Considering a number of options for a space launch vehicle propulsion system, between advanced rocket motors and airbreathers, in particular thermally integrated LRE-based combined cycle engines, a new cycle, given the name KLIN (meaning wedge in Russian), is proposed as the 'third' way. It consists of a combination of LRE and DCTJ (with oxygen addition to atmospheric air). Currently the KLIN concept is considered for application to a VTOHL vehicle, with the DCTJ and the LRE optimized individually with a possibility for incorporating an aerospike-type nozzle. Retaining a rocket trajectory up to Mach 3 the LRE and the DCTJ are assumed to operate together from take-off with a gradual reduction in the DCTJ output, tinally terminating the DCTJ at Mach 6. It can be shown that the KLIN, although somewhat heavy, can be manufactured with available or foreseeable technology, and provides a combination of engine weight and specific impulse that yields twice the payload mass fraction, in addition to other advantages, compared to a LRE operated vehicle.