Spaceflight Now





BY JUSTIN RAY

Follow the flight of space shuttle Atlantis to resume orbital construction of the International Space Station with delivery of the next solar array truss.

FRIDAY, SEPTEMBER 8, 2006
2050 GMT (4:50 p.m. EDT)


Engine cutoff - ECO - sensor No. 3, the one that "failed wet" earlier today and derailed an attempt to launch the shuttle Atlantis, continued indicating it was immersed in liquid hydrogen after the ship's external tank was drained this afternoon, officials said. The other three ECO sensors in the hydrogen tank correctly indicated they were dry as one would expect.

Read our story.

2030 GMT (4:30 p.m. EDT)

We have updated our main scrub story.

1639 GMT (12:39 p.m. EDT)

Briefing has just started.

1625 GMT (12:25 p.m. EDT)

Now 12:45 p.m. briefing time.

1620 GMT (12:20 p.m. EDT)

The post-scrub press briefing is now targeted for no earlier than 12:30 p.m.

1614 GMT (12:14 p.m. EDT)

The AstroVan is driving away from launch pad 39B now -- a little more than four hours after delivering the astronauts to board Atlantis.

1608 GMT (12:08 p.m. EDT)

Commander Brent Jett has exited the shuttle. All six astronauts will be heading back to crew quarters for dinner and await tomorrow's launch attempt.

1606 GMT (12:06 p.m. EDT)

Rookie shuttle pilot Chris Ferguson has emerged.

1602 GMT (12:02 p.m. EDT)

Steve MacLean from the Canadian Space Agency has egressed.

1600 GMT (12:00 p.m. EDT)

Flight engineer Dan Burbank has exited Atlantis.

1550 GMT (11:50 a.m. EDT)

Atlantis has was opened at 11:45 a.m., and mission specialists Joe Tanner and Heidemarie Stefanyshyn-Piper have climbed out of the middeck.

1531 GMT (11:31 a.m. EDT)

After a dramatic, down-to-the-wire debate, NASA's Mission Management Team called off the shuttle Atlantis' countdown today and delayed launch at least 24 hours because of concern about an apparently faulty low-level hydrogen fuel sensor in the ship's huge external tank.

Read our full story.

1530 GMT (11:30 a.m. EDT)

The Orbiter Closeout Crew and the AstroVan have arrived back at pad 39B to assist the astronauts out of Atlantis.

Meanwhile, NASA is planning a post-scrub news conference no sooner than 12 p.m.

1453 GMT (10:53 a.m. EDT)

SCRUB! The engine cutoff sensor issue has forced NASA to scrub today's countdown. The plan calls for the external tank to be drained and another countdown performed tomorrow to evaluate how the hydrogen fuel level gauge acts. If it behaves in the same manner, officials could allow Atlantis to launch with only three of the four sensors working. Tomorrow's launch time is 11:15 a.m. EDT.

1446 GMT (10:46 a.m. EDT)

T-minus 9 minutes and holding. Countdown clocks have gone into the planned 45-minute built-in hold. Today's launch remains set for 11:41 a.m. EDT. However, the failed engine cutoff sensor remains an unresolved issue right now.

1443 GMT (10:43 a.m. EDT)

The Main Propulsion System helium system has been reconfigured by pilot Chris Ferguson. Soon the gaseous nitrogen purge to the aft skirts of the solid rocket boosters will be started.

1440 GMT (10:40 a.m. EDT)

Now one hour away from launch of Atlantis.

Pilot Chris Ferguson is configuring the displays inside Atlantis' cockpit for launch while commander Brent Jett enables the abort steering instrumentation. And Mission Control in Houston is loading Atlantis' onboard computers with the proper guidance parameters based on the projected launch time.

1435 GMT (10:35 a.m. EDT)

T-minus 20 minutes and counting. The countdown has resumed after a 10-minute hold. Clocks will tick down for the next 11 minutes to T-minus 9 minutes where the final planned hold is scheduled to occur. The hold length will be adjusted to synch up with today's preferred launch time of 11:41 a.m.

Atlantis' onboard computers are now transitioning to the Major Mode-101 program, the primary ascent software. Also, engineers are dumping the Primary Avionics Software System (PASS) onboard computers. The data that is dumped from each of PASS computers is compared to verify that the proper software is loaded aboard for launch.

1433 GMT (10:33 a.m. EDT)

The launch team has been briefed on today's launch window and countdown procedures. Standing by to resume the clock momentarily.

1425 GMT (10:25 a.m. EDT)

T-minus 20 minutes and holding. The countdown has paused for a 10-minute built-in hold. Launch remains scheduled for 11:41 a.m. EDT, pending the engine cutoff sensor issue.

During this built-in hold, all computer programs in Firing Room 4 of the Complex 39 Launch Control Center will be verified to ensure that the proper programs are available for the countdown; the landing convoy status will be verified and the landing sites will be checked to support an abort landing during launch today; the Inertial Measurement Unit preflight alignment will be verified completed; and preparations are made to transition the orbiter onboard computers to Major Mode 101 upon coming out of the hold. This configures the computer memory to a terminal countdown configuration.

1415 GMT (10:15 a.m. EDT)

Commander Brent Jett is pressurizing the gaseous nitrogen system for Atlantis' Orbital Maneuvering System engines, and pilot Chris Ferguson is activating the gaseous nitrogen supply for the orbiter's Auxiliary Power Units' water spray boilers.

1407 GMT (10:07 a.m. EDT)

The ground pyro initiator controllers (PICs) are scheduled to be powered up around this time in the countdown. They are used to fire the solid rocket hold-down posts, liquid oxygen and liquid hydrogen tail service mast and external tank vent arm system pyros at liftoff and the space shuttle main engine hydrogen gas burn system prior to engine ignition.

The shuttle's two Master Events Controllers are being tested. They relay the commands from the shuttle's computers to ignite, and then separate the boosters and external tank during launch.

1405 GMT (10:05 a.m. EDT)

The final engineering assessements of the engine cutoff sensor are being made now. A decision from the management team is expected shortly.

1345 GMT (9:45 a.m. EDT)

The crew module hatch has been sealed and latched for flight, the closeout crew reports.

1345 GMT (9:45 a.m. EDT)

Now passing the T-minus 1 hour mark in the countdown. Two scheduled holds are planned at T-minus 20 minutes and T-minus 9 minutes, leading to the target liftoff time of 11:41 a.m., if the hydrogen fuel sensor issue is deemed not a violation of NASA rules.

1340 GMT (9:40 a.m. EDT)

The shuttle's crew compartment hatch is swinging shut

1335 GMT (9:35 a.m. EDT)

Approval has been given to close Atlantis' crew module hatch.

1328 GMT (9:28 a.m. EDT)

Weather conditions are looking good for today's 11:41 a.m. EDT launch time. Thunderstorms are likely this afternoon, something Atlantis would experience if a scrub is called and the ship remains on Earth for another day.

1320 GMT (9:20 a.m. EDT)

A series of routine communications checks between the Atlantis crew on various audio channels is underway.

1310 GMT (9:10 a.m. EDT)

The engine cutoff sensor situation continues to be discussed and debated among engineers and mission managers. No decision about today's launch attempt has been made yet.

1301 GMT (9:01 a.m. EDT)

Connecticut's Dan Burbank, the flight engineer for Atlantis' mission, is now climbing aboard the ship for today's launch to take the flight deck's center seat. He is the sixth and final astronaut to enter the shuttle this morning.

The 45-year-old is a commander in the Coast Guard with more than 3,500 flight hours, primarily in helicopters, and has flown over over 300 search and rescue missions. His space career includes the STS-106 space station assembly mission in 2000. On STS-115, Burbank will perform the second spacewalk with Steve MacLean. Read his biography here.

And a video interview with Burbank is available here.

During the interview, he explained his jobs on the mission.

"I'm the mission specialist 2, so for ascent and entry my job is to be the flight engineer on the flight deck. I kind of sit between the commander and the pilot and help with trajectory monitoring and systems monitoring, things like that. For the on-orbit phases, I've also got some responsibilities with the shuttle systems, to kind of back up Brent and Chris with their duties. I've also got the responsibility of being the prime shuttle robotic arm operator. We'll use it to pick up the P3/P4 payload and hand it off to the station arm for installation on the International Space Station. I've also got some other miscellaneous duties, as we all do. One of those is also managing the on board network of our laptop computers that basically support our missions with various software applications.

"I'm going to do a spacewalk as well. So we've got a series of three of them for the mission, and for the second spacewalk, or EVA, Steve MacLean and I will go out and help with some of the activation activities for the P3/P4 truss."

1248 GMT (8:48 a.m. EDT)

Canadian Space Agency astronaut Steve MacLean, Atlantis' mission specialist No. 4, has climbed to the flight deck aft-right seat.

MacLean, 51, was born in Ottawa, Ontario. Selected as one of the first six Canadian astronauts in 1983, he flew as a payload specialist aboard shuttle Columbia in 1992. His role on STS-115 includes conducting the mission's second spacewalk along with Dan Burbank and becoming the first Canadian to operate the space station's Canadarm2 robotic arm. Read MacLean's biography here.

And a video interview with MacLean is available here.

