The Epsilon-S is a successor to the current Epsilon launch vehicle which already used H-2A series rocket derived SRB-A3 solid rocket booster technology along with two Solid Motor Side Jets (SMSJ). The new rocket, which can carry 600 kg to a 700km sun-synchronous orbit, uses an improved SRB-3 first stage of the new H-3 rocket along with the M-35 solid rocket motor of the original Epsilon for its second stage, and a version of the KMV-2 third stage, plus the Post Boost Stage – a liquid fueled stage.

Epsilon-S has already been booked to fly the NEC-built 580 kg LotuSat-1 radar satellite for Vietnam on its maiden flight in 2023.