More info from
https://www.nasaspaceflight.com/2017/06/spacex-falcon-9-second-flight-bulgariasat-1-mission/SpaceX launched Bulgaria’s first communications satellite on Friday – the first of two Falcon 9 launches in the space of two days – via the company’s second flight-proven rocket – which also landed a second time. Liftoff from Launch Complex 39A at the Kennedy Space Center was at 15:10 Eastern Daylight Time (19:10 UTC).
SpaceX Launch:
The payload of Friday’s launch, BulgariaSat-1, was a 3.7-tonne geostationary communications satellite.
The launch was the second of three missions SpaceX plan to fly in June, setting up a weekend double-header with the third, which is scheduled to depart from Vandenberg Air Force Base on Sunday carrying eight Iridium satellites. The BulgariaSat mission was also the third launch to take place on Friday, with Indian and Russian rockets lifting off ahead of it.
Constructed by Space Systems/Loral, BulgariaSat-1 is based around the SSL-1300 bus. With a total mass at launch of 3,669 kilograms (8,089 lb) the satellite is designed for at least fifteen years of service but is carrying sufficient fuel for a minimum of eighteen years in orbit. The spacecraft will be operated by Bulgaria Sat, a company affiliated with Bulgarian television provider Bulsatcom.
Friday’s launch carried BulgariaSat-1 into a geostationary transfer orbit, with the satellite using its R-4D-11 apogee motor to circularize its orbit. Once in geostationary orbit, BulgariaSat-1 will be positioned at a longitude of 1.9 degrees East.
From this location, it will be able to provide direct broadcasting and fixed satellite services to much of Europe, and parts of North Africa and the Middle East. A second beam has a smaller footprint, providing additional coverage of the Balkans.
The communications payload aboard BulgariaSat-1 consists of thirty-three Ku-band transponders. Thirty of these will be used for broadcasting, while three will provide fixed satellite services (FSS).
BulgariaSat-1 is the first Bulgarian satellite to launch in almost thirty-six years and only the country’s second spacecraft. Bulgaria’s only previous spacecraft was Bulgaria-1300, or Interkosmos-22, a modified Soviet weather satellite outfitted with scientific instruments.
Constructed and launched under the Soviet Union’s Interkosmos program – aimed at helping promote space science and achievement within other Warsaw Pact countries – Bulgaria-1300 was launched from the Plesetsk Cosmodrome in August 1981 aboard a Vostok-2M rocket.
Friday’s launch was the second time SpaceX has used what they term a “Flight-Proven” Falcon 9 vehicle – that is, one whose first stage has already been used for a previous launch.
