NASA is pointing its finger at Congress after signing an updated contract with The Russian Federal Space Agency (Roscosmos) that will add $424 million to what it has already agreed to pay the Russian agency in order to keep U.S. astronauts aboard the International Space Station, according to a NASA statement published Tuesday. 

The money will go towards flights to and from the ISS, as well as training for six other astronauts in 2016 and 2017, but NASA administrator Charles Bolden indicated the contract modification would not have been necessary if Congress had approved NASA's request for more funding for its commercial space effort. 

"Because the funding for the President's plan has been significantly reduced, we now won't be able to support American launches until 2017. Even this delayed availability will be in question if Congress does not fully support the President's fiscal year 2014 request for our Commercial Crew Program, forcing us once again to extend our contract with the Russians," Holden wrote in a blog Tuesday.  

"Further delays in our Commercial Crew Program and its impact on our human spaceflight program are unacceptable. That's why we need the full $821 million the President has requested in next year's budget to keep us on track to meet our 2017 deadline and bring these launches back to the United States.'

According to an Associated Press report, the new figures break down to $70.6 million per seat, an increase of about $7 million per seat on trips to the ISS.