Mission Accomplished: Sunita,Akihiko tackle ISS coolant leak

November 2, 2012

mission

Houston, November 2: Indian American record-setting NASA astronaut Sunita Williams along with another cosmonaut today troubleshot an ammonia leak in the International Space Station's cooling system, accomplishing the chief objective of their marathon six-hour excursion outside the orbiting lab.

Williams and Japanese space flyer Akihiko Hoshide ventured yesterday outside the space station at 1229 GMT (1759 IST) and just a little more than five hours later, they had reconfigured some coolant lines and deployed a spare radiator, isolating the leak.

"Suni and Aki, heartfelt congratulations to you," NASA astronaut Mike Fincke, who helped walk the astronauts through their tasks from mission control at the agency's Johnson Space Center in Houston, said at 1741 GMT (2311 IST).

"We accomplished just about everything we set out to do today. A big, huge congratulations to you guys on the ground for putting this together," Williams responded.


Each of the space station's eight huge solar panels has its own associated power system, and circulating ammonia helps cool this gear down.

The leak, which NASA and its space station partners first noticed in 2007, has the potential to affect one of these power channels if it's not fixed.

Today's Spacewalk, or extra-vehicular activity (EVA), a crucial step in that process was slated to last about 6 1/2 hours, and it proceeded pretty much on schedule.

By 0128 hrs IST, both astronauts had re-entered the space station through its airlock, and the spacewalk was officially over nine minutes later.

At the start of the spacewalk, Williams — commander of the station's current Expedition 33 — and Hoshide made their way over to the port side of the station's backbone-like truss.

They rejiggered some lines in the affected coolant system and installed a spare radiator.

NASA officials hope this stops the leak, which they suspect may be coming from the old (swapped-out) radiator.

If ammonia continues to escape, the station's operators will eventually have to try something else.

But there likely won't be an urgent need for a new fix, since the spare radiator should provide enough ammonia to keep the coolant system operating until next October or so, officials said.

It should come as no surprise that Williams and Hoshide ticked off their tasks efficiently today, for the two are seasoned space walkers.

In late August and early September, they replaced a vital power unit on the station over the course of two spacewalks, defeating an unexpectedly stubborn stuck bolt in the process.

Today's EVA was the seventh for Williams, the third for Hoshide and the 138th to depart from the station overall.




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News Network
April 28,2020

Washington, Apr 28: After nearly three weeks in an intensive care unit in Los Angeles, doctors treating 41-year-old Broadway actor Nick Cordero for COVID-19 were forced to amputate his right leg.

The flow of blood had been impeded by a blood clot: yet another dangerous complication of the disease that has been bubbling up in frontline reports from China, Europe and the United States.

To be sure, so-called "thrombotic events" occur for a variety of reasons among intensive care patients, but the rates among COVID-19 patients are far higher than would be otherwise expected.

"I have had 40-year-olds in my ICU who have clots in their fingers that look like they'll lose the finger, but there's no other reason to lose the finger than the virus," Shari Brosnahan, a critical care doctor at NYU Langone said.

One of these patients is suffering from a lack of blood flow to both feet and both hands, and she predicts an amputation may be necessary, or the blood vessels may get so damaged that an extremity could drop off by itself.

Blood clots aren't just dangerous for our limbs, but can make their way to the lungs, heart or brain, where they may cause lethal pulmonary embolisms, heart attacks, and strokes.

A recent paper from the Netherlands in the journal Thrombosis Research found that 31 percent of 184 patients suffered thrombotic complications, a figure that the researchers called "remarkably high" -- even if extreme consequences like amputation are rare.

Behnood Bikdeli, a doctor at New York-Presbyterian Hospital, assembled an international consortium of experts to study the issue. Their findings were published in the Journal of The American College of Cardiology.

The experts found the risks were so great that COVID-19 patients "may need to receive blood thinners, preventively, prophylactically," even before imaging tests are ordered, said Bikdeli.

What exactly is causing it? The reasons aren't fully understood, but he offered several possible explanations.

People with severe forms of COVID-19 often have underlying medical conditions like heart or lung disease -- which are themselves linked to higher rates of clotting.

