Jeff Williams floats in the weightless environment of the International Space Station.

STARDATE: How will the assembly and operations work on the ISS help build future big space-space structures, such as a Mars craft or a space telescope?

JEFF WILLIAMS: Well, everything we do in space is, in some sense, a first-time event, so every step that we take in space exploration, we learn something new that can be applied for future programs.

Of course, when we go back to the Moon and on to Mars, at least for the spacecraft that are used in route, it won’t be anything as big as the space station or anything as complex in turns of assembly -- there will be smaller components, and the assembly will be taking place on the planet’s surface. But still, everything that we do, whether it’s the materials that we use, or the techniques in the design of the components, or the operational techniques that we use, there’s always something that we learn, practically every day, here in space.