Proton Rocket Fails to Put Satellite in Proper Orbit

An ILS Proton M rocket carrying the ArabSat 4A satellite is raised into launch position at Baikonur Cosmodrome, Kazakhstan. CREDIT: ILS. Click enlarge.

A Russian-made rocket booster malfunctioned during launch Tuesday, leaving an Arab telecommunications satellite below its intended Earth orbit and dealing a harsh blow to the commercial space industry.

The Proton M rocket roared off pad 39 at the Baikonur Cosmodrome in Kazakhstan at 2010 GMT (3:10 p.m. EST) carrying the ARABSAT 4A spacecraft. The commercial mission was managed by International Launch Services, the joint U.S.-Russian firm that markets Proton and American Atlas rockets.

About 10 minutes into the flight, the three lower stages of the Proton had completed their systematic firings and dropped away as planned. That left the Khrunichev-built Breeze M upper stage and attached satellite payload flying an initial suborbital trajectory.

The Breeze M's main engine ignited a few moments later to ascend into a 108-mile (173-kilometer) high parking orbit. ILS reported that the burn had occurred as scheduled, ending at T+plus 14 minutes, 45 seconds.

Three more engine firings were planned by the Breeze M over the next three-and-a-half hours to propel the 7,366-pound 3,341 (kilogram) satellite to geosynchronous transfer orbit.

Exactly when during the course of the launch the failure struck isn't clear based on information released by ILS tonight. But here is what was supposed to have happened:

The rocket was slated to remain in that parking orbit for 50 minutes, coasting across the Pacific and lower tip of South America before the next critical engine burn was expected, beginning at 2115 GMT (4:15 p.m. EST) and lasting 21 minutes. A minute after the burn's conclusion, the Breeze M would jettison its emptied Additional Propellant Tank -- a donut-shaped structure surrounding the stage's main body. The engine would then re-start at 2148 GMT (4:48 p.m. EST) for a three-minute burn.

The back-to-back burns were anticipated to produce an orbit with a high point of 22,236 miles (35,785 kilometers), low point of 538 miles (865 kilometers) and inclination of 51.5 degrees to the equator.

Had the mission been going according to plan, Breeze should have coasted in that orbit until 2349 GMT (6:49 p.m. EST) when a nearly eight-minute engine burn was designed to raise the low point upward to 1,957 miles (3,149 kilometers) and greatly reduce the inclination to 14.2 degrees. ARABSAT 4A was expecting to be released from the rocket motor at T+plus 4 hours to complete the launch.

"Preliminary flight information indicates that the Breeze M upper stage shut down early during its planned burn sequence," ILS said in its failure announcement. "As a contingency, the satellite was separated. We cannot comment on the disposition of the spacecraft at this time."

ARABSAT 4A carried enough fuel for its on-board propulsion system to maneuver the spacecraft to its final destination from the geosynchronous transfer orbit that the Proton rocket was targeting. Those maneuvers would circularize the orbit at 22,300 miles (35,888 kilometers) and reduce inclination down to the equator, reaching a geostationary orbit where the craft would match Earth's rotation and appear fixed over one location -- 26 degrees East longitude.

But a Breeze M failure in the midst of the complicated launch sequence likely strands ARABSAT 4A in a useless orbit with little hope of overcoming the mishap. The amount of fuel that would be required to cover missing altitude and inclination changes from the botched launch, plus the travels to achieve geostationary orbit, probably means the satellite cannot save itself.

The craft's current orbit, however, was not disclosed by ILS. The actual orbit the satellite is flying in will determine the chances of salvaging ARABSAT 4A.

The European firm EADS Astrium built the satellite based on the Eurostar E2000+ design. It is equipped with 24 C-band transponders and 20 Ku-band transponders as part of a communications package made by Alcatel Alenia Space.

ARABSAT 4A is the first in a new generation of spacecraft for the Arab Satellite Communications Organization of Riyadh, Saudi Arabia. The satellite would have provided direct broadcast television, data relay, Internet and telephony services across the Middle East, North Africa and Western Europe.

EADS Astrium is in the final assembly phase of readying the ARABSAT 4B spacecraft for launch later this year. That mission is scheduled to ride a Proton/Breeze M vehicle, too.

Tuesday's failure was the third in 36 launches of ILS Protons since commercial missions began in 1996. The two earlier mishaps -- in 1997 and 2002 -- involved Block DM upper stages, which ILS no longer actively markets for its Proton launches.

Ten previous ILS launches using the newer Breeze M had been successful since December 2002.

It is too soon to know the impact this failure will have on the year's Proton launch schedule. The next flight had been targeted for the end of April with the Hot Bird 8 communications satellite for European operator Eutelsat.

"A Russian State Commission is being formed to determine the reasons for the anomaly. In parallel with the State Commission, ILS will form its own Failure Review Oversight Board to review reasons for the anomaly and define a corrective action plan," ILS said in tonight's announcement.

"ILS remains committed to providing reliable, timely launch services for all its customers. To this end, ILS will work diligently with its partner Khrunichev to return Proton to flight as soon as possible."

Meanwhile, ILS' other rocket -- the Lockheed Martin Atlas -- has a remarkable record of 78 consecutive successful launches dating back to 1993. An Atlas 5 dispatched the first robotic probe to visit the unexplored planet Pluto last month, and the rocket's next launch is targeted for April 20 from Cape Canaveral.