U.S., British astronauts to perform urgent spacewalk Friday

CAPE CANAVERAL, Fla. -- Astronauts Tim Kopra and Tim Peake will venture outside the International Space Station on Friday to replace a failed voltage regulator and perform several tasks to prepare the outpost for the arrival of two new docking ports.

Peake will become the first Briton to walk in space as the two Tims perform NASA's 35th spacewalk based from the station's airlock. The nearly seven hour spacewalk is expected to begin at 7:55 a.m. EST.

Friday's planned spacewalk will be the 192nd in support of maintenance and repairs to the outpost since construction began in 1998. Kopra, who will be making his second walk in space in four weeks, will be identified as EV1 and sporting red stripes on his space suit, while Peake will be Extra Vehicular 2.

"I am thrilled at this opportunity for a spacewalk," Peake said from 255 miles above the planet. "Right now we are focusing on preparing the tools, equipment and procedures. If the spacewalk is successful, this will restore the International Space Station to 100% of its operational capability."

Space station commander Scott Kelly will assist the spacewalkers in donning and later removing their bulky suits. Kelly and Russian cosmonaut Mikhail Kornienko are currently nine months into a historic one year mission in space, their Soyuz craft set to carry them home in March.

Astronauts to perform urgent spacewalk repair Monday

CAPE CANAVERAL, Fla. -- Two NASA astronauts will perform an unscheduled spacewalk next week to help free a stuck cargo transport rail car outside the International Space Station allowing an arriving cargo ship to dock two days later.

Station commander Scott Kelly and flight engineer Tim Kopra will go outside the orbiting laboratory on Monday to release the Mobile Transporter rail car's brake handle which locked during the car's relocation on Wednesday. The rail car became stuck just four inches from its destined work site as flight controllers remotely moved the vehicle along the station's truss located above the U.S. Destiny Laboratory.

"The ISS Mission Management Team met Friday morning and is targeting Monday for the spacewalk, but will meet again in a readiness review Sunday morning," NASA spokesperson Kelly Humphries said. "Managers could elect to press ahead for Monday, or take an extra day and conduct the spacewalk Tuesday."

Humphries explained the relocation work is in support of Wednesday's arrival of the newly upgraded Russian Progress MS resupply craft set to Monday and later dock to the Pirs docking module at 5:31 a.m. EST. The mobile transporter has to be locked down and electrically connected prior to the arrival of Progress.

"We can get there in relatively short order and do the task, but while we are going out the hatch we are going to look and see if there is anything in that general area we can go and work on," Space Station operations manager Kenny Todd said of the possibility of additional work for the spacewalking duo. "All that said, our primary objective is to go out and get this mobile transporter secured at the site. The direction we've given the (planning) team is to look at those things that are out there in that general area we might be able to do."

NASA readies station for commercial dockings as Russia plans departure

Two spacewalking astronauts continued with jobs outside the International Space Station on Wednesday to prepare the orbiting outpost for a pair of new docking adapters arriving this summer.

Space station commander Butch Wilmore and Terry Virts switched their spacesuits to internal power at 6:51 a.m. EST, ahead of leaving the station's Quest airlock, beginning the second of three planned spacewalks during an eight day stretch. The duo quickly went to work beginning the nearly seven hour spacewalk by moving over to their work site -- a former space shuttle docking port.

Wilmore and Virts first removed a thermal cover from the former shuttle docking module in preparation for the June arrival of the first of two new International Docking Adapters (IDA). IDA-1 will be attached to the older docking module also known as Pressurized Mating Adapter 2 during a spacewalk in July. Both IDA's are due to launch from Cape Canaveral a top separate SpaceX Falcon 9 rockets tucked inside the Dragon 7 supply craft.

"Boeing built the two new docking adapters... Boeing’s Crew Space Transportation-100 and SpaceX’s Crew Dragon will use the adapters to deliver astronauts to the space station later this decade," NASA spokesperson Mark Garcia stated during today's spacewalk.

IDA-2 will launch two months later and then installed to PMA-3. The PMA-3 will first be moved from its current location and over to the space-facing side of the American Harmony module this summer. NASA has confirmed, "SpaceX is targeting its new Crew Dragon spacecraft to make an uncrewed flight test in late 2016 and a crewed flight test in early 2017."

The six hour spacewalk also featured several housekeeping chores by the spacewalking duo including lubricating the 57-foot robotic arm's latching end-effector, and rigging two final power and data cables over to PMA-2.

Virts stood on a special platform on the station's truss as he placed a special lubricate on the ball screws and bearings near the snares on the hand section of the Canadian-built arm. As Virts worked outside, station crew mate and Italian astronaut Samantha Cristoforetti worked from inside the Cupola module slowly moving the robotic arm and its wrist joint into position for Virts.

"We were the cable guys, and now we're the Grease Monkeys," Wilmore commented as the spacewalk wrapped up.