Next, being in intensive care makes a person likelier to develop a clot because they are staying still for so long. That's why for example people are encouraged to stretch and move around on long haul flights.

It's also now clear the COVID-19 illness is associated with an abnormal immune reaction called "cytokine storm" -- and some research has indicated this too is linked to higher rates of clotting.

There could also be something about the virus itself that is causing coagulation, which has some precedent in other viral illnesses.

A paper in the journal The Lancet last week showed that the virus can infect the inner cell layer of organs and of blood vessels, called the endothelium. This, in theory, could interfere with the clotting process.

According to Brosnahan, while thinners like Heparin are effective in some patients, they don't work for all patients because the clots are at times too small.

"There are too many microclots," she said. "We're not sure exactly where they are."

Autopsies have in fact shown some people's lungs filled with hundreds of microclots.

The arrival of a new mystery however helps solve a slightly older one.

Cecilia Mirant-Borde, an intensive care doctor at a military veterans hospital in Manhattan, told AFP that lungs filled with microclots helped explain why ventilators work poorly for patients with low blood oxygen.

Earlier in the pandemic doctors were treating these patients according to protocols developed for acute respiratory distress syndrome, sometimes known as "wet lung."

But in some cases, "it's not because the lungs are occupied with water" -- rather, it's that the microclotting is blocking circulation and blood is leaving the lungs with less oxygen than it should.

It has just been a little under five months since the virus emerged in Wuhan, China, and researchers are learning more about its impact every day.

"While we react surprised, we shouldn't be as surprised as we were. Viruses tend to do weird things," said Brosnahan.

While the dizzying array of complications may seem daunting, "it's possible there'll be one or a couple of unifying mechanisms that describe how this damage happens," she said.

"It's possible it's all the same thing, and that there'll be the same solution."

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News Network
June 30,2020

Six months since the new coronavirus outbreak, the pandemic is still far from over, the World Health Organization said Monday, warning that "the worst is yet to come".

Reaching the half-year milestone just as the death toll surpassed 500,000 and the number of confirmed infections topped 10 million, the WHO said it was a moment to recommit to the fight to save lives.

"Six months ago, none of us could have imagined how our world -- and our lives -- would be thrown into turmoil by this new virus," WHO chief Tedros Adhanom Ghebreyesus told a virtual briefing.

"We all want this to be over. We all want to get on with our lives. But the hard reality is this is not even close to being over.

"Although many countries have made some progress, globally the pandemic is actually speeding up.

"We're all in this together, and we're all in this for the long haul.

"We will need even greater stores of resilience, patience, humility and generosity in the months ahead.

"We have already lost so much -- but we cannot lose hope."

Tedros also said that the pandemic had brought out the best and worst humanity, citing acts of kindness and solidarity, but also misinformation and the politicisation of the virus.

In an atmosphere of global political division and fractures on a national level, "the worst is yet to come. I'm sorry to say that," he said.

"With this kind of environment and condition, we fear the worst."

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Agencies
July 17,2020

Washington, Jul 17: US President Donald Trump's economic adviser Larry Kudlow has said that TikTok may cut off ties to its Chinese parent and become a 100 per cent American company to circumvent demands to ban it as India has done.

"I think TikTok is going to pull out of the holding company which is China-run and operate as an independent American company," he told reporters at the White House on Thursday.

The US has not made a final decision on whether to ban it - which has been suggested by Secretary of State Mike Pompeo, he said.

TikTok being divested by ByteDance Technology Company "is a much better solution than banning or pushing away", said Kudlow, who is the Director of the National Economic Council.

He said that its services will be located in the US and "it will become an hundred per cent American company".

If it becomes a US company without Chinese links, India may have to reconsider the ban on the short video app wildly popular in the country.

India banned TikTok along with 58 other Chinese apps on June 29 citing threats to its defence and national security.

The ban came after a deadly clash between Indian and Chinese troops along the Line of Actual Control in Ladakh.

Under Beijing's National Security Law, all Chinese companies have to provide intelligence requested by the government, creating risks for users and their countries.

India was TikTok's biggest market outside of China, where it operates as Douyin.

There were about 200 million users in India and over 300 million downloads.

The US comes next with over 30 million users for the app.

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