| Endeavour launch on hold for 48 hrs to fix APU heaters. All suited up with no space to go: yfrog.com/h8ddodk |
Friday, April 29, 2011
A Little Scrub Humor
Why Launch Was Scrubbed
NASA held a briefing Friday afternoon to share details of the reason for scrubbing the launch.
Clearly all involved were disappointed, but as launch director Mike Leinbach said, "We will only fly when the time is right."
In his opening remarks Bob Cabana said, "I'd always rather be on the ground wishing I was in the air than be in the air wishing I was on the ground."
The problem was discovered about 9:30 a.m. Friday morning, when a heating coil on a hydraulic line failed to come on. Flight teams spent the morning attempting to resolve the problem. The hydraulic line is a pipe that carries fluid that powers the control surfaces of the wings and the gimbals that control the engines. In other words, everything that "steers" the shuttle. The heaters prevent the fluid from freezing in the cold of space. If the lines froze, it could cause them to rupture. A leak of the fluid in the lines could also cause a fire when the shuttle entered the atmosphere.
There appears to be an electrical power problem or a bad thermostat that is preventing the heater to turn on. After the external fuel tank (the big orange tank) has been drained, crew can gain access to the avionics bay on the rear left side of the orbiter. That should be possible by Saturday evening. Technicians will then test the electrical lines for shorts and test for malfunctioning thermostats. This would be the simplest situation to correct. If the control unit for this system is faulty and needs to be replaced things get more complicated. If the problem does not require the control unit to be replaced, the next launch attempt would be 2:33 p.m. Monday afternoon.
If the control unit needs to be replaced, it will require an additional 2 days of testing before readying the shuttle for launch. This puts the shuttle launch in conflict with an Atlas rocket launch on Thursday.
For more on the scrub check out these articles:
Clearly all involved were disappointed, but as launch director Mike Leinbach said, "We will only fly when the time is right."
In his opening remarks Bob Cabana said, "I'd always rather be on the ground wishing I was in the air than be in the air wishing I was on the ground."
The problem was discovered about 9:30 a.m. Friday morning, when a heating coil on a hydraulic line failed to come on. Flight teams spent the morning attempting to resolve the problem. The hydraulic line is a pipe that carries fluid that powers the control surfaces of the wings and the gimbals that control the engines. In other words, everything that "steers" the shuttle. The heaters prevent the fluid from freezing in the cold of space. If the lines froze, it could cause them to rupture. A leak of the fluid in the lines could also cause a fire when the shuttle entered the atmosphere.
There appears to be an electrical power problem or a bad thermostat that is preventing the heater to turn on. After the external fuel tank (the big orange tank) has been drained, crew can gain access to the avionics bay on the rear left side of the orbiter. That should be possible by Saturday evening. Technicians will then test the electrical lines for shorts and test for malfunctioning thermostats. This would be the simplest situation to correct. If the control unit for this system is faulty and needs to be replaced things get more complicated. If the problem does not require the control unit to be replaced, the next launch attempt would be 2:33 p.m. Monday afternoon.
If the control unit needs to be replaced, it will require an additional 2 days of testing before readying the shuttle for launch. This puts the shuttle launch in conflict with an Atlas rocket launch on Thursday.
For more on the scrub check out these articles:
Launch Scrubbed
There was a power failure on one of the fuel line heaters for the shuttle and the launch has been scrubbed for at least 72 hours while they troubleshoot and correct the problem. I will post further updates later today.
Launch Viewing at FL307 cancelled.
Launch Viewing at FL307 cancelled.
Thursday, April 28, 2011
The Future
Attn Students: "There is a brilliant future that is yours for the CREATING" Waleed Abdalati, @Nasa's Chief Scientist #nasatweetup
T-11 hrs and Holding
This is a 13 hour 20 minute built-in hold. The countdown is on schedule as of 11:00 am EDT.
NASA Prelaunch Press Conference just concluded. Everything go, though some weather concerns. Weather for pre launch work today and tonight at 90% good. Weather for launch downgraded to 70% for cloud cover and cross-winds.
10:30 am: STS_134: The crew of #sts134 is out at the Launch Pad to take one more look inside Endeavour before boarding tomorrow.
NASA Prelaunch Press Conference just concluded. Everything go, though some weather concerns. Weather for pre launch work today and tonight at 90% good. Weather for launch downgraded to 70% for cloud cover and cross-winds.
10:30 am: STS_134: The crew of #sts134 is out at the Launch Pad to take one more look inside Endeavour before boarding tomorrow.
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