On the eve of Discovery's final homecoming, the six shuttle astronauts paid tribute Tuesday to the world's most traveled spaceship, saying it may be some time before there's another vessel that's worthy of the name and capable of venturing farther.
Discovery is on the verge of ending its nearly 27-year flying career. Landing is set for Wednesday. NASA will spend several months decommissioning Discovery, then send it to the Smithsonian Institution.
All of NASA's space shuttles were named after great ships of exploration, the astronauts said as Discovery's last spaceflight drew to a close. There was Henry Hudson's Discovery in the 1600s that explored the northeastern United States and James Cook's in the 1700s that encountered the Hawaiian Islands.
"This Discovery has done that with flying colors," spaceman Michael Barratt told The Associated Press. "She retires with all of the honors and dignity due any of those ships that made great discoveries.
"So I think we salute Discovery in that way, with all the accolades that she deserves. But it also lays out a challenge. What will be the next ship named Discovery? The next ship to bear this name hopefully will go farther than this one and make every bit as much of a contribution to history and to discovery as this ship."
Astronaut Alvin Drew said he doesn't know if the country will have the audacity to build something as ambitious as the space shuttle, which dates back to the 1970s. Thirty-nine missions in not even 27 years is pretty amazing, added crewmate Stephen Bowen.
Commander Steven Lindsey noted that his entire crew was sad the mission was drawing to a close. "Wish we could have a few more days, but it's time for us to come home," he said. "Once we land, then we'll all have time to really reflect on what we did."
Former astronaut Michael Coats, who piloted Discovery's maiden journey in 1984, recalled Tuesday how the main engines fired and then shut down in the first launch abort of the shuttle program. The crew members and families ended up at Walt Disney World, he said with a chuckle. The shuttle lifted off two months later.
All of Coats' three spaceflights were aboard Discovery. "I'll tell you, it makes you feel old when you realize you flew the first flight of a spaceship that's about to go into a museum," said Coats, now director of Johnson Space Center in Houston.
In honor of Discovery's final flight, the astronauts received the first live wake-up music in the history of the shuttle program, a tune written in honor of the spaceship.
The lead guitarist of Big Head Todd and the Monsters performed a solo version of "Blue Sky." The group wrote the song at the request of the 2005 crew of Discovery, which returned NASA to orbit following the Columbia tragedy. The song was the top vote-getter in NASA's contest to mark the end of the shuttle program, just a few months away with only two missions remaining.
Lindsey didn't realize the acoustic performance was live until Todd Park Mohr radioed greetings.
"Did you just do that live?" Lindsey asked.
"I did just do that live, and I believe it's a first in history," replied Mohr. "On behalf of Big Head Todd and the Monsters, and songwriters and artists everywhere, we just want to thank you so much for your courage and your bravery and your effort in just giving all of us a better shot at knowing more."
Lindsey said he and his five crewmates wish everyone could see what astronauts see when they look down at Earth. "Hopefully sooner than later," he said.
On Monday, Mission Control beamed up a prerecorded message by actor William Shatner of 1960s "Star Trek" fame, in honor of Discovery's final mission. "Theme from Star Trek" was the music contest runner-up.
Discovery departed from the International Space Station on Monday, leaving behind a newly installed storage compartment and equipment platform, as well as the first humanoid robot in space. The shuttle will wrap up its 13-day mission with a noontime touchdown Wednesday, weather permitting. Good weather is forecast.
Discovery is the first of NASA's three shuttles to be retired. Many at NASA contend the fleet still has lots of flying lifetime left. But the space agency is under presidential direction to aim for true outer space, like asteroids and Mars. That means giving up the shuttles, which are confined to orbit.
Two shuttle launches remain: Endeavour next month and Atlantis at the end of June.
Deputy shuttle program manager LeRoy Cain said the team's mantra over the past several years has been to "finish strong." Discovery accomplished that, he noted, flying the cleanest, best-performing mission in memory.
The public had one last chance to see Discovery soaring overhead, just after sunset Tuesday. It was going to be visible over much of the United States, weather permitting, resembling a bright fast-moving star.
NASA sighting opportunities: http://spaceflight.nasa.gov/realdata/sightings/index.html