Atlantis Undocks From Space Station

HOUSTON, June 19, 2007 — -- The Space Shuttle Atlantis undocked from the International Space Station this morning after a mission plagued with computer failures at the station.

The undocking started as scheduled at 10:42 a.m. EDT.

The computers that control the space stations attitude in orbit, among other things, passed a critical test Monday which gave the Mission Management Team at the Johnson Space Center confidence the computers were really working. The computers failed last week and had engineers in Russian stumped for three days, prompting Space Station Program Manager Mike Suffredini to consider unmanning the space station if the computers couldn't be fixed.

The orbital outpost is kept aloft in the right position by a combination of Russian thrusters and U.S. gyros. The gyros alone aren't enough to keep the space station positioned, so the thrusters on the space shuttle Atlantis were used to give the space station the lift it needed until the problem could be fixed.

NASA manager Phil Engelauf is pleasantly surprised Atlantis is not staying another day. "It is amazing we are getting ready to undock given the challenges we had on this mission," he said.

It was a frustrating three days for engineers on the ground in Russia's Mission Control as they repeatedly tried to detect signs of life in their computers and reboot them.

Engelauf says they know where the computers failed, but they still don't know why the computers failed. "We do not have a definitive answer about the cause, we have traced where we think the computer board failed, we have isolated where that fault occurred, we still have not established the underlying cause yet."

STS 117 Cmdr. Rick Sturckow said goodbye to his colleagues on the International Space Station. "It's been a great mission but all good things come to an end. We are taking Suni Williams home. I know you will miss her but it is time for her to go back to planet Earth.

He also referenced the challenges the crew faced on the mission, saying, "we faced adversity together, but with the help of our crews and the mission controls on the ground we overcame it."

Fyodor Yurchikhin, the Expedition 15 Cmdr., responded, "It was just 10 days, but everyone excelled up here and on the ground they worked hard all day and all night together because we are one big group. Everybody have a good safe landing, thank you for Suni and thank you for Clay." Clay Anderson is the astronaut replacing Williams on the space station. He will stay in orbit until October.

The goodbye was particularly tough for Williams. She was choked up with emotion as she formally said goodbye to the morning Mission Control team. She is leaving the space station after becoming the most experienced female astronaut, setting records for spacewalks and endurance. She cut her hair on orbit to donate to charity and she ran the Boston marathon in space. Williams also kept Mission Control guessing where the photo of her dog Gorby would show up every day on the space station.

Williams said, "Exploration isn't necessary or always logical, it's something that comes from inside each and every one of us. I believe we're all born with this curiosity called exploration. Human spaceflight is just one aspect of exploration, but it's the one that I've been intimately familiar with over the past six months. So I feel I can talk to how it affects thousands of people around the world who have worked on and still work on this amazing engineering and science project we call the international space station. These folks, along with their families, have dedicated their lives to ensure the success of the astronauts and cosmonauts. Our curiosity is called exploration for the next generation.

"I'm saddened to say goodbye, but that means progress is being made and it's time for the International Space Station to grow a little more, you and the ISS will always be a part of me as you are part of so many who will pave the way for our future."

Yurchikhin floated through the hatch after Suni to hand over a single red rose.

After the hatch closed between the space station and Atlantis, astronaut Kevin Ford called up to the shuttle for Suni, "The job is never done until the paperwork is complete," referring to the list of items being transferred from the space station to Atlantis.

Williams sighed. "We'll get back to you," she said.

She gets back to Earth later this week. Atlantis is scheduled to land at Cape Canaveral, Fla., Thursday, though the weather forecast doesn't look very good right now. Mission managers say the shuttle has enough supplies and fuel on board to stay in space until Saturday.

The Associated Press contributed to this report.