A model of the Proton M rocket. Note the larger payload fairing. Photo: Anatoly Zak

The long-delayed maiden flight of the Proton M rocket, the more advanced version of the Russian workhorse launcher, finally lifted off from the Baikonur Cosmodrome today and placed a communications satellite into Earth orbit.

Launch occurred at 0347 GMT (11:47 p.m. GMT Friday) and deployment of the Ekran M-18 satellite cargo from the nw Breeze M upper stage followed about seven hours later.

"Congratulations to Khrunichev on this successful first Proton M/Breeze M flight," said Mark Albrecht, president of International Launch Services (ILS), the Lockheed Martin-Khrunichev-Energia space transportation partnership. "By taking an evolutionary approach and phasing in the upgrades, our partner has demonstrated increased capability while minimizing risk to reliability."

Today's flight was solely managed by the Russians. Later commercial flights will be take place under the auspices of ILS, which globally markets the Proton and American Atlas rocket fleets.

The flight version of the Proton M rocket arrived to Baikonur in July 2000 and at the time its first test launch was expected as early as August 2000. However, technical and financial problems repeatedly delayed the mission to October and November 2000 and then to March 2001.

In December 2000, the Proton-M was rolled out to the pad to test its interaction with the systems of the launch complex. According to the representatives of Rosaviacosmos and Khrunichev enterprise, the Proton manufacturer, several problems with the interfaces of the vehicle and the hardware of the launch complex were discovered during the tests on the pad.

The Proton-M mission became a priority after the problems with the orbiting Ekran-M 15 spacecraft had threatened to disrupt the delivery of TV programs in the vast areas of Siberia and the Russian Far East.

On March 27, the Proton-M was rolled to the launch Pad 24 in Area 81 in Baikonur Cosmodrome for the final integration tests of the vehicle and the launch complex.

Serviced by the personnel of the Russian Strategic Missile Forces, Pad 24 was specifically modified for the launches of the Proton-M vehicle and currently it is the only one of four Proton launch complexes compatible with the new vehicle.

The final tests of the Proton-M on the launch pad continued until March 30, when the rocket was returned to the processing complex for the fueling of the Breeze-M upper stage.

On April 2, the Proton-M, fully integrated with the payload and the upper stage returned to the Pad 24 for the final pre-launch processing.

Depending on the results of the first test launches -- two or three flights are planned -- before the vehicle will be certified for the routine commercial missions. Due to a high-cost of the Proton launcher, Rosaviacosmos plans all test launches will fly with actual payloads onboard.

Illustration of the Proton M vehicle with a Breeze M upper stage. Photo: ILS

Proton M: An updated launcher
The Proton M features several modifications designed to increase payload and reliability of the vehicle, comparing to the present version of the rocket, known as Proton K.

For the first time, digital flight control system will replace traditional analog hardware onboard Proton. It will allow more efficient propellant consumption during the flight and, as a result, the delivery of bigger payloads into the orbit.

The rocket will become even more powerful thanks to a new version of the RD-253 engines on the its first stage. Moscow's Energomash development center increased the trust of the engine from 151 to 160 tons.

With these two improvements the Proton M will be able to deliver 22 tons of cargo into the low Earth orbit comparing to 20.7 tons for the standard booster.

For the missions beyond initial low orbits, the new Proton will get more advanced fourth stage called Breeze M. The new stage has already completed its inaugural flight onboard regular Proton K booster in May 2000, when it is delivered the Gorizont communications satellite.

Breeze M takes much less room onboard the launch vehicle comparing to its predecessors leaving additional volume for the cargo. As a result, the new payload shroud topping the rocket will offer 2.5 times more volume for the satellites onboard Proton K.

The first payload
The Proton M test flight will also be an end of an era for a generation of the Russian communications satellites.

During its test mission the rocket will deliver Ekran M-18 communications satellite into the circular orbit 36,000 kilometers above the Equator.

This two-ton spacecraft was developed in the 1970s and it will be the last of its kind to be launched. The two-ton spacecraft carrying a single TV-relay channel seemed very small comparing to the modern communications satellites equipped with dozens of transmitters.

The representatives of the Russian Aviation and Space Agency said that one more Ekran M-type spacecraft would remain on the ground after the Proton M test launch. However, this spacecraft will likely end up in a museum, since its storage time has already expired and there are no plans to launch it.

More things to come
Khrunichev enterprise in Moscow, which develops the Proton rocket, hopes to introduce even more drastic changes in the Proton's design in the future. Currently, KB Salyut, Khrunichev's design arm, is developing even more powerful upper stage for the Proton M. Designated KVRB, it will employ super-cold liquid hydrogen and liquid oxygen -- the same propellant used in the US Space Shuttle's main engines.

The development of the cryogenic stage initiated by Khrunichev in 1980s has been stalled for years by Russia's financial problems. The work, however, was recently progressed somewhat thanks to commercial deals with India, which eyed similar technology for its own space launcher.

KB Salyut has developed the cryogenic upper stage for the Indian government and hopes to use its off-the-shelf technology for the even bigger stage for Proton. KB Salyut representatives said that the Proton's cryogenic stage would house 18 tons of propellants comparing to 12 tons carried by the stage developed for the Indian government.

With the new cryogenic stage, Proton rocket will be able to compete with Ariane 5 rocket, the most advanced European launcher, despite geographical disadvantage plaguing Russian launches from Kazakhstan comparing to Arian's launch site in equatorial region of French Guinea.

Spaceflight Now's Justin Ray contributed to this report.