“Earlier this year, there were two separate incidents of space debris Chinese rocket falling in unexpected places on Earth. A Chinese Long March 5B rocket was reported to have crashed in Australia’s New South Wales region in July after it went out of control and re-entered Earth’s orbit. They are now confirmed to be debris from the SpaceX Crew-1 mission.”
As the space industry grows, it is safe to say that such incidents will only increase and pose a threat. But how big a threat could space debris Chinese rocket falling to Earth be? china space station
Space debris refers to systems sent by humans into space, whose malfunctioning or redundant parts fall to Earth. It can also be a satellite that has reached the end of its life (as the International Space Station will reach the end of its operational life in 2031) or parts of a rocket system that has completed its mission in space and then deprecated on earth. spacex satellite space debris falling on earth
So far, China has launched three Long March 5B rockets into space and all three have been deliberately launched into uncontrolled orbits. This means that it is not known when and where they will fall.
As for the SpaceX satellite debris that landed in the Australian Snowy Mountains, it can be said that SpaceX satellite launches its rockets out of orbit with full control and designs them in such a way. When they re-enter Earth’s atmosphere, they burn up. But as you saw in the latest news, these things don’t always go according to plan. space debris removal
Is Space Debris Dangerous? space debris falling on earth
As far as we know, only one person on Earth has been hit by space debris. Lottie Williams, a resident of the US state of Oklahoma, was hit by a piece of shrapnel on her shoulder in 1997 but was unharmed. The debris was about the size of his hand and is believed to have come from a Delta-2 rocket. Ms. Luti picked it up, brought it home, and reported it to the authorities the next day. china space station
But as more and more systems, rockets, and space stations go into space, there are growing concerns that they could come back down and hit people or property. This is especially true of large and uncontrollable objects such as Long March 5B. space debris falling on earth
This model of the rocket has been launched three times. The first re-entered Earth’s atmosphere on May 11, 2020, and parts of it fell on two villages in Ivory Coast. The second one fell near the Maldives on May 9, 2021, while the third one re-entered the Earth’s atmosphere over Indonesia and Malaysia and its debris fell around those islands. space debris chinese rocket
So should we worry about space debris?
The chances of someone being injured by space debris are very low and are estimated to be about one in ten thousand. It can happen to anyone anywhere in the world. However, the chances of it happening to a particular person (like you or me) are on the order of one in a trillion.
There are many factors behind these estimations or estimates, but let’s focus on one important one for now. An image shows the path that the recent Long March 5BY-3 took in its last 24 hours (different objects follow different orbital paths), with its re-entry into Earth’s atmosphere marked in red. has been struck. It shows that the rocket orbits the earth for a long time. Specifically, in these orbits, it spends about 20 percent of its time on Earth. A rough estimate tells us that 20 percent of Earth is inhabited, which means there is only a four percent chance of Long March 5b re-entering a populated area.
This may sound overwhelming. But when you consider how many people the ‘populated earth’ is actually surrounded by, the chance of injury or death drops significantly. On the other hand, property damage is more likely. The chance of Long March 5b re-entering could also be at most one percent. However, the overall risk posed by space debris will increase as more objects are launched and re-entered the atmosphere. Many more launches are in the current plans of companies and space agencies around the world. china space station
China’s Tiangong space station is scheduled to be completed by the end of 2022. And South Korea recently became the seventh country to launch a satellite payload weighing more than one ton as it plans to expand its space sector (along with Japan, Russia, India, and the United Arab Emirates).
As a result, it is highly likely that the risk of injury from debris will only increase (but hopefully remain very low). space debris chinese rocket
Can we prepare to avoid space debris? china space station
Two questions come to mind: Can we predict debris re-entry into Earth’s atmosphere, and what can we do to reduce the risk? space debris removal space debris falling on earth
Let’s start with predictions. In this case, it can be extremely difficult to predict where an uncontrolled object in orbit will enter Earth’s atmosphere. As a general rule of thumb, the expected re-entry time will be 10 to 10 percent of the orbital time. space debris removal space debris chinese rocket
This means that a ten-hour reentry forecast for an object would mean an uncertainty margin of about one hour. So if an object is orbiting the Earth every 60-90 minutes, it can enter anywhere at any time.
Improving this uncertainty margin is a major challenge and requires much research. Even so, it is unlikely that we will be able to accurately predict the re-entry point of an object at a distance of 1,000 km (621 miles).
Ways to reduce the risk of falling space debris? china space station
Mitigating risk is a challenge, but there are certainly options. First, all objects sent into Earth’s orbit should be designed in such a way that they fall out of orbit in an unpopulated area. This is usually the SPOUA (South Pacific Uninhabited Area), also known as the ‘Spaceship Graveyard’.
It also involves carefully designing the components so that they break down completely when they re-enter the Earth’s boundary. If everything burns up on impact with the Earth’s upper atmosphere, then there will be no significant danger left. space debris falling on earth
There are already some guidelines for reducing the risk of space debris, such as the United Nations Guidelines for the Long-Term Sustainability of Outer Space Activities, but their methodology has not been defined. Moreover, how do these guidelines apply internationally, and who can enforce them? Such questions are still unanswered. SpaceX satellite china space station
In summary, should you worry about being hit by space debris? So the answer, for now, is no. Is more research on space debris necessary for the future? So the answer is an absolute yes.