This has spawned all sorts of alarming headlines, but even though it weighs 8,500 kilograms (18,700 pounds), it’s not actually that big. And it pales in comparison to other objects that have fallen onto our planet.
Pieces of Tiangong-1 may still make it to the ground, although you probably haven’t got too much to worry about. But here’s how the Chinese station stacks up to some of its bigger competitors.
The biggest re-entry in history was the return of Russia’s Mir space station on March 23, 2001. It weighed a whopping 130,000 kilograms (285,000 pounds), 15 times more than Tiangong-1.
Mir was the biggest space station to orbit Earth until the International Space Station (ISS) was built in the 21st century. It was launched by the Soviet Union in 1986, and was used to conduct research, perform experiments, and much more.
The arrival of the ISS, and a lack of funding, meant that Russia decided to purposefully deorbit Mir in 2001. This was a controlled re-entry, using a docked Progress spacecraft to lower the station’s orbit into the atmosphere and ultimately destroy it.
Re-entry occurred near Fiji, with footage showing the moments it burned up in the atmosphere. At the time, there were plenty of concerns about it hitting inhabited areas or ships, but fortunately it hit in the middle of the ocean, far from any people.
Space Shuttle Columbia
On February 1, 2003, NASA’s Space Shuttle Columbia broke apart during re-entry, killing its seven crew members on board.
With a mass of about 74,000 kilograms (163,000 pounds), it is the second-largest man-made object to break apart on re-entry. Debris from the re-entry fell across a band from Nacogdoches in East Texas to western Louisiana and southwestern Arkansas. No injuries or casualties were reported from the debris.
The breakup was caused by a hole in the wing of the shuttle, which had suffered from a piece of foam striking it at launch. The Space Shuttle program was put on hiatus for more than two years as a result of the accident, and in 2011 it was retired.
Skylab was NASA’s first space station, launched in a single launch by a Saturn V rocket in 1973. It weighed 77,000 kilograms (170,000 pounds), nine times Tiangong-1, and had space comparable to a three-bedroom house. Three crews visited the station, with the last crew leaving in 1974.
The station was left in orbit, but in 1978 it was revealed that increased solar activity would push it lower in its orbit. NASA had plans to boost its orbit with a Space Shuttle, but when the Shuttle program was delayed to 1981, they decided the station could not be saved.
Skylab fell uncontrollably, re-entering the atmosphere on July 11, 1979. Most of the station broke apart, but some pieces fell on a town called the Shire of Esperance in Western Australia. They jokingly fined NASA $400, which was paid in 2009 by a US radio host.
Another Soviet space station, Salyut 6 was brought back to Earth controllably in 1982. It had been in orbit for almost five years, having been launched in 1977.
Weighing 19,000 kilograms (42,000 pounds), more than two Tiangong-1s, it welcomed five crews over its lifetime (although the first crew was unable to dock).
It was commanded to re-enter on July 29, 1982, reportedly burning up safely.
The Soviet Union’s Salyut 7 space station was launch in April 1982, and welcome 12 crewed launches over its lifetime. It suffered a couple of problems, including a loss of power, but overall had a decent run. It weighed about 19,000 kilograms (42,000 pounds), more than double Tiangong-1.
Like Skylab, however, it was the victim of increased solar activity. In 1986, much of its equipment had been transferred to Mir, but by 1994 the remains of the station were in trouble.
It entered on February 7, 1991. The plan had been to dump it in the Pacific Ocean, but it overshot and rained debris over the town of Capitán Bermúdez in eastern Argentina.
Almaz-T2 (Kosmos 1870)
The Soviet Almaz-T2 satellite was launched on July 25, 1987. It provided radar imagery and is heralded as the first commercial radar satellite.
It was placed in an orbit about 250 kilometers (155 miles) high and weighed about 18,000 kilograms (40,000 pounds). Yes, that’s about two Tiangong-1s.
It was de-orbited on July 30, 1989. Not too much is recorded about the event, but based on the fact there aren’t many negative stories about it, we’d fathom it went pretty smoothly.
After Almaz-T2, you’ve got a host of other Soviet satellites and space stations that fell back to Earth, all about twice the size of Tiangong-1. These included Salyut 1 to 5 and Almaz 1.
Then you’ve got bits from the Apollo missions. These start with the Apollo 5 nose cone, coming in at 15,500 kilograms (34,000 pounds), followed by the command and service modules for Apollos 6 through 10.
Following this in terms of size, there's a host of other Soviet stations and satellites deorbited that were about twice the size of Tiangong-1.
So, China’s first space station really isn’t that big. Sure, there’s a chance some debris from it might make it to Earth, but you probably haven’t got that much to worry about.