MacLean was asked about the dangers of spaceflight and why it's worth taking the risk

"This is a very difficult question to answer. You cannot do this question in a sound bite; that's impossible. I think any one of us, me, for sure, if I thought I was going to die on such a mission, I would not go. The big privilege of being at NASA is the people that you work with. And when I go to the Cape, or when I go to Stennis [Space Center] and we're meeting the guys that actually do the work, it's a phenomenal experience. Just seeing these guys, the dedication that they have, how good they are, how smart they are, it's this that gives you a tremendous amount of confidence in the vehicle. There have been issues with the vehicle; there will be issues with the vehicle. But the people that work close to this vehicle are some of the most impressive people that I have met. And for me that's a privilege. Now, if you ask a politician about risk and, and his answer is valid, he will say, it's very important that we maintain leadership in space. Each country I've been in -- and this is true for Canada -- you will get that comment, that leadership in space is something that's important. I think leadership brings excellence, and excellence is something we can all be proud of.

"This is not an easy answer. In Canada, sometimes things are discussed on the short term, like bureaucratic responses -- what would be the cost/benefit ratio of flying in space. And if you put your blinkers on and then when they ask over the next two years, what is the real value for us to fly in space, as with any answer trying to get it out of a bureaucrat, it's difficult to get a good answer because you've constrained what he's able to do. But in Canada, that's an easy answer because our investment ratio is four-to-one: for every dollar we invest, invested in Canadarm, we got four dollars back. If you look beyond just the direct impact into the diffusion of the technology, it's 10 dollars. A bureaucrat would say, that's worth the risk.

"Now, if you kind of open up your blinkers, and open up your blinders and look long term it's a little easier to answer. Like, why are we involved in this in the long term; and, you know, we'll get a little bit more philosophical here but things like survivability, sustainability in the environment, there are answers to those issues in spaceflight. I can't guarantee that we will get all the answers, but by working in space, by living in space by observing space from the Earth so that we better understand it, we as a species have a better chance to survive. If you look at Venus, it's too hot; if you look at Mars, it's too cold. The Earth is just right; we've got to keep it that way. By working in space, we'll understand that a little bit better. There are energy sources out in space on the head of a pin that would power the Earth for hundreds of thousands of years, and they're energy sources that we don't fully understand.

"Now, that is, you know, an esoteric part of the answer but, by working in space and learning from space, maybe we'll understand that. And then a by-product of that is our environment. By living in space we're going to become more efficient. I could predict, perhaps, that our rivers will be cleaner; our air will be not polluted because we work in space. I can't guarantee that, but if we don't work in space, you can guarantee that it will take a lot longer to clean up our air and clean up our rivers. And so if you look at it that way, even an environmentalist, a respected environmentalist, is going to agree that it's worth the risk. Even an evangelistic environmentalist will probably agree that it's worth the risk, if you couch it like that. The problem is you can't promise it.

"I wouldn't underestimate the personal adventure, either. It has nothing to do with risk, really, but the personal adventure is amazing, to feel yourself floating in space, to look at the Earth from space, and to think about how you feel when you see that. To see the solar system dust cross the, the Milky Way or to feel suspended in this milk bath of light that you know that comes from another time; these are phenomenal feelings. Now they have nothing to do with risk that you know you can't justify it that way.

"But, come back to STS-115: We are building space station; we are building an, a laboratory that may do some phenomenal things if we handle ourselves properly, if we actually execute what the original plans were, it may do some wonderful things. And so for me, when I think about the risk that I'm taking, because it is a personal question that you have to answer, I, what I hope is that kids -- and this is just a thought -- what I hope is that children, before they understand that the world really is in quite a mess, see the space station, because once we're finished with the assembly of space station -- after our mission it's half complete; optically it will be a lot easier to see from the Earth, and you will be able to see it go over -- that those kids are inspired by what we've tried to do, by what all the countries -- I guess it's [16] countries in the world -- tried to do in peaceful cooperation, and that children inspired by that and end up showing leadership with respect to continuing that kind of idea. If that kind of thing happens, then for me it's worth the risk."

1241 GMT (8:41 a.m. EDT)

Launch of Atlantis is three hours away.

1229 GMT (8:29 a.m. EDT)

Now climbing through the hatch is mission specialist No. 3, Heidemarie Stefanyshyn-Piper. She is assigned the right seat on the middeck.

Piper, a Navy commander, was born in St. Paul, Minnesota. The 43-year-old is a space rookie. She will be performing the first and third spacewalks of Atlantis' mission along with Joe Tanner. Read her biography here.

And a video interview with Piper is available here.

So what led Piper to become an astronaut?

"I kind of think that I've always had a fascination with flying. That was one of the things that led me to apply for the astronaut program. I should say that when I was growing up my mother came from Germany, and every couple of years she and my father would send one or two of us, usually two of us, to Germany. I remember when I was 4 years old going and flying in an airplane and I thought that that was the neatest thing. And then the next time I went over was about five years later, and then it was just my brother and I. And I thought, you know, flying was neat. So I've always had this bug in the back of me that says I really want to fly, I really want to fly.

"I took an ROTC scholarship to help pay for college -- I was going in the Navy -- and I decided I was going to try to fly for the Navy. After I graduated, I stayed at MIT an extra year and got my master's degree, and decided that, or it was decided for me that, because I didn't pass the eye exam, I wasn't going to become a pilot. So I was looking at something else to do, and so I went and became a Navy diver. And, had a great time fixing ships underwater and doing salvage work.

"Then when I learned about NASA and building the space station and I saw how they were doing the construction and they were training underwater, I thought that looks to me more like diving than it does flying, and so I think I can do that in space. I think I had a lot to offer, to help build the space station. That's how I applied to the program, and I consider myself very, very fortunate that I was accepted and that now I get my dream of not only flying, because I get to fly in space, but also being able to help build the space station."

1227 GMT (8:27 a.m. EDT)

Pilot Chris Ferguson, the next crewmember to enter the shuttle, is making his way to the flight deck's front-right seat.

Ferguson is a spaceflight rookie. The 45-year-old Navy captain was born in Philadelphia. He has three childen, and when not preparing to fly in space he plays drums in the astronaut band Max Q. Read his biography here.

And a video interview with Ferguson is available here.

Learning of his selection to be the STS-115 mission pilot was an interesting moment for Ferguson.

"My Commander, Brent Jett, fantastic guy. I've learned more than anything from him, probably. The day before I had been told that I'd been put on this flight, we had a simulator together. We strive for perfections when we do our ascent and entry simulators, but you know, invariably we make a mistake from time to time, and in this particular simulator I think I made a small mistake; very, very small. The next day Brent stopped by my office and he said, 'Hey, Charlie Precourt wants to talk to us about the sim yesterday.' Charlie was the Chief of the Astronaut Office, and you never got called into his office for anything but the wrong reason. So at first I was a little flustered and then Brent couldn't conceal his smile. I think I kind of knew from that moment that this didn't really have anything to do with the simulator. So, that's my story."

1218 GMT (8:18 a.m. EDT)

Joe Tanner, mission specialist No. 1, just climbed aboard Atlantis to take the seat closest to the hatch on the left side of the middeck.

This will be Tanner's fourth trip to space. The Illinois native is 56 years old. His flight history includes the STS-66 atmospheric science mission in 1994, the second Hubble Space Telescope servicing in 1997 and the 2000 space station construction flight, STS-97, that launched the first solar array truss. His experience from that mission has proved valuable in planning STS-115. He will conduct the first and third spacewalks along with Heidemarie Stefanyshyn-Piper. Read his biography here.

And a video interview with Tanner is available here.

He discusses the resumption of space station construction beginning with Atlantis' mission.

"Well, I think it's very significant that, that we're able to proceed. We've gone through a very difficult period in the last 3 12 years. We had to fix a few things, and I think we had to develop tools that gave us some repair capability and some backup capability. We needed to understand some things that we weren't maybe paying enough attention to before. So the fact that, that we've done that work and feel pretty good about it and we can get back to the business of building a space station.

"We all thought that we would be core complete if not further by this time on the calendar, and, and everybody's champing at the bit to get this construction going again. You've got a house that's only partially built, and there's so much more capability sitting on the ground that needs to go up -- not just the trusses but for habitable volumes. The Japanese module is a beautiful science platform; it's magnificent. I've had a chance to work with those engineers and seen the module, and it's really magnificent. The European module, Columbus, is going to be fantastic. Node 2 is sitting at the Cape ready to go, and it needs to be launched.

"So I think it's a great shot in the arm for everybody in the partnership to say, OK, let's get going again, and let's finish this job that we started."

1216 GMT (8:16 a.m. EDT)

As skipper of the spacecraft, commander Brent Jett is the first astronaut to board the shuttle. He is taking he forward-left seat on the flight deck.

Jett, 48, calls Ft. Lauderdale, Florida, his hometown. This Navy captain has flown in space on three earlier missions, including serving as the pilot on STS-72 in 1996 to retrieve a Japanese science satellite, pilot on the STS-81 mission to the Russian space station Mir a year later, and commander of STS-97 in 2000 that delivered the first set of U.S. solar arrays to the International Space Station. Read his biography here.

And a video interview with Jett is available here.

In the interview, Jett talks about his philosophy on space exploration.

