[2] The satellite was developed by the Bulgarian Space Agency around the "Meteor" bus, provided by the Soviet Union as part of the Interkosmos program.

[3] Assembly took place in Bulgaria, and the spacecraft was launched from Plesetsk in 13:35 local time on 7 August 1981.

[4] During that same year the Bulgarian government organized a massive celebration to commemorate the 1300th anniversary of the country's founding.

The outer skin of the spacecraft, including the solar panels, is coated with a conducting material in order to allow the proper measurement of electric fields and low energy plasma.

[6] The satellite contains a large set of scientific devices, designed and built in Bulgaria: