BERLIN – If you want to get a last look at the Chinese satellite Tiangong-1, you should hurry. The 19,000-pound satellite, orbiting Earth at 17,500 miles per hour every 90 minutes, is likely to have disappeared by the end of this weekend, appearing somewhere as far as a minute or more as a fireball.
No one can tell exactly where the decaying satellite could literally fall from the sky – with pieces that can weigh up to 220 pounds and reach to the surface of the earth – the fate of the satellite has long been sealed. And even if you miss those missing people, scientists say there will be much more in the dirty skies of Earth's orbit.
First warning signals for the Chinese station appeared in 201
While the threat of debris hitting a human being is extremely small, the visual drama that could spread across European skies this weekend is perhaps only a first glimpse of a growing problem, based on monotonous predictions will manifest in the next few decades.
The European Space Agency estimates there are now more than 170 million pieces of space debris in circulation, though only 29,000 of them are larger than about 4 inches. While such smaller space debris objects pose no threat to the earth as they would dissolve before they reach the surface, each of these objects can cause damage to a functioning spacecraft. For example, a collision with a (4-inch) object would result in catastrophic fragmentation of a typical satellite. "Smaller parts could still destroy spacecraft systems or penetrate shields, potentially preventing larger satellites like Tiangong-1 from responding and turn them into massive pieces of rubble.
Ever since the first satellites were brought to Earth in the mid-twentieth century Orbit has long been treated by nations as a garbage dump nobody felt responsible for, mixing up used rockets and old satellites Now with smaller pieces of garbage left behind by human space programs, all of these pieces are moving faster than speeding balls.
And as the international community gradually becomes aware of the challenges that arise from doing so, much of the Damage already done.
At a conference in 2011, Gen. William Shelton, a commander of the Space Command of the US Air Force, predicted that much of the Earth's orbit around Earth "could be a rather difficult environment in the not-too-distant future," astronomy website Space.com said. The US military and NASA are both responsible for the most sophisticated system of tracking objects larger than four inches to predict their trajectories and eliminate active equipment.
The problem that Shelton hinted at at that time is that the accumulation of space debris itself is already enough to lead to an exponential increase in circulating parts. The more pieces there are, the higher the likelihood that they will collide – and even more smaller objects that can be extremely dangerous to other satellites or space labs.
On Earth, ecosystems can sometimes repair themselves, even if it could take decades or hundreds of years. But in space, the problem of debris will only get worse.
One possible solution proposed would be to persuade nations to limit their debris and prevent recurrence of past mistakes. It is estimated that in an anti-satellite test in 2007, China produced in low Earth orbit up to 25 percent of the objects in circulation today.
NASA graphics show why the international community was outraged when China expanded this zone of depletion. The stagnation is not evenly distributed on the earth: while some scattered parts are farther away, there is a concentration of objects within the so-called geosynchronous region – about 22,235 miles in elevation.
But the highest density of objects can be found in low Earth orbit within 1240 miles of the surface, which is the area that China targeted in its test. There most satellites can be found.
China has continued its military missile tests since 2007, despite refraining from destroying another satellite in orbit. Observers still fear that other nations could launch their own anti-satellite programs, which could lead to a kind of arms race in space.
With more than 50 nations now operating their own space programs, initiatives to limit the release of space debris are somehow easier. Some technological advances had a limited effect, for example, by dropping spent rocket boosters to earth faster than before. (Based on this argument, one could argue that the satellite crash this weekend might actually help relieve orbit.)
Other nations, such as Britain and Switzerland, have experimented with systems to eradicate disorder by removing debris to be collected . But the proposed programs are costly and inefficient, aside from legal challenges.
"Space has no salvage laws, and even if we had the political will to rescue garbage (which I do not believe), we would not be able to bring down the big pieces because we do not own them," Joan Johnson-Freese , A professor at a naval war college, told the Washington Post in 2014.
Therefore, some academics already argue that the lower orbit could soon be lost altogether. Instead, they believe that scientists should design smaller satellites that can travel closer to Earth – and at a safe distance from some of the orbit that could potentially become a killing zone for satellites.