The same two astronauts will step outside for a third time on Sunday to complete several more tasks in anticipation of the new docking adapters. NASA TV will provide live coverage of the orbital walk beginning at 6:00 a.m.

As Wednesday's American spacewalk began, the Russian Space Agency announced new plans to conclude their presence at the space station in 2024. ROSCOSMOS chairman of manned space flight Yuri Koptev announced early Wednesday plans to separate several of their science and docking modules in nine years to form a new Russian-based space station.

"The concept involves the use of the ISS until 2024, and then plan to create a Russian space base on the basis separated from the ISS modules," the Russian Space Agency said in a new press release. "Configuration of multipurpose laboratory module, nodal module and scientific power module to create a promising Russian space station to meet the challenges of providing secure access to the Russian space."

ROSCOSMOS added their interest in landing a Russian on the Moon beginning in 2030, "Russia will target study of the moon using unmanned spacecraft to lunar orbit and the surface of Earth's natural satellite. At the turn of 2030 and will be out for manned missions to the moon." The release also mentioned plans to "implement programs of deep space exploration".

"Cable Guys" prepare space station for new docking ports

Astronauts spacewalk to prepare the space station for docking ports. (NASA)

The first of three spacewalks to prepare the International Space Station for the arrival of future commercial spacecraft wrapped up on Saturday after astronauts strung new cables in preparation for two new docking ports launching this year.

NASA astronauts Barry "Butch" Wilmore and Terry Virts completed a six hour, 41 minute assembly spacewalk at 2:26 p.m. EST, having laid out eight of the 10 electrical and communication cables in preparation for the arrival of the ports.

Nicknamed the "Cable Guys" by NASA controllers, Wilmore and Virts "rigged a series of power and data cables at the forward end of the Harmony module and Pressurized Mating Adapter-2, and routed 340 of 360 feet of cable," NASA spokesperson Mark Garcia stated at the conclusion of the spacewalk.

The astronauts will pick back up in a few days, and plan to finish the necessary tasks with a third orbital stroll next Sunday, March 1. "The duo will venture outside the space station again on Wednesday to deploy two more cables and lubricate the end of the space station’s robotic arm," Garcia added.

Two Boeing-built International Docking Adapters (IDA) are due to arrive to the orbital outpost this summer and fall. The first IDA is at the Kennedy Space Center with the second adapter wrapping up construction near Houston. Each adapter will allow a visiting crewed commercial spacecraft to perform a soft-dock arrival to space station.

Each 1,150-pound adapter will be tucked inside a Dragon cargo craft's trunk launched a top two SpaceX Falcon 9 rockets. The adapters will require several spacewalks to mate each to the station, and then connect the power and communication cables which are being laid out during these three spacewalks.

Wilmore is the current space station commander, and performed one previous spacewalk last October. Saturday's walk in space marked Virts first time outside a spacecraft. Astronauts and cosmonauts have spent a combined 1,159 hours during 185 spacewalks conducting space station assembly and maintenance jobs.

The spacewalk was delayed by one day to give both flight controllers and the astronauts a break following an exhaustive week in troubleshooting the two spacesuits for contamination of its cooling system. Issues with previous spacesuits forced NASA to return them to Earth aboard a Dragon supply craft for analysis and checkout.

NASA schedules spacewalks to repair space station cooling system

CAPE CANAVERAL, Fla. -- On the heels of Christmas week NASA on Tuesday decided to delay this weeks launch of a resupply ship to the orbiting International Space Station in hopes to perform three spacewalks to repair a broken cooling system.

A failed valve on a pump module which controls the flow of coolant through lines to keep the space station's electrical systems cool stopped functioning on December 11 prompting NASA and the international partners to troubleshoot the exact cause and how to repair the issue.

"The pump is associated with one of the station's two external cooling loops, which circulate ammonia outside the station to keep both internal and external equipment cool," said Brian Dunbar, a spokesperson at the Johnson Space Center near Houston. 

Three 6 hour space walks by two NASA astronauts will allow the space agency to uninstall the failed cooling pump module with a spare located on the Starboard Truss segment of the station. 

The first spacewalk is planned to start on Saturday at 7:10 a.m. EST, and will see Rick Mastracchio and Mike Hopkins translate over to the external stowage platform to retrieve the replacement pump module.

Astronauts complete needed tasks during spacewalk

CAPE CANAVERAL, Fla. -- An American and an Italian astronaut took a stroll in space outside the International Space Station on Tuesday to perform much needed repairs and to retrieve a few experiments.

American Chris Cassidy and Italian astronaut Luca Parmitano spent just over six hours working in space, marking the second spacewalk of the year by an American.

Today's six hour, seven minute spacewalk officially began at 8:02 am EDT, as the pair switched their spacesuits to internal power. They then opened the station's Quest airlock hatch and floated outside.

This marked the first time an Italian astronaut walked in space, and was the first spacewalk by a European since February 2008.

