Human space exploration vehicles must be designed with a reliable and safe launch escape systems to be activated in the event of a failure on pad, or at altitude. A safe, reliable, highly flexible, and adaptable launch escape system which can be used with any commercial vehicle is designed using novel gas-gas propulsion system. Preliminary design of  this Joint Universal Launch Escape & Assist System or JULEAS is detailed. JULEAS is designed to accelerate a crew capsule away from a launch vehicle in case of an emergency on the pad or during the early portions of the trajectory. It is designed to tractor the spacecraft to a sufficient altitude and with enough downrange translation so that the capsule's parachute landing system can safely function. During mid and high altitude aborts, JULEAS reentry g reduction mode can additionally start and stop its high  pressure gaseous oxygen and gaseous methane engines, and direct thrust in such a way to shape the reentry trajectory to reduce the abort reentry deceleration. Finally, JULEAS has an ascent-assist mode that can be used to offset the normal payload penalty in the event that the emergency abort function is not used.