The Space Shot

A Russian Soyuz spacecraft carrying three fresh crew members bound for the International Space Station blasted off from the Baikonur Cosmodrome in Kazakhstan early Monday local time, lighting up a cold, pre-dawn sky with a torrent of flame visible for miles around.

With Soyuz commander Oleg Kotov, a station veteran, Japanese astronaut Soichi Noguchi, a shuttle veteran, and rookie astronaut Timothy Creamer strapped into the Soyuz TMA-17 capsule, the rocket roared to life at 4:52 p.m. EST Sunday (3:52 a.m. Monday local time) and quickly climbed away from the same pad used by Yuri Gagarin at the dawn of the space age.

The Soyuz TMA-17 spacecraft blasts off from the Baikonur Cosmodrome in Kazakhstan.

(Credit: NASA)

Liftoff was timed for roughly the moment Earth's rotation carried the launch pad into the plane of the space station's orbit. Kotov, seated in the spacecraft's center seat, was flanked by Creamer to his right and Noguchi on his left.

The climb to space appeared normal and live television views from inside the TMA-17's central module showed all three crew members relaxed and at ease as they monitored their cockpit instrument displays. Noguchi flashed a thumbs up and Creamer waved.

A little less than nine minutes after liftoff, the spacecraft slipped into its planned preliminary orbit and Kotov reported "everyone feels great, no problems." Later this evening, Kotov planned to oversee two rendezvous rocket firings to fine-tune the craft's approach to the lab complex.

A third rocket firing is planned for Monday and if all goes well, the TMA-17 spacecraft will execute an automated approach to the Earth-facing port of the station's Zarya module Tuesday for a docking around 5:54 p.m.

Waiting to welcome the new crew members on board will be Expedition 22 commander Jeffrey Williams and Maxim Suraev, launched to the outpost Sept. 30. Suraev and Williams, who has a previous station flight to his credit, have had the lab to themselves since December 1, when cosmonaut Roman Romanenko, European Space Agency astronaut Frank De Winne and Canadian Robert Thirsk returned to Earth after a six-month stay in space.

"One of the things we've learned over the last couple of years is it's really beneficial to have (experienced) crew members (on board) when a new crew arrives," said Kirk Shireman, deputy manager of the space station program at the Johnson Space Center in Houston.

"So while it'll be a new experience for these guys, the fact that Max and Jeff have already been up there, they'll know where everything is, they'll know how things work and that'll allow these three guys to quickly adapt and be able to hit the ground running."

According to an Associated Press report, Creamer told reporters he would miss his family over the Christmas holidays, but "we are going as a family together to a family in space." He has been using Twitter to keep friends, family and the public up to date and plans to continue posting from space.

"I thought if I can give you the status of what I am doing, what we are hoping for, what we are looking forward to seeing, those would be good little teasers," he said.

The Soyuz TMA-17 crew, bound for the International Space Station. Left to right: Soyuz commander Oleg Kotov, Timothy Creamer, Soichi Noguchi.

(Credit: NASA)

After a break for Christmas and the New Year holidays, the crew will face a busy month in January.

Using the station's robot arm, a NASA pressurized mating adapter currently attached to the left side of the central Unity module will be relocated Jan. 5 to clear the way for attachment of a new U.S. module in February.

Suraev and Kotov plan a spacewalk January 14 to finish outfitting a new Russian docking port known as Poisk, or MRM-2, that was recently attached to the Zvezda command module's upward-facing hatch. Once that work is done, the Soyuz TMA-16 spacecraft now docked to Zvezda's aft port--the capsule that carried Williams and Suraev to the station--will be moved to Poisk on January 20.

The shuttle Endeavour is scheduled for launch from the Kennedy Space Center on Fabruary 7 to deliver Tranquility, or Node 3, a roomy module that will be attached to Unity's left-side port. Once installed and checked out, a toilet now installed in the Destiny lab module will be moved into Tranquility, along with exercise equipment and other life support gear that has been temporarily housed elsewhere.

"This increment really sets the stage for the last year of the shuttle program," Shireman said. "It's a big growth year...the last major growth spurt for the International Space Station...We're looking forward to a really, really exciting year."

