A photo gallery showing shuttle Atlantis' arrival back home Tuesday evening at Kennedy Space Center is posted here.

Workers will spend about 18 hours getting Atlantis unbolted from the 747 and rolked back to its processing hangar, NASA's flow director says. Once back in its garage, the orbiter will begin post-flight deservicing, removal of the Hubble mission payloads and the start of another launch campaign leading toward liftoff in November on the ship's next flight.

The Shuttle Carrier Aircraft made its tire-smoking landing at the Kennedy Space Center, completing the cross-country ferryflight from Edwards Air Force Base, California.

After rolling to a stop on the runway, the 747 will wait for a tow vehicle to bring the jet into the Mate-Demate Device structure for removal of Atlantis from atop the aircraft.

Touchdown! Welcome home, Atlantis!

The 747 just gave the reporters and NASA officials at the runway a treat, making an incredibly low thundering pass right up the runway. The aircraft is climbing out and will making a loop around for landing in a few minutes on Runway 15.

Passed Ron Jons as it headed northward over Cocoa Beach.

The crowds at the beach are getting a stunning view of the low-flying space shuttle and 747 duo.

The shuttle is making its low-altitude pass above the Space Coast beaches on this beautiful Florida evening.

Now making a low buzz over Titusville.

Tally ho on the Shuttle Carrier Aircraft. The 747 and Atlantis have been spotted here at the Kennedy Space Center runway.

Atlantis now south of Daytona.

The pathfinder aircraft has safely landed on Runway 15.

The pathfinder aircraft, which has flown weather reconnaissance ahead of the Shuttle Carrier Aircraft, has been spotted just north of the Kennedy Space Center, setting up for landing.

After the weather aircraft passed over extreme north Florida and Jacksonville, it appears the shuttle will dodge some rain showers and not take the same path. The revised flight course now takes the 747 across the state and hits the coast around Daytona.

The pre-planned course calls for the Shuttle Carrier Aircraft to fly easterly along the Florida/Georgia border, then turn south over the Jacksonville area and fly down the Atlantic Coast.

Atlantis has entered into Florida.

The 747 crossed I-65 in south-central Alabama. The pathfinder is over the Florida panhandle already.

The trek southeasterly across Alabama continues. The planned flight path will clip the southwestern corner of Georgia, then pass near Tallahassee, Florida. The shuttle could be home before 6:30 p.m. EDT.

Space shuttle Atlantis is homeward bound. The carrier aircraft, led by the weather pathfinder plane, just left Columbus Air Force Base in Mississippi for the two-hour flight to Kennedy Space Center.

NASA says the 747 with Atlantis mounted on top could make a low-altitude pass along the beaches south of KSC just prior to touchdown.

Atlantis is heading home to the shuttle's homeport of Kennedy Space Center this evening. Plans call for the Shuttle Carrier Aircraft to depart Columbus Air Force Base in Mississippi around 3:50 p.m. local (4:50 p.m. EDT) and reach KSC around 6:40 p.m. EDT.

The weather briefing is underway to give a "go" or "no go" call on heading into Kennedy Space Center this evening.

Atlantis and the 747 carrier aircraft are parked at Columbus AFB in Mississippi awaiting the decision. So far today, the duo flew a 500-mile leg from El Paso to San Antonio, Texas, then traveled nearly 700 miles to the east-central Mississippi base.

Meanwhile, space shuttle Endeavour's seven astronauts just arrived at the Kennedy Space Center to participate in emergency training exercises and a countdown dress rehearsal for next weekend's launch. See our update here.

Nine days after returning from the Hubble Space Telescope servicing mission with a landing in California, shuttle Atlantis has now traveled east of the Mississippi River on its cross-country piggyback ride atop a modified Boeing 747 carrier jet.

The shuttle-747 duo just arrived at Columbus Air Force Base in east-central Mississippi, the third stop in the hop-scotch trek across the southern U.S. The aircraft will be refueled at the military facility while managers determine if the ferryflight can keep pushing toward home this afternoon or if the weather will prevent the final leg of this trip to Kennedy Space Center from being accomplished today.

NASA does not want the carrier aircraft flying after dark with the shuttle aboard. So Atlantis would have to arrive at the Cape before nightfall or else stay in Mississippi until tomorrow morning.

The descent into Columbus AFB has started.

The Shuttle Carrier Aircraft entered Mississippi just northwest of Vicksburg.

Atlantis has crossed the border into Louisiana. The 747 will slice across the northern half of the state before going over the Mississippi River, banking north of Jackson and then descending into Columbus Air Force Base near the Alabama state line.

Flying 15,000 feet up, the Shuttle Carrier Aircraft has passed over I-45 near the city of Huntsville, and will soon to fly near Lufkin and the communities of east-central Texas.

The Shuttle Carrier Aircraft being used today is known as NASA 911. It was purchased from Japan Airlines in 1989 and came online in November 1990. A second carrier -- NASA 905 -- was purchased from American Airlines in 1974 and modified to carry the shuttle orbiters beginning in the program's early years.