As the orbital laboratory soared 260 miles above Saudi Arabia in the darkness of night, the pair adjusted to their new surroundings to prepare for their first tasks.

Cassidy, wearing red stripes on his spacesuit, went right to work ten minutes later to replace a Ku-Band video and data transmitter controller. One of two used to send and receive information from the ground failed in December.

The new controller will give the space station "redundant capability for the station's Ku-Band" transmissions, stated NASA's Rob Navis during the spacewalk.

Using a space styled wrench known as a pistol grip tool, Cassidy had trouble with a stubborn bolt, and tried adjusting the proper torque setting to release the bolts which held the controller in place on the station's Z1 truss.

Meanwhile, Parmitano translated over to the station's right side truss to retrieve a couple of NASA experiments known as MISSE 8 which tested the effects of direct sunlight, radiation and the other harmful elements in the vacuum of space.

NASA will use the results from Materials on International Space Station Experiment 8 as they look for the best materials to create new spacecraft as they steer toward deep space flights by astronauts during the 2020's.

As the Italian astronaut returned the two experiments back to the Quest airlock for their return to earth later this year, Cassidy commented to Parmitano, "Outstanding! Nice job".

Cassidy later strung a few new power cables along a section of the station in a task which will be completed during a upcoming spacewalk to support of a new Russian laboratory module.

Russia plans to launch it's Nauak module in December, and will also serve as an airlock and docking port beginning in 2014.

Parmitano received an out of this world view of both the space station and earth as he rode high above at the end of the Canadian-built 57-foot robotic arm as he and Cassidy removed and replaced two radiator grapple bars.

Inside the American Destiny module, Karen Nyberg controlled the robotic arm and swung Parmitano over to the region of the station's truss so that Cassidy could bolt the grapple bars down on either side.

NASA's Josh Byerly explained to this aerospace reporter today that the new grapple bars will help in case one of the station's extended thermal radiators fail and needs to be replaced.

The thermal radiators are located across the core truss and help transfer heat from the station's electronics out into space.

Tuesday's spacewalk marked the 170th to support maintenance and construction of the space station since 1998.


(Charles Atkeison reports on aerospace, science and technology. Follow his updates via Twitter @SpaceFlight360.)

Shuttle astronauts mark milestones outside space station

Spacewalker Mike Fincke photographed the Cupola today. (NASA)

Shuttle Endeavour astronauts ventured outside the International Space Station one final time to perform several robotic chores as they marked a few milestones outside the outpost.

The fourth and final spacewalk by Endeavour's astronauts began earlier than planned at 12:15 a.m. EDT this morning, from the space station's Quest airlock.

Astronauts Mike Fincke and Greg Chamitoff went to work on the first task which will double the length and extend the reach of the space station's robotic arm.

Endeavour's orbiter sensor boom extension which was used to survey the orbiter's thermal protection system earlier on this flight for damage, was handed over to the space station to become a permanent fixture.

The orbital duo moved the boom over to the station's side for future use to double the reach of the existing arm to over 100-feet long.

It was also the final American equipment to be installed on the orbiting laboratory 220 miles high.

"Space station assembly is complete," Endeavour's commander Mark Kelly radioed his crew with pride.

"Assembly complete, amazing. Boy, this is a big space station," Chamitoff radioed back moments later from outside the complex.

Chamitoff also became the final shuttle astronaut to return inside an airlock as he followed Fincke to closeout this 159th spacewalk to construct and maintain the nearly one million pound complex.

The astronauts wrapped up their 7 hour and 24 minute spacewalk today at 7:39 a.m., completing 28 hours and 44 minutes of spacewalks performed during Endeavour's final flight.

The astronauts surpassed the 1000th hour of spacewalking time at 5:02 a.m. in support of constructing and maintaining the space station.

Since 1998, American, Russian, Canadian, European and Japanese astronauts have now spent 1,002 hours and 37 minutes of spacewalking time outside the station.

Today's spacewalk was also the final spacewalk performed by a space shuttle crew.

All future spacewalks will be performed by space station astronauts, including the single orbital walk planned during shuttle Atlantis' flight in July.

Also later today at 8:00 p.m., Fincke will become the American astronaut with the most time spent in space as he surpasses his boss Peggy Whitson's 377 days in space.

Whitson serves as the Chief of the Astronaut Corps at the Johnson Space Center.

Fincke served two six month tours aboard the station in 2004 and 2009, the later as the commander.

His two previous space flights ended with landings in Kazakhstan aboard Russian Soyuz spacecrafts. This flight aboard Endeavour is his first space shuttle flight.

Endeavour astronauts take a walk outside space station

Drew Feustel along the port side of space station at 5:48 a.m. (NASA)

Two of shuttle Endeavour's astronauts went outside the International Space Station to perform a few chores on the first of four spacewalks planned during the shuttle's twelve day visit.

