The Breeze M upper stage successfully completed its fifth burn and deployed the Satmex 8 satellite in orbit Wednesday, ending a 9-hour flight to return the Proton/Breeze M launcher to commercial service for the first time since December.

International Launch Services confirms the completion of the Breeze M's third burn, a successful jettison of the stage's auxiliary propellant tank, and a good fourth burn.

The Breeze M and Satmex 8 should now be in a transfer orbit with a low point of 264 miles, a high point of 22,245 miles, and an inclination of 49.1 degrees.

The upper stage will coast for nearly 5 hours before igniting a fifth and final time to inject Satmex 8 into geostationary transfer orbit.

Separation of the Satmex 8 satellite is scheduled for 0419 GMT (12:19 a.m. EDT).

The Breeze M upper stage has finished the second of five burns planned for today's mission, ILS says. The nearly 18-minute burn was supposed to place the stage and Satmex 8 in an intermediate orbit with a low point of 167 miles, a high point of 3,106 miles and an inclination of 50.3 degrees.

After a two-hour coast, the Breeze M will ignite its main engine again at about 2235 GMT (6:35 p.m. EDT) for two back-to-back burns separated by a brief intermission to jettison the stage's auxiliary propellant tank.

ILS says the first Breeze M burn is complete, and the rocket is now in a coast phase until ignition of the second upper stage burn at about 2014 GMT (4:14 p.m. EDT).

T+plus 14 minutes, 30 seconds. International Launch Services confirms the Breeze M upper stage has ignited for the first of five burns in this mission. The first burn is designed to accelerate the rocket and payload from a suborbital trajectory into a low-altitude parking orbit.

T+plus 11 minutes, 15 seconds. Officials confirm successful shutdown of the Proton's third stage and separation of the Breeze M upper stage, which should soon ignite for the first of five burns.

This first burn should last about four-and-a-half minutes, placing the Breeze M and Satmex 8 in a circular parking orbit 107 miles high with an inclination of 51.5 degrees.

T+plus 7 minutes, 30 seconds. Proton's second stage has separated, and the third stage RD-0213 engine has begun its burn. The rocket's payload fairing has also been released now that the launcher is in the upper atmosphere.

T+plus 2 minutes, 20 seconds. The Proton's first stage has shut down and jettisoned, and the second stage engines are firing with a half-million pounds of thrust.

T+plus 70 seconds. The Proton rocket has passed the speed of sound and the phase of maximum aerodynamic pressure.

Liftoff of the Proton rocket, returning to commercial service carrying Mexico's Satmex 8 communications satellite to serve the Americas.

T-minus 60 seconds.

T-minus 2 minutes. The countdown is being run by a master computer sequencer.

T-minus 5 minutes. The exact launch time is 1906:48 GMT (3:06:48 p.m. EDT). It will be 1:06 a.m. local time at the Baikonur Cosmodrome.

T-minus 10 minutes. The Proton launcher on the pad weighs about 1.5 million pounds, and it will be powered into the sky by six first stage RD-276 engines producing more than 2 million pounds of thrust.

The Satmex 8 satellite weighs 12,068 pounds at liftoff. Satmex 8 was transitioned to internal power a few minutes ago.

T-minus 16 minutes. The current temperature at the Baikonur Cosmodrome is about 47 degrees Fahrenheit. Winds are out of the southeast at about 11 mph, and the skies are partly cloudy, according to International Launch Services.

With 20 minutes left in the countdown, everything remains on schedule for launch at 1906:48 GMT (3:06:48 p.m. EDT; 1:06:48 a.m. local time). It will take more than 9 hours to deploy Satmex 8 in the proper orbit.

The rocket is now fully fueled for launch. All stages of the Proton and the Breeze M consume hypergolic hydrazine and nitrogen tetroxide propellants.