As it currently stands, four Soyuz flights to the station are planned in 2010, NASA's final five shuttle missions and up to six unmanned Progress supply ships. Along with Tranquility, a new Russian module will be delivered by the shuttle, along with a cargo transfer module that will be left aboard the station after the final shuttle visit.

"This is the beginning of another phase where we learn to operate with a larger crew size, more demands on the hardware, more demands on the space station," said Bill Gerstenmaier, NASA's associated administrator of space operations. "So for the systems to work right requires a lot of extra preparation and this is the beginning of that preparation."

Said chief astronaut Peggy Whitson: "It's obviously very complicated. I think we have done in the past several years a fantastic job of making very difficult things look easy. We always have problems, but we always seem to be able to overcome them and I think that's kind of NASA's theme for survival.

"We expect that adding on a new module, two new modules this year ... it's going to be pretty exciting, expanding the station even further. I know when I was up there when we increased the station volume with three new modules it was just really exciting, opening up this huge new space to live in and explore."

UPDATED at 5:30 p.m. EST with Soyuz launch.

The Soyuz TMA-15 spacecraft undocks from the International Space Station.

(Credit: NASA TV)

Outgoing space station commander Frank De Winne, cosmonaut Roman Romanenko, and Canadian astronaut Robert Thirsk strapped into a Russian Soyuz capsule, undocked and fell back to Earth on Tuesday, braving icy weather in Kazakhstan to close out a 188-day stay in space.

Descending under a large orange-and-white parachute, Soyuz TMA-15 spacecraft made a rocket-assisted touchdown about 50 miles northeast of Arkalyk, Kazakhstan, at 2:15:34 a.m. EST, about three hours and 20 minutes after undocking from the International Space Station.

Recovery forces, including U.S. and Russian flight surgeons, were near the landing site to help the returning spacemen out of the spacecraft's cramped descent module. Despite icy weather that forced authorities to ground the helicopters normally used, recovery crews in all-terrain vehicles reached the spacecraft within about 15 minutes of touchdown.

It was the first December landing of a Soyuz since 1990, but the Russians said the weather was acceptable for a safe descent.

Russian recovery teams surround the Soyuz TMA-15 spacecraft, helping extract the crew members.

(Credit: NASA TV)

Monitoring the re-entry and landing from the International Space Station were Expedition 22 commander Jeffrey Williams and flight engineer Maxim Suraev, who arrived at the outpost in early October.

"Four more months, guys, then it's your turn," De Winne said before departing. "Have a good flight. It's wonderful in space, enjoy it.

The Soyuz descent module landed upright, and recovery crews extracted Romanenko, Thirsk and then De Winne one at a time, transporting them on stretchers to nearby vehicles. All three were reported to be in good condition.

Because NASA is responsible for arranging Canadian, Japanese, and European Space Agency rides to and from the space station aboard Russian Soyuz spacecraft, NASA flight surgeons and managers joined Russian recovery crews to assist the returning station fliers and carry out initial medical checks.

Frank De Winne waves as he is helped from the Soyuz descent module.

(Credit: NASA TV)

With the departure of Romanenko, Thirsk and Belgium's De Winne, the European Space Agency's first station commander, the International Space Station was left in the hands of Williams and Suraev. It is the first time since mid-2006 the station has been staffed by just two crew members.

But the solitude will not last long. Three more crew members--cosmonaut Oleg Kotov, NASA flight engineer Timothy Creamer, and Japanese astronaut Soichi Noguchi--are scheduled for launch aboard the Soyuz TMA-17 spacecraft on December 20. Docking is expected two days later.

KENNEDY SPACE CENTER, Fla.--The shuttle Atlantis dropped out of a crystal clear Florida sky and glided to a "picture-perfect" landing at the Kennedy Space Center Friday to close out a successful 11-day space station mission, bringing astronaut Nicole Stott back to Earth after 91 days in space.

The view through shuttle pilot Barry Wilmore's heads-up display as Atlantis lined up on runway 33 at the Kennedy Space Center.

(Credit: NASA TV)

With commander Charles Hobaugh at the controls, Atlantis executed a sweeping right overhead turn to line up on runway 33, pilot Barry Wilmore deployed the ship's landing gear and the shuttle settled to a tire-smoking touchdown at 9:44:23 a.m. EST.

