Since unveiling its plans for developing a commercial crew spacecraft, Boeing has emphasized that its CST-100 spacecraft was launch vehicle agnostic: it could launch on an Atlas 5, Delta 4, or Falcon 9. And when ATK announced its plans in February for the Liberty launch vehicle, Boeing officials added it to the roster of vehicles compatible with the capsule. Now, however, the company plans to focus its attention on a single rocket.
At a media teleconference scheduled for noon Eastern time today, Boeing officials will announce the formal selection of the vehicle that will be used for the CST-100′s test flights in 2015 and operational missions to the ISS and other orbital destinations. This downselect is not surprising: at an April briefing, CST-100 program manager John Elbon said that they would select a specific vehicle to “really lay out the abort scenarios” and details associated with them.
The clear favorite in this vehicle competition is the Atlas 5. Two other Commercial Crew Development (CCDev) awardees, Blue Origin and Sierra Nevada, have already picked the Atlas 5 to launch their crewed spacecraft, and ULA has an unfunded CCDev agreement with NASA to continue work on human-rating that launcher. ULA also offers the Delta 4, which does have Boeing heritage, but does not appear to be the subject of active human-rating work. Falcon 9 would require boeing to depend on a competitor, SpaceX, for its launcher, while ATK’s Liberty, unlike the other three, isn’t flying yet, raising the question of whether it would be ready by mid-decade or not.