Japan has scheduled H-2 rocket launches for mid-May and late July carrying, respectively, a pair of Earth observation satellites and an unmanned cargo tug bound for the international space station.

Launch dates for the upcoming missions were announced March 21 by the Japan Aerospace Exploration Agency (JAXA) and Mitsubishi Heavy Industries Ltd., the Tokyo company that builds and operates Japan’s workhorse H-2 rockets.

First up is a May 18 launch from Tanegashima Space Center of an H-2A rocket carrying Japan’s Global Change Observation Mission-Water spacecraft, South Korea’s Kompsat-3 optical-imaging satellite and two small secondary payloads. The launch window runs through June 30.

Japan then plans to launch as soon as July 21 a station-bound H-2 Transfer Vehicle 3 (HTV-3) aboard the more powerful H-2B rocket. The launch window runs through Aug. 31. The mission will mark the third flight of the HTV and its brawnier booster, both of which debuted in September 2009 and last flew in July 2011.