KOROLYOV, Russia — From patriotic songs blaring on the metro to parties on the International Space Station, Russia on Tuesday proudly celebrated 50 years since rocketing Yuri Gagarin into the first human orbit.
In a video link with space, Russian President Dmitry Medvedev told astronauts aboard the orbital station that space exploration remained Russia's "priority."
"In those 50 years, we absolutely can't imagine life without space, without your flights," Medvedev told the crew from Russia's cavernous Mission Control Center, named after the legendary father of the Soviet space program Sergei Korolyov.
"Space is our priority."
Space station Commander Dmitry Kondratyev said his current six-person U.S., Russian and European crew would celebrate the holiday from the "front lines" in weightlessness.
Back on Earth, Muscovites on their way to work were reminded of one of the most enduring Cold War victories — Gagarin's epic single Earth orbit on April 12, 1961 — with rousing Soviet-era hymns piped through speakers on the underground.
Gagarin's 108-minute mission on April 12, 1961, remains a source of great national pride, and Russia marked the day with fanfare resembling Soviet-era celebrations. Schools had special lessons dedicated to Gagarin, billboards carried his smiling face and national television channels broadcast a flow of movies and documentaries about the flight.
"This flight stirred the whole world and showed what humanity was capable of," said veteran Soviet cosmonaut Alexei Leonov, 76, who completed the first space walk in 1965.
"He invited us all into space," Leonov told a Kremlin hall filled some of the world's most well-loved space icons, citing a tribute from the first man on the moon, U.S. astronaut Neil Armstrong, to Gagarin.
Since Gagarin's epic journey into the unknown 50 years ago, some 500 people have followed him into space.
"If Yuri Gagarin had not made this flight I would not have flown to the moon," said U.S. astronaut Thomas Stafford, commander on the first U.S. lunar landing in 1969. (Writing by Alissa de Cabronnel; Additional reporting by Denis Dyomkin)
Meanwhile, in Moscow, Medvedev declared Russia must preserve its pre-eminence in space.
His statement followed warnings by another cosmonaut that Russia risks losing its edge in space research by relying solely on Soviet-era achievements and doing little to develop new space technologies.
"We were the first to fly to space and have had a great number of achievements, and we mustn't lose our advantage," Medvedev said during a visit to Mission Control outside Moscow.
On Monday, Svetlana Savitskaya, who flew space missions in 1982 and 1984 and became the first woman to make a spacewalk, harshly criticized the Kremlin for paying little attention to space research after the 1991 collapse of the Soviet Union.
"There's nothing new to be proud of in the last 20 years," said Savitskaya, a member of Russian parliament from the Communist Party.
Russia has used the Soyuz and Progress spacecraft, whose designs date back to the 1960s, to send an increasing number of crew and cargo to the International Space Station. Russia's importance will grow even more after the U.S. space shuttle Atlantis closes out the U.S. program this summer, leaving the Russian spacecraft as the only link to the station.
But Savitskaya and some other cosmonauts have warned that Russia has done little to build a replacement to the Soyuz and could quickly fall behind America after it builds a new-generation spaceship.
Boris Chertok, the former deputy to Sergei Korolyov, the father of the Soviet space program, says it has become increasingly difficult for Russia's space industries to hire new personnel.
"Salaries in space industries are much lower than average salaries in banks and commercial companies," Chertok, 99, told reporters last week. "We need (more) people of Korolyov's caliber."
Korolyov, a visionary scientist as well as a tough manager, led the team that put the world's first manmade satellite in orbit on Oct. 4, 1957. He then spearheaded a massive effort to score another first with Gagarin's mission.
"Our competition with America was spurring us to move faster to make the first human spaceflight," Valery Kubasov, a member of Korolyov's design team who later became a cosmonaut, told The Associated Press.
Gagarin's accomplishment shocked the United States, prompting it to declare the goal of putting a man on the moon.
"Without Yuri Alexeyevich's flight, I wouldn't have flown to the moon," said Thomas Stafford, commander of the Apollo 10 mission that approached within eight miles of the moon in May 1969, the last U.S. mission before the U.S. moon landing three months later.
"He was a great hero for the Soviet Union and the entire world," Stafford said in Russian after receiving a medal from Medvedev at a Kremlin award ceremony that honored cosmonauts and astronauts.
Sergei Krikalyov, who holds the world record for total time spent in space — 803 days on six space missions — said the main unknown before Gagarin's flight was how a human body would respond to the conditions in outer space.
"The main tasks were to make sure that a cosmonaut could breathe and swallow in zero gravity," Krikalyov, who now heads Russia's Star City cosmonaut training center, told the AP. "It was not even certain that a man could eat and drink during weightlessness."
Gagarin, who later crisscrossed the world as a living symbol of Soviet talent, craved more space trips. Cosmonaut Vladimir Shatalov told the AP that Gagarin was dreaming about going to the moon and was among those selected to train for the mission in a race against the U.S. "He hoped to take part in that, he hoped to fly to the moon," Shatalov during an interview at Star City, where Gagarin trained.
Gagarin was a backup for his friend Vladimir Komarov, who died when his space capsule crashed on re-entry in April 1967. Fearing any injuries to their space star, Soviet authorities decided to bar Gagarin from flying into space again.
Gagarin's own death in a training jet crash on March 27, 1968, is shrouded in conspiracy theories to this day. Shatalov, who had planned to follow Gagarin on another training flight that day, told the AP that the most likely reason for Gagarin's crash was a sonic wave from another military jet flying too close.
Information from Reuters and The Associated Press was used in this report.
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