Gov. John Baldacci ordered state flags in Maine lowered to half-staff in memory of the crew of Columbia, saying its seven astronauts “will be remembered as heroes and a source of inspiration.”

“With great sorrow we recognize these extraordinary individuals whose dedication and intellectual and physical achievement helped them to reach the highest honors within their profession,” Baldacci said. “The Columbia astronauts, who gave their lives in search of scientific discovery, will be remembered as heroes and a source of inspiration.”

U.S. Sen. Olympia Snowe characterized the shuttle disaster as a national tragedy.

“America, Israel and the world have heavy hearts today for seven heroes who hungered to explore and learn about the frontier of space,” Snowe said.

Sen. Susan Collins said: “This is a catastrophic and tragic loss of human life that is difficult to comprehend. The dedicated and courageous crew of the Columbia were working for the advancement of science and progress for human kind. The families of these brave men and women are in my prayers.”