Sea Launch Zenit 3SL successfully lofts Eutelsat 3B

by Chris Bergin

Sea Launch has returned the Zenit 3SL rocket back to ocean launch activities via the lofting of the Eutelsat 3B satellite on Monday. Launch from the Odyssey Launch Platform occurred at the opening of the launch window at 21:10 GMT. This was the first launch since the February 1, 2013 failure of the rocket during first stage flight.

Zenit 3SL mission:

The Zenit-3SL is a hybrid concept developed by RSC Energia. The two stage Zenit features a modified Russian Block DM upper stage.

It is powered by the RD-171M engine on the first stage, with a RD-120 powering the second stage.

Sea Launch operations are under new management, after the old company’’s demise that came just a year after they returned to flight in January, 2007 – following the major impact of the failed launch which occurred with the NSS-8 communications satellite for SES New Skies

The vehicle dramatically exploded on the launch pad, destroying both the vehicle and satellite.

That initial RTF success came via the launch of the Thuraya 3 telecommunications satellite for the United Arab Emirates – a year after the NSS-8 failure.

Since reforming, mainly under the control of RSC Energia, the new company has successfully launched Atlantic Bird 7Intelsat 19,Intelsat 21 and Eutelsat 70B from their Odyssey Launch Platform in the Pacific Ocean.

However, another failure was suffered when the vehicle – along with its Intelsat 27 telecommunications satellite payload – suffered a failure during first stage flight, resulting in a complete loss of mission on February 1, 2013.

Zenit-3SL with Intelsat 27This latest launch was set to take place in April. However, during the final “dry” roll-out phase of integrated launch vehicle (ILV) processing at Home Port in support of the EUTELSAT 3B mission, a discrepancy in the nominal movement of the cable-mast and the Zenit-2S LV lateral plate occurred while installing the ILV onto the launch pad.

This caused mechanical damage to the lateral plate housing located on the inter-stage truss of the rocket.

A decision was made to de-mate the Payload Unit and Block-DM-SL onboard the Sea Launch Commander to resolve the issue, establish the root cause and perform additional checks of the interface between the launch vehicle and ground support equipment connectors.

With repairs successfully completed, the Sea Launch Commander and Odyssey Launch Platform set sail for their Pacific Ocean destination on the equator at 154 degrees West longitude. Preparations for launch have not suffered from any notable issues ahead of the launch of the Eutelsat bird.

Z8Based on the Eurostar E3000 platform of Airbus Defence and Space, the EUTELSAT 3B satellite has been designed to operate three commercial payloads in the C, Ku and Ka bands.

This tri-band configuration will deliver in-orbit flexibility and coverage from Eutelsat’s expanding 3 degrees East neighourhood.

“The satellite will enable Eutelsat to diversify its commercial response to Internet Service Providers, telcos, government agencies and broadcasters operating in Latin America, Europe, Africa, the Middle East and Central Asia. EUTELSAT 3B has a designed in-orbit lifetime exceeding 15 years,” according to the satellite company.

Z656Lofting the satellite into its designated transfer orbit involved the Zenit-3SL rocket enjoying a nominal first stage of flight, ending when the core stage of the vehicle separated 150 seconds after liftoff. The protective payload fairing was jettisoned 81 seconds later.

The second stage then conducted a six minute burn, followed by its separation from the Block DM-SL upper stage.

The Block DM-SL began the first of two burns at 521 seconds into the mission, for the duration of 279 seconds.  The upper stage then shut down for a 30.5 minute coast period, followed by the start of the second burn at 43:50 minutes into the mission.

ATKSpacecraft separation was confirmed at one hour and one minute hour after liftoff, over the Indian Ocean, successfully returning Sea Launch’s Zenit 3SL to launch operations.

“I am very pleased to once again announce the successful launch for our valued Eutelsat customer, our third in a row for them,” noted Sergey Gugkaev, CEO of Sea Launch. “I wish to express my gratitude to all of our colleagues at the launch site, Home Port and production and maintenance facilities for their hard work and dedication to Sea Launch program.”

(Images via Sea Launch, RSC Energia, Eutelsat and L2).

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