Spacewalkers Drew Feustel and Greg Chamitoff began the first spacewalk of the mission at 3:10 a.m. EDT, and then left the Quest airlock to translate over to the right section of the space station's truss.

The first order of business was for the duo to head over to the Starboard Truss to retrieve the Materials International Space Station Experiment or MISSE 7A and 7B, for their return to earth.

Delivered to the space station and placed on the Express Logistics Carrier 2 in November 2009 during STS-129, the astronauts began by removing the lone power cable attached to each experiment and closed it up. The pair then removed the two pins which held each experiment in place and then stored them in the shuttle's payload bay for the return back to earth.

Feustel then retrieved MISSE 8 from Endeavour's bay and carried it over to the express carrier and installed where 7A had been located.

Chamitoff then moved over to the Starboard 3 segment of the Truss, or backbone of the space station, to begin installing a light on Crew Equipment and Translation Aid cart.

Today's spacewalk is the fourth by Feustel and the first by Chamitoff, and it can be very exhausting to an astronaut during his first venture outside the spacecraft.

Several space station astronauts have depleted their oxygen early by either working to fast or breathing to much as they strain to become accustomed to their new environment.

Feustel, who performed three spacewalks two years ago during the final Hubble Space Telescope servicing flight, was able to control his oxygen intake through his suit. Meanwhile, first timer Chamitoff made a couple of returns back to the airlock to recharge his oxygen in the first three hours of the spacewalk.

Over four hours into the spacewalk, Chamitoff's carbon dioxide sensor in his spacesuit failed with Mission Control unable to receive data on the ground.

The failure forced the orbital duo to stop work outside the station so that Mission Control could access how much time would be needed to complete the tasks safely.

After much discussion, the control center informed the astronauts to begin wrapping up work and focus on the clean up of two work sites and prepare to return to the airlock early.

Feustel and Chamitoff began entering the Quest airlock at 9:13 a.m., a half-hour earlier than planned.

Several unplanned work details were performed, however most of the orbital walk in space ran 15 minutes behind schedule.

"I want to thank both of you on an outstanding EVA (extravehicular activity)," spacewalking coordinator Fincke radioed the pair upon entering the airlock. Fincke also congratulated Chamitoff on his first spacewalk and sent wishes to controllers on the ground.

Today's first spacewalk lasted a total six hours and 19 minutes, and was the 115th from the space station's airlock.

Today's 'walk was the 156th spacewalk in support of building and maintenance of earth's orbiting outpost in space, during a combined 980 hours and 12 minutes.

The second space walk by astronauts Feustel and Mike Fincke is planned for Sunday morning at 2:16 a.m.

Discovery astronauts wrap first of two spacewalks

Drew (left) and Bowen work outside station today. (NASA)

Two spacewalking astronauts wrapped up several long awaited chores outside the International Space Station today, the first of two planned walks in space this week.

Shuttle Discovery crew members Steve Bowen and Alvin Drew concluded a six hour, thirty four minute orbital walk in space this afternoon at 5:20 p.m. EST, as the station-shuttle complex flew 222 miles off the Newfoundland coast and out over the northern Atlantic Ocean.

On the agenda first was the installation of the J612 power cable, a back up which runs from the Unity to the Tranquility nodes.

The combined twelve crew members of both the shuttle and station over came a few issues during the spacewalk.

First, Bowen's helmet video camera failed to work. Controllers on the ground in talking with spacewalk coordinator Nicole Stott spent over an hour to troubleshoot the issue. It looked to be working halfway through the walk.

Just over 100 minutes into the spacewalk, the Robotics Work Station computer in the Cupola node shutdown, stopping control of the station's robotic arm.

Arm operators station commander Scott Kelly and Discovery astronaut Mike Barratt were told to switch to the Destiny module's backup work station to resume using the arm to translate Bowen around the truss segment.

As Bowen rode the end of the arm holding the ammonia pump section, Barratt swung the arm over to the Quest airlock. Drew then screwed in four bolts to secure the 780-pound pump module to a storage platform as Bowen held it in place.

Mission Control states that the ammonia pump will be returned back to earth on the final space shuttle mission aboard Atlantis this July.

In the closing minutes of the spacewalk, the astronauts approached the Japanese Kibo module and removed a bottle-styled container and opened the lid.

As the crew inside played The Police's "Message in a Bottle" over the radio communications channel, Drew filled the Japanese metal container with the elements of 'space'.

It will be returned to earth and handed over to JAXA, the Japanese Space Agency, and placed in a museum in Japan in support of space flight. It's designed to inspire future engineers and space voyagers.

"You guys did an excellent job today, you rocked," Stott radioed her crew mates as they concluded work outside the station.

Today's spacewalk was the 154th spacewalk by Americans, Russians, Japanese and Europeans to both construct and maintain the space station. A total 967 hours and 39 minutes of spacewalking since the orbiting lab complex began construction in 1998 have been completed.