"Any time you take off on an exploration, typically you take steps in a gradual nature. You know, space station has given us the ability to establish a permanent presence fairly close to home but still, in low Earth orbit, in a weightless environment in a vacuum. That's a good first step. When you explore the solar system, you're going to need to establish permanent presence, or at least temporary presence, on the moon, perhaps on Mars. So I think the way we're going about it seems fairly logical. You could almost draw an analogy between the Apollo missions and some of the early explorers who came from Europe to North America. Initially they sort of went, touched base, came home. But really it was establishing the permanent presence, over in North America, that proved to be a huge challenge. So I think we'll see, as we try to establish a presence on the moon and then move on and establish a presence on Mars, that it's going to be extremely challenging. We'll learn a lot from our presence in low Earth orbit, to make that successful.

"The other piece of that whole question is, why are we going? Well, I probably fall in the camp that says it's just our nature. It's human nature to want to explore and, and I hope that the United States leads that effort, among the entire world. We're going to prove that we can meet our obligations and build an International Space Station, and that will be important to leading an effort to explore the solar system. It's not just the U.S. but other nations as well."

1212 GMT (8:12 a.m. EDT)

Commander Brent Jett has made his way across the catwalk-like Orbiter Access Arm to the White Room positioned against the side of Atlantis. The closeout crew is helping him don other survival gear.

1209 GMT (8:09 a.m. EDT)

The Atlantis astronauts have ascended up to the 195-foot level of the tower.

1207 GMT (8:07 a.m. EDT)

Atlantis' crew arrived at launch pad 39B at 8:07 a.m. The AstroVan came to a stop on the pad surface near the Fixed Service Structure tower elevator that will take the six-person crew to the 195-foot level to begin boarding the shuttle.

1200 GMT (8:00 a.m. EDT)

The AstroVan just passed the 52-story Vehicle Assembly Building where Atlantis was attached to its external tank and solid rocket boosters and the adjacent Launch Control Center. The Press Site is located across the street, and reporters have run outdoors to watch at the passing convoy. This is a launch day tradition to say farewell and good luck to the astronaut crews.

1150 GMT (7:50 a.m. EDT)

Commander Brent Jett and his crew just walked out of the Kennedy Space Center crew quarters to board the AstroVan for the 20-minute ride from the Industrial Area to launch pad 39B on the edge of the Atlantic Ocean.

1145 GMT (7:45 a.m. EDT)

T-minus 3 hours and counting. The countdown has resumed on schedule from this planned three-hour built-in hold. Clocks will now tick down to T-minus 20 minutes when the next hold is planned. A final hold is scheduled at the T-minus 9 minute mark to synch up with the 11:41 a.m. EDT launch time.

1118 GMT (7:18 a.m. EDT)

All six astronauts have donned their day-glow orange launch and entry partial pressure spacesuits. After final adjustments and pressure checks, the crew plans to depart the suit-up room and take the elevator down to the ground level of the Operations and Checkout Building to board the AstroVan for the trip to launch pad 39B, pending an OK from launch managers.

1105 GMT (7:05 a.m. EDT)

NASA managers are mulling two options for dealing with the failure of a hydrogen fuel level sensor in the shuttle Atlantis' external tank: Flying as is today or standing down for 24 hours for additional troubleshooting.

Read our full story.

1102 GMT (7:02 a.m. EDT)

The mission management team is assembling on station for today's launch. They will be receiving an engineering report on liquid hydrogen engine cutoff sensor No. 3 that failed during fueling this morning. They could decide either to press ahead with launch today with three of the four sensors working or call a scrub, drain the tank and re-fuel tomorrow to see how the sensor performs.

1055 GMT (6:55 a.m. EDT)

The inspection team is looking at one of the shuttle's jet thrusters. The protective covering came off last night.

1045 GMT (6:45 a.m. EDT)

The countdown is holding at the T-minus 3 hour mark. Clocks are slated to resume ticking in an hour.

1035 GMT (6:35 a.m. EDT)

The Final Inspection Team is continuing its work at pad 39B. The team is responsible for checking Atlantis and the launch pad one last time prior to liftoff. The team is comprised of engineers and safety officials from NASA, United Space Alliance and tank-builder Lockheed Martin. At the conclusion of their two-hour tour-of-duty, the team will have walked up and down the entire fixed service structure and mobile launcher platform.

The team is on the lookout for any abnormal ice or frost build-up on the vehicle and integrity of the external tank foam insulation.

The team uses a portable infrared scanner that gathers temperature measurements on the surface area of the shuttle and can spot leaks. The scanner will be used to obtain temperature data on the external tank, solid rocket boosters, space shuttle orbiter, main engines and launch pad structures. The scanner can also spot leaks of the cryogenic propellants, and due to its ability to detect distinct temperature differences, can spot any dangerous hydrogen fuel that is burning. The team member also is responsible for photo documentation.

The team wears the highly visible day-glow orange coveralls that are anti-static and flame resistant. Each member also has a self-contained emergency breathing unit that holds about 10 minutes of air.

No significant problems or concerns have been reported by the inspection team so far.

1020 GMT (6:20 a.m. EDT)

No decision has been made yet on how to deal with the problematic engine cutoff sensor. The countdown continues pending the mission management team determining whether launch can occur today or if a scrub should be called. The rationale for launching with three good sensors of the four says launch should be scrubbed, the external tank drained and another countdown performed the next day to see how the suspect sensor performs during a second fueling. If the sensor acts the same on the second try, launch is allowed to proceed.

1011 GMT (6:11 a.m. EDT)

The Orbiter Closeout Crew has arrived in the White Room on the end of the Orbiter Access Arm catwalk that runs from the launch pad tower to Atlantis' crew module. They will make final preparations to ready Atlantis for the astronauts' arrival about two hours from now.

1003 GMT (6:03 a.m. EDT)

Atlantis' six astronauts are gathered around the dining room table in crew quarters for a snack and the traditional launch morning photo opportunity.

In a few minutes, commander Brent Jett, pilot Chris Ferguson and flight engineer Dan Burbank will receive a briefing on the weather forecast for KSC and abort landing sites in California, New Mexico, Spain and France. Then they will join their crewmates in the suit-up to don the launch and entry spacesuits in preparation for heading to pad 39B.

1000 GMT (6:00 a.m. EDT)

The Final Inspection Team team has arrived at pad 39B along with the Orbiter Closeout Crew, which is the team that will assist the astronauts during boarding.

0950 GMT (5:50 a.m. EDT)

Filling of Atlantis' external fuel tank was called complete at 5:46 a.m. EDT. The tank has been pumped full with 528,000 gallons of supercold liquid oxygen and liquid hydrogen. The process started at 2:49 a.m.

But given the cryogenic nature of the oxidizer and propellant, the supplies naturally boil away. So the tanks are continuously topped off until the final minutes of the countdown in a procedure called "stable replenishment."

With the hazardous tanking operation completed, the Orbiter Closeout Crew and Final Inspection Team will be heading to the pad to perform their jobs. The closeout crew will ready Atlantis' crew module for the astronauts' ingress in a couple of hours; and the inspection team will give the entire vehicle a check for any ice formation following fueling.

In addition, a red crew is going out to the pad to adjust a recirculation pump power supply.

0947 GMT (5:47 a.m. EDT)

Liquid oxygen has gone into replenish mode, completing the external tank filling for launch at 5:46 a.m.

0940 GMT (5:40 a.m. EDT)

Fast-fill of the liquid oxygen tank just concluded. Topping of the tank is beginning.

0937 GMT (5:37 a.m. EDT)

The liquid hydrogen tank is now fully loaded. The system has entered into replenish mode to keep the tank topped off through the rest of the count.

0915 GMT (5:15 a.m. EDT)

Engineers fueling the shuttle Atlantis for launch today are troubleshooting a possible problem with a hydrogen engine cutoff - ECO - sensor in the ship's external tank. During a test, hydrogen ECO sensor No. 3 indicated it was wet when it should have indicated dry. The three-hour fueling procedure is continuing while engineers look into the issue and launch remains on track for 11:40:37 a.m.

Read our full story.

0653 GMT (2:53 a.m. EDT)

FUELING UNDERWAY. The filling of space shuttle Atlantis' external fuel tank with a half-million gallons of supercold propellants has begun at launch pad 39B.

The tanking operation commenced with the chilldown thermal conditioning process at 2:49 a.m. This will be followed by the slow-fill mode and then the fast-fill mode.

The cryogenics are pumped from storage spheres at the pad, through feed lines to the mobile launcher platform, into Atlantis' aft compartment and finally into the external fuel tank.

There are two tanks inside the shuttle's external fuel tank. The liquid oxygen tank occupies the top third of the bullet-shaped tank. It will be filled with 143,000 gallons of liquid oxygen chilled to minus 298 degrees Fahrenheit. The liquid hydrogen tank is contained in the bottom two-thirds of the external tank. It holds 385,000 gallons of liquid hydrogen chilled to minus 423 degrees Fahrenheit.

0620 GMT (2:20 a.m. EDT)

The slight delay in the start of fueling is the result of workers having to replace a faulty gaseous nitrogen purge control valve, NASA spokesman Bruce Buckingham says.

