The Expedition 6 crew: Science Officer Donald Pettit, Commander Kenneth Bowersox and Flight Engineer Nikolai Budarin. Photo: NASA

On Saturday morning, Feb. 1, the three-man crew of the international space station was working through its 70th day in orbit, preparing for a daily planning session with flight controllers in Houston and Moscow. There were no technical problems of any great significance and the crew expected a routine update on the shuttle Columbia's re-entry and landing at the Kennedy Space Center to close out a 16-day science mission.

It was not the update they expected. Instead of having a routine chat with the astronaut "CAPCOM" in mission control, Johnson Space Center Director Jefferson Howell, a retired Marine Corps general, came on the line.

"We were scheduled for a normal planning meeting on Saturday," Expedition 6 commander Kenneth Bowersox said today. "And Gen. Howell, the director of the Johnson Space Center, came in and told us we lost the vehicle on entry.

"My first reaction was sheer shock, I was numb and it was hard to believe that what we were experiencing was really happening. And then as the reality wore on, we were able to feel some sadness. It's the classic grieving responses our psychologists had warned us about, you feel sad, you feel angry, all those things. And now, as time goes on, we're able to put those aside and focus a lot better on our work."

Said science officer Donald Pettit: "When I first heard, at that point it was not known what the condition the crew were in and so we were hoping that there were going to be survivors. And then as it unwound, we learned there were no survivors and that's when the magnitude of that really hit me."

Thinking about it later, he said, the disaster re-emphasized the risks of spaceflight.

"For myself, I had always imagined the launch phase to be the dangerous part with the pucker power to it," he said. "And now it's maybe (remember) that all that energy that those big boosters put into you on launch has to be taken out by the atmosphere when you re-enter. And that's a lot of energy, as we are so patently aware of now. It just made these things a little clearer in my mind in terms of where the risks really are."

Bowersox, Pettit and Russian cosmonaut Nikolai Budarin, the station's flight engineer, were launched Nov. 23, 2002. Today is their 80th day in space, their 78th aboard the station.

"The folks on the ground have been real good about reducing our schedule and we've had time to grieve our friends," Bowersox said of Columbia's fallen crew. "And that was very important. When you're up here this long, you can't just bottle up your emotions and focus all the time.

"It's important for us to acknowledge that the people on STS-107 were our friends, that we had a connection with them and that we feel their loss. And each of us had a chance to shed some tears. But now, it's time to move forward and we're doing that slowly. This press conference today is a huge step towards helping us move along toward our normal objectives and fulfilling our mission here."

Pettit said grieving "is sort of a personal thing and myself, I like the privacy to grieve in the quiet surroundings we have here on space station."

Three days after Columbia broke apart in the sky above Texas, President Bush attended a memorial service at the Johnson Space Center. Bowersox, Pettit and Budarin listened in via radio, sharing the moment with friends, family and co-workers on the ground.

"At the conclusion of that memorial service, after the bells had wrung on the ground and the T-38s had flown by and it was very quiet on board, we rang our ship bell seven times," Bowersox reflected. "And at that point, it was very, very quiet on board the international space station. We spent 15, 20 minutes in silence and then we moved on, we had work to do, we had to unload our Progress (supply ship). At that point, we started thinking about good things, we pulled out the fresh fruit, the oranges, the mail we got from home and it gave us quite a lift after the memorial service."

Bowersox and his two crewmates are the sixth full-time crew to live aboard the international space station. As of today, the outpost has been continuously manned for 832 days.

The Expedition 6 crew originally planned to return to Earth aboard the shuttle Atlantis in March, but with the shuttle fleet grounded indefinitely, it now appears they will return in May aboard the station's Soyuz lifeboat.

A three-seat Soyuz is always attached to the station to provide a way home for the lab's permanent crew in case of an emergency. The lifeboats are certified for six months in space and so-called "taxi" crews periodically ferry up fresh spacecraft and ride the old ones back to Earth. The next taxi flight is scheduled for launch April 26.

Sources say Bowersox and company will almost certainly return to Earth aboard the lab's current Soyuz. Current plans call for the taxi crew to remain aboard the station as a sort of caretaker crew until shuttle flights resume or until the next taxi mission in October.

While a Soyuz can launch with three crew members, only two are expected to launch in April. That's because the station's water supplies - normally topped off during shuttle visits - cannot support three people for a long-duration stay.

For their part, Bowersox, Budarin and Pettit have told U.S. and Russian station managers that they would be happy to stay aloft an additional six months or even longer.

"We are enjoying our mission up here, we enjoy the environment on the space station and we're going to enjoy the next two and a half, three months here," Bowersox said. "So the extra stay is not something that we consider a negative.

"In fact, for us it's positive. We actually volunteered to stay longer. We told our management if they needed us to stay a year, that's fine, they've got blanket approval for that. If they want us to go longer than a year, please give us a couple of months notice. So we like living on space station. And we feel comfortable that we have a way home, we have complete confidence in our Soyuz vehicle and the ability of our Russian partners to operate that vehicle and get us home safely."

He said the crew trained in Soyuz systems before launch, but "because it's been a few months since we've been in a simulator, we'll do additional training here on board if it should be required for us to come home in the Soyuz."

As for what a two-person crew could do aboard the station, Pettit said they would be "real busy just maintaining the systems on space station.

"However, there would be time to do some level of research and by virtue of having people here, you're always doing research on your body itself, looking at the effects of long duration weightlessness on human physiology. So it's important to keep people on station."

But for Bowersox, there's another, equally compelling reason to keep the complex staffed.

"The reason I came here to space is because I believe exploring is important, that we're laying a foundation for our children and their children to leave the planet someday," he said. "Part of that legacy we're going to leave them is a continuous human presence here (in space) that started back in the Mir program. And we would like to see that.

"But that's as much emotional as logical. If we were to have to de-man the station, it would not be a huge setback for our program, the station will keep flying and we'll be able to send people back here if we need to. But on an emotional level, I really want to see people stay."

But it won't be easy. Bowersox said a two-person crew would have a different social dynamic than the current three-person teams.

"Having two people on station would change things quite a bit, it would change the dynamic of how you support each other emotionally," he said. "It's really nice where if two people are getting a little bit irritated, one of them can go and talk to the third or the third can act as a referee. It's sort of like with our international partnership. The more people, the more partners you have, the more work is required to maintain that partnership but the stronger you are because you have more bodies, more hands to get things done."

The April Soyuz mission will include a Russian commander. European Space Agency astronaut Pedro Duque is currently assigned to the flight, but he is expected to be replaced by an American astronaut who has the training necessary to maintain U.S. systems. Sources say NASA already has a short list of candidates for the mission, but discussions with all of the station's international partners are not yet concluded and details remain to be worked out.

In the meantime, the ISS-6 crew will conserve their supplies while they wait for an official decision. Bowersox amused reporters with a discussion of what he's doing to help.

"One of the easiest things to conserve is clothing," he said. "Up here, we've got the perfect air temperature all the time and a good humidity level, so we really don't get our clothing sweaty. The only articles of clothing that do get that way are the ones we use on the exercise equipment.

"One of my personal sacrifices is I've been wearing the same pair of shorts for the past two-and-a-half months. They're very special shorts, I wore them up on the space shuttle, we call them our 'Dittemore shorts' because (shuttle program manager) Ron Dittemore is credited for getting us a bunch of those in the space shuttle program. And I like them so well, I just can't give them up and now they're sort of my lucky shorts. I'm going to try to keep them going until they've got holes in the bottom."