The aircraft have a wingspan of 195 feet, a length of 231 feet, a height to the top of the cockpit area of 32 feet and a maximum gross taxi weight of 713,000 pounds. They are powered by four Pratt & Whitney JT9D-7J gas turbine engines, each producing 50,000 pounds of thrust. Minimum crew for a flight is two pilots and one flight engineer. The minimum crew for a flight with the shuttle aboard is two pilots and two flight engineers.

The shuttle's flight path will go around the southeastern side of San Antonio, then eastbound along the I-10 about halfway to Houston before banking to the left and flying northward, eventually crossing the I-45 around Huntsville, Texas.

The third leg is underway for shuttle Atlantis' cross-country adventure from its landing site at Edwards Air Force Base in California to the spacecraft's homeport at Kennedy Space Center in Florida.

This two-hour stint by the Shuttle Carrier Aircraft will fly from central Texas, across Louisiana and then to east-central Mississippi. The next planned stop is Columbus Air Force Base where the 747's fuel tanks will be refilled and managers can get another check of the weather before deciding whether to press onward for home this afternoon.

The pathfinder aircraft just took off. The 747 will follow suit in a few minutes.

The ferryflight should be resuming shortly.

The latest flight plan times call for takeoff from San Antonio at 11:10 a.m. Central and arrival at Columbus AFB at 1:19 p.m. Central.

The tentative plan going forward today would see Atlantis leave San Antonio at 11 a.m. Central (12 noon EDT) and head for Columbus Air Force Base in Mississippi. Arrival there would be around 1 p.m. Central (2 p.m. EDT).

The next step on Atlantis' voyage back to Kennedy Space Center has reached Lackland Air Force Base in San Antonio after a 500-mile flight from El Paso.

The Shuttle Carrier Aircraft will be refueled while the ferryflight team receives another weather update and decides on the route for the trip's third leg. Managers have different options and locations to pick from today, depending on the weather conditions.

Strict weather rules about clouds, cold temperatures and avoiding flight through rain govern where the Shuttle Carrier Aircraft can go. In addition, NASA ensures that Atlantis won't be subjected to any bad weather while on the ground during a stopover. All of the guidelines are meant to protect the spacecraft and its delicate heat shield tiles.

The D-9 pathfinder landed. Standing by for the arrival of Atlantis.

The 747 with Atlantis has begun its descent for touchdown a short time from now.

Atlantis is a little past halfway to San Antonio now.

The 747-shuttle duo now flying over rural west Texas at a cruising altitude of 15,000 feet, continuing en route to San Antonio.

The Boeing 747 carrier aircraft with space shuttle Atlantis bolted on top has departed Biggs Army Airfield in El Paso for a 90-minute flight across the Lone Star State to Lackland Air Force Base in San Antonio.

Once at the refueling stop, ferryflight managers will assess how the weather picture is developing this morning and decide on the future course. NASA hopes to continue the trip today, eventually reaching Kennedy Space Center by 6 p.m. EDT.

The pathfinder aircraft, which flies ahead of the shuttle with the ferryflight team and performs weather reconnaissance, has taken off from El Paso.

The next leg of the ferryflight will begin at 6:40 a.m. Mountain (8:40 a.m. EDT) as the Shuttle Carrier Aircraft departs El Paso and travels to Lackland Air Force Base outside San Antonio, Texas. Arrival of the 747 is expected around 9:10 a.m. Central (10:10 a.m. EDT).

The earliest Atlantis would leave El Paso this morning has slipped an hour from the tentative time advertised yesterday. NASA says takeoff now could happen at 6:40 a.m. local (8:40 a.m. EDT). Weather and routes continue to be debated.

The earliest that the shuttle could reach Kennedy Space Center today would be about 6 p.m. EDT, managers say.

Managers are assessing the forecast weather conditions across Texas and the southeastern U.S. to plot possible flight path options for resumption of Atlantis' journey home later today. As of this moment, managers have not yet made any firm decisions about the game plan. Watch this page for continuing updates.

The ferryflight team, which saw the Shuttle Carrier Aircraft land in El Paso at 11:22 a.m. local time (1:22 p.m. EDT) Monday, is staying the night there.

A weather briefing is planned for 3:30 a.m. local (5:30 a.m. EDT) Tuesday to determine the route ahead for the cross-country trip. A tentative takeoff time from Biggs Army Airfield is approximately 5:40 a.m. local (7:40 a.m. EDT).

Whether Atlantis can make it all the way back to Kennedy Space Center on Tuesday will be decided by the weather conditions.

After a 700-mile trek across the southwestern United States, the Shuttle Carrier Aircraft and Atlantis have arrived in El Paso at the Biggs Army Airfield on the western border of Texas. This completes the one-and-only leg of the cross-country ferryflight planned to be accomplished today due to weather concerns blocking the pathway further east. The trip will continue tomorrow.

Atlantis' course has passed over the city of Deming, en route toward Las Cruces and a flyover of the White Sands complex. Landing in El Paso is coming up later this hour.

Spectacular photos of this morning's takeoff from Edwards Air Force Base are posted here.