This was lead spacewalker Bowen's sixth trip outside a spacecraft and has now logged 41 hours, 04 minutes. For Drew, this was his first trip outside and into the vacuum of space.

NASA's station control room capcom Stan Love spoke to station commander Scott Kelly and Discovery's commander Steve Lindsey at 6:00 p.m. to say that Discovery will receive an extra day docked to the space station.

The extra day in space may mean a special photo opportunity as a Russian Soyuz TMA could undock and fly out to photograph the visiting shuttle as she and several international unmanned craft sit parked at the complex. Russia may be uneasy with the idea.

NASA's Johnson Space Center informed this reporter tonight that NASA is "awaiting a formal decision on a Soyuz fly around which will be made tomorrow at the space station Mission Management Team meeting".

Landing will now be rescheduled for March 8 at about 11:35 a.m. at the Kennedy Space Center.

Discovery astronauts begin first spacewalk of mission

Discovery astronauts work outside space station today. (NASA)

(UPDATED: 2:05 p.m. EST) -- Shuttle Discovery astronauts Steve Bowen and Alvin Drew left the comfort of the International Space Station this morning to perform several chores in support of earth's orbital outpost.

Today's spacewalk began at 10:46 a.m. EST, and is Bowen's sixth orbital walk having accumulated 34 1/2-hours of spacewalking time on two shuttle flights.

Drew became the 200th person to perform a spacewalk in human history as he set out on his first walk in space.

Bowen and Drew paused prior to departing the airlock to acknowledge former Discovery crew mate and lead spacewalker Tim Kopra who will help the duo from Mission Control during the spacewalk.

"I'm really looking forward to working with you guys," Kopra radioed astronauts Bowen and Drew moments before the walk began. "You're a good man for the job," Kopra addressed to Bowen his replacement on the mission.

Bowen was added to Discovery's crew on January 19 to replace Kopra following a bike accident by Kopra a few days earlier in which he suffered a fractured hip in January.

As the crew worked 222 miles above earth, Discovery astronaut and former station resident in 2009 Nicole Stott is serving as the coordinator of the spacewalk.

The spacewalk is the first of two planned during Discovery's week long visit to the space station, and is the 154th 'walk in support of space station construction and maintenance.

Today's walk also marked the 234th venture outside a spacecraft by an American astronaut since Ed White first left his Gemini IV craft in 1965.

The duo will install a power extension cable to the Unity; relocate a failed ammonia module which failed last year to a storage platform for it's return to earth; and a Japanese "Message in a Bottle" experiment which will be released into space and return to earth.

The first issue in the early minutes of the spacewalk was Bowen's spacesuit helmet camera failed to work. Controllers on the ground along with Stott trouble shot the camera issue. It was later fixed a bit later.

"I think we're moving along pretty well here...", Stott radioed the astronauts as they completed the installation of the J612 power cable, a back up which runs from the Unity to the Tranquility nodes.

Bowen then transitioned over to the space station's 58-foot robotic arm followed by Drew to install a work platform on the end of the arm. Bowen will ride the arm as the pair moves the ammonia tank to a new storage location.

Just over 100 minutes into the spacewalk, the Robotics Work Station computer in the Cupola node shutdown, stopping control of the station's robotic arm.

Arm operators station commander Scott Kelly and Discovery astronaut Mike Barratt were told to switch to the Destiny module's backup work station to resume using the arm to translate Bowen over the lab complex.

By 2 PM, the astronauts were running fifteen minutes behind schedule.

Spacewalk begins busy weekend on Space Station

Russian Kondratiev early into the spacewalk today. (NASA)

One of the busiest weekends aboard the International Space Station began this morning with the start of a Russian spacewalk.

As two cosmonauts prepared to step outside of the station's airlock, on the ground Japan rolled out to it's launch pad their rocket which will deliver several tons of supplies to earth's orbital outpost in space.

Russian cosmonauts Oleg Skripohcka and Dmitry Kondratiev officially began their six hour orbital walk at 9:29 a.m. EST (1429 GMT) today as they opened the hatch of the Russian Pirs module.

The space station was 224 miles high over the central Pacific Ocean approaching Baja California as the walk began.

It is the twenty-seventh spacewalk by the Russians based from the space station.

"A space walk is a big and important event in an ISS space mission, that's why preparations for it receive special attention on Earth," Kondratyev stated on Thursday.

Kondratyev added, "Spacesuit systems provide a supply of oxygen and dispose of carbon monoxide, maintain a comfortable temperature for a cosmonaut and also provide a radio connection." He refered to his suit as "a small spaceship", the Russian Space Agency added.

The only issue of the spacewalk occurred as Kondratiev's medical harness in his Orlan spacesuit malfunctioned prior to airlock depressurization. He was approved to begin the spacewalk under the understanding he was to report how he was feeling over the six hours outside.

As the pair transitioned to the Zvezda service module a half-hour later, they activated an American helmet camera on Skripohcka blue-stripped suit.

