The LUS (Lyogkiy Udarnyi Samolyot, "Light Strike Aircraft") project's goal was to develop an attack aircraft to succeed the Sukhoi Su-25. Sukhoi's design was an unusual aircraft with two cockpits, a v-tail and a large fuselage. The left fuselage was to contain the piloting equipment and radar sensors, whereas the right fuselage was to accommodate the weapons systems and a Fire-control system. The aircraft was to be powered by one or two non-afterburning engines, and payload was to be stored within two large internal bays. Yakovlev and Mikoyan's design were based on their modified trainer models, the Yak-133 and the MiG-AC, respectively. The Yak-133 is a modification of the Yak-130, and the MiG-AC is a modification of the MiG-AT. The project was canceled in the early 1990s due to newer models of Su-25 proving to be sufficient in achieving this goal