The Chinese rocket has fallen safely into the ocean

Taking these factors into account, we can establish a window so that we can think of when and where the intensifier will re-enter the Earth’s atmosphere. However, even if you change it for a few minutes, you can set its location thousands of miles away. Thomas G. Roberts, a part-time researcher of the CSIS Aerospace Safety Project, said: “Accurate modeling can be difficult, which means that we still have some serious uncertainties in the re-entry time of space objects.”

This also depends on the structure of the booster to withstand the heat caused by friction with the atmosphere. Some materials may hold better than others, but resistance will increase as the structure breaks and melts. The more fragile the structure, the more it will rupture, and the greater the resistance it creates, which will make it off track faster. Some parts may land earlier or later than others.

By the morning of reentry, the estimate of when it will land should be reduced to only a few hours. Several different groups around the world are tracking this booster, but most experts are tracking the data provided by the U.S. Space Force. Space orbit website. Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, hopes that the timing window will shrink to just a few hours before returning to the morning, and the booster may orbit the earth Run twice. At that time, we should have a clearer understanding of the routes these orbits have traveled and which areas of the earth may be impacted by debris.

When re-entering space, the space force’s missile early warning system will already be tracking the infrared flares from the disintegrating rocket, so it will know where the debris is going. Of course, civilians will not know for a while, because these data are very sensitive-before updating the Space Track website, it will take several hours to complete the work of the entire bureaucracy. If the remnants of the booster land in a densely populated area, we may already know it due to social media reports.

In the 1970s, these were common hazards after the mission ended. McDowell said: “Then people began to feel that it was inappropriate to drop large pieces of metal from the sky.” NASA’s 77-ton Skylab space station was a wake-up call. The debris hit Western Australia. No one was harmed, and there was no property damage, but the world is eager to avoid any similar risks of uncontrolled re-entry of the atmosphere by large spacecraft (for smaller boosters, this is a problem of safe combustion).

As a result, after the core booster entered orbit and separated from the auxiliary booster and payload, many launch providers quickly carried out deorbiting combustion, brought it back to the atmosphere, and placed it on a controllable sea crash route. , Thereby eliminating the risk that if it stays in space, it will constitute. This can be achieved with a restartable engine or an additional second engine designed for derail combustion. The remnants of these boosters were sent to remote areas of the ocean, such as uninhabited areas in the South Pacific, and other large spacecraft (such as the former Russian Mir space station) were also abandoned.

Another method used during the space shuttle mission is to avoid large boosters like the Ariane 5 in Europe. This method is currently used to avoid putting the core stage completely in orbit, but only in Turn it off a few seconds before it is still in the earth’s atmosphere. Then, the smaller engine fired to carry the payload to a shorter distance into space, while the core booster was dumped in the ocean.

These options are not cheap, they will bring some new risks (more engines means more points of failure), but “this is what everyone has to do, because they don’t want to cause this kind of debris risk,” McDowell said. “Avoiding these boosters into orbit is standard practice worldwide. The Chinese are an exception.”

why? Roberts said: “Space security is not China’s top priority.” “With years of space launch business, China has the ability to avoid this weekend’s results, but choose not to do so.”

The past few years Many rockets launched by China were allowed to fall back to the ground, Destroying village buildings and exposing people to toxic chemicals. Roberts said: “No wonder they are willing to roll the dice in uncontrolled atmospheric reentry. In contrast, the threat to densely populated areas is much smaller.” “I found this behavior completely unacceptable, but not Not surprising.”

McDowell also pointed out what happened during the space shuttle Colombia When the disaster occurred, damage to the wing caused the entrance of the spacecraft to become unstable and rupture. Nearly 38,500 kilograms of debris landed in Texas and Louisiana. The large backlog of the mainframe is piled up into a swamp-if it broke a few minutes ago, then these parts may hit a major city, such as a skyscraper in Dallas. McDowell said: “I don’t think people appreciate our luck without ground casualties.” “We have been in these dangerous situations before and we are lucky.”

However, you cannot always count on luck. The CZ-5B variant of Long March 5B is planned for two more launches in 2022 to help expand the rest of the Chinese space station. There is no indication as to whether China plans to change the blueprint for these tasks. Maybe it depends on what happened this weekend.