The Russian space agency cannot afford to finance groundbreaking projects and could be overtaken by China, says its chief.
Roskomos head Anatoly Perminov warned that the agency does not currently have a large enough budget and would be at a disadvantage in the marketplace.
"The finance ministry's policy doesn't allow us to complete projects aimed at winning the foreign market," Perminov said.
Veteran cosmonauts have also complained of stagnation at the agency that beat the United States into space with Yuri Gagarin's first manned space flight 50 years ago.
Russia has budgeted 200 billion roubles ($7 billion) for space programmes in 2010-2011, making it the fourth largest spender after US space agency NASA at $18.7 billion, the European Space Agency and France, Prime Minister Vladimir Putin said.
Further space boundaries including manned flights to Mars could still be tackled by Russia, Perminov said - but only after 2035.
"It would be absurd to fly on the rockets we have now," he said, adding that a flight to Mars using today's technology would take a year and a half.
Rumours of Perminov's imminent sacking with have also marred official celebrations of Gagarin's pioneering flight and drawn attention to a string of embarrassing setbacks in recent months.
Two high-ranking space officials were fired after three high-tech GLONASS navigation satellites crashed into the Pacific Ocean after a failed launch in December.
Experts said Russia had neglected investment in space research and was content to sell seats on its Soviet-designed Soyuz spacecraft to foreign astronauts.
Roskosmos will receive $753 million for ferrying 12 US astronauts to the space station during 2014-2016, and has earned some $2.5 billion from NASA and partner agencies for 42 seats on Soyuz craft since 2007.
Putin responded that Russia should take pride in handling over 40 per cent of global space launches but must not be confined to the role of a "ferryman".