International Launch Services (ILS) utilized its Proton M rocket again on Friday, this time to successfully launch the Türksat-4B communications satellite on what was a multi-hour flight to its transfer orbit. Launch from the Baikonur Cosmodrome in Kazakhstan was on schedule at 20:40 UTC.
Proton M Mission:
The Proton booster used to launch the Türksat-4B satellite is 4.1 m (13.5 ft) in diameter along its second and third stages, with a first stage diameter of 7.4 m (24.3 ft). The overall height of the three stages of the Proton booster is 42.3 m (138.8 ft).
The Proton vehicle has a heritage of over 400 launches since 1965 and is built by Khrunichev Research and State Production Center, one of the pillars of the global space industry and the majority owner of ILS.
The first stage consists of a central tank containing the oxidizer surrounded by six outboard fuel tanks. Each fuel tank also carries one of the six RD-276 engines that provide first stage power. Total first stage vacuum-rated level thrust is 11.0 MN (2,500,000 lbf).
Of a conventional cylindrical design, the second stage is powered by three RD-0210 engines plus one RD-0211 engine and develops a vacuum thrust of 2.4 MN (540,000 lbf).
Powered by one RD-0213 engine, the third stage develops thrust of 583 kN (131,000 lbf), and a four-nozzle vernier engine that produces thrust of 31 kN (7,000 lbf).
Guidance, navigation, and control of the Proton M during operation of the first three stages is carried out by a triple redundant closed-loop digital avionics system mounted in the Proton’s third stage.
It has suffered its fair share of problems, but successfully conducted a Return To Flight (RTF) mission recently, following the May 16 failure that resulted in the loss of the MexSat-1 (Centenario) communications satellite on what was supposed to be a multi-hour flight to its transfer orbit.
This latest mission is also a long haul for the Breeze-M upper stage, utilizing a 5-burn mission design.
The first three stages of the Proton used a standard ascent profile to place the orbital unit (Breeze M upper stage and the TURKSAT-4B satellite) into a sub-orbital trajectory.
From this point in the mission, the Breeze M performed planned mission maneuvers to advance the orbital unit first to a circular parking orbit, then to an intermediate orbit, followed by a transfer orbit, and finally to a geostationary transfer orbit.
Separation of the TURKSAT-4B satellite occurred approximately 9 hours, 13 minutes after liftoff.
“This is the second ILS Proton launch for Mitsubishi Electric and Turksat, following the launch of TURKSAT 4A in February of last year,” noted ILS President Kirk Pysher.
“It has been an honor to be entrusted with these important satellites and to ensure their safe delivery to orbit. The teams at Mitsubishi Electric, Turksat, Khrunichev, and ILS are to be commended for their tireless work and dedication.”
The satellite is based on the Mitsubishi Electric’s DS2000 platform. It sports 36 transponders and has a 2084 MHz communications capacity. It is expected to have a lengthy 30 year lifetime in orbit.
Once operating in space, the satellite will provide telecommunication and direct TV broadcasting services over a wide geographic region between west of China and east of England spanning Turkey, as well as Europe, Central Asia, the Middle East and Africa.
It will be positioned at 50 degrees east longitude and consists of multiple transponders expanding the space capacity of Turkey and provide enhanced performance to its coverage areas. The satellite will provide high flexibility of switchability and connectivity among different service areas to its customers.
“Our first Proton launch with ILS last year was flawless; we are very pleased that our second launch with TURKSAT 4B was equally as successful with an extremely smooth mission and execution of the launch,” added Yasunori Kamochi, Mitsubishi Electric General Manager of Space Systems Division.
The fourth ILS Proton launch of 2015, this launch marked the 91st ILS Proton mission overall, the second for TURKSAT and also the second Mitsubishi Electric satellite to be lofted by the ILS Proton.
(Images via ILS and TURKSAT)