JAXA and Mitsubishi Heavy Industries successfully launched two new Earth Observation (EO) satellites in the days before Christmas: the Global Change Observation Mission–Climate (GCOM-C) spacecraft, nicknamed Shikisai, and the Super Low Altitude Test Satellite (SLATS), nicknamed Tsubame.

An H-2A F37 rocket carried both satellites into orbit on Dec. 23 from JAXA’s Tanegashima Space Center. JAXA announced it received telemetry signals from the two satellites the day after launch, confirming that solar array deployment and attitude control occurred as scheduled.

Shikisai carries an optical sensor as part of a long-term mission to monitor both global water circulation and climate change via aerosol-cloud interactions. Its Second Generation Global Imager (SGLI) conducts surface and atmospheric measurements related to the carbon cycle and radiation budget, according to JAXA.

Tsubame is unique in that it operates in a super Low Earth Orbit (LEO), at an altitude lower than 300 km (186 mi). The satellite uses an ion engine to counteract the higher air resistance it experiences in this orbit, and is part of JAXA’s efforts to verify that such technology can support orbiting at low altitudes over an extended period of time. The satellite will also collect atmospheric data, JAXA stated.