Posted on 08/25/2006 4:48:21 PM PDT by RightWhale
FRIDAY, AUGUST 25, 2006 1430 GMT (10:30 a.m. EDT)
The shuttle Atlantis' countdown continues to tick smoothly toward launch on a space station assembly mission. Liftoff is targeted for 4:30 p.m. Sunday. The latest forecast calls for a 60 percent chance of favorable weather, improving to 80 percent "go" Monday and Teusday. The concern Sunday is for possible afternoon thunderstorms within the launch area.
=================================================
(Excerpt) Read more at spaceflightnow.com ...
spaceflightnow.com
2049 GMT (4:49 p.m. EDT)
Retraction of the gantry-like rotating service structure from around space shuttle Atlantis at launch pad 39B has begun. The tower is being moved into its launch position for the remainder of the countdown.
Although few seem to care, here is an update:
spaceflightnow.com
2130 GMT (5:30 p.m. EDT)
The rotating service structure peeled away from space shuttle Atlantis this afternoon, revealing the spaceship on launch pad 39B.
The mobile structure provides the primary access and weather protection for Atlantis during its stay on the launch pad. The RSS was used for installing the solar array truss payload into the shuttle and feeding the reactants into the ship's three electricity-generating fuel cells, too.
Measuring 102 feet long, 50 feet wide and 130 feet high, the structure swings 120 degrees via hinges from the fixed launch pad tower.
Launch pad teams will spend the next several hours performing final work to prepare for pumping a half-million gallons of supercold rocket fuel into the external tank and to secure the complex for liftoff. The pad will be cleared of all personnel before beginning to load Atlantis' fuel tank with liquid hydrogen and liquid oxygen cryogenic propellants starting about 2:30 a.m.
Meanwhile, Atlantis' astronauts are heading to bed. They'll be awakened at 1:30 a.m. to begin launch morning activities. Departure from the crew quarters for the ride to the pad is scheduled for 8:38 a.m.
Liftoff remains set to occur a few seconds before 12:29 p.m. EDT.
Ping to #120
I'll be back tomorrow, but not much before scheduled launch. Here's to the appropriate north wind gods so they don't have a repeat of the Jovian thunderbolt they got last week.
spaceflightnow.com
0858 GMT (4:58 a.m. EDT)
NASA managers stopped the shuttle Atlantis' countdown early today and put launch on hold for at least 24 hours because of problems with one of the ship's three electricity producing fuel cells.
Engineers are continuing to troubleshoot the issue in hopes of getting Atlantis off the ground Thursday or Friday, the end of the current launch window. NASA's Mission Management Team plans to meet later today to discuss repair options.
NASA's being very tight-lipped about this one. They may have isolated the problem to a fuel-cell cooling pump. No telling what that means. The News Conference at 1:00 EST oughta be interesting...
Given that there is only so much work that can be done on the pad, I'd be willing to guess at this point that they may likely be looking at a rollback to the VAB afterall. I'll 70% chance of a rollback.
The fuel cell has stopped five launches so far. A repair typically takes a week.
The astronauts are taking this delay in stride. Actually, astronauts are pretty easy going in a highly competent way to begin with; so this shouldn't be news, but it is because the MSM is not easy going in any competent way.
spaceflightnow.com
1355 GMT (9:55 a.m. EDT)
Engineering meetings continue this morning to assess the problem experienced with one of Atlantis' fuel cells during activation.
"Teams are evaluating data on what might have caused a voltage spike in the fuel cell's coolant pump that cools the fuel cell system," NASA said in a statement.
A mission management team meeting is scheduled for 1 p.m. EDT. A news conference with shuttle officials will follow that meeting to announce the plan going forward.
NASA is keeping open the option of launching tomorrow.
spaceflightnow.com
1900 GMT (3:00 p.m. EDT)
NASA's Mission Management Team met today to discuss options for launching the shuttle Atlantis on a key space station assembly mission. A launch try today was scrubbed because of a possible short in one of the shuttle's three electricity producing fuel cells. It does not appear engineers have time to carry out any repairs before the current launch window runs out Friday, but they could opt to fly as is if troubleshooters can show the glitch can be isolated and not cause additional problems.
Press conference starts now on NASA TV.
Sorry, presser changed to 6 edt.
Keep us posted. Major decisions happening.
spaceflightnow.com
2122 GMT (5:22 p.m. EDT)
ANOTHER DELAY. Mission managers have postponed launch an additional 24 hours to continue the fuel cell troubleshooting. Friday's liftoff time would be 11:40:37 a.m. EDT (1540:37 GMT).
The news briefing is coming up shortly.
One phase of the AC motor for the freon (cooling) pump for fuel cell #1 is not working. The motor still works, but if it lost another phase, then it would violate launch constraints, or if it lost another phase after launch then the flight would be shortened. Right now they still have three working fuel cells. Saturday launch is possible, but it would be a minimum duration flight, which would cut some scheduled spacewalks. Looks like either Friday launch, or possibility of relaxing lighting constraints for a late September launch.
Okay. The rest of the vehicle must be checking out.
Given the size and complexity of the truss assembly, and the installation and checklut of it, how can they consider flying a minimum duration flight? How can they get the installation completed if they have to cut spacewalks out? I assume those tasks they cannot complete would have to fall to a later crew to complete, but if they haven't trained for it...
The problems just seem to cascade...
I don't think they will fly unless they can get full duration out of the mission. I believe that's why they are taking a 24 hour timeout...to decide through engineering if the freon motor will last or if they should change out the whole fuel cell and relax the lighting condition requirements so they can get launched in late September instead of late October. Wayne Hale called it "having runway in front of the airplane". They don't want to get behind in the whole building sequence, as things will cascade as you say.
spaceflightnow.com
WEDNESDAY, SEPTEMBER 6, 2006
NASA managers late today ruled out an attempt to launch the shuttle Atlantis Thursday but held open the possibility of a last-ditch Friday launching if engineers can resolve a problem with one of the ship's three electrical generators before time runs out.
spaceflightnow.com
2030 GMT (4:30 p.m. EDT)
Managers continue to meet. The news conference is not expected before 5:30 p.m.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.