With China’s space station about to crash land, who’s responsible if you get hit by space junk?



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An artist’s impression of Tiangong-1 in orbit.
Aerospace Corporation

Melissa de Zwart, University of Adelaide

The defunct Chinese space station Tiangong-1 is falling back to Earth and about to crash land some time over the next few days. Most experts expect much of it to burn up as it enters the atmosphere, but it is likely that some pieces of the 8.5-tonne station will survive re-entry.

While the odds of the debris falling on a person are small, you may ask: who is liable in the event of damage caused by a space object to a person or property?

Under international law, a State is liable for damage caused by its “space objects” to another State or its space objects. Liability arises under the provisions of the Outer Space Treaty, which deals both with State responsibility for activities in outer space and the attribution of liability where damage has been caused by a space object.




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China’s falling space station highlights the problem of space junk crashing to Earth


The Outer Space Treaty is an international agreement, which came into force in October 1967, has more than 100 member countries, including Australia and perhaps more importantly China.

Rules and liability

The Treaty provides the basic rules of use of outer space by nation States. It requires them to carry on activities in the exploration and use of outer space, in accordance with international law and in the interest of promoting international co-operation and understanding.

States who are parties to that Treaty “shall bear international responsibility for national activities in outer space” regardless of whether those activities are undertaken by or on behalf of the government or by non-government entities.

This is important as it imposes liability on States who are party to the Treaty, rather than the corporations or entities who are launching or operating the space object.

In other words, national governments are responsible to the international community for activities undertaken with respect to space activities by their nationals, whether the launch occurs from that State or not. They are also responsible for launches from their territory by foreign entities.

That means Australia is still responsible for the Australian-built satellites launched last year even though they were launched from Cape Canaveral, in the US.

States will be liable for damage to another State who is party to the Outer Space Treaty caused by the space object or its parts, on Earth and in air and outer space. This includes damage to people, property and corporations.

Thankfully Europe’s space freighter ATV Jules Verne burned up over an uninhabited area of the Pacific Ocean at the end of its mission.

Damages and compensation

No guidance is given under the Treaty regarding how liability for the damage is to be calculated. But a further treaty, called the Liability Convention, provides some further guidance.

The Liability Convention provides in Article II that a “launching state” will be:

(…) absolutely liable to pay compensation for damage caused by its space object on the surface of the Earth or to aircraft in flight.

This high standard of absolute liability reflects what were perceived by the drafters of the treaty as particularly vulnerable parties. People and property on Earth and aircraft in flight cannot avoid or reduce their potential harm from space from catastrophic launch failure or space debris.

But where damage is caused other than on the surface of the Earth or aircraft in flight the principle of fault is applied. The Convention does not elaborate on how fault is to be determined.

On Earth we are used to applying principles of negligence to accidents involving people or property. Negligence considers issues such as the potential of harm occurring, the foreseeability of that harm and whether sufficient measures were taken to reduce or avoid that harm.

It is not clear if these sorts of calculations exist with respect to space.

What is clear is that the Convention is intended to be “victim-oriented”. Claims for damage may relate to any harm caused by the space object including direct and indirect harm.

Article XII says compensation is to be determined on the basis that it should restore the person:

(…) to the condition which would have existed if the damage had not occurred.

But it wasn’t our fault

What about where objects collide in space causing harm to a third party? In this case liability may be shared by the launching States of the colliding space objects, again in accordance with their respective fault, where the damage is in space, absolutely if the damage is on Earth or an aircraft in flight.

Some exceptions exist where the State making the claim with respect to harm is actually responsible for that harm, through its own gross negligence or an intention to cause harm.

There has only been one claim made under the Liability Convention. The Government of Canada made a CA$6 million claim for compensation to the Soviet Union after its Cosmos 954, a nuclear powered satellite, crashed in Northern Canada on January 24, 1978.

While the final, diplomatically negotiated settlement of CA$3 million, did not specifically mention the Liability Convention, it is generally considered that the settlement was negotiated in the context of the Convention. Those costs related to clean up of the contaminated site in such a remote area.




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In 1979 debris from NASA’s Skylab fell to Earth in Western Australia. NASA advertised for claims with respect to damage caused by the debris, but no State-based claims were formally made under the Liability Convention.

There were some claims regarding illegal dumping: the local Shire of Esperance issued NASA with a A$400 littering fine. It was eventually paid in 2003 by a US radio presenter and his listeners who raised the funds.

Tiangong-1 was China’s first attempt at a space station. It was launched aboard a Long March 2F/G rocket from the Jiuquan Satellite Launch Center on September 30, 2011, so it is China’s responsibility.

In the unlikely event that a piece of the Tiangong-1 falls on an Australian, the Australian government would need to pursue a claim with respect to any injury the person suffered against the Chinese government. Such a claim could take many years through diplomatic channels.

Unfortunately, an individual cannot make a claim on his or her own behalf.

The ConversationI therefore suggest that before you get hit by a piece of space junk, you check your health insurance!

Melissa de Zwart, Professor, Adelaide Law School, University of Adelaide

This article was originally published on The Conversation. Read the original article.

China’s falling space station highlights the problem of space junk crashing to Earth



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China’s Tiangong-1 space station is due to hit Earth, and Australia is in the crash landing zone.
Cindy Zhi/The Conversation, CC BY-ND

Brad E Tucker, Australian National University

Any day now, the Chinese space station Tiangong-1 is expected to fall back to Earth – but it’s uncertain where it will crash land. We know that Australia is in the potential zone, and we have been hit before by a falling space station.

