Queda de Satélite espião dos EUA

Luis França

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Desta vez não é nenhum cometa nem asteróide mas um satélite-espião que parece que vai cair na Terra. Esperemos que não traga nenhum material perigoso consigo, o que é improvável. Algumas opiniões já aventaram que pode conter berilium (cancerígeno) e/ou plutónio (radioactivo).
No comments.


Defunct Spy Satellite Falling From Orbit

WASHINGTON (AP) - A large U.S. spy satellite has lost power and propulsion and could hit the Earth in late February or March, government officials said Saturday.
The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where on the planet it might come down, they said. The officials spoke on condition of anonymity because the information is classified as secret.
"Appropriate government agencies are monitoring the situation," said Gordon Johndroe, a spokesman for the National Security Council. "Numerous satellites over the years have come out of orbit and fallen harmlessly. We are looking at potential options to mitigate any possible damage this satellite may cause."
He would not comment on whether it is possible for the satellite to be perhaps shot down by a missile. He said it would be inappropriate to discuss any specifics at this time.
A senior government official said that lawmakers and other nations are being kept apprised of the situation.
 

Luis França

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Re: Asteróides, cometas e afins - 2008

American spy satellite 'the size of a bus' is out of control and hurtling towards Earth

seleneAP_468x316.jpg


A 10-ton American spy satellite has lost power and could hit the Earth in the next few weeks, government officials said today.
The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where on the planet it might come down, they said.
The spacecraft contains hydrazine - which is rocket fuel - according to a government official who was not authorized to speak publicly but spoke on condition of anonymity.
Hydrazine, a colorless liquid with an ammonia-like odor, is a toxic chemical and can cause harm to anyone who contacts it.
An uncontrolled re-entry could risk exposure of U.S. secrets, said John Pike, a defense and intelligence expert.


Agora é que tenho mesmo uma dúvida pertinente: se os cientistas conseguem calcular as órbitas de estrelas e planetas muito mais distantes do que os objectos que orbitam em volta do nosso planeta, porque raio dizem agora não saber onde vai cair um simples satélite artificial do tamanho dum autocarro? São estas incongruências que me deixam desconfiado. Além do mais parece que este satélite foi lançado o ano passado; será que se esqueceram de encher o depósito de combustível?
 

Luis França

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Re: Asteróides, cometas e afins - 2008

Falling U.S. satellite is not dangerous - NASA

MOSCOW. Jan 27 (Interfax-AVN) - The uncontrolled reentry of a U.S. satellite should not lead to any serious consequences on the Earth, NASA representative at the Russian Mission Control center Sergei Puzanov told Interfax-AVN on Sunday.
"Some parts of the satellite will be burnt in dense atmosphere, and only small parts, for example the engine unit, could fall on the Earth. This is not the case when rush should be kicked up," Puzanov said.
The Earth is constantly bombarded by meteorites and the fall of a satellite is not dangerous, Puzanov said.
Meanwhile, the Russian Federal Space Agency (Roscosmos) and the Russian Space Forces did not comment on the situation surround the uncontrolled reentry of the U.S. satellite.
Official representatives of the White House told journalists on Saturday that a large U.S. spying satellite, whose engine unit broke down, and is falling from the Earth's orbit. According to the White House, parts of the satellite will fall on the Earth either in late February or early March. As yet it is impossible to define the exact place of the fall.


US satellite on collision course with Earth

A US satellite weighing 10 tons is fast losing height and is expected to hit the Earth in late February or early March.
The device is thought to be an advanced spy satellite launched in December 2006 which failed properly to deploy into orbit.
Friction with the Earth's atmosphere is bringing it down, and there is no way to predict where it will land since the controllers have lost contact.
"Numerous satellites over the years have come out of orbit and fallen harmlessly," said Gordon Johndroe, a spokesman for the US National Security Council.
"We are looking at all potential options to mitigate any possible damage that this satellite may cause."
It is relatively common to bring satellites, and the occasional golf ball or paper plane, back to Earth to burn up in the atmosphere, but this is usually done when they reach the end of their operational life.
What is causing concern is that this satellite is still fully fuelled and would be dispersed into the atmosphere if it descends fast enough.
It not known whether the satellite is carrying a nuclear power source, but experts have confirmed that it is carrying hydrazine rocket fuel which is toxic to humans.
The risk from falling debris is slight, however, since 70 per cent of the world is covered in water and most of the mass is expected to burn away on re-entry.
 