The duo began several tasks including the removal of "the impulse plasma injector from Zvezda’s outer surface, and installation of Russia's high-speed data transmission equipment Photon-Gamma intended to study gamma-bursts and optical radiation during thunderstorms", the Russian space agency stated to this reporter.

By 10:10 am, the space walkers were twenty-two minutes ahead of schedule, having completed task number 8 of 30 planned.

Meanwhile on earth, Japan's HII-B rocket was moved out to it's launch pad during the night at 9 a.m. EST.

Japan's largest rocket the HII-B will carry their second supply ship, KOUNOTORI 2 loaded with supplies for the space station in both a pressurized and non-pressurized section.

Launch remains set for Saturday at 12:37 a.m. (2:37 p.m. JST) from the Tanegashima Space Center in southern Japan. The flight will mark the HII-B second flight.

On Sunday, the six member crew aboard the station will undock the Russian Progress 40P unmanned craft to make way for next Friday's launch of a fresh supply craft.

Second Spacewalk of Atlantis' Mission Underway

Atlantis astronauts today are performing the second of three planned spacewalks outside Earth's orbital outpost to install fresh batteries and repair a snagged cable on a sensor boom.

Mission specialists Steven Bowen and Michael Good switched their spacesuits to internal power officially beginning today's planned six and one-half hour spacewalk at 6:38 am EDT.

The first task the orbital duo began was to free a snagged cable at the camera on the orbital boom sensor.

"The cable was inhibiting a camera from maneuvering correctly. Bowen adjusted the cable and used a plastic tie to hold it in position," Mission control near Houston stated today.

This job only lasted only fifteen minutes, but when they finished it was fifty-one minutes into the spacewalk.

The second task the astronauts went to work on outside the space station is the replacement of at least three of six batteries at the Port 6 truss solar array.

The astronauts will replace each 375 pound battery at the array's integrated electrical assembly by releasing two hold down bolts. Once the battery is free, the two astronauts will hand-off the battery back and forth as they transition down the truss segment to store the battery.

The first new battery, battery A, will then be removed from the Intergrated cargo carrier which Atlantis brought up to orbit and houses all six fresh batteries.

In support of the spacewalk, Atlantis astronauts Garrett Reisman and Piers Sellers operated the station's fifty-foot robotic arm with the portable foot restraint attached.

A Friday spacewalk will install the final three batteries in the same region of the station.

Atlantis Astronauts Begin Station Spacewalk

Two of shuttle Atlantis' astronauts began an orbital walk in space this morning to install a new high gain antenna and perform several chores in support of the International Space Station.

Spacewalkers Garrett Reisman and Steven Bowen began the first of three planned 'walks at 7:54 am EDT today, as they switched their suits to internal power while in the Quest airlock of the station.

Running under the call sign nicknames of Big-G for Reisman and Steve-O for Bowen, the pair spent a few minutes getting accustomed prior to their planned six and one-half hour extra vehicular activity.

Today's spacewalk is the 144th devoted to space station construction and maintenance. At the start of today's spacewalk, astronauts and cosmonauts have logged a total time of 893 hours and 93 minutes outside the orbital complex.

First up saw Reisman began to transition over to the station's port 1 truss to the Ceta cart to pick up a portable foot restraint in which he will stand upon as he rides the station's robotic arm this morning. He completed installation of the PFR at 8:39 am.

Meanwhile, Bowen began removing several bolts at 8:36 am, removing the Ku-Band antenna dish which was mounted to the intergrated cargo carrier -- an eight foot long cargo support structure which Atlantis delivered to station on Sunday.

Operating the space station's fifty-foot robotic arm is Atlantis' Piers Sellers.

"There's a spectacular light show underneath us", Big-Garrett stated as he viewed lightning storms over Taiwan during the nighttime pass at 8:45 am.

At the helm of Atlantis is commander Ken Ham and pilot Tony Antonelli. Mission specialists Reisman, Michael Good, Bowen and Sellers round out the crew of NASA's 132nd space shuttle mission.

Orbiting high above earth in an orbit of 220 x 212 statue miles, the largest complex ever to fly in space with Atlantis docked now weighs in at 1.06 million pounds.

Final Spacewalk of Discovery Mission Concludes

Shuttle Discovery astronauts performed the third and final spacewalk of their ten day visit to the International Space Station today.

Spacewalkers Rick Mastracchio and Clay Anderson began their venture outside the station at 2:14 am EDT, this morning as the pair switched their suit to internal power. Minutes later, they left the Quest airlock to begin a busy next six hours.

Today's spacewalk marked the final spacewalk ever to take place aboard Discovery, on this the second from last flight by the grand ol' ship.

The first chore of the orbital walk saw Mastracchio connect two nitrogen pressurization umbilicals and two ammonia transfer lines between the newly installed ammonia tank and the space station.

The pair exchanged an empty ammonia tank on Sunday with a new 1,700 pound tank which was brought up aboard Discovery last week.