"Houston, Atlantis, wheels stopped," Hobaugh radioed as the orbiter rolled to a halt on the runway center line.

"Roger, wheels stopped, Atlantis, that was a picture-perfect end to a top-fuel mission to the space station," replied astronaut Chris Ferguson from mission control at the Johnson Space Center. "Everybody, welcome back to Earth, especially you, Nicole."

Hobaugh, Wilmore, flight engineer Leland Melvin, and spacewalkers Robert Satcher, Michael Foreman, and Randolph Bresnik doffed their pressure suits for a traditional runway inspection about an hour and a half after touchdown.

"We really had truly an amazing mission," Hobaugh said on the runway. "It was not us, it was not any single group, but it was just an incredible team from all around the nation.

"We were lucky, I mean, part of it's luck and part of it's just pure, great skill, workmanship in processing Atlantis, getting it ready for us. We had no hitches, we went off on time, we landed on time. ... Nicole came back with us, she's doing great, she's headed back to see her family."

Atlantis settles to a smooth landing at the Kennedy Space Center.

(Credit: NASA TV)

Launched to the lab in August, Stott made the trip back to Earth resting on her back in a recumbent seat on the shuttle's lower deck to ease her return to gravity after 91 days in orbit.

Flight surgeons were standing by to help her off the shuttle and carry out initial medical checks before accompanying her to crew quarters for a more detailed exam. Looking comfortable and in good spirits, she told a NASA interviewer a few hours later that while her vestibular system had not yet re-adapted to gravity, she was in good shape and glad to be home.

"As you move, everything else seems to be moving around you," she said. "And it's not a spinning, dizzy feel, it's more if I get up, then everything else seems to want to move up. ... But other than that, the main thing was when they opened the hatch, it smelled like fresh, clean, fall air. And that was really nice."

Her husband and 7-year-old son were on hand to welcome her back to Earth and "I have the promise of a Coca-Cola with crushed ice in a styrofoam cup and some good food, Thanksgiving left overs, waiting for me upstairs. There are also nice, warm showers here so that's a definite luxury I think I will enjoy for some time."

Stott, Hobaugh, Wilmore, Melvin, Foreman, and Satcher planned to fly back to Houston early Saturday. Bresnik, whose wife Rebecca gave birth to the couple's second child on Saturday, flew home right away aboard a NASA training jet to meet his daughter for the first time.

Stott is the last space station crew member to launch and land aboard a space shuttle. With just five more shuttle missions before the fleet is retired next year, all future U.S. station astronauts will fly to and from the lab complex aboard Russian Soyuz capsules.

Stott's former station crewmates face a busy weekend in orbit preparing for the December 1 departure and landing of Expedition 21 commander Frank De Winne of Belgium, cosmonaut Roman Romanenko and Canadian astronaut Robert Thirsk, who were launched to the lab May 27. They are scheduled to land in Kazakhstan aboard the Soyuz TMA-15 capsule around 2:16 a.m. EST Tuesday to close out a 188-day stay in space.

Expedition 22 commander Jeffrey Williams and cosmonaut Maxim Suraev, who arrived at the lab complex in October, will have the outpost to themselves until December 23 when three fresh crew members--cosmonaut Oleg Kotov, astronaut Timothy Creamer and Japanese astronaut Soichi Noguchi--are scheduled to arrive.

A braking parachute is deployed as the shuttle Atlantis races down the runway .

(Credit: NASA)

Hobaugh and his shuttle crewmates delivered nearly 15 tons of spare parts and equipment to the space station, including two pallets loaded with large components as a hedge against failures after the shuttle is retired.

The gear included two orientation control gyroscopes, a spare pump module, nitrogen pressurization tank and ammonia coolant for the lab's external cooling system, equipment for the mobile transporter that carries the station's mechanical arm, a new latching end effector, or hand, for the space crane, and equipment for the lab's electrical system.

The astronauts also carried out three spacewalks to prepare the complex for the attachment of NASA's final major module in February and the eventual arrival of additional spare parts and equipment that will be ferried up next year. In addition, a high-pressure oxygen tank was attached to the station's Quest airlock module.

