Faster than a speeding bullet and more dangerous than a locomotive, the damaged 8.5-ton Chinese space station is set to plummet to earth within the next few weeks.

Looking more like a small submarine than a satellite, the orbiting lab, complete with massive solar panels, is expected to crash land on the ground with whatever is left after the atmosphere burns up most of the structure.

Launched September 2011, the Tiangong-1 craft, literally: “Heavenly Palace 1,” was China’s first prototype station that served as both a manned laboratory and an experimental facility for many years, allowing tests with orbital rendezvous and docking maneuvers. Over its lifetime, Tiangong-1 was visited by a series of Shenzhou spacecraft bringing people and supplies to the lab. This included China’s first female astronauts, Liu Yang and Wang Yaping who are both still active in their space program.

By March 2016, the Space Engineering Office announced that Tiangong-1 had officially ended its service since the telemetry link with the satellite had been lost. Several months later amateur satellite trackers around the world found that although Tiangong-1 was 180 miles high in orbit it was out of control and falling at a rate of 7 miles per month – a number expected to increase as the craft hits denser atmosphere.

Jonathan McDowell, renowned Harvard astrophysicist and space industry enthusiast, told The Guardian that “It would be impossible to predict where the debris from the Tiangong-1 space station will land. You really can’t steer these things,” he said. “Even a couple of days before it re-enters we probably won’t know better than six or seven hours, plus or minus, when it’s going to come down.”

McDowell added that a slight change in atmospheric conditions could nudge the landing site “from one continent to the next” and conceded that while most of the eight tons of space station mass would vaporize as it passes through the atmosphere, some parts, such as the rocket engines, were so dense that they “wouldn’t burn up completely.”

You may recall that exactly the same thing happened to America’s Skylab which fell back to Earth amid huge worldwide media attention in July 1979. In orbit only six years, Skylab was the United States’ first and only space station and provided detailed observation of the Sun with a specially constructed solar observatory.

Sadly, Skylab was doomed from the start, having lost one of the main solar panels during launch and another completely jammed in its mounting. Although power was limited, numerous scientific experiments were conducted during its operational life and a great deal of data obtained.

Over the years many announcements were made in Congress to fund and refurbish Skylab using the new Space Shuttle to boost it higher. Unfortunately, due to delays with the development of the Space Shuttle, Skylab’s decaying orbit could not be stopped.

On the day it finally descended, NASA ground controllers attempted to adjust Skylab’s trajectory and orientation to try to minimize the risk of debris landing in populated areas. Hoping to hit a spot in the ocean 810 miles south of Cape Town, South Africa, the craft’s atmospheric reentry began on July 11, 1979, almost 10 years to the day that Neil Armstrong stepped foot on the Moon.

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Many people on earth and an airline pilot saw dozens of colorful firework-like flares as large pieces of the space station broke up in the atmosphere. Because the craft was as large as a Dutch windmill, Skylab did not burn up as fast as NASA expected and parts of its body hit the ground in Western Australia.

Analysis of some debris indicated that the station had disintegrated only 10 miles above the Earth, a point much lower than NASA predicted. But then again, falling satellites have existed since 1958 when Sputnik-1 burned up while reentering Earth’s atmosphere after three months in space.

Many will probably remember the secret Soviet Cosmos spy satellite that blew up over Canada in 1977, spewing deadly plutonium from its power generator over the Arctic frozen ground.

On June 4, 2000, the Compton Gamma Ray Observatory tumbled through Earth’s atmosphere, snapping off its solar panels and radar dishes as it plunged into the Pacific Ocean southeast of Hawaii. In November 2013, the one-ton European Space Agency’s GOCE satellite fell from space after it ran out of its xenon ion fuel.

Some people have been actually hit by space junk that has fallen out of orbit. On Jan. 22, 1997, a woman in Turley, Oklahoma was struck in the head by a piece of charred woven material, debris from a Delta 2 rocket booster which had reentered the atmosphere and did not fully burn up on its travel down.

Besides death, we can also say that gravity is a great leveler.

Gary Hanington is Professor Emeritus of physical science at Great Basin College and chief scientist at AHV. He can be reached at garyh@ahv.com or gary.hanington@gbcnv.edu.

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