The ‘B’ Variant of the CV family of crew vehicles is designed for exploration beyond LKO. This variant differs from the ‘A’ variant by having a larger fuel reserve, more advanced propulsion system, larger power generation and commutation systems. The latest version also incorporates a refuelling port, enabling the CV-3B to launch on a smaller rocket to LKO before using a pre-positioned ACUS stage to perform a TMI burn. The CV-3B has enough fuel reserves to return to Kerbin without the aid of the ACUS