An expendable Japanese solid-fuel rocket for launching scientific satellites into low-Earth orbit. Developed in 2007 at the Japan Aerospace Exploration Agency, Epsilon replaces the more expensive Mu rocket that retired the previous year. The rocket has three solid-fuel stages, with an optional liquid-fuel fourth stage for precise injections required by certain payloads. It stands 24.4 metres tall, measures 2.5 metres wide, has a lift-off mass of 91,000 kg, and is capable of carrying a 500-kg payload. The first Epsilon rocket (Epsilon X) was launched on 14 September 2013 and placed the Hisaki (SPRINT-A) scientific satellite into Earth orbit. A more powerful vehicle (Epsilon-2), featuring upgraded upper third and fourth stages, was successfully launched on 20 December 2016, from the Uchinoura Space Center, placing the Arase satellite into orbit. On 18 January 2018, JAXA successfully launched its new Epsilon-3, a 26-m-long, three-stage solid-fuel rocket, which placed a small radar satellite into Earth orbit