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STS-127: The programs

In advance of shuttle Endeavour's STS-127 mission to the station, managers from both programs discuss the flight.

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STS-127: The mission

A detailed step-by-step preview of Endeavour's STS-125 mission to install an external exposure platform on the station's Kibo science facility.

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STS-127: The EVAs

The lead spacewalk officer provides indepth explanations of the EVAs on Endeavour's assembly mission to the station.

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STS-127: The crew

The seven astronauts launching on Endeavour meet the press in the traditional pre-flight news conference.

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Endeavour will be fueled Wednesday to test repairs
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: June 30, 2009


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Engineers at the Kennedy Space Center are preparing to load the shuttle Endeavour's external tank with liquid oxygen and hydrogen rocket fuel early Wednesday in a critical test that could either pave the way to launch July 11 or trigger another lengthy delay.

 
Technicians work on the leaky venting system. Credit: NASA-KSC
 
At issue is whether a different internal seal in an external tank gaseous hydrogen vent line, along with shims intended to offset an alignment problem, will prevent the sort of leaks that grounded Endeavour June 13 and 17.

If the line is leak free Wednesday, or at least tight enough to prevent concentrations higher than 4 percent near the vent line umbilical plate, NASA will press ahead with plans to launch Endeavour on a 16-day space station assembly mission July 11.

But if higher-than-allowable leakage is detected, shuttle managers could be forced to move Endeavour to a different external tank, a move that would delay launch up to two months or more in a worse-case scenario.

Engineers believe they understand the problem - the rectangular vent port housing in the side of the tank was riveted into place slightly out of alignment - and they are hopeful the alternate seal and shims will, in fact, keep the vent line quick-disconnect fitting from leaking.

Complicating the issue for troubleshooters, the leaks only show up when the hydrogen section of the tank is nearing a full load and the hardware in the vent line is subjected to ultra-low cryogenic temperatures. Shuttle Program Manager John Shannon ordered Wednesday's fueling test to assess the performance of the vent line fixes before committing to a full-up launch countdown.

 
A worker removes the old seal from the umbilical assembly. Credit: NASA-KSC
 
Engineers began fueling test preparations Monday. If all goes well, super-cold liquid hydrogen will begin flowing from storage dewars to the shuttle around 7 a.m. EDT Wednesday. So-called "fast fill" operations will begin an hour later and the hydrogen section of the tank should be nearing its full load shortly after 9 a.m.

As of Tuesday evening, there were no technical problems of any significance at launch pad 39A, but forecasters say morning showers and thunderstorms may develop near the space center. For fueling, the probability of thunderstorms near the pad must be 20 percent or less.

NASA will provide television coverage of the fueling test starting at 7 a.m. A news briefing with Mission Management Team Chairman Mike Moses and launch director Pete Nickolenko is planned for 1 p.m. to discuss the results of the test.

Here is a timeline of major countdown events:


EDT...........EVENT

Wednesday, July 1

01:00 AM...Final preparations for fuel loading
03:00 AM...Personnel clear launch pad
06:00 AM...Countdown enters a one-hour hold at the T-minus six-hour mark
06:30 AM...External tank ready to load
06:30 AM...Mission Management Team meets to assess readiness for fueling
07:00 AM...NASA television coverage begins
07:00 AM...Main propulsion system transfer line chill down
07:45 AM...Liquid hydrogen low-level engine cutoff sensors are submerged
08:00 AM...Fast fill begins
09:15 AM...Liquid hydrogen tank 98 percent full
09:45 AM...Liquid hydrogen topping begins; hydrogen vent valve cycling
10:00 AM...External tank in stable replenish mode
10:00 AM...Final Inspection Team (FIT) launch pad walkdown
12:00 PM...Test team 'go' for tank drain (duration approximately 2.5 hours)
01:00 PM...NASA TV: Post-tanking test press briefing with MMT Chairman
...........Mike Moses and Launch Director Pete Nickolenko
01:30 PM...LH2 boil off (duration approximately 19 hours)
04:00 PM...Pad opened for limited access

In a bit of good news for NASA, engineers successfully extracted an astronaut work light attachment knob that was jammed between one of the shuttle Atlantis' cockpit windows and an instrument panel housing after the ship's just-completed mission to repair the Hubble Space Telescope.

The knob, apparently lost by the crew during the mission, was pressing against window No. 5's critical internal pressure pane. It apparently got lodged in place during re-entry when the pressurized crew module contracted slightly.

The knob had to be removed to allow engineers to assess what, if any, damage had been done to the pressure pane when the knob got stuck. Engineers initially tried to cool it with dry ice, but the knob refused to budge. They then attempted to reverse the effects of the shuttle's descent by pressurizing the crew module. That worked, and engineers were able to retrieve the troublesome knob without having to resort to more invasive measures.

The issue was potentially significant because replacement of a pressure pane would require engineers to remove or disconnect cockpit instrumentation and other structures, work that could take four to six months to complete. NASA managers are hopeful the knob caused no significant damage to the window, but inspections are not yet complete.

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Additional coverage for subscribers:
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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