0610 GMT (2:10 a.m. EDT)

The launch team anticipates fueling will start about 2:30 a.m., a bit behind the timeline but within the allowable margin to keep the countdown on track for liftoff at 11:41 a.m. this morning.

There are "no showstopper issues at this time," a NASA spokesman says, and the weather outlook remains unchanged at a 70 percent chance of favorable conditions for launch.

0559 GMT (1:59 a.m. EDT)

The management team met for its pre-fueling meeting this morning and gave the approval to begin loading space shuttle Atlantis' external tank. The three-hour fueling process is expected to start shortly.

0550 GMT (1:50 a.m. EDT)

NASA has not yet announced results from the management team meeting or the start of fueling operations. We'll post updates as official information becomes available.

0345 GMT (11:45 p.m. EDT Thurs.)

The countdown is heading for the start of fueling operations overnight. Clocks will resume ticking from the T-minus 6 hour scheduled hold point at 1:45 a.m., which is the same time filling of Atlantis' external tank with cryogenic propellants should begin.

Managers will convene the pre-fueling meeting at midnight to finish reviewing the final analysis reports on the orbiter fuel cells, discuss countdown status and receive a weather briefing. The meeting will conclude with a "go" or "no go" decision on fueling.

Atlantis' six astronauts are asleep in crew quarters. Their wakeup call for launch morning activities is 12:42 a.m.

THURSDAY, SEPTEMBER 7, 2006
2340 GMT (7:40 p.m. EDT)


NASA managers today cleared the shuttle Atlantis for launch Friday despite a suspect electrical generator, deciding the risk of an in-flight fuel cell shutdown that could prompt a shortened mission was not a credible threat to the thrice-delayed space station assembly flight. Liftoff time is 11:41 a.m. EDT (1541 GMT).

Read our full story.

2201 GMT (6:01 p.m. EDT)

Shuttle program manager Wayne Hale says "cloud over fuel cell No. 1" has lifted and the device should be safe to launch as-is without repairs. But that decision was not fully unanimous. A final piece of analysis will be reviewed at the next management team meeting prior to fueling overnight.

We'll post a complete story following the news conference.

2139 GMT (5:39 p.m. EDT)

GO FOR LAUNCH. Space shuttle Atlantis has been given approval to proceed toward launch Friday morning at 11:41 a.m. The press briefing to explain how the fuel cell issue was resolved is coming up in about 20 minutes.

2117 GMT (5:17 p.m. EDT)

The briefing start time has been pushed back to 6 p.m. EDT.

2030 GMT (4:30 p.m. EDT)

Managers continue to meet. The news conference is not expected before 5:30 p.m.

1630 GMT (12:30 p.m. EDT)

The mission management team will be meeting this afternoon to assess the engineering results on the fuel cell test and analysis. Launch on Friday remains the target, if the fuel cell can be cleared for flight as-is.

The weather outlook for Friday is posted here.

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.

Read our full story.

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.

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.

Read our full story.

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.

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.

Read our full story.

0802 GMT (4:02 a.m. EDT)

SCRUB! Today's launch attempt has been stopped by the fuel cell problem. Another try could come as early as Thursday, with a target liftoff time of 12:03 p.m. EDT.

The concern involves a voltage shift noted during activation of fuel cell No. 1. Atlantis has three fuel cells -- located beneath the payload bay -- that use liquid hydrogen and liquid oxygen reactants to generate the electricity needed to power the shuttle's systems during flight and create drinking water for the astronauts as a byproduct. NASA won't allow a shuttle to launch unless all three fuel cell devices are working properly.

Backup launch opportunities are available Thursday and Friday. If Atlantis doesn't fly by then, the shuttle must wait until after the Russian Soyuz flight to the space station proceeds later this month. That would delay Atlantis until at least the end of September, and possibly longer, depending on NASA's decision whether to keep daylight launch conditions a requirement for this mission. The next daytime launch slot for Atlantis is late October.

0648 GMT (2:48 a.m. EDT)

Engineers at the Kennedy Space Center are troubleshooting a problem with fuel cell No. 1 aboard the shuttle Atlantis. The loading of rocket fuel is on hold and if the problem is not resolved by 4 a.m. or so, today's launch attempt will be scrubbed, officials said. In the meantime, launch remains scheduled for 12:29 p.m.

Read our full story.

0250 GMT (10:50 p.m. EDT Tues.)

GALLERY: This collection of pictures was taken on Tuesday, September 5 on the eve of space shuttle Atlantis' planned blastoff from pad 39B to resume construction of the International Space Station.

See the image gallery here.

0235 GMT (10:35 p.m. EDT Tues.)

IMAGE: As space shuttle Atlantis stands bathed in powerful flood lights at launch pad 39B on the evening before blastoff, its destination -- the International Space Station -- soars overhead as photographed in this time-lapse image from the Kennedy Space Center press site.

See the image here.

TUESDAY, SEPTEMBER 5, 2006

The countdown was released from the T-minus 11 hour hold period at 7:33 p.m. EDT this evening.

Tonight's work includes activating Atlantis' three electricity-generating fuel cells about 8:45 p.m., clearing the blast danger area of all non-essential personnel and switching the orbiter's purge air to gaseous nitrogen around 9:20 p.m.

The next hold begins at 12:33 a.m. when clocks reach the T-minus 6 hour point. That hold will last two hours in duration, during which time the control room team verifies no violations of launch commit criteria prior to external tank fueling and the mission management team meets starting at 1:45 a.m. to review status. If there are no problems and the weather outlook still appears favorable, fueling of shuttle Atlantis for launch will commence as early as 2:30 a.m.

Wednesday's launch window opens at 12:23:51 p.m. and extends to 12:33:52 p.m. EDT. The target liftoff time is the optimum moment in that window at 12:28:51 p.m. EDT.

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.

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.

1730 GMT (1:30 p.m. EDT)

NASA managers are holding open the possibility of extending the shuttle Atlantis' mission by at least one and possibly two days to give the crew time to carry out additional heat shield inspections and to handle any unexpected problems that might crop up, officials said today.

Read our full story.

1445 GMT (10:45 a.m. EDT)

On this eve of launch, the mission management team has completed today's meeting to review the status of the countdown. There are no problems being worked and activities remain on schedule for tomorrow's liftoff of Atlantis.

Countdown clocks have entered the planned hold at T-minus 11 hours. This pause lasts 13.5 hours, through 7:30 p.m. tonight.

Final preparations of the shuttle's three main engines for fueling and launch were performed overnight, as well as filling the launch pad's sound suppression system water tank. Closeouts of the tail service masts on the mobile launcher platform that feed power, data and fuel lines to the shuttle and orbiter star tracker functional checks were underway this morning.

Other tasks today include activating Atlantis' inertial measurement units in the guidance system, turning on the ship's communications systems, stowing the final pieces of the astronauts' equipment in the crew module and retracting the rotating service structure from around the shuttle. That rollback of the gantry is targeted for 3 p.m. EDT, but the time can and will be adjusted based upon afternoon thunderstorms.

1305 GMT (9:05 a.m. EDT)

The weather forecast for Wednesday has worsened slightly. Meteorologists now predict a 70 percent chance of favorable conditions at launch time -- that's down from 80 percent. The two worries are cumulus clouds within 10 miles of the pad and showers within 20 miles of the Kennedy Space Center runway where Atlantis could make an emergency landing during launch. See the full forecast here.

MONDAY, SEPTEMBER 4, 2006

NASA managers Monday agreed to make three consecutive attempts to get the shuttle Atlantis off the ground if bad weather or technical problems prevent an on-time liftoff Wednesday.

Read our full story.

1600 GMT (12:00 p.m. EDT)

Engineers loaded the shuttle Atlantis' fuel cell system with liquid hydrogen and oxygen early today, a key step in readying the spacecraft for launch Wednesday on a weather-delayed space station assembly mission. There are no technical problems of any significance at launch complex 39B, officials said today, and forecasters are continuing to predict an 80 percent chance of good weather.

Read our full story.

1405 GMT (10:05 a.m. EDT)

The countdown is progressing smoothly without any significant problems, launch team officials report this morning. The weather outlook continues to predict an 80 percent chance of acceptable conditions at Wednesday's 12:29 p.m. EDT launch time. Check back a little later for a full update following this morning's countdown status news conference.

SUNDAY, SEPTEMBER 3, 2006
1330 GMT (9:30 a.m. EDT)


With little fanfare, NASA restarted the shuttle Atlantis' countdown today for blastoff Wednesday on a long-awaited mission to restart space station assembly.

Read our full story.

1300 GMT (9:00 a.m. EDT)

The countdown has begun for Wednesday's launch of space shuttle Atlantis that will deliver a set of power-generating solar wings to the space station.

Clocks in Firing Room 4 of the Complex 39 Launch Control Center starting ticking from the T-minus 43 hour mark at 8 a.m. EDT this morning. The countdown includes more than 33 hours of planned, built-in hold time leading to the targeted liftoff at 12:29 p.m. EDT Wednesday.

Today's activities at launch pad 39B involve buttoning up shuttle compartments and ground equipment, checking out backup flight systems, reviewing software from the ship's mass memory units and displays, and loading Atlantis' main computers with the backup flight system software. Later tonight, the shuttle's navigational systems will be activated and tested starting about 9 p.m.

