Delta IV stage eyed for Orion test

NASA plans to use a modified Delta IV second stage atop an early version of the Space Launch System for the unmanned Orion test flight in 2017, as well as for the manned flight four years later. In a May 3 procurement notice, NASA said the Boeing-designed Delta IV second stage is the only means available to support the immediate propulsion needs, and it’s the only one that requires relatively minor modifications to launch astronauts by 2021. (Source: Florida Today, 05/16/12; NASA procurement notice, 05/03/12) The SLS first stage will use RD-25 engines tested at Stennis Space Center.