Astronauts Thomas Marshburn and Christopher Cassidy staged a 4-hour 54-minute spacewalk today, the fifth and final excursion planned for the shuttle Endeavour's space station assembly mission. The spacewalkers installed two Japanese television cameras on a new experiment platform, fixed an insulation problem on a Canadian robot and re-wired a gyro control circuit.

They also completed a variety of minor "get-ahead" tasks after flight controllers decided there might not be enough carbon dioxide absorbent available in Cassidy's spacesuit to complete deployment of a cargo storage mechanism on the right side of the station's main truss. That task will be carried out by station astronauts or a future shuttle crew.

"Great job, outstanding EVA," Japanese astronaut Aki Hoshide radioed from Houston after Marshburn and Cassidy floated back into the Quest airlock module. "We're all very happy to work with you, it's a privilege. Thanks and congratulations on five EVAs."

Said lead Flight Director Holly Ridings: "Today was a great day."

"With the completion of our fifth spacewalk, that really marks the end of an amazing list of objectives that have been successfully finished during this mission," she said.

Through five spacewalks, along with near daily work with three robot arms on the shuttle and the space station, the astronauts attached a sophisticated experiment platform to the Japanese Kibo lab module, installed three experiment packages, replaced aging solar array batteries and mounted critical spare parts on the station's main truss.

With today's installation of two television cameras on the Japanese Exposed Facility experiment shelf, or porch, the astronauts completed the assembly and outfitting of the three components making up the Kibo lab complex.

"Congratulations, you guys just completed the JEF assembly," Hoshide called from mission control.

"Well, that is a big deal," David Wolf replied from the shuttle-station complex. "You guys have a fabulous space agency and it's an amazing laboratory, both internal and at vacuum. It's been a privilege to work with you to complete it."

Commander Mark Polansky and his crewmates - pilot Douglas Hurley, Canadian flight engineer Julie Payette, Wolf, Cassidy, Marshburn and returning space station flight engineer Koichi Wakata - plan to undock from the International Space Station on Tuesday and land back at the Kennedy Space Center on Friday to close out a marathon 16-day mission.

"We've had our challenges and as a team," Ridings said. "We've all worked together to overcome those challenges and complete what looks like a very, very nominal mission almost exactly like we planned it."

During his first spacewalk last week, Cassidy, a former Navy SEAL, used up more CO2-absorbing lithium hydroxide than expected, forcing flight controllers to order an early end to the excursion. During his second spacewalk two days later, CO2 levels rose only slightly and he was able to complete a full-duration seven-hour 12-minute spacewalk.

But for today's EVA, Cassidy and Marshburn used a different type of CO-absorbent called METOX, a "rechargeable" compound that is slightly less effective than lithium hydroxide. An analysis of Cassidy's usage early in the spacewalk raised concern he might run into problems by the end of a full-duration EVA.

"Consumables, METOX for Tom is seven (hours) plus zero zero, METOX for Chris is five plus three zero. Those are non-conservative numbers," Hoshide radioed. "When we did the math on the ground, with the 15 minutes out for cleanup, we're past the bingo time for the PAS deploy. Just wondering what you guys think."

"We'll declare bingo. Simple," Wolf replied from orbit.

The payload attach system - PAS - mechanism on the starboard truss must be deployed before a November shuttle mission delivers spare parts and equipment that are scheduled to be stored at that location. It's not yet clear whether the crew of a late-August shuttle mission will inherit the deployment or whether the station crew will have to take it on.

"We had a lot of discussions before this EVA, we were very concerned with how much consumables we would have," lead spacewalk officer Kieth Johnson said later. "So we built a timeline with a full set of activities, hoping to get to those. But we knew if we went at the last task we had assigned without enough time we could get caught in the middle of it.

"And so at a certain point in the EVA, we had to make a decision as to whether or not we were going to do the payload attach system deploy. ... Unfortunately, because of the consumables, we had to back up our bingo time and we made the decision at that point not to go do the payload attach system."

Ridings said the decision might appear conservative to outsiders, but it was the right call given the past problems with Cassidy's suit, earlier trouble with similar attachment mechanisms and the arrival Wednesday or a Russian Progress supply ship.

"When you do the task, you're actually taking structural pieces of the truss apart," she said. "You've got to get the platform out and you've got to get it put back together. We've got a Progress coming less than 48 hours after the end of the EVA today and if you get yourself in a configuration where those beams are not structurally mated to the truss, then it's not a good idea to dock vehicles.

"When you think consumables, which we were tracking a little bit conservatively just based on our previous experience on this mission, plus the Progress in just a couple of days ... it made a lot more sense to be a little conservative. On paper, that task (PAS deploy) was going to take an hour and 30 minutes. The only two we've done, we've had trouble with both of them. ... We did the calculation, we had about an hour and 40 minutes. That was too close to go and do the activity."

