After attaining orbit, the engines of the Zenit's second stage were shut down at 6:20 a.m. EST (10:20 GMT) and, one second later, the satellite separated from the vehicle.

As typical for classified launches, the Russian Ministry of Defense identified the spacecraft only as Cosmos 2372, with no details on its mission. However, earlier reports from the former Soviet Union indicated that a super-secret imaging reconnaissance satellite code-named Enisei could have been the Zenit's payload.

Enisei, named after a Siberian river, could not be immediately tied to any known Russian project. However, sources said that the satellite could be a likely successor to the Orlets 2 reconnaissance satellite previously launched by a Zenit 2.

The Orlets 2 is known to be one of the most advanced Russian imaging spy satellites providing high-resolution intelligence imagery. The 12-ton spacecraft sports 22 reentry capsules used to return exposed film to Earth. The Orlets are built by the TsSKB development center in the Russian city of Samara. The last spacecraft of this type was launched in 1994.

There were indications that a newer version of Orlets has been under development in Russia for some time, possibly renamed Enisei. A spacecraft of this type would allow the transmission of high-resolution photos in real-time -- similar to the U.S. intelligence satellites currently operating in orbit.

This was the second launch of the Zenit 2 booster from Baikonur Cosmodrome this year. In February, the rocket successfully delivered a Tselina 2 signal-intelligence satellite. The Tselina, built by the Yuzhnoe production and development center in Dnepropetrovsk, Ukraine, is the most common government payload for the Zenit 2 booster. This time, however, the company representatives said that the rocket would not carry a Yuzhnoe-built payload.