The shuttle-747 duo now traveling over New Mexico.

Atlantis just soared over the Phoenix area, then passing by Tempe and Gilbert. The 747 is on a southeasterly trajectory now.

The flight path will take the shuttle near Phoenix a short time from now.

NASA says the Shuttle Carrier Aircraft will perform a flyover of the White Sands Test Facility in New Mexico before traveling down to El, Paso, Texas.

Atlantis has crossed the border into Arizona.

After getting airborne toward the southwest from Runway 22, the carrier aircraft banked to the right for a U-turn to head eastward over Bartstow and then onward as it climbed to the cruising altitude of 15,000 feet.

The first leg of Atlantis' ferryflight will last about two hours as the shuttle is carried over Southern California, Arizona, New Mexico and into the western edge of Texas for a stop in El Paso.

WHEELS UP! The Shuttle Carrier Aircraft departed from Edwards Air Force Base in California at 8:06 a.m. local time (11:06 a.m. EDT), starting the cross-country trek back to Atlants' homeport in Florida.

The 747 and Atlantis are bound for the Biggs Army Airfield at Fort Bliss in El Paso, Texas, where NASA says an overnight stay is planned. The ferryflight should resume on Tuesday, weather permitting.

The shuttle spent nearly 8 days in the Mojave Desert following its landing there to conclude the Hubble Space Telescope servicing mission. Bad weather in Florida prevented Atlantis from landing at Kennedy Space Center and forced Mission Control to divert the shuttle to the backup site at Edwards Air Force Base.

Technicians spent several days safing onboard systems and readying the shuttle for its ferryflight trip. After an aerodynamic tailcone was installed, the 100-ton spaceplane was lifted on top of the aircraft and bolted in place.

Once back home, Atlantis will be prepared for a scheduled November launch on another construction flight to the space station.

The 747 has been cleared onto Runway 22 for takeoff.

The modified 747 carrying the space shuttle is taxiing into position for takeoff from Edwards Air Force Base in California to begin the eastward coast-to-coast journey that will return Atlantis home to the Kennedy Space Center in Florida over the next few days.

The weather pathfinder C-9 aircraft and an F-18 jet for aerial photography are airborne.

The news media and photographers are in position at the runway to cover this morning's takeoff.

NASA officials say the ferryflight will likely go no further than El Paso today, given the weather outlook further east. An overnight stay at the secure Biggs Army Airfield is planned.

The 747 plans to depart from Runway 22, getting airborne toward the southwest before looping around and heading east.

A gallery of photos taken a short time ago shows shuttle Atlantis perched atop the 747 and ready to begin the ferryflight. The pictures are posted here.

The first leg of the ferryflight will begin around 8 a.m. local time (11 a.m. EDT) and head for Biggs Army Airfield in El Paso, Texas.

Takeoff of the carrier aircraft has been retargeted for approximately 8 a.m. local time (11 a.m. EDT) today. NASA says the departure is running behind schedule because technicians encountered some difficulties while trying to tighten a bolt on the right attach point for connecting Atlantis to its modified Boeing 747 aircraft. The bolt now is securely in place, officials say, and another weather briefing will be given to ferryflight managers at 6 a.m. local (9 a.m. EDT).

Attachment of shuttle Atlantis atop the modified 747 carrier jet is underway at today at the gantry-like Mate-Demate Device structure. The orbiter has been hoisted up and the aircraft towed underneath Atlantis in preparation for the duo to be bolted together.

The preliminary plans call for the ferryflight to depart Edwards on Monday at 5:20 a.m. local time (8:20 a.m. EDT) to begin the first leg of the cross-country trip, NASA said this morning. At least one overnight stop is expected in addition to refueling points along the way. Arrival back in Florida isn't likely before sometime Tuesday or Wednesday, weather permitting.

As expected, NASA has formally delayed the ferryflight departure from California until Monday morning at the earliest. Workers have battled weather-related delays getting Atlantis ready for the trip and now officials have to find a safe path for the carrier aircraft to take. Managers will receive another weather update on Sunday at 11 a.m. local (2 p.m. EDT) to assess the forecast and flight path options.

The ferryflight readiness review is planned for 1 p.m. local (4 p.m. EDT) today to determine when Atlantis will leave California and begin heading eastward.

For now, NASA says crews hope to have the shuttle and carrier aircraft ready for departure by Sunday afternoon. Whether the takeoff would occur late Sunday or not until sunrise Monday remains to be seen. We'll post official information on this page as it is confirmed.

The tail cone that covers the shuttle's main engines during the flight home has been installed by the ground crews. Mounting of Atlantis atop the 747 could occur later today.

Space shuttle Atlantis' cross-country piggyback ride atop a modified Boeing 747 jet from Edwards Air Force Base in California to the spacecraft's homeport at the Kennedy Space Center in Florida could begin sometime Sunday.

Ground crews completed the hazardous offloading of fluids from the shuttle Thursday and were working with the hydraulics Friday to set the aerosurfaces and retract the landing gear. Other key work remaining to be completed included installation of the aerodynamic tail cone onto Atlantis and the subsequent hoisting of the shuttle atop the carrier aircraft.