For the trip back to Earth, the shuttle carried 2,100 pounds of station gear, including a urine distillation centrifuge that failed shortly before Atlantis took off. A replacement will be carried aloft on the next shuttle mission in February.

Only five shuttle flights reamin on NASA's manifest between now and the end of September as the agency works to complete the space station and retire the fleet.

UPDATED at 4 p.m. EST: Astronaut Randy Bresnik flew back to Houston shortly after landing to meet his new daughter; adding comments from Stott.

JOHNSON SPACE CENTER, Houston--Astronaut Randy Bresnik carried out a spacewalk Saturday awaiting word of the birth of his second child. Responding to a wake-up call from Houston early Sunday, he delivered the news that his wife, Rebecca, had given birth, saying "good morning, Houston. Good morning, Rebecca, good morning, Wyatt, and good morning to our little girl."

"I just wanted to take this opportunity to report some good news," he said later in the morning. "At 11:04 last night, Abigail Mae Bresnik joined the NASA family and momma and baby are doing very well. I'm very thankful for everyone...that's been so supportive and so helpful the last couple of days with everything that's been going on."

Rebecca and Randy Bresnik discussed the pending birth of their daughter in a pre-flight NASA interview.

(Credit: NASA TV)

The shuttle crew's wake-up music--chosen by Bresnik's wife--was a song titled "Butterfly Kisses," which starts off with the lyrics: "There's two things I know for sure: She was sent here from heaven and she's daddy's little girl."

For medical reasons, Rebecca Bresnik was scheduled for an induced delivery Friday, two weeks before her December due date. There was no word Friday, and her husband, after participating in a six-hour spacewalk Saturday, presumably went to bed awaiting word of the birth.

"Like most parents, I would prefer to be there at the birth for sure, but we don't pick this timing," he said during a pre-launch NASA interview. "Fortunately, through the wonders of modern technical advancements and our amazing communications systems on the ISS and space shuttle, hopefully I'll be able to see the pictures and maybe talk to her on the IP (internet protocol) phone and see some video shortly thereafter. I'll be home only a few days afterward."

Rebecca said she, too, was "a little disappointed he won't be able to be there, but understanding that we don't choose the timing. I'm excited for him that he's doing what he's doing. He's trained one year for this mission, but really he's been here five, almost six years and I'm just real excited for him, excited for us, and just be gone basically a week beyond her being born."

She said the couple's son Wyatt "thinks he's naming the baby Nemo. He's just ready to be big brother, he's excited about the baby, he's always asking 'when is the baby going to come out and play?'"

"He goes up to her belly button and says 'baby, come out!'" said her husband.

"I say that too, sometimes," she joked.

"The amazing thing about him, you know, a year ago today we hadn't even met him yet," Bresnik said. "Within 48 hours of me being assigned to (shuttle mission) STS-129, we got the call saying we had a date to go to the Ukraine for our adoption.

"So we were over there 40 days last fall adopting him, came back in late December. So we've got this wonderfully happy, healthy little three-and-a-half-year-old boy who's life changed completely and he's gone from being in an orphanage on the other side of the planet to being in the space shuttle simulator here flying with his dad a couple of weeks ago.

"A miracle adoption as well as the miracle of childbirth, all in one year," he said. "We're just amazingly blessed."

Bresnik and his shuttle crewmates are scheduled to land at the Kennedy Space Center the day after Thanksgiving.

JOHNSON SPACE CENTER, Houston--Commander Charles "Scorch" Hobaugh piloted the shuttle Atlantis to a precision docking with the International Space Station Wednesday after a spectacular back-flip maneuver 220 miles above the Atlantic Ocean that allowed the lab crew to inspect the ship's fragile heat shield.

Approaching from directly in front of the 670,000-pound lab complex, the shuttle's docking mechanism engaged its counterpart on the station at 10:51 a.m. CST to cap a two-day rendezvous as the two ships orbited southeast of Australia.

The shuttle Atlantis docked with the International Space Station.

(Credit: NASA TV)

A few moments later, the docking mechanism pulled the two spacecraft firmly together. And after a series of leak checks were conducted, the hatches were opened around 12:28 p.m.

