MOSCOW (AFP) - - South Korea's first astronaut, Yi So-Yeon, was to star Saturday in celebratory sing-song aboard the crowded International Space Station (ISS) as back on Earth Russia marked the 47th anniversary of sending the first man in space.


Yi, 29, docked Thursday along with Russian cosmonauts Sergei Volkov and Oleg Kononenko after a successful Soyuz space capsule journey from the Russian cosmodrome at Baikonur in ex-Soviet Kazakhstan.

The excited South Korean space debutante promised to celebrate her arrival and Russian Cosmonauts' Day with a song and a dinner of traditional South Korean food -- albeit adapted to the rigours of eating in zero-gravity.

Yi was guaranteed a full house of five other crew members on the International Space Station, a permanently staffed orbiting home for US, Russian and other astronauts.

Back on Earth, Russian President Vladimir Putin congratulated space sector employees with the 47th anniversary of Soviet legend Yury Gagarin's 1961 mission to become the first man in orbit.

"We are proud that our country in particular paved humanity's road to the stars," Putin said in a statement.

Officials laid flowers at Gagarin's tomb under the Kremlin wall in Red Square.

But schoolchildren in Yekaterinburg in the Ural Mountains found a more unusual way to mark the anniversary by writing a letter of greeting to extra-terrestrials, Interfax reported.

The city's post office agreed to accept the envelope, but had not quite decided how to make the delivery, the agency said.

In a video link-up with the ISS from mission control outside Moscow, the head of Roskosmos space agency, Anatoly Perminov, jokingly urged the station's crew to "help Yi So-Yeon do her scientific experiments. You promise?"

"They've already helped me," a smiling Yi replied, RIA Novosti news agency reported.

Perminov laid out optimistic plans, including for a new generation of heavy space rockets to replace the current Soyuz workhorse for manned flights.

He suggested a possible space-based "factory" to "put together a heavier kind of spacecraft than now and use them for flights to other planets, to the Moon or Mars," Interfax reported.

Yi and the two Russians accompanying her joined the current crew consisting of US commander Peggy Whitson, another NASA astronaut Garrett Reisman, and Russian cosmonaut Yury Malenchenko.

Yi, whose expedition is touted by South Korea as the cornerstone of the Asian nation's growing space ambitions, was to return to Earth on April 19 along with Whitson and Malenchenko.

Reisman, who arrived at the ISS on the US space shuttle on March 13, will remain aboard with Volkov and Kononenko.

Volkov's arrival meant the start of the first father-son space dynasty, as his father is Alexander Volkov, a cosmonaut famous for having launched from the Soviet Union and returned following the 1991 Soviet collapse to modern Russia.

After years of financial difficulties, Russia is now awash in profits from gas and oil exports -- a perfect time, Putin said, to put the space programme on a new footing.

Putin told a meeting Friday of the Kremlin security council that Russia was ready to switch from Soviet-era space programmes to "new, truly ambitious projects," Interfax reported.

"Conquering space at the same time means defence of Russia, modernised communications, navigation, the possibility for early warning of global cataclysms," Putin was quoted as saying.

One priority for Russia is completion of the GLONASS navigation system, which is touted as a potential rival to the US Global Positioning System or GPS and a planned European navigation satellite network.

The other is to build the new Vostochny space centre in Russia's southeast, near the Chinese border, to end reliance on Baikonur, a Soviet-era base that Russia must now rent from Kazakhstan.

"We must ensure guaranteed Russian access to space," Putin said in comments broadcast on national television.

Perminov said that all manned space flights would take off from Vostochny by 2020