In its second year of operation, research aboard the International Space Station reached a new level of maturity as investigators in a variety of science disciplines and commercial endeavors took advantage of its ever-expanding capabilities. Two new research facilities were added to the five existing ones, opening possibilities in new science disciplines.

All science activities on the station are orchestrated by the Payload Operations Center at NASA's Marshall Space Flight Center in Huntsville, Ala. It will soon celebrate its second year as the command post for science operations aboard the station.

Expedition Four -- December 2001 to June 2002 -- performed 27 science experiments, while Expedition Five -- June 2002 to November 2002 -- participated in 25 science experiments, devoting more than 1,000 hours to research. In addition, during Expedition Five, NASA Administrator Sean O'Keefe named Expedition Five crewmember Peggy Whitson as the first NASA ISS Science Officer.

The Expedition Six crew kicks off the third year of science operations with NASA ISS Science Officer Don Pettit, who will oversee 18 experiments.

 Year 2 Featured Science Disciplines

Expeditions Four and Five performed scientific investigations into several fields of study, including bioastronautics, Earth science, physical sciences and the development of new space products.

Bioastronautics

• Measured, for the first time, the long-term effects on the lungs of doing spacewalks and living in microgravity for long periods.
• Developed and began testing two new training regimens to lessen the time it takes to physically readapt to Earth's gravity after spending a long time in space.

Earth Science

• Took more than 30,000 images of the Earth.
• Obtained the first high-resolution images by astronauts, with station crews routinely acquiring images of Earth with resolutions of 6 meters (19.7 feet).

Physical Sciences

• Performed the first materials science experiments in the Microgravity Science Glovebox and processed 16 samples in two different furnaces.

Space Product Development

• Grew the first human liver cells in space to develop earlier and more reliable drug-candidate screening for patients in need of liver and kidney treatments prior to transplants.
• Completed first station experiment to grow a common agricultural crop plant from seed to seed.
• Researchers used the microgravity environment aboard the space station to test a technique for putting two different drugs in a tiny, liquid-filled microballoon, as well as putting a drug and magnetic trigger particles together in the same capsule.