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 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.
The Breeze-M upper stage is the Phase III variant, a recent upgrade which utilizes two new high-pressure tanks (80 liters) to replace six smaller tanks, along with the relocation of command instruments towards the centre – in order to mitigate shock loads when the additional propellant tank is being jettisoned.
It was a problem with that upper stage which resulted in the loss of the Ekspress-AM4 communications satellite in August – which was not an ILS mission – when the stage, otherwise known as the Briz-M, failed to insert the satellite into the correct transfer orbit due to a problem with the last of the mission profile burns.
This failure led to a delay for the ViaSat-1 mission by ILS, which was initially scheduled for September. The launch was successfully conducted in October.
The Proton M launch vehicle, utilizing a 4-burn Breeze M mission design, lifted off from Pad 39 at Baikonur Cosmodrome, Kazakhstan, with the AsiaSat 7 satellite on board. The first three stages of the Proton used a standard ascent profile to place the orbital unit (Breeze M upper stage and the AsiaSat 7 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 orbit.
Separation of the AsiaSat 7 satellite occurred approximately 9 hours, 13 minutes after liftoff, at an orbital location of 13,814 km Perigee and 35,586 km Apogee – with an inclination of zero degrees.
AsiaSat 7 is designed as a replacement satellite for AsiaSat 3S at 105.5 degrees East. This new generation satellite will carry 28 C-band and 17 Ku-band transponders as well as a Ka-band payload. Its region-wide C-band beam covers over 50 countries across Asia, the Middle East, Australasia and Central Asia.
AsiaSat 7 also offers 3 Ku-band beams with intra beam switching capability, serving East Asia and South Asia, and a steerable Ku beam. AsiaSat 7 will provide satellite capacity for television broadcast and VSAT Network services across the Asia-Pacific Region.
The 3,813 kg (8,406 lbs) satellite was built by Space Systems/Loral and is expected to enjoy 15 years of service in orbit.
The launch is the fourth AsiaSat Satellite launched on ILS Proton, the 20th Space Systems/Loral Satellite launched on ILS Proton, the fifth ILS Proton launch in 2011 and 8th Proton launch in 2011 – marking the 69th ILS Proton launch overall.
(Images via ILS).