Meteorologists are predicting favorable weather for Columbia's homecoming, scheduled for 4:32 a.m. EST. The shuttle left the Florida spaceport 11 days ago for NASA's fourth orbital service call to the Hubble Space Telescope.
"I just couldn't be prouder of the whole team," Columbia commander Scott Altman said during a news conference early Monday. "We are exhausted, but we are also exhilarated. It's unbelievable we got everything we set to do accomplished. We're really thrilled about that and looking forward to coming home."
For five consecutive nights, alternating pairs of space-walking astronauts left Columbia's crew cabin to work on replace the telescope's electrical system, install new scientific instruments and revive a dormant infrared camera.
"The work on the telescope for me was just a dream come true," said lead space-walker John Grunsfeld. "The truth is we're just happy we got our job done, we did it well and we didn't break the telescope."
With the challenging servicing mission behind them, Hubble scientists are eager to check out Hubble's new digital camera, which is expected to yield 5- to 10-times sharper pictures than the telescope's current wide-field imager.
The $75 million Advanced Camera for Surveys also is faster and has twice the depth of field as the older camera, enabling scientists to capture faint light from distant stars over hours, rather than days.
"Knowing that there are, in round numbers, 100 billion stars in each of a trillion galaxies -- it boggles the mind, certainly mine," said Columbia astronaut Jim Newman. "I wonder, what's really out there? Are there other opportunities for life? ... These are fundamental questions for people who are conscious -- and we're all conscious of ourselves, of our mortality. We all wonder about the bigger picture."
The first pictures from Hubble's new camera are expected to be released in April.