Waiting in the forward Harmoney module, European Space Agency commander Frank De Winne of Belgium, cosmonauts Maxim Suraev and Roman Romanenko, NASA astronauts Jeffrey Williams and Nicole Stott, and Canadian astronaut Robert Thirsk welcomed Hobaugh and his shuttle crewmates--pilot Barry Wilmore, Leland Melvin, and spacewalkers Robert Satcher, Michael Foreman, and Randolph Bresnik.

Facing a busy afternoon in space, the two crews shared brief hugs and handshakes before a mandatory safety briefing and the start of equipment transfers from the shuttle to the station.

Along with delivering 15 tons of spare components and supplies to the orbital complex, Atlantis will bring Stott back to Earth after three months in space. With Atlantis docked to the station, Stott is now considered a shuttle crew member and will start sleeping aboard the orbiter.

Approaching the station from behind and below, Hobaugh paused at a distance of roughly 600 feet directly below the lab complex as the two spacecraft passed high above South America. He then kicked off a computer-controlled 360-degree back-flip maneuver, exposing heat shield tiles on the orbiter's belly to the space station.

Shuttle Atlantis begins a back-flip maneuver crossing the northeastern coast of South America. The rendezvous pitch maneuver allows station crew members to photograph fragile heat shield tiles on the shuttle's belly to look for signs of damage.

(Credit: NASA TV)

Stott and Williams, looking down through portholes in the Russian Zvezda command module, then snapped hundreds of digital images using powerful telephoto lenses to help engineers assess the health of the shuttle's heat shield.

Spectacular television images from the station showed Atlantis slowly flipping about as the shuttle passed over the coast of northeastern South America and out over the Atlantic Ocean. Zoomed-in views of the shuttle's belly revealed no obvious problems, but engineers will base their assessment on the digital images shot by Stott and Williams.

After the rendezvous pitch maneuver was complete, Hobaugh guided Atlantis up to a point directly in front of the space station before the final approach to docking.

The primary goal of the 129th shuttle mission is to deliver some 15 tons of spare components and equipment to the station to protect against failures after the shuttle is retired next year. The equipment is mounted on two Express Logistics Carrier pallets in Atlantis' cargo bay.

Atlantis, midway through the rendezvous pitch maneuver.

(Credit: NASA TV)

Mounted on the pallet's upper deck are a 600-pound control moment gyroscope, a solar array battery charge-discharge unit, a device to prevent electrical arcing between the station and the space environment, and a latching end effector for the station's robot arm. Mounted on the lower surface are a 550-pound nitrogen tank assembly, a 780-pound external cooling system pump module, and a 1,700-pound ammonia coolant tank.

Shuttle Flight Director Mike Sarafin said Atlantis completed the rendezvous in good shape. The only technical problem of any significance was a bandwidth issue that is slowing data transfers to and from the ground.

On the station side, engineers are continuing to troubleshoot a problem with the lab's water processing system, but Sarafin said enough stored water was available to avoid any near-term concern.

JOHNSON SPACE CENTER, Houston--The United States and China have agreed to discuss expanded cooperation in space science and to start a "dialogue" on human space flight and exploration, according to a joint statement released in Beijing on Tuesday. The U.S.-China Joint Statement said both nations looked forward to reciprocal visits by the NASA administrator and appropriate Chinese space leaders in 2010.

"The United States and China look forward to expanding discussions on space science cooperation and starting a dialogue on human space flight and space exploration, based on the principles of transparency, reciprocity, and mutual benefit," the joint statement said. "Both sides welcome reciprocal visits of the NASA administrator and the appropriate Chinese counterpart in 2010."

President Obama visits the Forbidden City in Beijing.

(Credit: Pete Souza/White House)

John Logsdon, a space policy analyst at George Washington University, said expanded cooperation makes sense, but only if both sides are open with each other and share the technical data necessary to ensure safe operations.

"I think it's great," he said in a telephone interview. "It opens the door to see whether, in fact, there's a basis for cooperation. I think the operative word in there is 'transparency.' If China is willing to provide the information we need to work with them and vice versa--they were the ones who have been somewhat reticent to do that--I think it makes total sense."

