Two major rocket companies - ATK and Astrium - are in talks with NASA about a new vehicle which would carry out manned flights to the International Space Station (ISS).
The Liberty rocket would be based on two existing propulsion systems.
ATK would supply the human-rated first stage, developed under NASA’s Space Exploration Program. This five-segment solid rocket first stage is based on the Space Shuttle’s four-segment solid rocket boosters, which have flown 107 successful missions since 1988.
Astrium - developer and manufacturer of the Ariane 5 launcher - is teaming up with propulsion company Snecma for the second stage, based on the liquid-fueled cryogenic core of the Ariane 5 vehicle, powered by the Vulcain 2 engine.
Ariane 5, operated by Arianespace, has launched more commercial satellites than any other launch vehicle in the world.
"This team represents the true sense of international partnership in that we looked across borders to find the best for our customers," said Blake Larson, president of ATK Aerospace Systems Group.
"Together we combine unique flight-proven systems and commercial experience that allows us to offer the market’s most capable launch vehicle along with flexibility to meet a wide variety of emerging needs. Liberty provides greater performance at less cost than any other comparable launch vehicle."
Liberty would be able to deliver 44,500 pounds to the ISS, allowing it to carry any crew vehicle in development.
As it's based on already-approved technologies, the team believes it can carry out an initial flight by the end of 2013 and a second test flight in 2014, moving to full operational capability in 2015.
"The Liberty initiative provides tremendous value because it builds on European Ariane 5 launcher heritage, while allowing NASA to leverage the mature first stage," said Charlie Precourt, vice president and general manager of ATK Space Launch Systems.
"We will provide unmatched payload performance at a fraction of the cost, and we will launch it from the Kennedy Space Center using facilities that have already been built. This approach allows NASA to utilize the investments that have already been made in our nation’s ground infrastructure and propulsion systems for the Space Exploration Program."