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.

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VIETNAM: ALLEGED MURDERER OF CHRISTIAN STRIKES AGAIN


Local authorities complicit or turn blind eye to assaults on Christians.

LOS ANGELES, May 11 (Compass Direct News) – A Hmong man in Vietnam’s Northwest Mountainous Region who murdered his mother in February because she had become a Christian has assaulted another Christian, leaving him critically wounded, according to area Christian sources.

Lao Lia Po on April 25 allegedly attacked Koua Lo of Meo Vac district, Ha Giang Province because he had become a Christian, according to a local church leader. Koua sustained severe head injuries; according to witnesses, his head was split open in two places with parts of his brain visible.

Koua was taken to a hospital, but after three days doctors said they could do nothing more for him and sent him home. As his injuries were life-threatening, those close to Koua did not expect him to recover.

The alleged attacker, Lao, is still at large and has not been charged. The assault took place in Sung Can Village, Sung Tra Commune, Meo Vac district, Ha Giang Province.

In the same area two years ago, a 74-year-old woman became the first Christian in the village. Today there are about 100 families who follow Christ, but the cost has been high. Stories of harassment and abuse of Christians in Meo Vac district have circulated for several months, with local Christians saying government officials are either complicit or look the other way.

On Feb. 3, local Christians said, Lao murdered his mother in a similarly brutal fashion, smashing her head until she died. Police only held him overnight before releasing him without charge. The day he was released, local sources said, he again threatened Christians with death.

A Vietnamese pastor petitioned the government to investigate – with no result. Another leader informed U.S. diplomats of the details. Some Vietnamese Christians have complained to Vietnam diplomatic missions abroad, all to no avail.

Advocates of religious freedom in Vietnam say such impunity puts a serious blot on Vietnam’s slowly improving religious liberty record.

Following heavy international scrutiny of Vietnam’s oppression of religion in general and Protestantism in particular, Vietnam promulgated new religion legislation in 2004 and 2005. To date this has led to the legal recognition of six church/denominational organizations, raising the total to eight out of about 70. Additionally, a few hundred of Vietnam’s thousands of house church congregations have been given interim permission to carry on religious activities, and large-scale government campaigns to force ethnic minority Christians to recant their faith have ceased.

High hopes for improvement following the new religion legislation led the U.S. Department of State to take Vietnam off its blacklist of the worst violators of religious freedom in late 2006, which enabled the U.S. government to endorse Vietnam’s accession to the World Trade Organization. And Christian support organization Open Doors this year dropped Vietnam to No. 23 on its World Watch List ranking of religion persecutors. In eight of the last 12 years, Vietnam had been placed among the organization’s top 10 worst religious persecutors.

The U.S. Commission on International Religious Freedom (USCIRF), however, found exceptions to progress so widespread that it again recommended naming Vietnam a Country of Particular Concern (CPC) this year. The recommendation by USCIRF, responsible for monitoring state department compliance with the U.S. 1998 Law on International Religious Freedom, was announced on May 1.

The commission’s report recognizes progress but notes, “There continue to be far too many serious abuses and restrictions of religious freedom in the country. Individuals continue to be imprisoned or detained for reasons related to their religious activity or religious freedom advocacy; police and government officials are not held fully accountable for abuses; independent religious activity remains illegal; and legal protections for government-approved religious organizations are both vague and subject to arbitrary or discriminatory interpretations based on political factors.”

Given the uneven pace of religious freedom progress after removing Vietnam from the list of CPCs, continued detention of prisoners of conscience, and an overall deteriorating human rights situation, USCIRF recommended that Vietnam be re-designated as a CPC.

In Tra Vinh Province in the Mekong Delta Region of southern Vietnam, another Christian was murdered on April 5. Thugs ambushed Thach Thanh No, described as a young and enthusiastic church elder, on his way home from Sunday worship, according to local Christian sources. His family was unable to find him quickly, and he died from his injuries as he was transported to a hospital.

The congregation in Ngoc Bien Commune to which he belonged has long been harassed and threatened by local thugs supported by militant Buddhists, according to area Christians, who emphasized that authorities have done nothing to intervene.

Indeed, in Thach’s case, rather than prosecute the killers, the Ministry of Public Security’s World Security newspaper published an article on April 24 – concocted without any factual basis, according to area Christians – which portrayed him as dying from crashing his motorbike while drunk. His motorbike, however, was found entirely unmarked without any signs of a crash, and his body showed clear signs of a vicious beating, according to area Christians.

“In one case the law winks at the murder of a Christian and does nothing to punish the murderer – in another, authorities actively work to cover up a murder with elaborate lies,” said one long-time advocate for religious freedom in Vietnam. “Such behavior on the part of authorities convinces many Vietnamese Christians that their country’s top officials are still not sincere about improving religious freedom for all.”

Report from Compass Direct News

NEW YORK STATE: 49 DEAD IN PLANE CRASH


Tragedy has struck Buffalo in New York State (USA) with a commuter plane crashing into a home. The crash and fiery explosion that followed has killed all 48 people on board the plane and one person on the ground.

Continental Connection Flight 3407 (Colgan Air) struck the home in Buffalo at about 10.20 pm. The plane involved was a 74-seat Q400 Bombardier aircraft which was carrying a large quantity of fuel when it exploded on impact with the house.

The flight was taking passengers from Newark Liberty International Airport in New Jersey to Buffalo Niagara International Airport in New York State. According to reports, the weather at the time was light snow, some fog and 17 mph winds.

According to witnesses the plane sounded like it was having problems just prior to the crash. The plane has been reported as flying low, with the left wing a little lower than the right. According to air control the plane simply dropped off the radar.

Authorities at the Department of Homeland Security have been quick to rule out terrorism as a cause for the crash. The National Transportation Safety Board is investigating the accident, along with the Federal Aviation Administration.

A family assistance number is available for family and friends of those involved in the crash: 1-800-621-3263.