Managers plan a Flight Readiness Review around mid-day Saturday to plan the ferry timeline and initial path.

Arrival back at the Kennedy Space Center isn't expected before Monday or Tuesday.

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A comprehensive directory of more than 250 videos from the STS-125 mission to service the Hubble Space Telescope is posted for Spaceflight Now+Plus users to watch or download. See the full listing here.

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A comprehensive directory of more than 250 videos from the STS-125 mission to service the Hubble Space Telescope is posted for Spaceflight Now+Plus users to watch or download. See the full listing here.

You can become a subscriber today!

Some quotes released following landing today:

"This mission highlights what the challenges of spaceflight can bring out in human beings," said Bill Gerstenmaier, associate administrator for Space Operations at NASA Headquarters in Washington. "This mission required the absolute best from the shuttle team, the Hubble science and repair teams, and the crew. The results are a tribute to the entire team and the years of preparation."

"This is not the end of the story but the beginning of another chapter of discovery by Hubble," said Ed Weiler, associate administrator for Science at NASA Headquarters. "Hubble will be more powerful than ever, continue to surprise, enlighten, and inspire us all, and pave the way for the next generation of observatories."

"Extending Hubble's mission and increasing its capabilities gives scientists, both in Europe and worldwide, new tools to learn even more about our Universe and our origins," said David Southwood, European Space Agency's director of Science and Robotic Exploration.

Our gallery of landing photos is posted here.

Delayed two days by stormy Florida weather, the shuttle Atlantis glided to a California landing today, closing out a successful mission to overhaul the Hubble Space Telescope with a picture-perfect Mojave Desert touchdown.

Read our full story.

The astronauts will fly back to Johnson Space Center later today or tomorrow.

A welcoming ceremony in Houston at Ellington Field's Hangar 990 is scheduled for 4 p.m. local time on Tuesday. The public is invited to attend.

All seven astronauts -- commander Scott Altman, pilot Greg Johnson, robot arm operator Megan McArthur and spacewalkers John Grunsfeld, Drew Feustel, Mike Massimino and Mike Good -- have exited the Crew Transport Vehicle to chat with the officials waiting on the runway and take the traditional walkaround inspection of their spaceship.

The transport vehicle has backed away from Atlantis. Standing by for some of the astronauts to emerge.

The Crew Transport Vehicle -- a modified airport "People Mover" -- is pulled up to the side hatch for the astronauts to enter. The CTV features beds and comfortable seats for the astronauts to receive medical checks after returning to Earth's gravity from the weightless environment of space.

Atlantis' side hatch was opened at 12:18 p.m. EDT and all seven crew members have egressed the vehicle now. Commander Scott Altman was the final astronaut to climb out of the shuttle at 12:37 p.m. EDT.

Shuttle launch director Mike Leinbach, speaking at the post-landing news conference, says Endeavour will make its transfer from pad 39B over to pad 39A next Friday night. The payload for the shuttle's construction flight to the space station has been delivered to the pad. That launch is targeted for June 13.

Atlantis' ferryflight back to Kennedy Space Center from Edwards Air Force Base atop a 747 carrier jet will occur in about a week. Arrival back here at the Cape is expected in 8 or 9 days, Leinbach says.

Auxiliary Power Units have been deactivated. The three APUs provided the pressure needed to power shuttle's hydraulic systems that moved the wing flaps and rudder/speed brake, dropped the landing gear and turned the nose wheel during today's entry and landing.

Here are the landing times in Eastern Daylight Time and Mission Elapsed Time:

Main Gear Touchdown
11:39:05 a.m. EDT
MET: 12 days, 21 hours, 37 minutes, 9 seconds

Nose Gear Touchdown
11:39:15 a.m. EDT
MET: 12 days, 21 hours, 37 minutes, 19 seconds

Wheels Stop
11:40:15 a.m. EDT
MET: 12 days, 21 hours, 38 minutes, 19 seconds

The astronauts were just given permission to remove their entry spacesuits.

The main engine nozzles have been moved. That's the last task for the hydraulics following touchdown, so Atlantis' three Auxiliary Power Units can be shut down now.

On the runway, technicians are using instruments to "sniff" the shuttle's exterior to check for any hazardous vapors.

The main engine nozzles are being repositioned, or gimbaled, to the "rain drain" orientation.

And the body flap is being set by pilot Greg Johnson.

The pyrotechnics for the crew module hatch, landing gear and drag chute have been safed by the crew.

"Houston, Atlantis. Wheels stopped, Edwards, 22," commander Scott Altman radioed as he brought Atlantis to a halt.

"Welcome home, Atlantis. Congratulations on a very successful mission giving Hubble a new set of eyes that will continue to expand our knowledge of the universe," the CAPCOM replied from Mission Control.

"Thank you, Houston. It was a thrill from start to finish. We've had a great ride. It took a whole team across the country to pull it off. My hat's off to you all. Thank you so much."