Meanwhile, Anderson began retrieving the dual debris shields from their storage since last November to the airlock for their return home aboard Discovery in one week.

The two silver rectangular shields will be stowed later today in the Leonardo module.

"Wow, what a view," Anderson noted at late in the spacewalk at 8AM today as the orbital complex flew 213 miles off the coast of Mauritania, Africa. "The earth is a beautiful place," he added.

Over two hours into the sixth spacewalk for the orbital duo, the pair worked to stow the old ammonia tank into the aft section of Discovery's payload bay.

Using the space station's robotic arm, mission specialist Stephanie Wilson used the arm to lower the tank into position so that Anderson and Mastracchio could lower it into place and use four bolts to lock it down.

However, as is the trend in recent spacewalks over the past year, drama unfolded as Mastrscchio began having trouble with the alignment and boltdown of the spent tank.

Meanwhile, as the astronauts worked the torque wrench to get the bolts to turn the needed 16 times, controllers in Mission Control near Houston began having issues in the activation of the newly connected ammonia tank located on the Starboard Truss one.

An issue with a nitrogen valve is the likely issue as the ground continued to work the problem late into this morning.

Forty-five minutes of wrestling with the alignment of the tank's support bracket paid off and the bolts began turning and sinking into place.

The bolt wrenching delay forced NASA to delete the task of retrieving a European Space Agency experiment located outside of the Columbus module for it's return to earth.

"It's been awesome working with you guys, and Stephanie working robotics...", spacewalk coordinator Dottie Metcalf-Lindenburger told her crew from inside the station's Destiny laboratory as the spacewalk concluded.

Today's spacewalk concluded at 8:38 am, following six hours and 24 minutes of work outside in the harsh vacuum of space.

In total, Discovery's three spacewalks added up to 20 hours and 16 minutes; It was the 143rd spacewalk in support of space station construction and maintenance; and the 236th 'walk in the American space program's history.

In all, astronauts and cosmonauts have spent 893 hours and 33 minutes outside of the space station performing tasks and upgrades to build and resupply earth's outpost in space.

Astronauts Successfully Install Station Cooling Tank

The old ammonia tank hangs near the spacewalkers today. (NASA)

Shuttle Discovery astronauts Rick Mastracchio and Clay Anderson fought hard to tighten down hold down bolts on a new cooling tank aboard the International Space Station this morning.

Working at the Starboard Truss segment 1, the station's robotic arm slowly moved a new ammonia tank over to the waiting astronauts so that they could bolt it down in place.

As Anderson began installing four bolts at 5:05 am EDT, however two would simply would not align up so that he could torque them down.

The space walkers tried different approaches as they struggled to tighten bolt number one. Frustration began to takeover on the space walkers an hour after first trying to get the tank bolted down.

Inside the space station, Discovery crew mate and coordinator of today's 142nd orbital walk to service the station, Dorothy Metcalf-Lindenburger, gave the crew advice and procedures to assist the pair.

Anderson even went back back to the airlock to retrieve a few extra tools.

Ninety minutes after starting the task, Anderson belted a "come on baby" as he successfully tightened down one and then two of the bolts.

The 1700-pound ammonia tank began to take root on the space station.

Anderson and Mastracchio then plugged in the tanks two electrical connections.

However, the longer than planned bolt down forced NASA to scrub connecting the fluid and nitrogen umbilical during this second of three planned orbital walks by the pair.

That task along with one other planned for today will be added to the final Extra Vehicular Activity or spacewalk planned for Tuesday morning.

As the EVA wrapped up, Metcalf-Lindenburger gave the space walkers praise for the hard work today, "You guy did a great job -- it was a long, long day. You did a great job".

Today's spacewalk concluded at 8:56 am EDT, as the astronauts began to repressurize the American Quest airlock following a seven hour and 26 minute longer than planned excursion.

Twelve minutes later, the hatches leading into the space station were opened, and the spacewalkers were safely inside as they began to doff their white suits.

Today's spacewalk was the fifth by both Anderson and Mastracchio, who now each total just over 32 hours outside a speeding spacecraft. The pair have spent nearly 14 hours working in the vacuum of space during the flight of Discovery.

Discovery Astronuts Spacewalk to Install Cooling System

Astronauts Rick Mastracchio and Clay Anderson went outside their home in space this morning to install a new cooling system and to perform several house keeping chores 220 miles above earth.

This second of three planned spacewalks began 45 minutes earlier than planned. It is expected to last 6 1/2-hours.

The second spacewalk of shuttle Discovery's ten day's of docked operations at the International Space Station began today at 1:30 am EDT, as the complex flew 219 miles above Australia and toward.

Six minutes later, the orbital duo left the American Quest airlock to begin the installation of a new ammonia tank assembly on the starboard truss segment. This is the 142nd spacewalk to assemble and maintain the station.

