ISS Astronauts Celebrate Holidays in Orbit

NASA astronaut Rick Mastracchio performs a spacewalk outside the International Space Station on Dec. 22, 2013, the first of two spacewalks to replace an ammonia coolant pump in one of two cooling loops on the orbiting lab.

Credit: NASA

Six space travelers living in orbit definitely aren't home for Christmas today, but that doesn't mean they won't get into the holiday spirit on the International Space Station.

The space station's six-man Expedition 38 crew includes two Americans, three Russians and one Japanese astronaut.

This year, Christmas falls between two spacewalks — a Christmas Eve spacewalk to fix the outpost's cooling system and a Dec. 27 excursion by Russian cosmonauts — so it is likely a welcome rest in an otherwise busy week.

"Hey folks, MERRY CHRISTMAS!" NASA astronaut Rick Mastracchio wrote in a Twitter post Sunday (Dec. 22), adding that he would write more after finishing the station's "home improvement project" to replace a cooling system pump.

He and NASA astronaut Mike Hopkins finished that work in a spacewalk on Tuesday.

ISS Astronauts complete Coolant Pump repair

Astronauts aboard the International Space Station have received a gift just in time for Christmas: a new pump module to repair their ailing cooling system and to restore the outpost to full power.

Rick Mastracchio and Mike Hopkins embarked on their second spacewalk together, setting out at 6:53 a.m. EST (1153 GMT) on Tuesday (Dec. 24) to complete the work they began Saturday to remove and replace an ammonia pump module with a faulty flow control valve.

NASA's Mike Hopkins holds the space station's new pump module while floating past a Russian Soyuz spacecraft. 

Hopkins is riding the orbiting outpost's robotic arm to install the new pump module and fix the laboratory's vital cooling system.

NASA astronaut Rick Mastracchio on EVA to repair cooling system

NASA astronaut Rick Mastracchio stands on the International Space Station's robotic arm during an urgent spacewalk to fix the station's vital cooling system.

This NASA graphic shows the position for QD operations.

A NASA graphics show the starboard pump module worksites on the International Space Station and how the starboard pump module removal will take place outside the International Space Station, scheduled for Dec. 21, 23 and 25, 2013.

ISS Astronauts Prepare for EVA Spacewalks to Repair Coolant System

Expedition 38 crew member Mike Hopkins checks out the spacesuit he will wear outside the International Space Station on Saturday, Dec. 21, 2013. 

He and fellow astronaut Rick Mastracchio will conduct a series of spacewalks to replace an ammonia pump that is part of the station's coolant system. 

This will be Hopkins' first spacewalk, while Mastracchio has had six previous ones on STS-118 and STS-131

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ISS Astronauts to conduct Three EVAs to repair Coolant Module

American astronauts will undertake a series of urgent spacewalks to repair a broken cooling line on the International Space Station.

NASA has announced that two American astronauts will move soon to replace a busted valve within an external pump module on one of the station's two coolant loops that shut down last week when it reached pre-set temperature limits.

The replacement will be undertaken during three spacewalks by the International Space Station (ISS) crew. The first is set for Saturday, followed by another on Monday and next Wednesday, on Christmas Day.

The spacewalks have directed NASA's attention away from the launch of the Cygnus-3 supply ship, which has been rescheduled for January 2014.

Orbital Sciences Corp.'s unmanned Cygnus cargo craft had been due for launch this week on Virginia's coast.

NASA was forced last week to reroute coolant systems when one of the station's coolant loops, Loop-A, automatically shut down due to a temperature fluctuation.

The ISS crew proceeded to move certain electrical systems over to the second loop, NASA reported.

The two coolant loops circulate ammonia to keep internal and external equipment cool.

"At no time was the crew or the station itself in any danger," NASA reported.

The space agency said that some non-critical systems were "powered down" as teams analyzed how the valve malfunctioned.

This is not the first time a coolant problem has hampered the ISS.

The ISS crew took an unscheduled spacewalk in May to inspect and fix a coolant leak in its power system. They installed a new cooling pump during a six-hour-long session.

That same coolant loop had a similar problem in November 2012, when an emergency spacewalk was needed to fix a leak.

Chemical reaction keeps Stroke-damaged brain from repairing itself

Stuart A. Lipton, M.D., Ph.D., is director of the Del E. Webb Neuroscience, Aging, and Stem Cell Research Center at Sanford-Burnham Medical Research Institute and a clinical neurologist. 

Credit: Sanford-Burnham Medical Research Institute.

Nitric oxide, a gaseous molecule produced in the brain, can damage neurons.

When the brain produces too much nitric oxide, it contributes to the severity and progression of stroke and neurodegenerative diseases such as Alzheimer's.

Researchers at Sanford-Burnham Medical Research Institute recently discovered that nitric oxide not only damages neurons, it also shuts down the brain's repair mechanisms.

Their study was published by the Proceedings of the National Academy of Sciences (PNAS) the week of February 4.

"In this study, we've uncovered new clues as to how natural chemical reactions in the brain can contribute to brain damage—loss of memory and cognitive function—in a number of diseases," said Stuart A. Lipton, M.D., Ph.D., director of Sanford-Burnham's Del E. Webb Neuroscience, Aging, and Stem Cell Research Center and a clinical neurologist.

Lipton led the study, along with Sanford-Burnham's Tomohiro Nakamura, Ph.D., who added that these new molecular clues are important because "we might be able to develop a new strategy for treating stroke and other disorders if we can find a way to reverse nitric oxide's effect on a particular enzyme in nerve cells."