The external tank umbilical doors on the shuttle's belly are being opened.

The crew is beginning the post-landing procedures on Atlantis.

"It was a thrill from start to finish. We've had a great ride," commander Altman just radioed Houston.

WHEELS STOP. The final servicing mission to the Hubble Space Telescope is over. The dramatic five-spacewalk flight prepared the iconic observatory for a new revolution of discovery, installing two new science instruments, brought two broken instruments back from the dead, replaced the spacecraft's 19-year-old battery packs, refurbished the pointing and control system with an upgraded guidance sensor and six fresh gyroscopes, changed out the partially failed science instrument command and data handling unit, mounted a capture mechanism on the craft for future use and added thermal shielding on equipment bay doors. All in all, every single task planned for the Atlantis mission was successfully achieved.

Atlantis is rolling out at Edwards Air Force Base after a highly successful mission spanning 197 orbits and over five million miles that gave breathed new life into the Hubble Space Telescope.

TOUCHDOWN! Main gear touchdown. Pilot Greg Johnson is unfurling the drag chute as commander Scott Altman brings the nose gear to the surface of Runway 22.

Pilot Greg Johnson is deploying the landing gear. Standing by for touchdown.

Now 4,000 feet.

Wings are level on final approach now. The shuttle descending at a rate seven times steeper than that of a commercial airliner.

"Field in sight at 10,000 feet," commander Altman just radioed.

Atlantis is traveling 12,000 feet in altitude

The commander back in control. Less than two minutes to touchdown as Atlantis continues in the sweeping turn.

Pilot Greg Johnson getting a moment of stick time flying Atlantis.

Atlantis is 34,000 feet up, traveling at 560 mph.

The twin sonic booms have rumbled across the Edwards Air Force Base area, announcing the shuttle's arrival.

The shuttle is in the Heading Alignment Cylinder, an imaginary circle to align with Runway 22. Commander Scott Altman is piloting Atlantis through a 200-degree left-overhead turn over the Mojave Desert to loop around for landing on the northeast to southwest runway.

Altitude 50,000 feet.

The crew has been given a "go" for normal deployment of the drag chute after main gear touchdown.

Now projecting a touchdown 2,900 feet down the runway.

Atlantis remains on course with good energy.

Altitude now 81,000 feet, traveling at 1,700 mph.

Seven minutes to touchdown. Air data probes are being deployed from the shuttle's nose to feed air speed, altitude and angle of attack information to the computers for navigation.

Altitude now 107,000 feet, 140 miles from the runway, traveling at 3,000 mph.

Tally ho on Atlantis. Powerful tracking cameras at the landing site have spotted the descending shuttle as it makes the California landfall near Ventura.

Altitude now 135,000 feet, 220 miles from the runway, traveling at 4,100 mph.

Ten minutes from landing. Space shuttle Atlantis nearing the western coast of the United States. The spacecraft will fly just south of Point Conception and Vandenberg Air Force Base, traverse the Santa Barbara Channel and make landfall near Ventura.

Taking aim at the Edwards Air Force Base complex, the shuttle will pass just south of the runway and then perform the incredibly wide and sweeping 200-degree left-overhead U-turn to align with Runway 22.

Now 11 minutes from touchdown. Mission Control computes Atlantis will land 2,600 feet down the runway at 205 knots.

The shuttle is 320 miles from the runway.

Now 12 minutes from landing.

Atlantis is 32 statute miles up, traveling at 8,200 mph.

The shuttle is 35 statute miles up, traveling at Mach 15 over the Pacific.

The shuttle is about to perform the first roll-reversal.

Atlantis is 202,000 feet in altitude, 1,080 miles away from Edwards Air Force Base.

The shuttle remains on course.

Twenty minutes to go.

Atlantis is 234,000 feet up, some 2,200 miles from Edwards Air Force Base.

Communications with Atlantis have been established again. Commander Scott Altman says the shuttle is nearing sunrise over the Pacific. "Looks good."

Atlantis' trajectory is taking the shuttle just north of the Hawaiian Islands.

As predict, communications between Atlantis and the ground has been temporarily lost during this first turn. Contact should be restored in about five minutes.

Atlantis is beginning the first of four banks to scrub off speed as it plunges into the atmosphere. These turns basically remove the energy Atlantis built up during launch.

The shuttle is streaking 350,000 feet over the Pacific at a speed of 16,800 mph now.

ENTRY INTERFACE. Atlantis' thermal protection system is feeling heat beginning to build as the orbiter enters the top fringes of the atmosphere -- a period known as entry interface.

The shuttle is flying at Mach 25 with its nose elevated 40 degrees, wings level, at an altitude of 399,000 feet over the southern Pacific Ocean.

Touchdown remains set for 11:39 a.m. EDT in the Mojave Desert.

Mission Control expects to lose communications with Atlantis about eight minutes from now due to the build up of plasma around the shuttle and the specific antennas being used. Communications should be regained as the vehicle nears the West Coast.

Now 35 minutes to touchdown. The shuttle will using the concrete landing strip at Edwards known as Runway 22 that stretches from the northeast to the southwest. The runway is 15,000 feet long and 300 feet wide.

