An upgraded solid fuel rocket was successfully launched Tuesday from the Uchinoura Space Center in Kagoshima Prefecture, the Japan Aerospace Exploration Agency said.

The Epsilon rocket was launched at about 8 p.m. and the ERG satellite for studying Earth's radiation belts was released at about 8:15 p.m., JAXA said.

The 26-meter-long, three-stage rocket is Japan's second solid fuel rocket following a successful maiden flight in 2013. Its design allows lower operating costs and more frequent launches than the mainstay H-IIA and H-IIB rockets, which burn liquid propellants.

The Epsilon has been improved to send 30 percent more weight into orbit, with the second stage rocket carrying more propellants and expanded room inside the rocket nose allowing a larger payload. It can carry a payload of up to 590 kg, according to the agency.

As part of efforts to reduce launch costs for the Epsilon, a descendant of the M5 rocket that was retired in 2006, such technologies as an autonomous checkout system and mobile control via two personal computer units are employed.

Costs have been cut to ¥5 billion per launch.

The ERG satellite will orbit through the radiation belts and observe electrons and electromagnetic fields to study phenomena that cause satellite malfunctions and disrupt communications.