The cost of the Orion crew exploration vehicle that will carry up to six astronauts to the International Space Station (ISS) from March 2015 has increased by $385 million and it will take two more years to design.

This is because of a NASA requested engineering change proposal issued on 15 December 2006. Because of this change NASA has extended its $3.9 billion five-year contract, won by Lockheed Martin last August, to design, test and build Orion, by two years and increased its total cost to about $4.3 billion.

Two test flights of Orion’s Orbital Sciences designed launch abort system have also been added, increasing the cost. NASA announced the cost increase late on Friday 20 April.