Nitric oxide inhibits the neuroprotective ERK1/2 signaling pathway Learning and memory are in part controlled by NMDA-type glutamate receptors in the brain.

These receptors are linked to pores in the nerve cell membrane that regulate the flow of calcium and sodium in and out of the nerve cells. When these NMDA receptors get over-activated, they trigger the production of nitric oxide.

In turn, nitric oxide attaches to other proteins via a reaction called S-nitrosylation, which was first discovered by Lipton and colleagues. When those S-nitrosylated proteins are involved in cell survival and lifespan, nitric oxide can cause brain cells to die prematurely—a hallmark of neurodegenerative disease.

In their latest study, Lipton, Nakamura and colleagues used cultured neurons as well as a living mouse model of stroke to explore nitric oxide's relationship with proteins that help repair neuronal damage.

They found that nitric oxide reacts with the enzyme SHP-2 to inhibit a protective cascade of molecular events known as the ERK1/2 signaling pathway. Thus, nitric oxide not only damages neurons, it also blocks the brain's ability to self-repair.

NASA ISS EVAs: Repair P6 Truss Radiator and Microbe-III Experiment

Commander Suni Williams and Flight Engineer Aki Hoshide configure spacewalk equipment in the Quest airlock. 

Credit: NASA TV

The Expedition 33 crew members living and working aboard the International Space Station made preparations for an upcoming spacewalk and worked with a variety of science experiments Wednesday.

Commander Suni Williams and Flight Engineer Aki Hoshide reviewed procedures with flight control teams and prepared equipment in the Quest airlock for an upcoming spacewalk.

During the EVA, Williams and Hoshide will venture out of the Quest airlock on to the exterior of the station to repair an ammonia leak in the P6 truss radiator.

Hoshide worked with the Microbe-III experiment, which monitors the abundance and diversity of fungi and bacteria in the Kibo module.

The results will be used to produce a microbiologically safe environment which is essential for a long-time stay in space.

› Read more about Microbe-III

Remnants of Iraq Air Force Are Found - NYTimes.com

Remnants of Iraq Air Force Are Found - NYTimes.com

BAGHDAD - Iraqi officials have discovered that they may have a real air force, after all.

Johan Spanner for The New York Times

So far, the Iraqi Air Force has only 87 aircraft, mostly transport and reconnaissance planes.

The Defense Ministry revealed Sunday that it had recently learned that Iraq owns 19 MIG-21 and MIG-23 jet fighters, which are in storage in Serbia. Ministry officials are negotiating with the Serbs to restore and return the aircraft.

The Serbian government has tentatively promised to make two of the aircraft available “for immediate use,� according to a news release from the ministry. The rest would be restored on a rush basis, the ministry said.

An Iraqi delegation went to Serbia as part of an effort by the government to locate assets stashed abroad by Saddam Hussein to evade sanctions. Serbia had had friendly relations with Mr. Hussein’s government.

During that visit, Serbian defense officials told the Iraqis that Mr. Hussein had sent 19 fighter jets to Serbia for repairs in the late 1980s, during the Iran-Iraq war, but was unable to bring them back after sanctions were imposed on his country.

Iraq immediately sent a technical delegation, led by the air force chief, Gen. Anwar Mohammed Amin.

The Web site of the Iraqi Supreme Islamic Council, the leading Shiite political party, quoted the Defense Ministry spokesman Mohammed al-Askari as saying that the aircraft had been sent in 1989 “for maintenance, and everything was paid for by Iraq’s money.� Mr. Askari said the discovery was important because Iraq had no jet aircraft with defensive or offensive capabilities. “Our air force only has helicopters,� he said.

“Everyone knows how much we need fighter aircraft,� the ministry statement said. “We have reached a tentative agreement with the Serbian side to rehabilitate the aircraft and deliver them to Iraq in the shortest possible time, in recognition of Iraq’s need for such aircraft.�

The Defense Ministry statement was issued as a rebuttal to Iraqi news reports claiming that secret negotiations were under way with Serbia as part of a corrupt arms deal.

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Large Handron Collider (LHC) stopped by Small Dry Joint (SDJ)

THE Large Hadron Collider (LHC), possibly science's greatest ever project, was undone in September by one badly soldered joint. With 10,000 such joints around the accelerator's ring, it is proving a struggle to check them all in time to restart this autumn as hoped.

A splice between two sections of superconducting cable melted when the current was turned up. As well as repairing the one that failed, engineers have so far found and fixed 20 slightly under-par splices. It is a slow process as each of the LHC's eight sectors must be gently warmed from its 1.9 kelvin operating temperature to about 300 K to be checked and repaired.

The repairers are now testing if they can check the splices at a moderately cool 80 K. "We'll know by Tuesday," says LHC technical director Steve Myers. If so, the last three sectors can be screened much more quickly. Any urgent repairs will delay the start-up, but less serious faults could be left and the LHC switched on anyway, perhaps at reduced energy.

It is an interesting dilemma that, as you approach the atomic layers the technology and physics that bring you there, are starting to break down. This is particularly so for materials and their interconnectivity.

NASA Hubble (HST) Off-line again! Cntrl-ALt Re-boot!

The 19-year-old Hubble Space Telescope is back to normal after an alarming hiccup earlier this week.

A vital unit stopped communicating with the telescope's main computer on Monday, a development that sent the observatory into standby, or "safe", mode.

The device, which is needed to communicate with the telescope's science instruments, was installed in May during a mission to repair and upgrade the telescope in the hopes of extending Hubble's life until at least 2014.

The unit replaced the original, which was hobbled in September 2009. (Image: NASA)