The countdown will enter the first in a series of planned hold points at T-minus 27 hours beginning at midnight. The hold will last four hours. The launch pad will be cleared of all non-essential personnel during the hold for a test of the shuttle's pyrotechnic initiator controllers. Once the clocks resume counting at 4 a.m., filling of Atlantis' fuel cell storage tanks with liquid hydrogen and liquid oxygen reactants will commence. The three fuel cells -- located beneath the payload bay -- generate the electricity needed to power the shuttle's systems during flight and create drinking water for the astronauts as a byproduct.

Meanwhile, the early weather forecast for Wednesday predicts an 80 percent chance of favorable conditions at launch time. The two worries to be monitored will be cumulus clouds within 10 miles of the pad and showers within 20 miles of the Kennedy Space Center runway where Atlantis could make an emergency landing during launch. See the full forecast here.

SATURDAY, SEPTEMBER 2, 2006

The Atlantis astronauts flew back to the Kennedy Space Center today for launch Wednesday on a weather-delayed space station assembly mission. The countdown begins at 8 a.m. Sunday with launch on tap, weather permitting, at 12:29 p.m. Wednesday.

Read our full story.

FRIDAY, SEPTEMBER 1, 2006

This collection of photos shows space shuttle Atlantis' rollback from launch pad 39B forced by tropical storm Ernesto. Before reaching the Vehicle Assembly Building, however, forecasters lowered their outlook for winds at Kennedy Space Center and officials opted to halt the move in favor of getting Atlantis back on the pad that day.

Enter the photo gallery here.

THURSDAY, AUGUST 31, 2006

NASA managers today formally selected September 6 as the new target launch date for shuttle Atlantis after inspections revealed no damage from tropical depression Ernesto's encounter with Kennedy Space Center. Liftoff is set for 12:28:49 p.m. EDT.

The peak wind experienced at launch pad 39B from Ernesto was 44 mph, and the total rainfall accumulation was 4.16 inches. The space center was reopened this morning.

The Atlantis crew -- commander Brent Jett, pilot Chris Ferguson, flight engineer Dan Burbank, Joe Tanner, Steve MacLean and Heide Stefanyshyn-Piper -- will return to the Cape on Saturday morning. The flew back to Houston earlier this week for some additional mission simulations while launch was delayed for Ernesto.

The countdown is scheduled to begin Sunday at 8 a.m. EDT.

As it now stands, NASA will have three days to get Atlantis off the ground: Sept. 6, 7 and 8. If not, the flight will be delayed to late October or, if NASA relaxes a daylight launch requirement, at some point after the Sept. 29 landing of a Russian Soyuz spacecraft carrying the international space station's outgoing crew.

WEDNESDAY, AUGUST 30, 2006
1800 GMT (2:00 p.m. EDT)


NASA and Russian space managers agreed today to extend the shuttle Atlantis' launch window by one day, to Sept. 8, to bolster the U.S. space agency's chances of getting the weather-delayed shuttle off the ground this month.

Read our full story.

TUESDAY, AUGUST 29, 2006

Space shuttle Atlantis arrived back on launch pad 39B this evening after its extraordinary day of travels on the Complex 39 crawlerway. The mobile launch platform was firmly secured in place atop the pad pedestals by 8:45 p.m. The rotating service structure is expected to be swung into its cocoon position around Atlantis -- providing the primary access and weather protection -- about 11 p.m. tonight.

Atlantis left the pad at 10:04 a.m. and rolled for almost five hours toward the Vehicle Assembly Building to escape the approaching tropical storm Ernesto. But at 2:45 p.m. and a mile east of the VAB, the transporter went into reverse to haul the shuttle back to the pad after NASA officials concluded the threat posed by the storm was no longer great enough to chase Atlantis indoors.

2230 GMT (6:30 p.m. EDT)

If shuttle Atlantis weathers tropical storm Ernesto without any major problems, and if engineers can complete hurried preparations, NASA may be ready to make a launch attempt as early as Sept. 6, one day before the shuttle's launch window closes, officials said late today.

Read our full story.

2054 GMT (4:54 p.m. EDT)

Shuttle launch director Mike Leinbach says Atlantis could be ready for flight on September 6 or 7, depending on how Tropical Storm Ernesto disrupts Kennedy Space Center operations. The launch team currently expects to resume work on Thursday after the storm passes.

1943 GMT (3:43 p.m. EDT)

This afternoon's news conference is now not expected to take place before 4:30 p.m. EDT (2030 GMT).

1935 GMT (3:35 p.m. EDT)

NASA mission management team chairman LeRoy Cain and shuttle launch director Mike Leinbach are expected to hold a news briefing at 4 p.m. (2000 GMT) to discuss this afternoon's turn of events.

1920 GMT (3:20 p.m. EDT)

We have posted our initial report on the surprise turn of events this afternoon.

1905 GMT (3:05 p.m. EDT)

Atlantis was about a mile from VAB when the decision was taken to reverse course. The shuttle started back to the launch pad at about 2:45 p.m. EDT (1845 GMT). The shuttle is expected to arrive back at the pad by 8 p.m. EDT (0000 GMT).

1850 GMT (2:50 p.m. EDT)

NASA has cancelled its plans to shelter shuttle Atlantis in the Vehicle Assembly Building and is returning it to the launch pad. The latest forecast from the National Hurricane Center has given NASA the confidence the shuttle can ride out the storm at the launch pad. The worst conditions expected at the space center are winds of 45 knots with gusts to 60.

1720 GMT (1:20 p.m. EDT)

Atlantis has reached the point in the crawlerway where it joins up with the path from pad 39A.

The crawlerway running from the Vehicle Assembly Building to the launch pads is 130 feet wide -- almost as broad as an eight-lane highway. Two 40-foot-wide lanes are separated by a 50-foot-wide median strip. The average depth is seven feet.

1650 GMT (12:50 p.m. EDT)

In the news telecon underway, shuttle program manager Wayne Hale and space station program manager Mike Suffredini say September 7 remains the firm cutoff date for launching Atlantis before the Russian Soyuz. Kennedy Space Center officials say it will take eight days to ready the shuttle for launch after it is returned to the pad following the tropical storm's passage. But it seems highly unlikely Atlantis could roll out on Thursday to support a September 7 countdown.

Missing this launch window would push Atlantis to the end of October, if NASA keeps the daylight ascent requirement in place.

1624 GMT (12:24 p.m. EDT)

Among the options on the table, shuttle program manager Wayne Hale says, is the requirement to launch this flight in daylight for external tank foam photography. Relaxing that requirement would allow NASA to open up additional launch opportunities after the Russian Soyuz mission to the space station in September. The next daytime shuttle launch window opens October 26.

1610 GMT (12:10 p.m. EDT)

Space shuttle program manager Wayne Hale says NASA has kicked off a number of studies to determine what options are available for rescheduling the launch of Atlantis after today's rollback for tropical storm Ernesto.

"It does not make any sense to fool with Mother Nature," Hale is telling reporters at news telecon right now.

"It was the prudent thing to go back to the barn."

Atlantis is making good progress on the road off the launch pad under sunny skies.

1516 GMT (11:16 a.m. EDT)

Shuttle program manager Wayne Hale will hold a telecon at noon EDT (1600 GMT) to update reporters on the impact of today's rollback. We will provide updates during the briefing.

1513 GMT (11:13 a.m. EDT)

The crawler has reached the base of the pad is passing through the perimeter gate. So far weather conditions are excellent for the rollback activities.

1500 GMT (11:00 a.m. EDT)

The latest update from the National Hurricane Center puts Tropical Storm Ernesto 180 miles (285 km) south-southeast of Miami. Maximum sustained winds are near 45 mph (75 km/hr) and some strengthening is expected as the storm travels across the warm waters between Cuba and Florida. The outer rainbands of the storm are near to the Florida Keys and the southeast coast of the Florida peninsula.

1445 GMT (10:45 a.m. EDT)

The shuttle stack is now making its way down the concrete ramp toward the crawler way.

1441 GMT (10:41 a.m. EDT)

We have posted a full story on today's decision to roll Atlantis to safety and the implications for the shuttle's launch date.

1431 GMT (10:31 a.m. EDT)

NASA has yet to announce a new launch date for Atlantis. Today's decision to move the shuttle to safety all but rules out a launch before the current cut off date of September 7, imposed by the need to launch a new Soyuz capsule to the space station.

In a statement the space agency said: "NASA and the Russian Federal Space Agency continue to discuss the timing of Atlantis' mission and the Soyuz spacecraft, which will send the next crew to the station in September. Factors to be considered are the lighting constraints for the shuttle launch and Soyuz landing and the timing for docking and undocking the spacecraft with the station. NASA is also investigating additional launch windows later in the fall."

The shuttle's crew, Commander Brent Jett, Pilot Chris Ferguson, and mission specialists Joe Tanner, Dan Burbank, Heide Stefanyshyn-Piper and Canadian astronaut Steve MacLean, will return to Houston to await a new launch date.

1426 GMT (10:26 a.m. EDT)

The mobile launcher platform has cleared the pedestals that supported it on the launch pad and will soon be starting down the ramp to the crawler way. During the climb down the 5 percent grade, the crawler will use hydraulic leveling systems to keep the mobile launcher platform level.

