Direct TV which is in the thick of a merger with Echostar is going to see the addition of another satellite to its constellation when an Ariane 4 rocket (Flight 146) launches DirecTV-4S into space (26 November 9:35 pm, French Guiana Time, 27 November morning India time).
A Boeing 601HP satellite, it is the largest of its type built by Boeing Satellite Systems (BSS) and will be the sixth Boeing-made satellite launched this year. In all, it will be the 61st Boeing 601 spacecraft launched to date built by Boeing Space and Communications, the world's largest satellite manufacturer.
The Ariane 4 rocket that will take the satellite into geostationary orbit at 101 degrees West longitude carries two solid and two liquid strap-on boosters. DirectTV-4S has five antennae, and features highly focused spot beam technology, the first in the DirectTV fleet to have this capability. This technology reuses the same frequencies on multiple spot beams to reach the major television markets where DirecTV delivers the signals of local network affiliates.
The satellite is designed to provide the DirecTV digital satellite television service with more than 300 channels of additional capacity to deliver additional local channels and to strengthen the redundancy of its existing in-orbit fleet of its earlier five satellites.
DirecTV-4S will also be the world's first commercial satellite to employ high-efficiency solar arrays with triple-junction gallium arsenide solar cells built by Spectrolab a BSS subsidiary. These solar cells are called triple-junction because they employ a three-layered structure, with each layer able to capture and convert a different portion of the solar spectrum.
The DirecTV-4S solar cells will be able to convert 24.5 percent of the sun's energy into electricity. The spacecraft's two solar arrays are together designed to deliver 8.3 kilowatts of power at the end of its 15-year design life.
The spacecraft will carry two Ku-band payloads: spot beams for local channels, and a national beam payload. The spot beam payload will use a total of 38 traveling wave-tube amplifiers (TWTAs) ranging in power from 30 to 88 watts. The national beam payload will carry two active transponders with further capability for two active high-power transponders and six active low-power transponders.
Once deployed, the DirecTV-4S solar arrays will stretch to more than 85 feet long from tip to tip, and its antennae will span 24.5 feet in width. The spacecraft fully fueled at launch will weigh 9,400 lbs. (4,260 kg).
The mission is scheduled to lift off during a 38-minute launch window that opens at 9:35 p.m. local time (7:00 am, IST, 4:35 pm PST, 12:35 am GMT, 27 November) from Arianespace's Guiana Space Center on the northeast coast of South America on 26 November.
