The dead Russian supply ship Progress 59 is predicted to fall to Earth sometime in the next 24 hours. How much of a danger will it pose?





The sky is falling! Well, not really, but a dead Russian spacecraft certainly is. It’s a seven-tonne Progress cargo vessel that was attempting to take supplies to the International Space Station. However, minutes after launch on 28 April, things went wrong. It started spinning uncontrollably and contact was lost.

Now it’s going to fall back to Earth some time in the next 24 hours, but as yet no one knows where.

Although most of Britain is outside the danger zone, the spacecraft’s orbit sweeps it across many of the major inhabited areas in the world. And even though most of the spacecraft will burn up during the fiery plunge through the atmosphere, perhaps a tonne of fragments is expected to survive.



So what are the chances of being hit by one of these fragments? The short answer is: almost infinitesimal. Experts calculate that Progress 59 has a 62% chance of falling into an ocean or sea. Even if it falls on land, chances are that it will hit an unpopulated area.

It is thought that a piece of space debris falls to Earth on average once a day. However, these pieces are usually small. The last major satellite to fall to Earth was the European Space Agency’s GOCE craft in November 2013, which weighed about a tonne before its downfall.

The largest uncontrolled re-entry took place in 1973 when Nasa’s 85-tonne space station Skylab fell over Western Australia and the Indian Pacific. The Columbia disaster in 2003 scattered debris from the 100-tonne space shuttle across the southern states of the US. The 1977 re-entry of nuclear powered Russian spy satellite Cosmos 954 shot radioactive debris across Northwestern Canada, and another Russian artefact, the defunct Mir space station, was purposely de-orbited over the Pacific in 2001. It weighed 135 tonnes.

All told, Nasa estimates the odds of a person being hit by a piece of space debris are around 1 in 3200. This means that the chances of any particular individual being struck is trillions to one. With odds like that you are millions of times more likely to be struck by lightning.

Even if you are hit, there is no guarantee that it would be fatal or even injurious. The only confirmed incident of a person being hit by space junk took place in 1997. American Lottie Williams was walking through a park in Tulsa, Oklahoma in the early hours of the morning when she saw a beautiful shooting star. Some minutes later she felt a tap on her shoulder, and discovered that a charred piece of metallic-looking fabric had been responsible. After analysis, it was found to be part of a fuel tank from Delta II rocket launched by the US Air Force a year before. The shooting star was the fuel tank re-entering and the shard with Lottie’s name on it had drifted down to earth like a sycamore wing.



To put the danger from space debris into context, consider that the number of naturally occurring meteorites that hit our world is much higher. Tens of thousands of meteorites weighing more than 10 grams hit the Earth every year. Not all of these survive to strike the ground. While there are anecdotes of people being struck by meteorites, the only confirmed case is that of Ann Hodges. In 1954, a meteorite punctured the roof of her house and struck her on the thigh after bouncing from the radio. It left a large bruise.

Converting the number of meteorites into mass, and adding in the contribution from space dust that strikes our atmosphere constantly, gives about 37,000-78,000 tonnes per year, or 101–214 tonnes per day. So, even a couple of tonnes from Progress represents an increase of just a percent or two about the daily average.

The bottom line? Leave the hard hat at home: you’re far more likely to be eaten by a man-eating shark than to be killed by something falling from orbit. And even if you are, it’s most likely to be by a meteorite not a piece of space junk.