Today's spacewalk began at 7:33 a.m. EDT and ended at 12:27 p.m. It was the 130th spacewalk devoted to station assembly and maintenance since construction began in 1998, the 11th so far this year and the fifth for Endeavour's crew. Total station spacewalk time now stands at 810 hours and 36 minutes, or 33.8 days. Endeavour's total through five spacewalks is 30 hours and 30 minutes.

Additional coverage for subscribers:
VIDEO: MONDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY

VIDEO: FLIGHT DAY 12 HIGHLIGHTS MOVIE PLAY
VIDEO: INTERNATIONAL NEWS CONFERENCE WITH ASTRONAUTS PLAY
VIDEO: SUNDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: SUNDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY
VIDEO: OVERVIEW OF FLIGHT DAY 12 ACTIVITIES PLAY

VIDEO: FLIGHT DAY 11 HIGHLIGHTS MOVIE PLAY
VIDEO: INTERNATIONAL MESSAGE FROM SHUTTLE AND ISS CREWS PLAY
VIDEO: INDY, CBS NEWS AND MEMPHIS MEDIA INTERVIEWS PLAY
VIDEO: SATURDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY

VIDEO: FLIGHT DAY 10 HIGHLIGHTS MOVIE PLAY
VIDEO: FRIDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: DELIVERY PALLET RETURNS TO SHUTTLE PLAY
VIDEO: LAST OF THE OLD BATTERIES STOWED AWAY PLAY
VIDEO: SIXTH AND FINAL NEW BATTERY IS PLUGGED IN PLAY
VIDEO: SPACEWALKERS RESUME WORK WITH BATTERY CHARLIE PLAY
VIDEO: FRIDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY

VIDEO: FLIGHT DAY 9 HIGHLIGHTS MOVIE PLAY
VIDEO: THURSDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: MORE INTERVIEWS WITH LAS VEGAS, HOUSTON AND FOX PLAY
VIDEO: NORTH CAROLINA, MAINE AND ORLANDO TV INTERVIEWS PLAY
VIDEO: COMMUNICATIONS PACKAGE PUT ON SCIENCE DECK PLAY
VIDEO: X-RAY ASTRONOMY PAYLOAD INSTALLED ON STATION PLAY
VIDEO: THURSDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY
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VIDEO: FLIGHT DAY 8 HIGHLIGHTS MOVIE PLAY
VIDEO: WEDNESDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: EARLY END TO SPACEWALK NO. 3 DECLARED PLAY
VIDEO: SECOND FRESH BATTERY PUT INTO STATION TRUSS PLAY
VIDEO: FIRST OF THE NEW BATTERIES INSTALLED PLAY
VIDEO: SPACEWALKERS REMOVE FIRST OLD BATTERY PLAY
VIDEO: CHRIS CASSIDY PREPS JAPANESE EXPERIMENTS PLAY
VIDEO: WEDNESDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY
VIDEO: STEP-BY-STEP SUMMARY OF SPACEWALK NO. 3 PLAY

VIDEO: LEFT-HAND BOOSTER CAMERA LOOKING UPWARD PLAY
VIDEO: LEFT-HAND BOOSTER CAMERA LOOKING INBOARD PLAY
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VIDEO: RIGHT-HAND BOOSTER CAMERA LOOKING DOWNWARD PLAY

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VIDEO: CREW ANSWERS PUBLIC'S QUESTIONS FROM SPACE PLAY
VIDEO: EXPOSED FACILITY RECEIVES EXPERIMENT CARRIER PLAY
VIDEO: JAPANESE EXPERIMENTS UNBERTHED FROM SHUTTLE PLAY
VIDEO: OVERVIEW OF FLIGHT DAY 7 ACTIVITIES PLAY
VIDEO: TUESDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY

