File image of a Proton rocket lifting off. Photo: ILS

The first heavy-lift Proton rocket launch of 2003 occurred this morning with a classified Russian military cargo aboard that is rumored to be an early warning satellite.

Liftoff was at 0423 GMT (12:23 a.m. EDT) from the Baikonur Cosmodrome in Kazakhstan, kicking off a series of three launches from there over the next few days.

The Block-DM upper stage conducted a series of firings in the hours after launch to guide the new Kosmos 2397 satellite into the proper orbit. The spacecraft, believed to have been built by NPO Lavochkin, will operate in geostationary orbit 22,300 miles above Earth.

Today's flight marked the 15th orbital launch of 2003 overall, and the second of the year from Baikonur.

The next Proton is scheduled to lift off at 2215 GMT (6:15 p.m. EDT) Monday with the AMC-9 communications craft under the auspices of International Launch Services.

Meanwhile, the Russian Soyuz rocket that will ferry the next resident crew to the international space station was rolled to its launch pad earlier today. It is scheduled for blastoff at 0354 GMT Saturday (11:54 p.m. EDT Friday)