For the Americans, it's still something of a novelty to climb aboard a rocket and arrive at a destination in orbit. Before hitching up with Russia, the only time the United States had a base in space was in the mid-1970s, during the short-lived Skylab program.

The realities of running a permanently occupied space station are about to unfold. Every single item for human existence — air, water, food, fuel, batteries, toilet paper — must be painstakingly planned for, purchased, packed, flown, unloaded and put away. With delivery costs to low-Earth orbit running about $10,000 per pound, there is no room for excess baggage.

You will hear no complaints from Bill Shepherd, the NASA astronaut tapped to command the first live-aboard station crew, or from his two Russian crew mates, Sergei Krikalev and Yuri Gidzenko. Not a word that there are only two staterooms — neither any bigger than a toilet stall — for three men, or that there is no shower and little fresh food.

They have been training for years not only to set up and fix hundreds of devices aboard the space station, but also to learn how to live and care for themselves in orbit. They know how to use the space toilet and how to keep it clean. They have sampled the space foods and practiced setting up and taking apart the exercise bike. If they haven't done so already, they will soon have to choose what movies, music and electronic reading material to bring along for rare quiet moments in orbit.

Shepherd, Krikalev and Gidzenko will be the first people to live in Zvezda — the heart, brains, helm and home of the still-under-construction International Space Station. The outpost also includes a propulsion module, called Zarya, which was the station's foundation, and a connecting node, named Unity.

Structurally, Zvezda is a virtual twin of the 1980s-era Mir core module — same size, same layout, same tan walls. The upgrades went to the electronics, navigation and control systems, not creature comforts.

Each man will have a sleeping bag to attach to a wall. Two crew members can set up bedrooms in the semiprivacy of the two tiny staterooms; one will have to make do in the main chamber itself, hanging up and putting away his bedding every day.

The chamber contains everything needed for daily living, including a kitchen with a small refrigerator and freezer, hot and cold water dispensers and hot plates to warm food. Zvezda also will house the station's toilet, exercise equipment, air purifiers and oxygen generators. Its best feature, however, may be its 14 windows and a view that cannot be duplicated anywhere on Earth.

Eventually, many of Zvezda's systems will be supplemented or replaced by later additions to the International Space Station. The last component slated for launch is a U.S. habitation module that will enable the number of crew members to grow from three to seven — enough people to conduct full-time science operations.

Zvezda's path into orbit has been particularly difficult. Delayed by the Russian government's inability to pay its bills, criticized by congressional watchdog groups as below U.S. standards and then grounded by technical problems with its launch system, the service module became the first of what is likely to be many tests of the U.S.-Russian commitment to jointly operate their human spaceflight programs.

"We've put a lot of blood, sweat and tears into the manufacture of this vehicle," said NASA's Kirk Shireman, a space station manager who oversees Russian elements.

Until Zvezda is in orbit, the era that NASA has been planning for since the end of the Apollo moon missions remains on hold — a time when Americans are living in space permanently.

"I think people ought to stop doubting and start believing," said astronaut and space station manager Bob Cabana. "We are going to build this space station. It is going to happen."