The future direction of the U.S. manned space program is unclear as NASA waits for the Obama administration to make a decision on how the agency should proceed after the space shuttle is retired next year.

KENNEDY SPACE CENTER, Fla.--The space shuttle Atlantis roared to life and raced into orbit Monday on a critical mission to deliver 15 tons of equipment and spare parts to the International Space Station, gear needed to protect against failures after the shuttle fleet is retired next year.

The shuttle's three hydrogen-fueled main engines fired up at 120-millisecond intervals and six seconds later, after computers verified the powerplants were operating normally, Atlantis' twin solid-fuel boosters ignited with a flash at 2:28 p.m. EST, instantly pushing the orbiter skyward.

The space shuttle Atlantis begins an 11-day space station delivery mission with an on-time launch from the Kennedy Space Center.

(Credit: NASA TV)

As commander Charles Hobaugh and pilot Barry "Butch" Wilmore monitored the computer-controlled ascent, Atlantis wheeled about its vertical axis and arced away to the northeast, into the plane of the space station's orbit in the first step of a complex two-day rendezvous.

The shuttle's boosters operated normally, separating from Atlantis' external fuel tank as planned two minutes and four seconds after liftoff, and the spaceplane continued toward its planned preliminary orbit on the power of its three main engines.

A television camera mounted on the side of Atlantis' external tank provided spectacular views as the shuttle thundered toward space, showing the Florida coastline and scattered clouds dropping away below as the ship accelerated toward space.

Making a bigger splash than expected, the crash of an empty rocket stage in a permanently shadowed crater near the moon's south pole last month kicked up a surprising amount of water ice and vapor, confirming the presence of a potentially valuable resource for future space travelers.

"I'm here today to tell you that indeed, yes, we found water," said Anthony Colaprete, the project scientist and principal investigator for the Lunar Crater Observation and Sensing Satellite. "And we didn't find just a little bit, we found a significant amount."

Holding up water jugs to make the point, he said "if you remember, a month ago we were talking about teaspoons going into glasses over football fields. Well, now I can say today that in the 20- to 30-meter (65- to 100-foot-wide) crater LCROSS made, we found maybe about a dozen of these two-gallon buckets worth of water."

And more than water. Data from the LCROSS instruments show signs of other compounds that may shed light on the moon's evolution.

"It's a whole lot more beyond the water," Colaprete said. "That's the exciting part in my mind, it's not only about the water now. There's actually a lot more here that we're going to be talking about in the months ahead, looking at the LCROSS data."

Spectroscopic data from NASA's LCROSS lunar impactor shows the presence of water in two specific bands (yellow regions).

(Credit: NASA)

Said Greg Delory, a researcher at the University of California at Berkeley: "This is not your father's moon. Rather than a dead and unchanging world, it could in fact be a very dynamic and interesting one that could tell us unique things about the Earth-moon system and the early solar system."

After months of tests and analysis, engineers plan to beam commands to NASA's Spirit Mars rover Monday, kicking off a long-awaited attempt to free the hardy craft from the talcum powder-like soil of a hidden crater that trapped it last April.

"Spirit's facing the most challenging situation it's seen yet on the surface of Mars," Doug McCuistion, director of NASA's Mars exploration program, said Thursday. "We know a lot of people around the world...view Spirit with great affection, exploring the Red Planet along with it, experiencing the excitement, seeing new and exciting vistas, seeing new landscapes, uncovering some incredible new knowledge about our sister planet.

The view from the Spirit rover looking north, back along its path, from the point where it got trapped last April. The rover is believed to be straddling the rim of a hidden crater. Note the front-left wheel, nearly buried in powdery soil.

(Credit: NASA)

"I'd like everybody to be hopeful, but I'd also like them to be realistic," he said. "If Spirit cannot make the great escape from this sand trap, it's likely that this lonely spot, straddling the edge of this crater, might be where Spirit ends its adventures on Mars."

Designed to operate for just three months on the frigid surface of Mars, Spirit and its twin rover, Opportunity, have been exploring opposite sides of the planet since early 2004, collecting data in concert with orbiting spacecraft to help scientists understand the role of water in the Martian environment.

