Visitors are rare these days to the museum of Russia's Space Research Institute in Moscow even though it holds gems like the model of the Soviet Lunokhod, the first ever space rover to land on the Moon, in 1970.

While the Cold War space race fired such cutting-edge projects, Russia's planetary exploration has stalled for the past three decades -- until now.

Under an ambitious plan with the European Space Agency (ESA), scientists have new hope of again sending missions to the Moon and to Mars.

"The last decade was truly difficult for us," the institute's director Lev Zeleny told AFP.

Among the biggest blunders was the tragic Phobos-Grunt probe, which in 2011 failed to reach its planned course to one of the moons of Mars and crashed back to Earth over the Pacific Ocean.

"But now the programme is entering a new stage for this decade."

Next month, a Russian Proton rocket is scheduled to launch the first of two missions under ExoMars, a joint venture with the ESA, to snoop out possible life, past or present, to the red planet.

Zeleny's hopes are high that this will return Moscow to its glory days of space exploration -- if the project actually gets off the ground.

In the first mission, an orbital spacecraft will search for traces of methane in the atmosphere of Mars -- possible evidence of biological activity.

For the second part in 2018, Russian engineers are to build a complex landing system to drop an ESA-built Martian rover to the planet's surface, a platform not only to ensure a soft landing but also to serve as "a science lab in itself" for inspecting the landing site, said Zeleny.

"If we manage this, it will be a major breakthrough," he said.

- Financial limbo -

The ambitious plan, however, has caused jitters among some observers and is dismissed as a pipe dream by others.

In January, the ESA already warned that the 2018 mission could be delayed due to cash flow problems.

With the economic crisis, the Russian government is likewise pressed to make budget cuts and space exploration is far from one of its priorities.

The Russian Federal Space Agency, Roscosmos, is itself in financial limbo but went ahead and announced its programme for the next decade in January, though the plan has yet to be confirmed, said Igor Marinin, editor of Space News magazine.

"Now there is no plan, so there is no financing and Roscosmos is taking out loans just to pay salaries," he told AFP. "For this reason, I'm sceptical, and I don't think we will make a good landing platform in the time that's left."

Roscosmos chief Igor Komarov last month admitted that Russia "does not have financial capabilities for advanced space projects."

He also complained that it was difficult to import some critical components, a problem caused by Western sanctions imposed over Moscow's intervention in Ukraine.

While sanctions "are not fatal," conceded Zeleny, they "are rather like an ant crawling under your collar -- they tickle and distract you."

Beyond the money issues, sceptics note that Russia has not carried out a Mars landing since the 1970s and a failure could destroy ESA's rover.

This would be disastrous since the ExoMars-2018 rover is "the most expensive European planetary spacecraft under development for almost two decades," said Anatoly Zak, the editor of RussianSpaceWeb.com, a website that tracks the country's space industry.

But if the landing does succeed, "it could serve as a model for the future cooperation with Europe in deep-space exploration," Zak said.

- Cooperation -

Zeleny has far-reaching plans for such cooperation, notably resuming Moon exploration which largely stopped in 1976 when the US and the Soviets focussed on other parts of space.

He said Russia wants to help set up an international research base on the planet, where the absence of atmosphere or radio noise create perfect conditions for astronomers.

It hopes to launch a first mission by 2019 to explore the Moon's south pole, seen as a potential spot to set up a system of telescopes that humans would fly in and out to adjust in shifts. This would be "much like people working in the Arctic in Russia," said Zeleny, adding that some sort of "lunar dugouts" would have to be constructed to protect the moon visitors from cosmic rays.

Called Luna-25, the project would be the first such probe since Russia's Luna-24 discovered water on the Moon in 1976 -- and will pick up on the famous Soviet Luna series that was the first to land a spacecraft on the moon, in 1959.

Only the US landed men on the Moon, the first in 1969, and ended its programme with the Apollo 17 space flight in 1972.

Back then, no expense was spared in the space race and "scientists reaped many benefits from the competition," Zeleny said.

But now the only way forward is to collaborate.

Zeleny said his institute recently resumed discussions with US colleagues about a joint mission to send "a long-term" landing craft to Venus, a project on hold since 2013 due to political frictions over Ukraine.

"Scientists have long been interested in this cooperation, but now it's finally supported by Roscosmos and NASA," Zeleny said.