Vince

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Re: Asteróides, cometas e afins - 2008

Agora é que tenho mesmo uma dúvida pertinente: se os cientistas conseguem calcular as órbitas de estrelas e planetas muito mais distantes do que os objectos que orbitam em volta do nosso planeta, porque raio dizem agora não saber onde vai cair um simples satélite artificial do tamanho dum autocarro? São estas incongruências que me deixam desconfiado. Além do mais parece que este satélite foi lançado o ano passado; será que se esqueceram de encher o depósito de combustível?


Sobre o cálculo das órbitas celestes penso que deves ter uma ideia de como é feito.
Quanto ao satélite, do qual se sabe pouco porque é espião, mas tudo indica tratar-se do satélite exprimental "USA 193" lançado em Dezembro de 2006 por um Foguetão Delta. Embora nunca oficialmente confirmado, este satélite logo após o lançamento deixou de funcionar, ou nunca chegou mesmo a funcionar em orbita. Desde essa altura que tem sido apanhado por spotters e sempre se suspeitou que estaria fora de controlo pois nunca fez o deployment dos paneis solares e perde altitude desde então. Ou seja, provavelmente está sem energia e à deriva desde que chegou ao espaço.

Todos os anos reentram na atmosfera toneladas de lixo espacial à deriva. Nalguns satélites/estações de maior dimensão por vezes aproveita-se o remanescente de energia disponivel para uma reentrada calculada de forma a cair se possível no Oceano.
Em casos como estes, não há qualquer controlo sobre ele, é possível prever mais ou menos quando acabará por reentrar mas sem qualquer exactidão.
Todos os anos estima-se que caem cerca de 100 toneladas de lixo de volta à Terra, a maioria desintegra-se e arde na reentrada, mas talvez cerca de 10% a 40% da massa total dos objectos acabe por resistir à e chegar à superficie, mas até hoje nunca houve nenhum problema sério, pois os Oceanos cobrem 70% da Terra e há vastas regiões desabitadas.

As reentradas descontroladas mais famosas foram o do Satélite russo Cosmos 954 em 1978 e da estação amercana Sky Lab (75 toneladas) em 1979, eventos muito falados na altura, mesmo em Portugal. Alguns detritos de um e outro cairam em regiões habitadas, Canadá no primeiro caso e Australia no segundo. O Cosmos tinha um reactor nuclear e alguns deritos recolhidos no Canadá apresentavam alguma radioactividade, o que na altura gerou alguma instabilidade política.

Mais recentemente em 2003 um satélite holandês e italiano chamado BeppoSAX também reentrou e caiu no Pacífico e em 2001 todos se recordam do fim da estação russa MIR que também se desintegrou na atmosfera mas neste caso numa reentrada controlada de modo a maximizar a sua destruição e queda de detritos no Oceano.

Reentrada da MIR em Março de 2001
mirreentryphotoxd4.jpg
 

Luis França

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Hawaii-based ship could shoot down dead satellite

Associated Press - February 15, 2008 1:54 PM ET

HONOLULU (AP) - A Pearl Harbor-based Navy ship could be called to shoot down the dying U.S. spy satellite over the Pacific.
The Pentagon has not yet announced which ship will take down the US-193 satellite loaded with toxic fuel.
The action is expected during a three- or 4-day window starting next week. It will use three ships, with two as a back-up in case the planned single shot misses.


Ora viste... ;)
 

Vince

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Ora aí está uma notícia que me surpreendeu. Depois da polémica toda com os chineses que encheram a órbita da Terra com milhões de pedaços de lixo perigosos para a exploração espacial e os satélites quando destruiram um deles, fiquei pasmado ao ler esta notícia.

À primeira vista pensei, grandes segredos que aquilo tem para tomarem essa decisão pois é sabido que era um dos satélites espião mais sofisticados de sempre. Mas é quase impossível que algo sobrevivesse à reentrada em condições de depois alguém se apropriar desses segredos.

Andei a investigar e pelos vistos a órbita já é tão baixa e sem uso e que quando o abaterem os detritos acabarão também eles por cair, pelo que é capaz de não ser má ideia dado que pelo menos o combustível é toxico. E juntam o útil ao agradável (para o Pentágono claro...) destroem tecnologia sofisticada para que não possa cair nas mãos de outros e testam também o sistema deles de misseis anti-satélite.

Satellite Shot Offers Navy Key Space Defense Trial: How It Works
The Pentagon today announced that a Navy warship has been tasked with shooting down a failing United States spy satellite that, if left alone, was expected to hit Earth within weeks.