1412 GMT (10:12 a.m. EDT)

ROLLBACK BEGINS. Space shuttle Atlantis has begun the slow trek from launch pad 39B to the safe confines of Kennedy Space Center's cavernous Vehicle Assembly Building. The four-and-a-half mile journey to high bay 2 on the 52-story building's west side will take about 10 hours. First motion was officially clocked at 10:04 a.m. EDT (1404 GMT).

It is the fifth time in the 25-year history of the space shuttle program that threatening tropical weather has forced a rollback. Previous weather-related moves include:

  • Oct. 9, 1990: Columbia's STS-35 mission was rolled back for Tropical Storm Klaus
  • Aug. 1, 1995: Endeavour's STS-69 mission was rolled back for Hurricane Erin
  • July 10, 1996: Atlantis' STS-79 mission was rolled back for Hurricane Bertha
  • Sept. 4, 1996: Atlantis' STS-79 mission was rolled back (for a second time) due to Hurricane Fran
Twelve additional rollbacks have occurred for technical reasons, starting with Columbia's STS-9 mission in October 1983 and most recently Discovery's STS-114 return to flight mission last year.

1341 GMT (9:41 a.m. EDT)

It's now official. Shuttle Atlantis is heading for shelter from tropical storm Ernesto. The decision was made after countless weather briefings over the past few days about the storm's path toward the Kennedy Space Center and how severe conditions could become. In the end, NASA officials concluded they couldn't risk leaving Atlantis standing on its launch pad.

The trip back to the Vehicle Assembly Building, which is expected to take about 10 hours, will begin shortly. The crawler-transporter will hydraulically lift the shuttle's mobile launch platform off the launch pad pedestals in the next few minutes to complete preparations for the move.

1300 GMT (9:00 a.m. EDT)

Space shuttle Atlantis is ready to begin the roll back to the Vehicle Assembly Building. The Apollo-era crawler-transporter is positioned beneath the mobile launch platform to haul the shuttle. But NASA leaders are receiving a final weather briefing right now and a final "go/no-go" decision to begin the move has not yet happened.

1041 GMT (6:41 a.m. EDT)

NASA officials have decided to proceed with rollback of space shuttle Atlantis today because of the high wind and flying debris threats posed by tropical storm Ernesto. One final review of the situation will be made around 9 a.m. EDT, just before the shuttle begins the four-mile trip back to the Vehicle Assembly Building.

This will be the fifth time in program history that a shuttle has been moved off the launch pad to seek shelter from tropical weather.

1015 GMT (6:15 a.m. EDT)

The gantry-like rotating service structure that has enclosed space shuttle Atlantis at launch pad 39B is swinging open right now in advance of the ship possibly being rolled off the seaside complex later this morning.

0940 GMT (5:40 a.m. EDT)

The center of Ernesto has moved off the northern coast of Cuba and become slightly stronger this morning. The storm is forecast to approach the southern shore of Florida at or near hurricane strength tonight. A tropical storm warning is in effect for the Kennedy Space Center. The newest track is available here, which shows Ernesto churning up through the center of Florida and passing just west of the shuttle launch site as a tropical storm.

Work to ready for the Atlantis rollback have continued overnight. However, no final decision has been made on actually moving the shuttle to the Vehicle Assembly Building.

0255 GMT (10:55 p.m. EDT)

Little has changed tonight with Ernesto. The tropical storm remains largely disorganized as it moves over Cuba. The newest track is available here.

MONDAY, AUGUST 28, 2006
2050 GMT (4:50 p.m. EDT)


Problems with one of NASA's ponderous crawler-transporters will force engineers to take the shuttle Atlantis to the far side of the Vehicle Assembly Building Tuesday if a rollback from the launch pad is ordered because of tropical storm/hurricane Ernesto. The change in plans will add three hours or so to the time necessary to get Atlantis out of harm's way.

Read our full story.

2040 GMT (4:40 p.m. EDT)

The newest track is available here.

Ernesto is located over Cuba and moving northwest near 13 mph. The National Hurricane Center says this general motion is expected to continue for the next 24 hours, and the tropical storm should emerge into the Atlantic north of Cuba tonight.

The storm has sustained winds of 40 mph. Some strengthening is forecast once Ernesto moves over the warm Florida Straits. However, the system may not regenerate into a hurricane after all.

1700 GMT (1:00 p.m. EDT)

In what amounts to a "perfect storm" of high winds, high stakes and international drama, tropical storm Ernesto threatens to bring hurricane-force winds to the Kennedy Space Center by Wednesday night. NASA managers today ordered engineers to begin work to roll the shuttle Atlantis off its seaside launch pad Tuesday, raising the prospect of a lengthy launch delay.

For NASA, which is poised to resume space station assembly after a three-and-a-half year hiatus, rollback is a last-resort option that would end any chance of getting Atlantis off the ground before the launch window closes Sept. 7. If that scenario plays out, launch could slip to late October when a brief two-day lighted window is available.

An October launch, in turn, almost certainly would force NASA to delay a planned December flight by the shuttle Discovery to January at the earliest in a ripple effect with consequences for downstream flights.

Read our full story.

1545 GMT (11:45 a.m. EDT)

The mobile launch platform with half of one solid rocket booster intended for the December shuttle launch is beginning to pull out of the Vehicle Assembly Building right now. The platform is being transferred to clear this bay within the VAB for Atlantis' arrival tomorrow afternoon. The partially stacked SRB will be parked in the spare bay on the west side of the VAB.

1500 GMT (11:00 a.m. EDT)

Cape Canaveral is now under a hurricane watch.

The 11 a.m. advisory from the National Hurricane Center indicates Ernesto is down to 40 mph sustained winds as it interacts with Cuba. But it is expected to regain hurricane strength after emerging over water before striking Florida.

The projected track, which continues the trend of shifting eastward, is available here.

1420 GMT (10:20 a.m. EDT)

At launch pad 39B, the offloading of the liquid hydrogen and liquid oxygen reactants from the fuel cell storage tanks beneath the payload bay of space shuttle Atlantis is underway. That operation should be completed around noon today, launch director Mike Leinbach says.

The pad will be reopened to workers after this hazardous operation is finished, allowing the rest of rollback preparations to continue in earnest. Disconnection of ordnance will occur this afternoon.

NASA had been targeting the 4-mile rollback of Atlantis to begin around 2 p.m. on Tuesday. But given the weather outlook, Leinbach has told the teams to look at ways to do some work in parallel so that the timeline could be compressed. That would allow the shuttle to begin the 6-to-8-hour trip back to the Vehicle Assembly Building around 8 or 10 a.m. EDT.

Hurricane force winds are expected at Kennedy Space Center by late afternoon or early evening on Wednesday.

1305 GMT (9:05 a.m. EDT)

The NASA news briefing is now expected around 10 a.m. this morning.

1205 GMT (8:05 a.m. EDT)

In what amounts to a "perfect storm" of high winds, high stakes and international drama, tropical storm Ernesto is now predicted to hit southern Florida as a possible category two or three hurricane early Wednesday, passing within a few miles of the Kennedy Space Center later that day.

NASA managers early today ordered engineers to begin preparations for rolling shuttle Atlantis off the launch pad and back to the protection of the Vehicle Assembly Building, eliminating any chance of launching the shuttle Tuesday.

While its movement over land will decrease Ernesto's strength, the current track likely will bring tropical storm-force winds to Florida's space coast by Wednesday morning and possible category one hurricane-force winds by Wednesday night.

Read our full story.

1158 GMT (7:58 a.m. EDT)

The 8 a.m. updated Ernesto track from the National Hurricane Center is available here.

The tropical storm is currently located near the southeastern coast of Cuba packing 45 mph winds. The official forecast takes Ernesto across Cuba and then over the warm waters of the Florida Straits where it can strengthen into a hurricane before making landfall late Tuesday or early Wednesday in South Florida.

NASA is planning a news conference from Kennedy Space Center in an hour to talk about the shuttle rollback preparations. The agency decided to start those preps this morning, which could lead to Atlantis moving off the launch pad tomorrow. But managers will be reviewing the situation at points along the timeline and have the option, obviously, of leaving the shuttle on the pad if the storm somehow changes.

1048 GMT (6:48 a.m. EDT)

NASA officials this morning ordered rollback preparations to begin at launch pad 39B. The predicted track of Ernesto continues to shift ever closer to Kennedy Space Center. The latest map is posted here.

0300 GMT (11:00 p.m. EDT Sun.)

The new National Hurricane Center forecast track for Ernesto, which pushes the course even closer to Kennedy Space Center, is posted here.

0130 GMT (9:30 p.m. EDT Sun.)

NASA managers met Sunday evening and agreed to wait until Monday morning to make a decision on whether to roll the shuttle Atlantis back to the Vehicle Assembly Building, preserving for now the option of launching the ship Tuesday on a space station assembly mission.

Read our full story.

0020 GMT (8:20 p.m. EDT Sun.)

A decision for rollback of Atlantis to the Vehicle Assembly Building to escape the hurricane has been deferred until Monday morning around 7 a.m. Technicians will either begin draining the ship's fuel cell reactants at that point to begin work to get the shuttle off the launch pad or else push forward for liftoff on Tuesday as currently planned.

