to take astronauts to the ISS was $ 3 billion. “Therefore, the level of effort here is very small compared to the desired result,” he added.
There is also a question about what such a large spacecraft is used for. According to Lembeck, the possibilities are space manufacturing facilities that use microgravity and abundant solar power to build high-value products such as semiconductors and optics, and long-term for off-world life. Habitat is included. However, both come with enormous maintenance costs.
“Space stations are a $ 3 billion company annually,” Lembeck added. “If you have a large facility, multiply it and you’ll quickly become a fairly large and expensive company.”
China is also showing interest Build a huge PV array in orbit It then sends power back to Earth via a microwave beam, but Peck said the economics of such projects are not stacking up. Peck has done some back-of-the-box calculations and estimates that it will cost about $ 1,000 per watt, compared to just $ 2 per watt of energy generated from solar panels on Earth.
Perhaps the most promising application of such a large space structure is scientific, Peck said. Space telescopes of that size can potentially see surface features of planets in other solar systems. “It can change our understanding of exoplanets and potentially life in space,” he added.
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https://www.scientificamerican.com/article/china-wants-to-build-a-mega-spaceship-thats-nearly-a-mile-long/ China wants to build a mega spacecraft about a mile long