WASHINGTON, May 29 (RIA Novosti) - NASA has signed a $306 million deal with Russia's Federal Space Agency Roscosmos extending the current contract for transporting crew to the International Space Station.

The deal covers four Soyuz launches - two in spring 2012, and another two in fall 2012. It provides for post-flight rehabilitation of crewmembers, limited cargo transit to the ISS, and trash disposal.

NASA said in a statement on its website on Thursday that the contract modification also includes "comprehensive Soyuz support, including all necessary training and preparation for launch, crew rescue, and landing of a long-duration mission for six individual station crew members."

Alexei Krasnov, director of manned flight programs at Roscosmos, said earlier this month that Russia would be charging NASA $51 million for each seat on Soyuz spacecraft traveling to the ISS from 2012.

In October 2005, Congress permitted the resumption of space deals with Roscosmos after amending the Iran Nonproliferation Act.

The act had banned such deals due to Russia's nuclear cooperation with Iran, which Washington accuses of pursuing a covert atomic weapons program. Iran says it needs the program to generate electricity.

In 2007, NASA signed a $719 million contract for 15 Soyuz seats on return trips to the ISS as well as for 5.6 tons of cargo. That came out to about $48 million per seat, or $144 million for a three seat flight.

NASA said in April "these services are being procured through Roscosmos because the Soyuz is the only proven crew transportation and rescue vehicle [other than the Space Shuttle which is scheduled for retirement in September 2010] currently compatible and able to dock to the ISS and capable of providing the needed services."