In a joint news conference, NASA administrator Michael Griffin and Gen. James Cartwright, the No. 2 officer at the Defense Department, announced that an SM-3 missile, designed to hit inbound ballistic missiles, will be fired from a Navy cruiser or destroyer during the next month to obliterate the inbound spacecraft. The idea is to break apart the satellite to rid it of toxic fuel onboard by smashing its tank, which is the largest intact piece left. If successful, it would be the first direct U.S. test against a satellite since 1985, when an F-15 climbed to 80,000 ft. to fire a three-stage missile at a defunct solar-monitoring platform in low-Earth orbit.

A growing number of guided missile cruisers* are fitted with Aegis Ballistic Missile Defense systems that are designed to track and destroy short- and medium-range ballistic missiles just outside Earth’s atmosphere. The powerful radars on board the ships that detect ballistic missiles can also spot satellites at low orbits. Reportedly, one of three cruisers will have a shot at the inbound satellite.

Several successful anti-ballistic mile tests have been conducted from the cruisers, most frequently from the USS Shiloh, but no test has the urgency or high profile as the impending satellite shoot-down. The SM-3, when fired vertically, can target a satellite as high as 310 miles. After the third stage of the rocket is spent, the kill vehicle finds the target with forward-looking infrared sensors and steers itself into the satellite. “What we’re talking about is a minor modification in software, from the Aegis system and the missile itself,” Cartwright said.

The Bush administration has made ballistic missile defense a priority, fielding various interceptors at bases in Alaska and on ships. Although the odds were in favor of the satellite crashing in the ocean and/or losing much of the sensitive equipment during a fiery reentry, the chance to use the ballistic defenses against a real-life target was likely considered too good to pass up.

The operation is reminiscent of last year’s strike by the Chinese military against one of its defunct spy satellites. However, the impact of the Chinese test produced a halo of space junk that remains in orbit. The U.S. Navy strike should only leave debris that will burn up harmlessly during reentry. Also, the Chinese test left debris that will last decades due to its higher orbit, Griffin said. The lower in orbit that the Navy can shoot down the satellite, the quicker debris gets pulled back in to the atmosphere. Griffin said the debris should be cleared out of Earth’s orbit within weeks.

The Chinese and U.S. tests are also similar in that both strikes use rockets (in China’s case, reportedly a four-stage rocket instead of the SM-3’s three stages) to take a non-explosive warhead into low-Earth orbit and steer it into the target. Ways to knock out satellites at high altitudes—like communications satellites soaring at over 20,000 miles—are more esoteric and largely untested. Most high-orbit methods would require weapons already launched into orbit.

The target spacecraft is reportedly a spy satellite that launched on a Delta II rocket at Vandenberg Air Force Base in December 2006, but failed within minutes after the launch. After a fiery reentry, tens of pounds of material would be left—posing a small but real risk of landing in a populated area. The likelihood of gathering usable intelligence from the crash is thought to be minimal, since its antennae and sensors would be among the most fragile components—and would not likely survive the heat of reentry. The craft’s fuel, however, is considered toxic. “[We want to] get rid of the hydrazine and have it land in the ocean,” Cartwright said. “That is the only thing that breaks it out and makes this different.”

That could be worrisome, because predicting exactly where the satellite will land has to wait until reentry begins. Cartwright and Griffin said NASA and the military could get a quadrant of the impact, but would not know the location of the impact until it was too late. “Nothing we can do makes it worse, and almost everything we do would make it better,” Griffin said.

http://www.popularmechanics.com/science/air_space/4249458.html
 

Luis França

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Agora fiquei a pensar: e o que acontecerá aos detritos que se espalharão em órbita? Não será perigoso para os outros satélites que cruzarem esses detritos mais tarde? Será que pensaram nisso, ou não há problema se cairem outros? :)
 

Vince

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Agora fiquei a pensar: e o que acontecerá aos detritos que se espalharão em órbita? Não será perigoso para os outros satélites que cruzarem esses detritos mais tarde? Será que pensaram nisso, ou não há problema se cairem outros? :)

Era o que eu estava a pensar. Mas pelo que percebi aquela órbita já é tão baixa que tudo o que está nela acaba por cair, não há satélites a essa altitude, é demasiado baixo. E aparentemente vão disparar sobre ele mesmo na véspera, quando estiver iminente a reentrada prevista para a 1ª semana de Març
 

Luis França

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Éjá esta quinta-feira que o satélite vai tentar ser atingido por um balázio...animação (carregar em missão)

Navy likely to attempt shoot down of failed satellite Thursday

WASHINGTON (CNN) — The U.S. Navy will likely attempt to shoot down a faulty spy satellite on Thursday, the day after the space shuttle Atlantis is scheduled to land, two officials familiar with the planning told CNN Monday.
 

iceworld

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Éjá esta quinta-feira que o satélite vai tentar ser atingido por um balázio...animação (carregar em missão)

Navy likely to attempt shoot down of failed satellite Thursday

WASHINGTON (CNN) — The U.S. Navy will likely attempt to shoot down a faulty spy satellite on Thursday, the day after the space shuttle Atlantis is scheduled to land, two officials familiar with the planning told CNN Monday.