Liftoff of the Proton rocket is 30 minutes away. This will be the:

• 384th Proton rocket launch since 1965
• 78th International Launch Services Proton since 1996
• 63rd Proton M using a Breeze M upper stage since 2001
• 25th Space Systems/Loral satellite on ILS Proton
• 1st Satmex satellite on ILS Proton
• 1st Proton of 2013

The launch pad gantry has moved away from the Proton rocket at Baikonur, revealing the silver booster as the countdown approaches the final hour until liftoff.

Russia's Proton rocket and Breeze M upper stage, a workhorse launcher used to boost communications satellites into orbit, will return to flight Tuesday for the first time since the expendable rocket put a payload in the wrong orbit on a flight in December.

Tuesday's launch will deploy Mexico's Satmex 8 communications satellite, a 12,068-pound spacecraft designed to aid video distribution, telemedicine, broadband connectivity, distance learning, and emergency services across North, Central and South America.

Liftoff from the Baikonur Cosmodrome in Kazakhstan is set for 1906:48 GMT (3:06:48 p.m. EDT), or in the predawn hours Wednesday at the launch site.

The mission will be conducted under the auspices of International Launch Services, the U.S.-based firm responsible for commercial flights of the Proton rocket.

Built by Space Systems/Loral, the Satmex 8 satellite was shipped from its California factory to Kazakhstan in November, where it was stored until Russian officials finished an investigation into a mishap during a Proton/Breeze M mission in December.

The Dec. 8 anomaly, which occurred during a burn of the Breeze M upper stage engine, resulted in the release of Russia's Yamal 402 communications craft in the wrong orbit. Engineers recovered the payload and placed it in the correct orbit several weeks later, but the orbit-raising process used more propellant than planned, reducing the satellite's operational lifetime.

It was the third in-flight problem with a Breeze M upper stage since August 2011. Officials with Khrunichev, the Proton/Breeze M contractor, halted subsequent Proton launches to diagnose the cause of the Dec. 8 anomaly and identify corrective actions.

Engineers looking over telemetry data found the Breeze M's nitrogen tetroxide oxidizer showed higher than previously recorded propellant temperatures at liftoff and higher than previously recorded thermal soak-back of engine heat, further raising the temperature of the oxidizer.

The higher than expected temperatures caused the oxidizer to evaporate from liquid to gas, and the Breeze M engine's turbopump ingested the gas, leading to over-speed of the pump's bearing without cooling normally supplied by the liquid oxidizer.

The over-speed damaged the bearing, leading to the premature shutdown of the engine, according to International Launch Services.

ILS said technicians would improve management of satellite and Breeze M thermal constraints on future missions.

Workers resumed Proton launch preparations in February, bolted together the rocket's three core stages, and fueled the Satmex 8 satellite and encapsulated it inside the rocket's nose shroud.

The Proton rocket on Saturday rolled from a fueling station to launch pad 39 at Baikonur. A giant hydraulic erector lifted the rocket vertical, and a servicing tower moved into position around the 191-foot-tall vehicle.

The rocket's three core stages will be loaded with hypergolic propellants in the hours before liftoff Tuesday, followed by removal of the launch pad's servicing gantry less than two hours before launch.

A computer-controlled countdown sequence will manage the final steps before liftoff.

After a nearly 10-minute flight under the power of the Proton core booster, the Breeze M upper stage will take over for five burns to inject Satmex 8 into an elliptical geostationary transfer orbit.

The first Breeze M burn, scheduled to last about four-and-a-half minutes, will place the rocket and Satmex 8 in a temporary low-altitude parking orbit.

Four more firings of the Breeze M main engine are planned in the ensuing hours. Shutdown of the engine's fifth burn is expected at about 0406 GMT (12:06 a.m. EDT) Wednesday.

Spacecraft separation is scheduled for 0419 GMT (12:19 a.m. EDT) in an orbit with a low point of 3,827 miles, a high point of 22,236 miles and an inclination of 18.38 degrees.

Satmex 8 will use is on-board propulsion system to reach a circular orbit 22,300 miles above the equator. The satellite's operating location in geostationary orbit is at 116.8 degrees west longitude.