Russia successfully test launched an RS-18 (SS-19 Stiletto) intercontinental ballistic missile from the Baikonur Space Center in Kazakhstan on Tuesday, Defense Ministry spokesman Vadim Koval said.

“The goal of the test launch is to prove the stability and basic technical characteristics of missiles of this kind,” Koval said.

The Russian Strategic Missile Forces are considering the possibility of extending the RS-18 missiles’ service term by one year to 33 years, he added.

A source in Russia’s defense industry said RS-18 missiles are currently used to test advanced warheads designed to penetrate missile defenses.

Developed by the Chelomei Design Bureau, the RS-18 is a silo-based, liquid-propellant missile, which together with the RS-16 (SS-17) and RS-20 (SS-18) comprises the fourth generation of Russian strategic missiles. The missile is capable of carrying up to six warheads.

The first RS-18 missiles entered service in 1975, with its improved version being put into service five years later.

In late November, Russian President Dmitry Medvedev ordered a series of steps intended to strengthen Russia’s missile defense capabilities in response to U.S.-European missile shield plans. Those plans include a possible deployment of Iskander tactical missiles near Russia’s Baltic Sea exclave of Kaliningrad “in the near future.”

Russia is seeking written, legally binding guarantees that the U.S. missile shield will not be directed against it. Washington, however, has refused to provide those guarantees to Moscow and said it will not alter its missile defense plans despite increasingly tough rhetoric from Moscow.