"This flight has been absolutely fantastic, the science has been spectacular and we just can't wait to bring it all home so the scientists can really take a close look at what we've done," Columbia payload commander Michael Anderson said during the crew's inflight news conference.
"I think a lot of our experiments have exceeded our expectations by 100 percent," he said. "We've seen things we never expected to see."
Anderson and his six crewmates, including Israel's first astronaut, Ilan Ramon, have been working in split, 12-hour shifts around the clock since the shuttle arrived in orbit on Jan. 16. The marathon mission is scheduled to end with a touchdown at the Kennedy Space Center on Saturday.
The astronauts have been overseeing more than 80 science investigations that delve into a wide array of scientific fields including materials sciences, combustion, medical research, plant research and technology development.
"A lot of what we're doing now is really in preparation for future flights aboard the space station," said Anderson. "Once (these experiments) are fully developed, they'll reside aboard the space station, and the scientists will have years to conduct the experiments we're trying to do here in a relatively short period of time."
The astronauts themselves are serving as subjects for several investigations. Other tests will be performed on an assortment of critters also aboard the shuttle, including fish, rats, bees, ants, moths, spiders and silkworms.
"They're all doing well," said Anderson.
Ramon has spent much of his time on an Israeli atmospheric experiment that is intended to study how dust affects weather systems in the Middle East.
"In the first seven days, I believe, we didn't have any dust up in the atmosphere, but ... (then) we had a big dust storm over the Atlantic that lasted for two or three days, and I think the scientists were very, very successful with their experiment," Ramon said.
The view of Earth from space has been particularly striking to Ramon.
"The world looks marvelous from up here, so peaceful, so wonderful," he said. "For the people of Israel, I wish we will have a peaceful land to live in very soon."