But Tiangong-1 is just one of many pieces of space junk left orbiting our Earth.

The United Nations Office for Outer Space Affairs (UNOOSA) says more than 8,000 objects have been launched in to space, with 4,788 currently still in orbit around the Earth.




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With every launch, even more space junk is produced ranging from the rocket boosters, to flakes of paint and the satellites themselves. In 2009 an old communication satellite crashed into a new one, creating thousands of pieces of smaller debris.

By some estimates, the amount of space junk is in the hundreds-of-thousands to millions of pieces and this interactive illustration shows some of them.

An illustration of some of the space junk left orbiting Earth.
ESA/ID&Sense/ONiRiXEL, CC BY-SA

From a heavenly place

Tiangong-1, or “Heavenly Palace”, was China’s first space station – a small version of the International Space Station – and was launched in September 2011. Weighing a bit more than 8 tonnes, about 10 metres long and 3 metres in diameter, it was the first of three planned space stations.

An illustration comparing the Tiangong-1 with a US school bus.
Aerospace Corporation

After delays in Tiangong-2, the Tiangong-2 and Tiangong-3 were merged and Tiangong-3 was launched in 2016. Tiangong-1 has subsequently not been in use and was always designed to come down back to Earth.

But where will it crash land?

A drop in the ocean

Halfway between New Zealand and South America in the Pacific Ocean is one of the most un-inhabited places on the Earth. This is the ideal location to have large pieces come back down, as the risk to lifeforms is minimal.

While most of these objects will break up into smaller bits, choosing a remote location then further minimises the risk of these bits.

In this part of an ocean there are literally hundreds of parts of automated space vehicles, rocket boosters, and even the Russian Space Station Mir, which splashed down east of Fiji in March 2001.

When you look at maps of satellite and space junk re-entry, the majority go straight over Australia and New Zealand. That is because re-entry starts roughly between 80km and 100km above the ground, takes around 15 to 20 minutes, and creates debris footprints hundreds-to-thousands of kilometers wide.

Therefore in order to hit the target of the southern Pacific Ocean, it must start over Australia and New Zealand.

But there’s one important feature that makes Tiangong-1 different in all of this: it is out of control, according to China’s space agency.

Crashed in Australia

If you were around in 1979 and happened to be in Western Australia, you might have a unique souvenir – part of the NASA space station Skylab, which re-entered near the southern town of Esperance.

An overhead view of the Skylab space station.
NASA

While most missions now plan on re-entry, this was not always the case and Skylab did not have a good plan for coming back to the Earth. It was designed for a nine-year lifetime, but no clear manoeuvrability was built to re-enter at a specific point.

As news came out that it was going to re-enter, and it was not clear where, there was a varied response. Some people staged Skylab parties, others operated safety measures (such as air raid siren preparedness in Brussels).

After it hit WA, the local Shire of Esperance issued NASA with a cheeky A$400 littering fine for scattering debris across its region. It was eventually paid in 2003 – not by NASA, but by a US radio presenter and his listeners who raised the funds.

NASA fined for littering when Skylab fell near Esperance, WA.
Flickr/Amanda Slater, CC BY-SA

So in 2016 when China notified UNOOSA that Tiangong-1 was uncontrolled in its point of re-entry, this made scientists pay attention. Of course this made the public and media take notice, causing a bit of a panic in some coverage.

Don’t panic!

Every day, hundreds of tons of debris, both human and natural (i.e. meteors), hit the Earth. Even those that survive re-entry and land pose a minute risk. Keep in mind, most of the Earth is unpopulated – from the oceans to vast deserts and land, nearly all people are safe.

The total surface are of the Earth is over 500 million square-kilometres. Even if a piece of space junk leaves a 1,000 square-kilometre debris field, that is only 0.0002% of the Earth’s surface.

A graphic showing how Tiangong-1 could break up as it crashes back to Earth, but where will it crash?
Aerospace Corporation

In fact, the Aerospace Corporation has calculated the odds of getting hit by Tiangong-1 parts at 1 million times LESS than winning the lotto.

Map showing the area between 42.8 degrees North and 42.8 degrees South latitude (in green), over which Tiangong-1 could reenter. You are many more times likely to win the lotto then getting hit by a piece of space debris from it.
ESA, CC BY-SA

Now that you know you don’t have to worry, if you do end up being in a path that can see re-entry, you will see a show not unlike in the 2013 movie Gravity.

SPOILER ALERT: Don’t watch if you don’t know the ending of Gravity.

What are we doing about it

Of course the question has to be asked – what are we doing to both solve the junk already in space and prevent more? Well, lots actually.

A large source of space junk is all the rocket boosters and engines that are still up there and can be seen re-entering. If you remember the excitement in February around the Space X Falcon 9 Heavy launch, one of the huge reasons for excitement was that those rockets come back down safely, making them re-usable and not another piece of space junk.




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Making satellites smaller not only means they are cheaper and quicker to build, but at the end of their life they can break up even more in the atmosphere, eliminating the possibility of large pieces surviving and landing.

And for all those small bits out there, Electro-Optic Systems (EOS) and Mount Stromlo Observatory are part of the Space Environment Research Centre (SERC) which is planning to build a laser system capable of safely de-orbiting small bits of space junk

The ConversationSo don’t worry about Tiangong-1 or other space junk hitting you, we’re on it.

Brad E Tucker, Astrophysicist, Australian National University

This article was originally published on The Conversation. Read the original article.