International Launch Services (ILS) have launched the SkyTerra 1 telecommunications satellite via their veteran Proton-M launch vehicle and Breeze-M upper stage on Sunday. Lift-off from the Baikonur Cosmodrome in Kazakhstan was on schedule at 17:29 GMT, ahead of over nine hours of flight until the spacecraft was placed into orbit.
The Proton booster 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). Overall height of the three stages of the Proton booster is 42.3 m (138.8 ft).
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).
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, with Sunday’s launch being the sixth flight of the new configuration for the avionics bay. The Phase III upgrade uses 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.
The Proton M will be utilizing a 5-burn Breeze M mission design, after lifting off from Pad 39 at Baikonur. The first three stages of the Proton will use a standard ascent profile to place the orbital unit (Breeze M upper stage and the SkyTerra 1 satellite) into a sub-orbital trajectory.
The Breeze M will perform 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 geosynchronous transfer orbit. Separation of the SkyTerra 1 satellite is scheduled to occur approximately 9 hours, 14 minutes after liftoff.
The 5,400 kg Boeing Space and Intelligence Systems built 702HP satellite is designed for geomobile services, which will be a “major step in LightSquared’s creation of its next-generation, nationwide network that will be among the world’s first to combine satellite and terrestrial technologies,” according to the customer.
“The Light-Squared network will enable the company to offer 4G speed, value, and reliability which enables universal wireless connectivity throughout the United States.
“The company’s next-generation satellite system allows users within the United States to use standard handsets or other devices, equipped with the LightSquared chipset, to access the satellite system with high link availability and long battery lifetimes, with devices that have the same form-factor and functionality as conventional handsets and devices.
“Further, the combination of the LightSquared satellite system and the LightSquared 4G terrestrial network provides an unprecedented level of coverage throughout the United States.”
The satellite will be located at 101.3 degrees west longitude and is expected to have a service life of 15 years.
The launch was the tenth Proton launch in 2010, the 361st overall. It was also the 63rd ILS Proton launch, and the seventh ILS Proton launch in 2010. The mission – when completed – will be the first LightSquared Satellite to be launched on an ILS Proton, and the 14th Boeing satellite to ride on the Russian vehicle.