DB Salyut designed it on the basis of the transportation supply ship (TSS). Module Spectrum was launched from Baikonur on May 20, 1995 by the LV Proton-K. The mass of the module at the launch was 19640 kg. Its hermetic volume is 62 m³. The area of the main panels of the SB is 2*27 m2 (6.9 kW); the area of the additional panels of the SB is 2*38 m2 (9.3 kW). NiCd batteries of capacitance 360 Ah are set up on the module. It docked to the nose docking port of the core vehicle and by its robot arm redocked to the side port. It was primarily intended for setting up the optical equipment of high resolving power. Later the task was corrected and module was reaimed at the supporting the service systems of the complex in the working condition. Specifically, the second complement of the SB was set up on the module. At present module Spectrum is depressurized and is in partly working condition (3 from 4 SB panels are functioning). The composition of the scientific equipment of the module is given below.