The most recent forecast track for Ernesto, which has weakened to tropical storm status with 50 mph winds, is posted here.

Meanwhile, LeRoy Cain, the launch integration manager, reports that space shuttle Atlantis has been fully cleared of any lingering concerns from Friday's lightning strike that hit pad 39B. Additional testing of the solid rocket booster pyrotechnics is no longer required based on data collected from other systems on the shuttle.

0000 GMT (8:00 p.m. EDT Sun.)

The management team meeting should be wrapping up. A news conference from the Kennedy Space Center to update the hurricane and post-lightning test situation is scheduled for this hour.

SUNDAY, AUGUST 27, 2006
1950 GMT (4:50 p.m. EDT)


NASA managers plan to meet tonight to make a decision on whether to proceed with an attempt to launch the shuttle Atlantis Tuesday on a space station assembly mission or roll the spacecraft back to the protection of the Vehicle Assembly Building because of hurricane Ernesto.

Read our full story.

1847 GMT (2:47 p.m. EDT)

A hypothetical scenario potentially could see Atlantis being rolled back to the VAB in a couple of days, the hurricane passing on Friday, the shuttle returning to the pad perhaps Sunday and launch as early as September 7 or 8. But Gerstenmaier says nothing has been decided yet.

Another management team meeting is planned for 6 p.m. EDT tonight.

1840 GMT (2:40 p.m. EDT)

No decisions have been made about rolling back Atlantis from the launch pad. Officials continue to watch the progress of Hurricane Ernesto, with a decision expected later tonight whether Atlantis will be safe on its seaside pad or should be transferred back to the 52-story Vehicle Assembly Building.

Meanwhile, teams analyzing the shuttle from Friday's launch pad lightning strike have now cleared the orbiter and external tank systems from concern. The orbiter power bus issue discussed yesterday has been resolved. The solid rocket boosters and associated pyrotechnics still need to be confirmed healthy, however.

So NASA space operations chief Bill Gerstenmaier says two agendas are competing against each other at Kennedy Space Center today. While the lightning testing work continues to verify Atlantis is ready for launch as early as Tuesday, preparations for a possible rollback are being made, including attaching the fuel cell servicing umbilical to Atlantis for draining the liquid oxygen and liquid hydrogen reactants and moving the crawler-transporter that would haul the shuttle to the VAB.

1753 GMT (1:53 p.m. EDT)

Officials received a Hurricane Ernesto briefing earlier this hour. Details on the storm's forecast and whether Atlantis might have to be rolled off the launch pad to seek shelter in the Vehicle Assembly Building will be addressed in the upcoming NASA news conference, now expected to begin no sooner than 2:30 p.m.

1555 GMT (11:55 a.m. EDT)

NASA has finally announced that launch of space shuttle Atlantis will be delayed until Tuesday at the earliest. The target launch time would be 3:42 p.m. EDT.

"This delay is as a result of the lightning strike at the pad on Friday and the need for additional time for further analysis of the shuttle and ground systems. No damage to the vehicle or pad has been found at this time, but more time for analysis requires an additional launch delay," says a NASA statement released a short time ago.

A news conference with NASA space operations chief Bill Gerstenmaier is scheduled for 2 p.m. EDT today.

1500 GMT (11:00 a.m. EDT)

The latest forecast track for Hurricane Ernesto has just been released. See the track here.

1420 GMT (10:20 a.m. EDT)

NASA managers debating launch options for the shuttle Atlantis have a new issue to contend with: Hurricane Ernesto, now predicted to strike the west coast of Florida late this week just north of Tampa.

Read our full story.

1222 GMT (8:22 a.m. EDT)

NASA officials continue to wrestle with the post-lightning strike data collection and analysis, plus trying to decide whether to perform additional tests on the solid rocket booster pyrotechnics. Launch team engineers have been told liftoff is likely to slip to no earlier than Tuesday. However, a NASA spokesman says a decision to delay from Monday has not yet been made.

Also in the mix is Hurricane Ernesto, which has become the Atlantic's first hurricane of 2006. The latest forecast track by the National Hurricane Center now takes the storm into Florida later this week. See the track here.

0600 GMT (2:00 a.m. EDT)

NASA's Mission Management Team decided early Sunday to continue testing and analysis to assess the possible effects of a launch pad lightning strike Friday on the shuttle Atlantis' solid-fuel booster and self-destruct systems. A Monday launch attempt remains feasible for now, sources said, but only if the community agrees time-consuming tests to verify the health of booster and range safety pyrotechnic systems are not needed. If the tests are required, launch likely would slip to mid week or later.

Read our full story.

SATURDAY, AUGUST 26, 2006

The lightning bolt that hit launch pad 39B Friday was one of the most powerful on record at the Kennedy Space Center, sending some 100,000 amps of current through the lightning protection system, officials said today. While the lightning protection system worked, shielding the shuttle Atlantis from a direct hit, engineers are concerned about induced currents that showed up in a brief spike in one of the shuttle's main circuits and another in a launch pad pyrotechnic system.

Read our full story.

1923 GMT (3:23 p.m. EDT)

Technicians performing launch pad inspections this morning reported smelling a charred odor near the liquid hydrogen vent arm that extends from the service tower to the backside of the external tank. Engineers will be inspecting all of the wiring and circuitry to verify the pyrotechnics that fire at liftoff to separate the arm from the shuttle weren't harmed in the lightning strike.

1920 GMT (3:20 p.m. EDT)

In addition to the data reviews, engineers will be looking at one of Atlantis' power buses that had a voltage shift during the lightning strike and the various orbiter systems that feed off that power bus.

1910 GMT (3:10 p.m. EDT)

Yesterday's lightning strike appears to be the most powerful to ever hit a space shuttle launch pad, integration manager LeRoy Cain is telling a news conference right now at Kennedy Space Center.

Mission managers opted to delay launch of Atlantis until no earlier than Monday so engineers could continue gathering data about the health of shuttle and ground systems -- from electronics to pyrotecnics -- and ensure all equipment survived the lightning event without damage.

Cain said engineers have noted a couple of indications of the strike on one of the shuttle's power bus systems and on the launch pad hydrogen vent arm. But thus far Cain said they don't have enough information yet to know if there are any problems.

The mission management team will meet at 10 a.m. Sunday to review the progress of the engineering work.

1835 GMT (2:35 p.m. EDT)

NASA managers are to hold a news conference at 3 p.m. EDT (2000 GMT) to discuss the launch delay. The mission management team took the decision to delay tomorrow's planned liftoff during the routine L-1 meeting.

Launch is rescheduled for no earlier than Monday at 4:04 p.m. EDT, if engineers can complete the post-lightning strike testing in time.

1815 GMT (2:15 p.m. EDT)

NASA has delayed the launch of shuttle Atlantis by 24 hours to allow for additional testing following a direct lightning strike at launch pad 39B yesterday. A news conference will be held later this afternoon. A launch on Monday would occur at 4:04 p.m. EDT (2004 GMT).

1515 GMT (11:15 a.m. EDT)

The shuttle Atlantis' countdown is back on track today after delays Friday because of stormy weather. More afternoon storms are expected today and again tomorrow, prompting forecasters to predict a 60 percent chance of weather that would block the shuttle's planned 4:30 p.m. Sunday launch on a space station assembly mission.

Read our full story.

The latest weather forecast is posted here.

FRIDAY, AUGUST 25, 2006

A lightning bolt struck near the space shuttle Atlantis Friday 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.

Read our full story.

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.

Read our full story.

1400 GMT (10:00 a.m. EDT)

The shuttle Atlantis is poised for blastoff Sunday on a long-awaited flight to restart assembly of the international space station three years after the Columbia disaster derailed construction. Atlantis and its six-person crew will deliver a $372 million set of solar arrays to the outpost, kicking off the most ambitious series of manned space flights since the Apollo moon program. This is our 16,000-word preview of Atlantis' mission.

Read our full report.

THURSDAY, AUGUST 24, 2006

The shuttle Atlantis' astronauts flew to Florida Thursday to prepare for launch Sunday on a long-awaited flight to restart space station assembly. With forecasters predicting a 70 percent chance of good weather, liftoff from pad 39B is targeted for 4:30 p.m. Sunday.

Read our full story.

WEDNESDAY, AUGUST 2, 2006

Finally catching a break from the weather, the shuttle Atlantis was hauled to its ocean-side launch pad early today for final preparations before blastoff at the end of the month on a space station assembly mission. Read our full story.

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1215 GMT (8:15 a.m. EDT)

ON THE PAD! Atlantis has arrived at pad 39B for its liftoff in a few weeks to resume construction of the space station.

In the next few hours and days, the methodical process of hooking up the crew module assess and hydrogen vent arms extending from the launch tower, as well as electrical, propellant, communications and other lines between the ground systems and mobile launch platform will begin.

A hot-fire test for Atlantis' auxiliary power unit system is scheduled. The APUs provide the hydraulic pressure needed to move the ship's wing flaps and main engine nozzles and deploy the landing gear. Then the gantry-like Rotating Service Structure will be moved around Atlantis. That will allow the payload bay doors to be opened and the mission cargo to be loaded aboard the shuttle later in the week.

1135 GMT (7:35 a.m. EDT)

The vehicle is arriving on the flat surface of the pad. A precision laser guidance system helps align the mobile launch platform over the pad pedestals. The crawler-transporter will lower the platform onto the pedestals to complete the rollout.

