NASA celebrated 10 years of continuous human presence at the International Space Station on Tuesday while readying shuttle Discovery for one last trip into orbit.
Liftoff is set for Wednesday afternoon.
Discovery is bound for the space station, currently home to six U.S. astronauts and Russian cosmonauts who fielded calls of congratulations on this special anniversary.
"You all are incredible ambassadors," NASA Administrator Charles Bolden Jr. said in a broadcast hookup from Kennedy Space Center. "What you do is actually a modern-day 'Star Trek.'"
On Nov. 2, 2000, three men moved into the young space station. People from around the world have been there ever since, living and working more than 200 miles above Earth.
On its 39th and final voyage, Discovery will bring six visitors as well as thousands of pounds of supplies, including a humanoid robot. Forecasters said there is a 70 percent chance that the weather will cooperate for the 3:52 p.m. liftoff.
NASA test director Steve Payne said there is a lot of excitement as the countdown enters its final stages. Shuttle workers "put their heart and soul into this one," with the intent of making this last voyage of Discovery as good as the 38 that have come before, he said.
"She's now poised to take to the skies tomorrow, and when she goes, she's going to take a little bit of every one of us with her," Payne told reporters.
NASA overcame two minor problems late Monday and early Tuesday, including a sluggish controller for one of the main engines.
Discovery has carried 180 individuals into orbit over its 26-year career, and logged nearly 150 million miles (240 million kilometers) and more than 5,600 orbits of Earth. It is NASA's oldest surviving shuttle and fleet leader, and will be the first to be prepared for museum retirement.