Cassini faces fiery finish

3 astronauts reach ISS for 5-month mission

CAPE CANAVERAL, Florida, Sept 13, (AP): After a 20-year voyage, NASA's Cassini spacecraft is poised to dive into Saturn this week to become forever one with the exquisite planet.

There's no turning back: Friday it careens through the atmosphere and burns up like a meteor in the sky over Saturn.

NASA is hoping for scientific dividends up until the end. Every tidbit of data radioed back from Cassini will help astronomers better understand the entire Saturnian system – rings, moons and all.

The only spacecraft ever to orbit Saturn, Cassini spent the past five months exploring the uncharted territory between the gaseous planet and its dazzling rings. It's darted 22 times between that gap, sending back ever more wondrous photos.

On Monday, Cassini flew past jumbo moon Titan one last time for a gravity assist– a final kiss goodbye, as NASA calls it, nudging the spacecraft into a deliberate, no-way-out path.

During its final plunge early Friday morning, Cassini will keep sampling Saturn's atmosphere and beaming back data, until the spacecraft loses control and its antenna no longer points toward Earth. Descending at a scorching 76,000 mph (122,000 kph), Cassini will melt and then vaporize. It should be all over in a minute.

"The mission has been insanely, wildly, beautifully successful, and it's coming to an end," said NASA program scientist Curt Niebur. "I find great comfort in the fact that Cassini will continue teaching us up to the very last second."

Telescopes on Earth will watch for Cassini's burnout nearly a billion miles (1.6 billion kilometers) away. But any flashes will be hard to see given the time – close to high noon at Saturn – and Cassini's minuscule size against the solar system's second largest planet.

The plutonium on board will be the last thing to go. The dangerous substance was encased in super-dense

caused by flooding from Hurricane Harvey, according to media reports.

The Environmental Protection Agency has asked the company whether it followed risk management plans submitted to the government ahead of the explosions at the plant, which began on August 31, EPA Administrator Scott Pruitt told the Washington Examiner.

Unprecedented flooding from Hurricane iridium as a safeguard for Cassini's 1997 launch and has been used for electric power to run its instruments. Project officials said once the iridium melts, the plutonium will be dispersed into the atmosphere. Nothing – not even traces of plutonium – should escape Saturn's deep gravity well.

The whole point of this one last exercise – dubbed the Grand Finale – is to prevent the spacecraft from crashing into the moons of Enceladus (ehn-SEHL'-uh-duhs) or Titan. NASA wants future robotic explorers to find pristine worlds where life might possibly exist, free of Earthly contamination.

It's inevitable that the $3.9 billion US-European mission is winding down. Cassini's fuel tank is almost empty, and its objectives have been accomplished many times over since its 2004 arrival at Saturn following a seven-year journey.

The leader of Cassini's imaging team, planetary scientist Carolyn Porco, already feels the loss.

Successful

"There's another part of me that's just, 'It's time. We did it.' Cassini was so profoundly, scientifically successful," said Porco, a visiting scholar at the University of California, Berkeley. "It's amazing to me even, what we were able to do right up until the end."

Until Cassini, only three spacecraft had ventured into Saturn's neighborhood: NASA's Pioneer 11 in 1979 and Voyager 1 and 2 in the early 1980s. Those were just flybys, though, and offered fleeting glances. And so Cassini and its traveling companion, the Huygens (HOY'-gens) lander, actually provided the first hard look at Saturn, its rings and moons. They are named for 17th-century astronomers, Italian Giovanni Domenico Cassini and Dutch Christiaan Huygens, who spotted Saturn's first moon, Titan. The current count is 62.

Cassini discovered six moons – some barely a mile or two across – as well as swarms of moonlets that are

Harvey, which made landfall in southeast Texas on August 26, cut power and knocked out backup generators at the plant – disabling the refrigeration required to prevent volatile organic peroxides from exploding.

Authorities had already evacuated an area within a 1.5 mile (2.4 kms) radius of the plant. But emergency workers who responded to the explosions have since sued still part of Saturn's rings.

All told, Cassini has traveled 4.9 billion miles (7.9 billion kilometers) since launch, orbited Saturn nearly 300 times and collected more than 453,000 pictures and 635 gigabytes of scientific data.

The European Space Agency's Huygens lander – which hitchhiked all the way to Saturn aboard Cassini – still rests on Titan. It parachuted down in 2005, about six months after Cassini arrived at Saturn, and relayed data for more than an hour from the moon's frigid surface.

Still believed intact, Huygens remains the only spacecraft to actually land in one of our outer planetary systems.

Other than Titan's size – about as big as Mercury – little was known about Saturn's biggest and haze-covered moon before Cassini and Huygens showed up. They revealed seas and lakes of methane and ethane at Titan – the result of rainfall – and provided evidence of an underground ocean, quite possibly a brew of water and ammonia.

Over at the little moon Enceladus, Cassini unveiled plumes of water vapor spewing from cracks at the south pole.

BAIKONUR, Also:

Kazakhstan:

Two US astronauts and a Russian cosmonaut docked at the International Space Station for a five month mission on Wednesday following a night-time launch from the Baikonur cosmodrome in Kazakhstan.

Russia's Roscosmos space agency said that the Soyuz MS-06 spacecraft "successfully docked" at the ISS at 0255 GMT in a statement on its website.

The Soyuz rocket carrying Alexander Misurkin of Roscosmos, NASA first-time flyer Mark Vande Hei and his veteran colleague Joe Acaba launched as scheduled from Baikonur at 3:17 am (2117 GMT).

The trio will now join Paolo Nespoli of Italy, Sergey Riazanski of Russia and Randy Bresnik of the US aboard the orbital lab.

the plant's operators for exposing them to smoke.

"There is some question about whether the RMP that was in place was actually complied with," Pruitt told Washington Examiner, referring to a risk management plan. The September 7 letter gave Arkema 10 days to answer to EPA queries.

The EPA wants to determine what quantity of chemical substances were stored at the plant and what safety measures had been taken in advance of possible flooding and power loss. (AFP)

‘Monster fatberg’ clogs sewer:

Sewage workers have found a 130-tonne ball of congealed fat – dubbed a "monster fatberg" – clogging a Victorian-era sewer in London, utility company Thames Water said Tuesday.

Engineers expect it will take up to three-weeks to remove the rock-solid mass of festering food fat mixed with sanitary wipes found in drains under a major road in Whitechapel, east London.

"This fatberg is up there with the biggest we've ever seen. It's a total monster and taking a lot of manpower and machinery to remove as it's set hard," Matt Rimmer, Thames Water's head of waste, said in a statement.

"It's basically like trying to break up concrete. It's frustrating as these situations are totally avoidable and caused by fat, oil and grease being washed down sinks and wipes flushed down the loo," he added.

Images show that the sewer totally blocked by the 250-metre (273-yard) long fatberg. (Agencies)