A hefty entry in the next round of NASA’s Commercial Crew Development (CCDev-2) seed-money effort would be able to lift 44,500 lb. of payload to the International Space Station, enough for any of the commercial crew capsules under development as potential space shuttle replacements.
Dubbed “Liberty,” the proposal would combine the uprated version of the shuttle’s solid-fuel booster rockets developed as a first stage for the terminated Ares I crew launch vehicle, and the first stage of Europe’s powerful Ariane 5 , with a Vulcain 2 main engine modified to start at altitude.
U.S.-based ATK, which built the shuttle rockets and developed the Ares I first stage, would be joined in developing the Liberty vehicle by Europe’s Astrium Space Transportation, the EADS subsidiary that builds the Ariane 5; Snecma (Safran Group), the Vulcain 2 manufacturer; United Space Alliance, which would integrate the big rocket and handle ground operations; and L-3 Communications, for first-stage avionics.
“The Liberty initiative provides tremendous value because it builds on European Ariane 5 launcher heritage, while allowing NASA to leverage the mature first stage,” says Charlie Precourt, a former shuttle astronaut who is 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.”
ATK already has static-tested the five-segment Ares I version of the four-segment shuttle solid-fuel booster twice , and the Ariane 5 has flown more than 40 times with commercial and scientific payloads over the past eight years. Introduced in 2002, the gas-generator liquid oxygen/liquid hydrogen Vulcain 2 generates 1,340 kn in vacuum.
Although the Vulcain would have to be modified to start after the first stage burns out, instead of at sea level, Astrium says it already has mastered in-orbit restart with the storable-propellant Aestus upper stage engine used on the Ariane 5 ES that lofts the Automated Transfer Vehicle. The company plans to introduce the capability for cryogenic applications in the Vinci upper stage earmarked for the Ariane 5 ME, a midlife update due to enter service around 2016-17.
NASA hopes to announce its selections in the $200 million CCDev-2 competition next month, pending congressional approval of the funding. Under the ATK/Astrium proposal, the first flight of the new Liberty vehicle would come in 2013, with a second test flight in 2014. The launcher would be ready to carry crew and cargo to the space station in 2015, the companies say.
Ariane 5 photo: ESA