The astronauts aboard the orbiting shuttle-station complex celebrated two big anniversaries Monday as they geared up for the third and final spacewalk of their mission.
And the world was treated to the first recital of traditional Japanese music and poetry in space.
Monday marked the 49th anniversary of the first human spaceflight — by Soviet cosmonaut Yuri Gagarin on April 12, 1961 — and the 29th anniversary of the first shuttle launch.
"April 12th's a really special day for astronauts," said space shuttle Discovery's commander, Alan Poindexter.
In honor of Russia's Cosmonauts Day, Russian President Dmitry Medvedev called the residents of the International Space Station to wish them well. Three are Russian, two are American and one is Japanese.
"Space is something that unites all of us. It's a global issue," Medvedev told them.
Medvedev suggested that world leaders hold a summit to discuss space exploration, as they do other matters. On Thursday, President Barack Obama will visit Kennedy Space Center to elaborate on NASA's role once the shuttle era ends. Only three shuttle flights remain after this one.
"Space is our highest priority, regardless of how hard the economic situation was in the country and will be, I'm sure," Medvedev told the station crew.
In addition to the space station's six occupants, there are seven shuttle visitors — a Japanese woman and six Americans.
The two Japanese — the station's Soichi Noguchi and shuttle astronaut Naoko Yamazaki — took a call Monday from dignitaries and schoolchildren in Tokyo.
This is the first time two Japanese astronauts have flown together in space.
Yamazaki shared a haiku — or Japanese poem — she wrote after seeing Earth for the first time from space. Then, with Noguchi accompanying her on an electric keyboard, she performed a Japanese folk music springtime piece, "Sakura Sakura," which translates as "Cherry Blossom." Noguchi opened the piece with a few notes on a traditional wooden flute.
"This is probably the first time that you are going to hear the historic performance from space," Noguchi said.
The recital took place in Japan's big science lab, Kibo, or Hope.
It was a slower pace for the astronauts Monday. They got some time off one week into Discovery's flight.
One more spacewalk still needs to be conducted to finish installing a new ammonia tank, on Tuesday. The astronauts will place a big cargo carrier back aboard Discovery on Thursday, after it's stuffed with old equipment and trash. Then on Friday, one day before departing, the shuttle will be inspected for any signs of micrometeorite damage.
This survey of the shuttle wings and nose usually is conducted after undocking. But Discovery's main antenna is broken, and there would be no way to transmit all the laser 3-D images to Mission Control for analysis. NASA added a day to the shuttle's visit so the inspection could be carried out at the station and the data could be sent using station resources.
Shuttle inspections became mandatory in space following the 2003 Columbia disaster.
Columbia lifted off on the first shuttle flight on April 12, 1981.