Shuttle commander James Wetherbee says his crew has more than enough food, fuel and other supplies to remain in orbit a few extra days if the weather doesn't permit an on-time landing Wednesday. But just in case, the shuttle skipper said the crew is foregoing second helpings.

"We've sort of been doing that all along," he told CBS News. "The weather is something that we can't control, of course. On the other hand, we never worry about it, but we do want to conserve power and food and water and we think we're in pretty good shape to stay up as long as we need."

Forecasters are predicting a chance of rain and thundershowers near the Kennedy Space Center for both of Endeavour's two landing opportunities Wednesday. The crew's best shot appears to be the first opportunity, with a touchdown at 3:48 p.m. If Endeavour can't get back to Florida Wednesday - and if the forecast doesn't change - flight director Wayne Hale likely will forego a landing attempt Thursday, when the forecast is even worse, and shoot instead for a landing Friday. Conditions are expected to improve dramatically late in the week after an approaching front moves through the area.

For astronaut Peggy Whitson, Sergei Treschev and Expedition 5 commander Valery Korzun, landing will mark the end of a six-month space odyssey that began with launch to the international space on June 5. Asked if the prospect of an additional few days in orbit was frustrating in any way, Whitson said "it's not really a big deal."

"But the shuttle is quite a bit smaller than the station, we're pretty cozy here!" she joked. On the other hand, she said, the view is out of this world.

"The station is an incredibly beautiful structure that we've got up here and I was just in awe," she said of her impressions after Endeavour's undocking Monday. "Inside, we sometimes forget how beautiful it is from the outside. And so it was a very impressive sight for me."

Asked what advice she had for the station's new crew - Expedition 6 commander Kenneth Bowersox, Nikolai Budarin and science officer Donald Pettit - Whitson said "I just tried to advise them that being flexible is really important in terms of getting along with the ground and the folks they're working with (in orbit) and I said just to enjoy themselves."

"I really had a very good time and I wanted them to as well," Whitson said. "So just relax and have fun! And I don't think they're going to have any problem with that!"

Whitson and her Expedition 5 crewmates, like all returning station crews, will make the trip back to Earth resting on their backs in recumbent seats bolted to the floor of the shuttle's lower deck. Korzun is a veteran of an earlier long-duration flight aboard the Russian Mir space station and he said today the onset of gravity after six months in space is a difficult experience.

"You know, how did I feel when I was born? But I've heard people say it looks like this," he said, laughing. "After a long-duration flight, of course, I will feel gravity first of all, the body will be so heavy and my coordination will not be good. I will ... feel Earth after landing."

Whitson said she plans to walk off the shuttle if she's physically able.

"Why not? If I can, I want to walk off. Our station crew members have been coming back in better shape than the folks who came back from Mir and I think a lot of it has to do with the exercise training program that we're working on now, using resistive exercises in addition to the treadmill and ergometer."

In a news conference Friday, Whitson said she was looking forward to a steak dinner with a Caesar salad and "tons of garlic." Today, she added one more item to her dream meal: "Drinking a soft drink, something carbonated. We don't have any carbonated drinks up here so I'm looking forward to that. And anything with ice in it would be very nice as well!"