 U.S. Congress was aware a spaceflight gap could occur and accelerated funding in 2008 and 2009 in preparation for the retirement of the Shuttle.At that time the first crewed flight of the planned Ares I launcher would not have occurred until 2015, and its first use at ISS until 2016.Another option that has been analyzed is to adapt Orion to a humanman-rated heavy launch vehicle like the Delta IV Heavy.