Atlantis' path approaches the base from the west, requiring commander Scott Altman to fly a 200-degree U-turn to align with the runway.

Atlantis just crossed the equator heading northeastward across the western Pacific.

Now 40 minutes to touchdown. Atlantis has maneuvered from its heads-down, tail-forward position needed for the deorbit burn to the re-entry configuration of heads-up and nose-forward. The nose will be pitched upward 40 degrees. In this new position, the black tiles on the shuttle's belly and the reinforced carbon-carbon panels on the wing leading edges and nose cap will shield the spacecraft during the fiery plunge through the Earth's atmosphere with temperatures reaching well over 2,000 degrees F. Atlantis will begin interacting with the upper fringes of the atmosphere above the Pacific at 11:08 a.m. EDT.

Pilot Greg Johnson has all three Auxiliary Power Units up and running.

Atlantis is passing to the northwest of Australia now.

The propellant dump is complete.

Touchdown is 50 minutes away. This will be the 53rd shuttle landing at Edwards Air Force Base, the 47th to occur in daylight and the first since last November when Endeavour touched down there to conclude STS-126.

Now over the central part of the Indian Ocean.

Sixty minutes to touchdown. The planned path of Atlantis to Edwards on this Orbit 197 landing opportunity is illustrated here.

Excess propellant reserves in the maneuvering thrusters on the shuttle's nose will be dumped overboard. The dump time will be 16 seconds using four jets.

Onboard guidance commands are maneuvering Atlantis to the orientation for entry.

The shuttle has passed over the southern part of Africa, now about to cross the Indian Ocean.

"Atlantis, good burn. No trim required," CAPCOM told the crew.

"Houston, we concur. Atlantis is a fantastic ship," commander Scott Altman replied.

DEORBIT BURN COMPLETE. Atlantis has successfully completed the deorbit burn for the journey back from space. Landing is scheduled for 11:39 a.m. EDT (8:39 a.m. local) at Edwards Air Force Base in California to complete this mission that renewed the Hubble Space Telescope.

A "slightly high" drain line temperature reported on APU 2. Mission Control just told the crew that no action is required.

Both engines continue to fire, each producing about 6,000 pounds of thrust.

DEORBIT BURN IGNITION. Flying upside down and backwards above the South Atlantic Ocean just off the coast of Africa, Atlantis has begun the deorbit burn. The firing of the twin Orbital Maneuvering System engines on the tail of the shuttle will last two minutes and 36 seconds, slowing the craft by about 307 mph to slip from orbit. The retro-burn will send Atlantis to Edwards Air Force Base in California for a touchdown at 11:39 a.m. EDT.

Atlantis is in the proper orientation and systems are configured for the deorbit burn.

Pilot Greg Johnson is activating one of three Auxiliary Power Units in advance of the burn, now four minutes away. The other two APUs will be started later in the descent to provide pressure needed to power shuttle's hydraulic systems that move the wing flaps and rudder/speed brake, drop the landing gear and steer the nose wheel. NASA ensures that at least one APU is working before committing to the deorbit burn since the shuttle needs only a single unit to make a safe landing.

Atlantis is maneuvering to the deorbit burn attitude.

A "beautiful day in the desert" awaits space shuttle Atlantis.

GO FOR THE DEORBIT BURN! Entry flight director Norm Knight in Mission Control just gave formal approval for Atlantis to perform the deorbit burn that will commit the shuttle for the trip back to Earth.

Touchdown at Edwards Air Force Base in California is set for 11:39 a.m. EDT, based on the latest projections from Mission Control.

For the upcoming Edwards Air Force Base opportunity on Orbit 197, if selected, the deorbit burn ignition time will be 10:24:41 a.m. EDT. The twin braking rockets will fire for two minutes and 36 seconds, slowing the shuttle by about 307 mph.

The deorbit burn will drop Atlantis out of its 303 x 160 nautical mile orbit and put the shuttle into a trajectory for entry over the Pacific Ocean and bound for landing at the Mojave Desert military base. Once near Edwards, the shuttle will make a 200-degree left-overhead turn to align with Runway 22 for touchdown at 11:39 a.m. EDT.

CALIFORNIA BOUND. Space shuttle Atlantis will not touch down at Kennedy Space Center to conclude its mission. Persistent unfavorable weather conditions at the Florida spaceport has forced NASA to divert Atlantis' landing to the backup site at Edwards Air Force Base, California.

The deorbit burn is scheduled for 10:24:41 a.m., leading to touchdown at 11:39 a.m. EDT (8:39 a.m. local; 1539 GMT) to finish the final servicing mission to the Hubble Space Telescope.

Ideal weather conditions await the shuttle in California's Mojave Desert today. At landing time, meteorologists are expecting clear skies, good visibility and southwesterly winds of 11 peaking to 17 knots down the runway.

Another weather briefing is being given to Mission Control as decision time nears.

With Atlantis going to land somewhere on the next orbit, pilot Greg Johnson has put the Auxiliary Power Units cockpit switches in the ready-to-start configuration.