Thirty minutes into the EVA -- NASA-speak for spacewalk -- Anderson disconnected several electrical lines between the station the the old ammonia tank.

Mastracchio then began loosening the four bolts -- counter clockwise sixteen turns each -- which are holding the aging tank in place.

The old ammonia tank, which weighs 1295 pounds here on earth, will be exchanged with a new tank which weighs 1700 pounds.

Endeavour astronauts begin orbital walk in space

Two crew members of the space shuttle Endeavour began their third and final spacewalk of the mission this evening which will see them connect power cables and open the shutters on earth's orbital bay window.

Tonight's spacewalk began at 9:15 pm EST, as the International Space Station flew 220 miles high above the southern Pacific Ocean.

Astronuts Robert Behnken and Nicholas Patrick left the Quest airlock minutes later to begin their six and one-half hour orbital walk in space.

Behnken began work by opening up a second coolant loop which will flow ammonia into the new Tranquility node.

Later tonight, the pair will remove the protective covers from the windows of the newly installed cupola observation module. Once the covers are removed, station crews will have a panaromic 360-degree field view of the earth and the space beyond as they sail upon the ocean of space.

A Saturday Night Orbital Spacewalk Concludes

A Saturday evening stroll outside earth's orbiting outpost in space concluded following the successful completion of several tasks designed to prepare the space station for a future module and the replacement of a failed gyroscope.

The third and final spacewalk of the space shuttle Discovery's servicing mission to the international space station ended at 11:40 pm EDT, as astronauts Danny Olivas and Christer Fuglesang switched their spacesuits back to external power after entering the Quest airlock.

Last evening's seven hour, one minute spacewalk wrapped up three productive days of work outside the station. Combined, all three spacewalks of Discovery's docked operations total 20 hours and 15 minutes. To date, there have now been 830 hours and 50 minutes of spacewalking time devoted since 1998 to space station construction and maintenance.

On what had been a very quiet and productive spacewalk, European astronaut Fuglesang's helmet camera came loose near the end of the orbital walk. The loose camera caused some initial concern in Mission Control and prompted them to radio, "We thought you were doing acrobatics."

Olivas transitioned over to his helmet cam and quickly unplugged it and gave it to Fuglesang to carry back to the airlock so that it accidentally did not break off and float away.

Final Spacewalk of Discovery Mission Underway

The final spacewalk of the space shuttle Discovery's mission to the international space station got underway late today as two astronauts perform several maintenance tasks to service the station and prepare it for a new module.

Discovery launched astronauts Danny Olivas and Christer Fuglesang (above), of the European Space Agency, switched their spacesuits to internal power at 4:39 pm EDT, and stepped outside the Quest airlock of the station to begin a six and one-half hour spacewalk.

First up for the orbital duo is the replacement of a failed space station rate gyro assembly. They will disconnect cables and remove four attachment bolts as they remove the old gyro. They then will install a new gyro and later store the old one for it's return back to earth.

This 133rd spacewalk in support of space station construction and maintenance will also see several 60-foot long heater cables attached to the station's Unity module in preparation for their attachment to the Tranquility module which is due to launch aboard Endeavour this February.

Discovery's 37th flight crew includes commander Rick "CJ" Sturckow, pilot Ford, and mission specialists Jose Hernandez, Patrick Forrester, Olivas, Fuglesang and former station expedition 20 member Tim Kopra. Kopra was replaced last week with new expedition flight engineer Nicole Stott who rocketed into earth orbit aboard Discovery in the closing seconds of August 29th.

Space station expedition 20 crew members include commander Gennady Padalka, Michael Barratt, Roman Romanenko, Frank De Winne, Robert Thirsk, and Stott.

Final Discovery Spacewalk set for Today

Two of the space shuttle Discovery's astronauts will head back outside of the international space station late today as they prepare the outpost for the February arrival of the final U.S. module, Tranquility.

Mission specialists Danny Olivas and Christer Fugelsang (European Space Agency) are scheduled to switch their suits on internal power and head out of the station's Quest airlock at 4:49 pm EDT. The spacewalk is planned to last six and one-half hours.

A few of the prime tasks planned for this evening will be the replacement of a rate gyro assembly which failed several months ago. The orbital duo will disconnect cables and each remove two attachment bolts apiece to remove the old gyro. They then will install a new gyro and then store the old one for it's return back to earth.

Next, Olivas will separate from Fugelsang and transition over to the PMA-3 and set up a few heater cables, with one of them connected to the Unity module and the others tied down on one of the module's handrails. The cables will be used to connect the module with the upcoming arrival of the Tranquility module.

Tranquility is a pressurized module which will have windows providing a 360-degree view of the space station, and provide living quarters for off-duty residents. Endeavour will bring Tranquility to the station in February.

As Olivas works with the heater cables, Fugelsang will work to replace an nonoperational power control module located at the center of the space station. The removal and installation will be a one bolt operation.

This will be the 133rd spacewalk devoted to the construction of the space station.