As RTV testing continued, the decision was made to build a larger version, RTV.2, which would be more typical of a production missile. During early testing, the design was further modified and renamed GPV, for General Purpose Test Vehicle. Several liquid rocket motors were tested as part of this program. Early tests demonstrated shifts in the center of gravity that required active damping, which in turn led to the lengthening of the overall fuselage to become the "long round". This version used forward-mounted boosters, which were mounted so their exhaust was just in front of the mid-mounted wings.