Now sixty minutes from the first Edwards deorbit opportunity. Houston just told Atlantis that plans will focus on California for now, since it comes first. A decision whether to divert to the West Coast or land in Florida will be made around 10:10 a.m. EDT.

Maps showing Atlantis' path to either Edwards Air Force Base or Kennedy Space Center on the Orbit 197 landing opportunities can be seen here.

The next available deorbit burn would ignite at 10:24:41 a.m. EDT to land in California at the backup site of Edwards AFB at 11:39 a.m. EDT.

Performing the deorbit maneuver a few minutes later at 10:40:56 a.m. EDT would set up Atlantis for landing at the Kennedy Space Center in Florida at 11:48 a.m. EDT.

Mission Control has not made any decisions about the upcoming landing options. Florida has not been ruled out, with meteorologists watching to see if the rain and clouds will remain far enough off the coast and not violate any of the weather rules. But diverting to California will be the next course of action if the Florida weather doesn't become acceptable in the next hour.

As the sun rises at Edwards Air Force Base in California, astronaut Chris Ferguson is taking off in the Shuttle Training Aircraft to evaluate weather conditions out there. Skies are clear and it appears to be a beautiful morning in the Mojave Desert.

WAVEOFF. The day's first shot at landing has been cancelled due to the weather conditions at the Kennedy Space Center. "Weather is good, but not good enough," say Mission Control, adding that the situation is just too unstable right now to predict the conditions at the 10:09 a.m. EDT landing time. The official forecast still calls for thunderstorms around the runway.

So Atlantis and crew will add another orbit to their mission and look for the next set of deorbit opportunities that would bring the shuttle into a landing at either Edwards Air Force Base in California at 11:38 a.m. EDT or Kennedy at 11:48 a.m. EDT.

Now 30 minutes until the deorbit burn would have to ignite for Atlantis' first landing opportunity of the day.

The crew has been told to hold off on Auxiliary Power Unit pre-start procedure. Weather evaluations continue.

"The weather at the Cape is marginal, as you might expect. We're still watching it. We are going to continue marching down the timeline. We need a little bit more time to analyze it, but at this point we will continue doing all of the steps nominally toward a potential deorbit burn," the CAPCOM in Mission Control just radioed the astronauts.

"Sounds great Houston, keep our options open," commander Scott Altman replied.

Two hours from touchdown. It's clear overhead the Kennedy Space Center runway, but meteorologists continue to watch the weather off shore and whether additional rain pops up closer to the landing strip due to morning heating of the atmosphere. There's at least a fighting chance today that Atlantis coud be given approval to land in Florida unlikely the solidly "no go" weather Friday and Saturday.

The crew has been given a "go" to start the "fluid loading" protocol. That involves drinking large amounts of liquids and salt tablets to assist in the readaptation to Earth's gravity. Water, chicken consomme, orange and lemon-lime drinks are on the menu for the astronauts to pick from.

"Atlantis, we are continuing to look at the weather. The weather patterns are better today than the past two days. We are not foregoing this opportunity here at KSC, so we would like you to start fluid loading. However, you can delay it a little or take it easy at first as we continue to analyze the weather," CAPCOM just radioed the crew.

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The crew is performing an alignment of the inertial measurement units.

So far, all of the rainshowers are staying over the Atlantic to the east and south of Kennedy Space Center. But whether more rain develop closer to the runway is the question.

Now 90 minutes from the scheduled deorbit burn to begin Atlantis' glide back to Earth.

Chief astronaut Steve Lindsey is airborne at the Kennedy Space Center in the Shuttle Training Aircraft to fly weather reconnaissance around the Florida spaceport today. Earlier this morning, he was flying in a T-38 jet to examine how the weather situation was developing.

The Shuttle Training Aircraft is a modified Gulfstream jet that offers a close simulation to the flying characteristics of a space shuttle during landing.

Commander Scott Altman and pilot Greg Johnson are getting suited up. They'll be strapping into their flight deck seats while the five mission specials don their suits.

The latest data from Mission Control shows the upcoming deorbit burn ignition time will be 8:57:06 a.m. EDT. The twin braking rockets will fire for two minutes and 29 seconds, slowing the shuttle by about 172 mph.

The deorbit burn will drop Atlantis out of its 303 x 160 nautical mile orbit and put the shuttle into a 303 x 26 nautical mile trajectory for entry over the Pacific Ocean and bound for landing at Kennedy Space Center. Once at the spaceport, the shuttle will make a 230-degree right-overhead turn to align with Runway 33 for touchdown at 10:09 a.m. EDT.

Of course the weather will decide if Atlantis can proceed with this deorbit burn plan. Once that burn is performed, there's no turning back. So the weather must be judged to be within limits for a safe landing about 90 minutes before the actual touchdown.

"The weather at the Cape is a little better than yesterday, and we would like you to suit up per the plan," Mission Control just told the shuttle crew.

There are showers off to the east and south. But there's at least a small bit of optimism that the Florida weather could possibly cooperate later this morning for landing.

