NASA working around stormy weather at the Cape
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: August 25, 2006
A lightning bolt struck near the space shuttle Atlantis today as powerful thunderstorms rolled across the Kennedy Space Center, but the launch pad lightning protection system shielded the orbiter and officials said the countdown was on track for a Sunday launch try, weather permitting.
Forecasters are continuing to predict a 40 percent chance of afternoon storms that could block the planned 4:30 p.m. launch, but the outlook improves to 80 percent "go" Monday and Tuesday. NASA's launch strategy supports four attempts in five days and LeRoy Cain, director of shuttle integration at the Florida spaceport, told reporters "we feel very good about where we are going into the weekend."
NASA started Atlantis' countdown six hours early Thursday, knowing storms today could interrupt work to load liquid hydrogen and oxygen to power the ship's electricity producing fuel cells. Engineers were able to load the oxygen tanks today but work to load hydrogen was delayed when the powerful afternoon storms developed.
Lightning struck a thick wire that runs to either side of the launch pad as part of its lightning protection system, but launch director Mike Leinbach said telemetry from the shuttle showed no signs of any unusual electrical activity.
As for fuel cell loading, Leinbach said engineers had plenty of time in a long built-in hold to make up for lost time and by tomorrow morning, the countdown was expected to be back on track.
NASA and Air Force meteorologists are monitoring the development of tropical storm Ernesto in the southern Caribbean, but it does not pose any immediate threat to Florida's space coast. If Atlantis gets delayed, however, the storm could come into play next week depending on where it is, where it's going and how strong it might be.
While the Kennedy Space Center likely will be unaffected, the storm at some point could have an impact on Houston and mission control at the Johnson Space Center.
"The storms we're looking at and talking about now are just too, too far away," Cain said. "There's far too much uncertainty in terms of what they will or will not do and quite frankly, I don't see any scenario between here and the launch period, at least for the first several days, where we would have any concerns that would cause us to stand down. I suppose there might be a scenario way out there at the end of our launch period, but I don't envision that at this point."
Atlantis' launch period is defined by the need to launch the shuttle into the plane of the international space station's orbit, temperature constraints based on the angle between that plane and the sun and a self-imposed requirement to launch in daylight for photo-documentation of the shuttle's external tank and heat shield.
All of those factors, plus the upcoming Sept. 14 launch of a Russian Soyuz rocket carrying the next full-time station crew, combine to limit Atlantis' launch opportunities to Aug. 27 through Sept. 7. Within that period, NASA can make seven launch attempts, including four in five days - Sunday, Monday, Wednesday and Thursday - before standing down to top off on-board fuel cell supplies. After that, the agency would have opportunities on Sept. 2, 4 and 6.
While it's too soon to tell whether Ernesto might threaten Houston at some point, NASA has contingency plans are in place to move a small team of flight controllers to the Kennedy Space Center in Florida, if mission control ever had to be evacuated, to oversee shuttle operations.
But under that scenario, a shuttle crew would be ordered home at the first safe opportunity. NASA does not have the ability to oversee shuttle operations from a backup control center, much less carry out the complex commanding required for a mission to the international space station.
The goal of Atlantis' flight is to install a $372 million solar array truss segment that will require back-to-back spacewalks and complex ground commanding to attach and connect to the station's existing power system.
"If we get to the point of having to evacuate the mission control center in Houston, we would not be able to execute the docked mission," Cain said. "We do not have the capability to do a docked mission, certainly not of the complexity of the one we're about to embark on."
Instead, he explained, "we would undock from space station and deorbit at the first, safest opportunity we had and perform entry and landing. And we would leave station in the safest configuration we could and come back and pick up the pieces, if you will, on a subsequent mission."
Assuming a launch on Sunday, Atlantis will dock with the space station Tuesday. The new solar array truss element, known as P3/P4, would be attached the next day using the station's robot arm. Two spacewalkers then would make the electrical connections needed to power heaters and other critical components to keep the new gear alive.
Two more spacewalks are planned to remove launch restraints, deploy the arrays and to activate a massive rotary joint that will keep the giant panels facing the sun. But in a worst-case scenario, P3/P4 could survive in orbit if the shuttle crew was forced to depart after the first spacewalk.
"There is a point at which we're going to leave the truss on orbit," said MIke Suffredini, space station program manager at the Johnson Space Center. "Before that point, the truss can be put back in the payload bay and brought home. I hope we don't do that, that would really be not much fun, but once we get the truss attached and umbilicals hooked up, which happens very early in the docked time frame, we are in a safe configuration. The heaters are working, the hardware would be safe. The shuttle could leave if it needs to do that."
But such a scenario would derail NASA's space station assembly schedule. Work to activate and check out the new truss and solar arrays would have to be carried out by the space station crew, which hasn't trained for the complicated procedures, "so what you're looking at is a pretty long delay while we do all that work," Suffredini said.
NASA managers are hopeful, of course, that it won't come to that. Atlantis' flight is the first in a series of challenging assembly missions that must be carried out in sequence as the agency attempts to finish station construction by the Bush administration's 2010 deadline for retiring the space shuttle.
"This flight has to work for the next flight to occur and the next flight to occur and the next flight to occur," Suffredini said. "The next few have to kind of happen in the right order. If we don't get P3/P4 installed, then I can't go reconfigure the power and cooling system, which I'm doing on the next flight. Which means I can't go bring up the next major power element, which comes on the next flight (after that), and so on and so forth.
"So this flight is critical to our ability to do this truss reconfiguration, this growth to the power system and the central cooling system, which has been dormant on orbit for about three years or so. This is all critical. If we don't do this flight, then the next ones donšt get to happen until we get this work done. So in the big scheme of things, even though we say we take things one step at a time, this one's a key, we have to let this one occur before the next ones can go."
The official crew patch for the STS-115 mission of space shuttle Atlantis to resume orbital construction of the International Space Station.
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