Kazakhstan would gradually reduce Proton carrier rocket launches from Baikonur space port and end them in 2025, an official with the national space agency (Kazcosmos) said Wednesday.

Kazcosmos Deputy Chairman Meirbek Moldabekov said Kazakhstan had signed an agreement with Russia on the reduction.

The Proton family of rockets was developed in the 1960s and first launched in 1965.

The current model, the Proton-M heavy launch vehicle, was designed to deliver satellites and automatic spacecraft to a near-Earth orbit and outer space. It uses toxic heptyl and nitric oxide and is therefore criticized by environmentalists.

The Proton series would eventually be replaced by a new launch vehicle known as the Zenit LV, which was under an upgrade program which would last until 2018, the official said.

But this did not mean the end of Proton launches in 2018, as the Zenit needed to "learn to fly," he said.

According to Moldabekov, Proton is Baikonur space port's "workhorse," and the port will be useless if Proton operations shut down.

Baikonur is the world's first and largest operational space facility. It launched the first manned spacecraft and the first satellites in history.

It now undertakes all of Russia's manned space missions, and is leased to Moscow by the Kazakh government until 2050 for an annual fee of 115 million U.S. dollars.

Source: Xinhua News Agency