VIDEO: FLIGHT DAY 6 HIGHLIGHTS MOVIE PLAY
VIDEO: MONDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: REPLACEMENT COOLING PUMP PUT ON STATION PLAY
VIDEO: SPARE COMMUNICATIONS ANTENNA TRANSFERRED PLAY
VIDEO: SPACEWALKER HOPS ABOARD STATION ARM PLAY
VIDEO: WOLF AND MARSHBURN BEGIN EVA NO. 2 PLAY
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VIDEO: FLIGHT DAY 5 HIGHLIGHTS MOVIE PLAY
VIDEO: CANADIANS IN SPACE PLAY
VIDEO: SUNDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: PALLET HANDED OFF TO SPACE STATION PLAY
VIDEO: CARGO CARRIER UNBERTHED FROM SHUTTLE BAY PLAY
VIDEO: SUNDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY
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VIDEO: FLIGHT DAY 4 HIGHLIGHTS MOVIE PLAY
VIDEO: SATURDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: UPDATE ON ENDEAVOUR'S HEAT SHIELD CHECKS PLAY
VIDEO: JAPANESE OUTDOOR SCIENCE PLATFORM ATTACHED PLAY
VIDEO: SHUTTLE AND STATION ARMS HANDOFF SCIENCE DECK PLAY
VIDEO: JAPAN'S EXPOSED FACILITY UNBERTHED FROM SHUTTLE PLAY
VIDEO: THERMAL COVER JETTISONED FROM THE KIBO MODULE PLAY
VIDEO: HELMET-CAMERA VIEWS AS KOPRA CLIMBS TO SHUTTLE PLAY
VIDEO: TIM KOPRA EMERGES FROM AIRLOCK FOR EVA NO. 1 PLAY
VIDEO: SATURDAY MORNING FLIGHT DIRECTOR INTERVIEW PLAY
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VIDEO: NARRATED TOUR OF ENDEAVOUR'S PAYLOAD BAY PLAY

VIDEO: FLIGHT DAY 3 HIGHLIGHTS MOVIE PLAY
VIDEO: FRIDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: SHUTTLE CREW WELCOMED ABOARD STATION PLAY
VIDEO: ENDEAVOUR DOCKS TO THE SPACE STATION PLAY
VIDEO: ASTRONAUTS' ONBOARD CAMCORDER FOOTAGE PLAY
VIDEO: SHUTTLE FLIES OUT IN FRONT OF STATION PLAY
VIDEO: ENDEAVOUR PERFORMS 360-DEGREE BACKFLIP PLAY
VIDEO: BEAUTIFUL VIEWS OF ENDEAVOUR APPROACHING PLAY
VIDEO: STATION CAMERA CATCHES ENDEAVOUR'S "TI BURN" PLAY
VIDEO: NARRATED PREVIEW OF RENDEZVOUS AND DOCKING PLAY

VIDEO: FLIGHT DAY 2 HIGHLIGHTS MOVIE PLAY
VIDEO: TUESDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: PREVIEW ANIMATION OF HEAT SHIELD INSPECTIONS PLAY

VIDEO: FLIGHT DAY 1 HIGHLIGHTS MOVIE PLAY
VIDEO: THE FULL STS-127 LAUNCH EXPERIENCE PLAY
VIDEO: INSIDE MISSION CONTROL DURING LAUNCH PLAY
VIDEO: LAUNCH REPLAY: VAB ROOF PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PRESS SITE PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PAD PERIMETER PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: BEACH TRACKER PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: UCS-23 TRACKER PLAY | HI-DEF
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VIDEO: SHUTTLE ENDEAVOUR BLASTS OFF! PLAY | HI-DEF
VIDEO: STS-127 POST-LAUNCH NEWS CONFERENCE PLAY
VIDEO: FOOTAGE OF FUEL TANK AFTER JETTISON PLAY
VIDEO: ASTRONAUTS REACH PAD 39A PLAY | HI-DEF
VIDEO: CREW DEPARTS QUARTERS FOR LAUNCH PAD PLAY | HI-DEF
VIDEO: ASTRONAUTS DON SPACESUITS FOR LAUNCH PLAY | HI-DEF

VIDEO: WEATHER SCRUBS LAUNCH AGAIN PLAY | HI-DEF
VIDEO: CREW ARRIVES AT PAD 39A ON MONDAY PLAY | HI-DEF
VIDEO: CREW DEPARTS QUARTERS ON MONDAY PLAY | HI-DEF
VIDEO: ASTRONAUTS SUIT UP ON MONDAY PLAY | HI-DEF

VIDEO: THUNDERSTORMS SCRUB SUNDAY'S ATTEMPT PLAY | HI-DEF
VIDEO: CREW DEPARTS QUARTERS ON SUNDAY PLAY | HI-DEF
VIDEO: ASTRONAUTS SUIT UP ON SUNDAY PLAY | HI-DEF
VIDEO: NARRATED SUMMARY SHUTTLE'S PREPARATIONS PLAY | HI-DEF
VIDEO: NARRATED SUMMARY PAYLOADS' PREPARATIONS PLAY | HI-DEF

VIDEO: LIGHTNING STRIKES POSTPONE ENDEAVOUR LAUNCH PLAY
VIDEO: FRIDAY'S PRE-LAUNCH NEWS CONFERENCE PLAY
VIDEO: THURSDAY'S STATUS REPORT ON THE COUNTDOWN PLAY
VIDEO: COUNTDOWN PREVIEW AND WEATHER BRIEFING PLAY
VIDEO: ASTRONAUTS RETURN TO CAPE FOR LAUNCH PLAY | HI-DEF