Atlantis will soon maneuver into a new orientation in space to improve the communications link with NASA's orbiting data relay satellite network.

And Mission Control has given the crew a "go" to transition the onboard computers from the OPS-2 software used during the shuttle's stay in space to OPS-3, which is the software package that governs entry and landing.

Space shuttle Atlantis' payload bay doors have been closed and locked in preparation for today's descent into Earth's atmosphere and landing at either Kennedy Space Center in Florida, if the weather allows, or the alternate site of Edwards Air Force Base in California.

The left-hand door has been closed.

The official "go" has been radioed to the crew for payload bay door closing.

The crew completed the work to bypass the shuttle's radiators on the insides of the payload bay doors and checked out of the ship's flash evaporator cooling system for entry.

Mission Control tells the crew that the astronauts should proceed with an on-time closing of the payload bay doors a short time from now.

Delayed two days by stormy weather in Florida, the Atlantis astronauts rigged the shuttle for re-entry again today, prepared to head for California if necessary to finally close out their Hubble Space Telescope repair mission.

A landing in California would cost NASA's about $1.8 million and a week to 10 days of lost processing time. But another concern is getting access to an avionics box in the orbiter's engine compartment that failed right at liftoff May 11.

The aerosurface actuator control box is one of four redundant units used to format computer commands to the hydraulic actuators that move the shuttle's elevons and rudder/speedbrake. The failure in ASA-1 caused no problems for Atlantis, but NASA managers need to make sure it's not the result of some generic problem that could affect the shuttle Endeavour, scheduled for launch June 13.

If Atlantis is diverted to California, access to the failed unit will be delayed and engineers will not have as much time for troubleshooting. Endeavour's flight readiness review is planned for June 3.

Read our full story.

The forecast for the first Kennedy Space Center landing opportunity at 10:09 a.m. EDT calls for scattered clouds at 2,000 feet, a broken deck forming a ceiling at 3,500 feet and overcast skies at 12,000 feet, 7 miles of visibility, southeasterly winds from 150 degrees at 5 peaking to 8 knots and thunderstorms with rain within 30 miles of the runway.

The outlook for the following orbit and the 11:48 a.m. EDT touchdown time has scattered clouds at 2,500 feet, a ceiling at 4,500 feet and overcast skies at 12,000 feet, 7 miles of visibility, southeasterly winds from 150 degrees at 7 peaking to 10 knots and thunderstorms with rain within 30 miles.

Edwards Air Force Base in California has clear skies, 7 miles of visibility and southwesterly winds from 220 degrees at 11 peaking to 17 knots down the runway for the 11:38 a.m. EDT touchdown there.

The astronauts are beginning their deorbit preparation timeline for today's landing on one coast or the other of the United States. The official weather forecast for Florida's Kennedy Space Center remains "no go" due to predicted low cloud ceilings and rain, while California's Edwards Air Force Base has clear skies and acceptable weather.

Flight Day 14 and surely the day that shuttle Atlantis will return to Earth began for the seven astronauts with a wakeup call just received from Mission Control.

The crew has a couple of hours to eat breakfast and go about their morning routine before beginning the deorbit preparation timeline at 4:56 a.m. EDT.

The ship's 60-foot-long payload bay doors are scheduled to be closed at 6:16 a.m., followed by the transition of onboard computers to the software for entry and the crew donning its spacesuits.

A final decision whether to land on the day's first opportunity will come from Houston around 8:30 a.m., leading to ignition of Atlantis' braking rockets at 8:57 a.m. to start the trek home. The shuttle would hit the upper atmosphere at 9:38 a.m.

Landing on Runway 15 at the Kennedy Space Center is scheduled for 10:09 a.m. EDT.

If the weather remains unfavorable for that opportunity, there's one more shot into Kennedy Space Center an orbit later that begins with a deorbit burn at 10:41 a.m. and landing at 11:48 a.m. EDT.

Should the Florida be uncooperative for the third day in a row, then entry flight director Norm Knight would have no choice but order a detour and send Atlantis to the alternate landing site at Edwards Air Force Base in the Mojave Desert of California.

There's two back-to-back orbits that NASA is considering for Edwards today. The first starts with the deorbit burn at 10:24 a.m. and lands on Runway 22 at 11:38 a.m. EDT (8:38 a.m. local). The subsequent opportunity has a deorbit burn at 12:07 p.m. EDT and touchdown at 1:17 p.m. EDT.

Although the Florida weather is dynamic, the conditions in California are stable and well within limits for a safe shuttle landing.

The spacecraft has enough consumables and supplies to remain aloft through tomorrow, but NASA typically likes to keep one day in reserve in case of a hardware problem aboard the shuttle that prevents a re-entry. So that means Atlantis will land either in Florida or California today, assuming all systems remain "go" for landing.

Maps showing the path that Atlantis would take into the Kennedy Space Center and Edwards Air Force Base for any of the four landing opportunities can be seen here.

Watch this page for continuing updates throughout the day as the astronauts prepare for the return to Earth.

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