As the U.S. space agency prepares to retire the current fleet of space shuttles, it knew there would be a price to pay for relying on the Russian space agency for space travel.  That price is estimated to be $51 million USD for each trip from Earth to the International Space Station (ISS), several Russian news agencies have reported.

Starting in 2012, Roskosmos will begin to charge for each launch that has NASA astronauts, Anatoly Perminov said during a press conference.  The shuttles will be retired in 2010, though it's unknown what price will be paid for the first two years of space travel.

Roskosmos charged NASA $21.8 million for a flight to the ISS in 2006, but space tourists now pay upwards of $35 million for a two-week stay aboard the ISS.  Even though Russia will be responsible for ferrying NASA astronauts into orbit, the agency will continue to take paying tourists into space.

When NASA officially retires the shuttle next year, each partner nation will also be forced to rely on Russia to transport astronauts into space.  The next-generation Ares I/Orion space technology isn't scheduled to be released until 2014 – at the earliest – so NASA will need to purchase multiple trips into space aboard Russian Soyuz spacecraft.

NASA's dependence on Russia led some politicians and space experts to try and convince President Obama to delay the fleet's retirement until 2011.  However, possible safety issues would make even an additional spaceflight on each shuttle too dangerous for consideration, along with the minimum $3 billion per year that would be necessary to keep the fleet flight-ready.

The U.S. space agency is desperately trying to finish construction of the ISS before the shuttle fleet is retired, which would help reduce the number of necessary flights to the ISS.  It's still possible the ISS will be completed by 2010, when the shuttle fleet is retired.