VIDEO: NO LEAKS FOUND DURING SPECIAL TEST PLAY
VIDEO: EXPLANATION OF THE HYDROGEN LEAK AND THE REPAIR PLAY

VIDEO: POST-SCRUB NEWS BRIEFING PLAY
VIDEO: FIRING ROOM UPDATE WITH LAUNCH DIRECTOR PLAY
VIDEO: SCRUB NO. 2 DECLARED DUE TO HYDROGEN LEAK PLAY

VIDEO: SUNDAY'S UPDATE FROM MISSION MANAGEMENT TEAM PLAY
VIDEO: LEAK POSTPONES SHUTTLE ENDEAVOUR LAUNCH PLAY

VIDEO: TIME-LAPSE OF SUN SETTING OVER PAD 39A PLAY
VIDEO: ANOTHER TIME-LAPSE OF GANTRY RETRACTION PLAY
VIDEO: TIME-LAPSE OF LAUNCH PAD TOWER ROLLBACK PLAY

VIDEO: PRE-LAUNCH INTERVIEW WITH MARK POLANSKY PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH DOUG HURLEY PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH CHRIS CASSIDY PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH JULIE PAYETTE PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH TOM MARSHBURN PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH DAVE WOLF PLAY

VIDEO: THE STS-127 MISSION PREVIEW MOVIE PLAY
VIDEO: THURSDAY'S PRE-LAUNCH NEWS CONFERENCE PLAY
VIDEO: JAPANESE SCIENCE FACILITIES ABOARD STATION PLAY
VIDEO: COUNTDOWN BEGINS TICKING FOR SATURDAY'S LAUNCH PLAY
VIDEO: LAUNCH COUNTDOWN PREVIEW BRIEFING PLAY
VIDEO: CREW ARRIVES JUST BEFORE MIDNIGHT PLAY | HI-DEF
VIDEO: GET TO KNOW ENDEAVOUR'S ASTRONAUTS PLAY

VIDEO: ASTRONAUTS PRACTICE EVACUATION OF SHUTTLE PLAY | HI-DEF
VIDEO: CREW BOARDS SHUTTLE FOR PRACTICE COUNT PLAY | HI-DEF
VIDEO: ASTRONAUTS SUIT UP FOR DRESS REHEARSAL PLAY | HI-DEF
VIDEO: CREW INSPECTS CARGO IN THE PAYLOAD BAY PLAY | HI-DEF
VIDEO: TRAINING SESSIONS AT LAUNCH PAD AND BUNKER PLAY | HI-DEF
VIDEO: INFORMAL CREW NEWS CONFERENCE AT LAUNCH PAD PLAY
VIDEO: ASTRONAUTS ARRIVE FOR PRACTICE COUNTDOWN PLAY

VIDEO: FLIGHT READINESS REVIEW SETS LAUNCH DATE PLAY

VIDEO: PAD 39A GANTRY ENCLOSES SHUTTLE PLAY | HI-DEF
VIDEO: ROLLAROUND MOVES ENDEAVOUR TO PAD 39A PLAY | HI-DEF
VIDEO: ENDEAVOUR IS HAULED OFF LAUNCH PAD 39B PLAY | HI-DEF
VIDEO: TIME-LAPSE OF SHUTTLE'S LAUNCH PAD SWITCH PLAY

VIDEO: SHUTTLE AND STATION PROGRAM UPDATE PLAY
VIDEO: THE STS-127 MISSION OVERVIEW BRIEFING PLAY
VIDEO: PREVIEW BRIEFING ON MISSION'S SPACEWALKS PLAY
VIDEO: THE ASTRONAUTS' PRE-FLIGHT NEWS BRIEFING PLAY

VIDEO: PAD 39B AND ITS LAST SPACE SHUTTLE PLAY | HI-DEF
VIDEO: ENDEAVOUR'S SUNRISE ARRIVAL AT PAD 39B PLAY | HI-DEF
VIDEO: MIDNIGHT ROLLOUT FROM ASSEMBLY BUILDING PLAY | HI-DEF
VIDEO: ENDEAVOUR HOISTED FOR ATTACHMENT TO TANK PLAY | HI-DEF
VIDEO: CRANE ROTATES ENDEAVOUR VERTICALLY PLAY | HI-DEF
VIDEO: ENDEAVOUR MOVES TO ASSEMBLY BUILDING PLAY | HI-DEF
VIDEO: ORION AND ARES ROCKET PROGRESS REPORT PLAY
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