Chalking up a steady stream of discoveries over the past five years, the unexpectedly long-lived rovers are held in high esteem by the scientists and engineers who drive them across the surface of Mars and eagerly await the data they send back.

"In many ways, we think of these rovers kind of as our children that we've sent off into the world way too early," said Ashley Stroupe, a rover driver at the Jet Propulsion Laboratory in Pasadena, Calif. "And like most parents, when their kids go off to college, we can't reach out to help them every time they really need us. So it really is a bond, not just between us and the rover, but also the team has become a very close family as well."

Last April 23, the six-wheel Spirit was slowly rolling backward on the western side of a feature known as "Home Plate," heading toward the south and a pair of volcanic structures that scientists wanted to examine. The rover was driving backward because its right front wheel stopped working in 2006.

The ground to the south of Spirit looked normal, but as it rolled along, its wheels broke through an upper-crust-like layer of soil and into a softer, unseen material.

"Essentially, the rover was driving on what we call a dirt crust," said John Callas, the project manager of the Mars exploration rovers at JPL. "It was a hard surface that we broke through, and underneath this material, camouflaged underneath, was this loose, fine material where the rover is challenged right now."

Scientists later determined that Spirit's path was straddling the rim of an ancient, 26-foot-wide crater just beneath the surface. The crater was filled in with sulfate sands that formed layers with different compositions.

Initial attempts to drive out in a crablike fashion by turning the front and back wheels in the same direction only made matters worse.

Pictures from navigation cameras on the rover show its forward and rear wheels almost buried in the soil, their treads caked with a powdery coating that reduces traction. Even worse, photographs show a pyramid-shape rock sticking up from the soil directly below Spirit's body that threatens to rub against the belly, possibly lodging in an indentation. If the rock ends up bearing any of the weight of the rover, traction could be reduced even more.

A view under the Spirit rover showing a pyramid-shape rock close to the belly of the robot.

(Credit: NASA)

NASA managers decided to halt any additional attempts to free Spirit until engineers could complete a thorough analysis using a full-scale mockup and simulated Martian soil.

"Unfortunately, Spirit may have met its match in this one," McCuistion said. "We will see if we can get it out of this talcum powder-type soil that laid beneath a seemingly innocuous surface crust that we broke through...The rover teams have been working very hard since April, they've been testing, strategizing, analyzing, and modeling to figure a way out. We even called experts in soil mechanics and mechanical systems in to try to help us understand the environment. But there's only so much you can do on Earth to simulate Mars."

Late Monday, commands will be uplinked to Spirit in an attempt to drive north, back along the furrows its wheels dug as the rover moved into the sand trap last April. Engineers will find out how the move went on Tuesday. No one expects a quick extraction, and engineers said it likely will take weeks or months to either free the rover or determine that it can't be done.

A mockup of the Spirit rover in a "sand box" at the Jet Propulsion Laboratory in Pasadena, Calif., where engineers have been testing techniques for driving the vehicle out of loose soil.

(Credit: NASA)

"Our best plan at this point is to try to drive forward, retracing our steps as we drove in," Stroupe said. "And we believe this is our best plan for several reasons. One is that we believe this softer material may be easier to plow through than trying to break through the crust and cut new tracks. So if we follow our old tracks out, we may be able to make better progress.

"We have very little ground clearance under the vehicle. Wheel turns cause us to sink further into this material, and there is no guarantee that any plan we come up with will succeed in extricating the vehicle," she said. "This is going to clearly be a very long process, to either get to extrication or perhaps even to determine if extraction is going to work."

The team's progress will be assessed in February. Depending on the success or failure of the work at that point, NASA could opt to continue with additional attempts or decide to call it off. Even in that worst-case scenario, scientists could still use Spirit's instruments to study nearby rocks and soil, and to monitor the martian weather.

But Stroupe hopes it won't come to that.

"I think a lot of us, while we're waiting for that plan to execute (Monday), will not get a lot of sleep," she said. "But regardless of the outcome, none of us can have anything but primarily positive emotions about this mission. It's been such an incredible experience, we've come so far beyond what we thought we would accomplish...We're so proud of them, and we're so thrilled to have been part of this project. It will be sad to see them go. But we're not ready to let go yet, and we don't plan to let go yet. We still have a lot of work to do."