Pois muito bonito mas e onde vai cair aquilo? Ou queima tudo? Com sorte na cabeça do Bush :lmao: :lmao: :lmao:
 

Luis França

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SPY-SAT UPDATE: Rumor has it that the US Navy may make its first attempt to hit USA 193 this Wednesday evening as the satellite passes over the Pacific Ocean. An air traffic advisory warns pilots to avoid a patch of ocean near Maui from 4:30 p.m. to 7:00 p.m. Hawaii time on Feb. 20th (0230 - 0500 UT, Feb. 21st). This would center the missile strike on the darkness of Wednesday's lunar eclipse and possibly render reentering debris visible from the west coast of North America.
Until the satellite is shot down, it remains visible to sky watchers who know when to look. Amateur astronomer Dan Bush photographed USA-193 last night as it passed over Albany, Missouri:

Dan-Bush1_strip.jpg



Dia 20 Fevereiro

PassGTrackLargeGraphic.aspx
 

Rog

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No site www.heavens-above.com estão a fazer um acompanhamento sobre este satélite.
Como o satelite está numa orbita baixa, e como é relativamente grande, torna-se visível a olho nu. Na pagina inicial, se indicarem a vossa localização, ficam a saber se será possível o ver antes da reentrada da vossa casa.

Pagina incial http://www.heavens-above.com/

Texto explicativo com tradução http://translate.google.com/transla...aspx?lat=0&lng=0&loc=Unspecified&alt=0&tz=CET

Texto original http://www.heavens-above.com/usa193.aspx?lat=0&lng=0&loc=Unspecified&alt=0&tz=CET

Escolham a vossa localização http://www.heavens-above.com/countries.aspx#P

depois de escolheres a localização, vão à página inicial e cliquem num dos primeiros links em destaque sobre o satelite.
 

Vince

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O Departamento de defesa americano informou que atingiu com sucesso o satélite nesta madrugada com o objectivo principal de destruir o depósito de combustível completamente cheio de hydrazine pois o satélite nunca chegou a funcionar.
Os pedaços do satélite irão gradualmente cair nos próximos dias ou semanas mas como estão muito fragmentados o risco para populações que já era baixo reduziu-se ainda mais. É opinião de muitos especialistas que a hydrazine foi um pretexto útil mas que simultaneamente os EUA procederam assim a um teste real dos seus sistemas de defesa sem grandes polémicas nacionais ou internacionais.

DoD Succeeds In Intercepting Non-Functioning Satellite

A network of land-, air-, sea- and spaced-based sensors confirms that the U.S. military intercepted a non-functioning National Reconnaissance Office satellite which was in its final orbits before entering the earth's atmosphere.

At approximately 10:26 p.m. EST today, a U.S. Navy AEGIS warship, the USS Lake Erie (CG-70), fired a single modified tactical Standard Missile-3 (SM-3) hitting the satellite approximately 247 kilometers (133 nautical miles) over the Pacific Ocean as it traveled in space at more than 17,000 mph. USS Decatur (DDG-73) and USS Russell (DDG-59) were also part of the task force.

The objective was to rupture the fuel tank to dissipate the approximately 1,000 pounds (453 kg) of hydrazine, a hazardous fuel which could pose a danger to people on earth, before it entered into earth's atmosphere. Confirmation that the fuel tank has been fragmented should be available within 24 hours.

Due to the relatively low altitude of the satellite at the time of the engagement, debris will begin to re-enter the earth’s atmosphere immediately. Nearly all of the debris will burn up on reentry within 24-48 hours and the remaining debris should re-enter within 40 days.

DoD will conduct a press briefing at 7 a.m. EST to provide further information related to the operation. The briefing can be viewed live on www.Defenselink.com through the Pentagon Channel.
http://www.defenselink.mil/releases/release.aspx?releaseid=11704
 

Minho

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O video....


[YOUTUBE]http://www.youtube.com/watch?v=U8wqPGtMOKw[/YOUTUBE]