1105 GMT (7:05 a.m. EDT)

Atlantis is beginning the slow creep up the ramp of pad 39B as rollout passes the six-hour mark. The rollout crew has activated the crawler-transporter's jacking and leveling system. The crawler uses hydraulic lifts to keep the shuttle level during the ascent up the pad's ramp by jacking up the front-end of the mobile launch platform.

1020 GMT (6:20 a.m. EDT)

The Apollo-era crawler has been making good time on the road to the pad. Atlantis is nearing pad 39B as dawn begins to break. The rollout officially commenced with first motion at 1:05 a.m.

The crawler-transporter is powered by 16 traction motors that feed from two 2,750 horsepower diesel engines. Two 1,065 horsepower diesel engines are used for jacking, steering, lighting and ventilating.

The transporter consumes 126 gallons of diesel fuel in each mile it travels from the VAB to pad. The vehicle has a fuel capacity of 5,000 gallons.

0535 GMT (1:35 a.m. EDT)

Space shuttle Atlantis' trip to the launch pad has begun this morning. The ship just emerged from the 52-story Vehicle Assembly Building for the four-mile, eight-hour journey to the seaside pad.

TUESDAY, AUGUST 1, 2006

After a two-day delay because of stormy weather, space shuttle Atlantis is now scheduled to make the slow move from the Vehicle Assembly Building to launch pad 39B beginning at 2 a.m. EDT Wednesday.

The weather looks much improved this evening.

0030 GMT (8:30 p.m. EDT Mon.)

Another evening of nasty weather in Central Florida has forced NASA to scrub the planned transfer of space shuttle Atlantis from the Vehicle Assembly Building to launch pad 39B. The rollout has been rescheduled for 2 a.m. EDT Wednesday.

MONDAY, JULY 31, 2006
0340 GMT (11:40 p.m. EDT Sun.)


Workers are being told that rollout has been scrubbed for the night. Atlantis' trip to the pad is now anticipated to start at 10 p.m. EDT on Monday evening.

We're awaiting official word from NASA public affairs about the situation.

SUNDAY, JULY 30, 2006

Space shuttle Atlantis was supposed to make the slow crawl from the Vehicle Assembly Building to launch pad 39B at Kennedy Space Center before sunrise Monday. The 8-hour trek was scheduled to begin just after midnight. But heavy rain and thunderstorms pounding the Space Coast tonight make a delay all but certain.

THURSDAY, JULY 27, 2006

Space shuttle program officials today formally changed the opening of Atlantis' launch window to Sunday, August 27 based on projected lighting conditions for photographing the ship's fuel tank. The window had been targeted to open August 28.

NASA has required the first three shuttle flights after Columbia be launched in daylight to allow cameras good visibility for snapping imagery of the redesigned external fuel tanks. The pictures are critical in determining how the tanks' foam insulation perform during ascent.

Engineers recently completed an analysis that showed if the launch occurred August 27 the orbital lighting would be sufficient to photograph the tank in space after its separation from Atlantis.

By moving up the launch a day, the liftoff time actually shifted later in the afternoon -- changing from 4:04 p.m. on August 28 to 4:30 p.m. on August 27.

There will be just 12 days available to launch Atlantis. The usable portion of the daylight window extends through September 7. A liftoff after that isn't believed possible due to scheduling conflicts with the Russian Soyuz mission to ferry the next Expedition resident crew to the space station.

Assuming Atlantis launches by September 3, the Soyuz with Expedition 14 commander Mike Lopez-Alegria, flight engineer Mikhail Tyurin and Japanese space tourist Daisuke Enomoto would blast off at 1:44 a.m. EDT September 14 from Baikonur Cosmodrome, Kazakhstan.

A scenario in which Atlantis' launch is delayed to the final days of the window would result in the Soyuz rescheduling to September 18.

Russian officials want the Soyuz off the ground by September 18 to start the change of command aboard the space station. The departing Expedition 13 crew will return to Earth about 10 days after Expedition 14 is launched, and beginning the handover sequence any later than September 18 would put the homeward-bound capsule's landing in darkness. The Russians are using a recovery team with new personnel and want to avoid nighttime landing activities.

If Atlantis misses the August-September opportunity for some reason, the next window would come at the end of October.

Atlantis has been attached to its fuel tank and boosters inside the Vehicle Assembly Building in preparation for Monday's early morning roll to launch pad 39B. The four-mile trek is set to begin at midnight.

The solar array truss the shuttle will launch to the station was delivered to the pad Wednesday as planned.

MONDAY, JULY 24, 2006
1245 GMT (8:45 a.m. EDT)


IN THE VAB! Space shuttle Atlantis has arrived inside the cavernous Vehicle Assembly Building where the ship will be mated to the external fuel tank and twin solid rocket boosters.

A metal "sling" is poised to capture Atlantis later today, lifting the shuttle from the transport hauler that carried it from the hangar during the past hour. A heavy-duty crane will rotate the spacecraft vertically, then begin the methodical process of hoisting the ship high into the rafters, over to the assembly bay and carefully lowering Atlantis into position next to the awaiting fuel tank for attachment.

Once the completed shuttle stack is fully mated, the integrated verification test will be conducted to ensure good electrical and mechanical connections between the vehicle elements.

Rollout to launch pad 39B is targeted for next Monday. The exact timing depends on the pace at which the VAB work progresses and the weather outlook.

The space station solar array truss that Atlantis will launch heads for the pad this Thursday for loading into the rotating service structure's payload changeout room. Once Atlantis gets to the pad next week, the ship's payload bay doors will be opened to receive the 35,000-pound truss structure.

The six astronauts are due at Kennedy Space Center on August 7 for the traditional countdown demonstration test. They will board Atlantis on the morning of August 10 for the final three hours of the launch day rehearsal that concludes with a simulated ignition and shutdown of the main engines.

NASA leaders will hold the two-day flight readiness review August 15 and 16 to select an official launch date for Atlantis. Officials are hoping liftoff can occur August 27, if ongoing analysis determines lighting will be sufficient to photograph the external tank after separation from the shuttle given the 4:30 p.m. EDT launch time that day. But if engineers find that the lighting will be too dark to get the necessary views to see how the tank's foam insulation performed during ascent, NASA could set August 28 as the launch date. The liftoff time that day, based on the space station's orbit, would be 4:04 p.m.

Atlantis' 11-day mission will feature three spacewalks to install and activate the station's second set of power-generating solar wings.

1134 GMT (7:34 a.m. EDT)

MOVE IN PROGRESS! Space shuttle Atlantis has started to slowly back out of the hangar. It should take about an hour for the 106-foot long trailer-like transporter to ferry the shuttle over to the Vehicle Assembly Building.

1124 GMT (7:24 a.m. EDT)

The move has not yet commenced. But the transporter just started its engine.

1010 GMT (6:10 a.m. EDT)

The hangar doors on Orbiter Processing Facility bay 1 are opening right now as preparations continue for this morning's move of Atlantis to the Vehicle Assembly Building. The transfer is expected to begin within the hour.

THURSDAY, JULY 20, 2006

Space shuttle Atlantis will move closer to its first flight in almost four years when the orbiter is hauled into Kennedy Space Center's Vehicle Assembly Building at sunrise Monday.

Perched atop the 76-wheel Orbiter Transporter System, the shuttle will driven a quarter-mile from its hangar to the VAB around 6 a.m. EDT (1000 GMT).

Technicians will hoist Atlantis upright inside the cavernous 52-story building, attach the spaceplane to the external fuel tank and twin solid rocket boosters and then conduct a series of tests.

Rollout to launch pad 39B is expected on Monday, July 31, if all goes well.

Atlantis will resume construction of the International Space Station with delivery of the outpost's second set of power-generating solar arrays. Liftoff had been targeted for August 28. However, managers are looking at moving up the launch date to Sunday, August 27. The preferred launch time within the day's 10-minute window would 4:30 p.m. EDT (2030 GMT).

Veteran commander Brent Jett will lead the STS-115 crew, and rookie astronaut Chris Ferguson will serve as pilot. The four mission specialists are paired up as the spacewalking teams that will activate the new solar arrays. Joe Tanner and Heidemarie Stefanyshyn-Piper are scheduled to perform the first and third spacewalks; Dan Burbank and Canadian Steve MacLean will do the second EVA.

This will be the third shuttle flight since the Columbia disaster. The two previous missions were flown by Discovery.

Atlantis last launched in October 2002 when it carried the Starboard 1 truss structure to the station.

MONDAY, JULY 17, 2006

Under an overcast sky, the shuttle Discovery glided to a smooth touchdown on runway 15 at the Kennedy Space Center today, closing out a successful space station repair and resupply mission that appears to clear the way for resumption of station assembly in September.

With commander Steve Lindsey at the controls, Discovery settled to a tire-smoking, high-speed touchdown at 9:14:43 a.m. A few moments later, pilot Mark Kelly deployed the shuttle's braking parachute, the ship's nose gear dropped to the runway and Discovery rolled to a stop to close out a voyage spanning 5.3 million miles and 202 complete orbits since blastoff July 4.

Read our landing story.

STS-115 patch
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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