DS-U3-S satellite Credit - © Mark Wade

The original DS series spacecraft made maximum possible use of a common design scheme and equipment. The sealed casing of the spacecraft consisted of two hemispherical bulkheads joined by a cylindrical center section of 800 mm diameter. The length of the cylinder was varied according to the requirements of the internal payload. The casing was filled with nitrogen, and internal trusses allowed mounting of batteries, standard telemetry equipment, and mission-specific research equipment. Sensors for the research equipment were installed on the cylindrical section or on the upper hemisphere.

Common avionics included the BKRL-E command radio line equipment developed by NII-648, the Tral-MCD radio telemetry system and Rubin-1D orbit radio control systems developed by the Experimental Design Bureau of the Moscow Institute of Energy, the chemical batteries developed by All-Union Research Institute of Current Sources.

The thermal control system used two fans, a control unit, temperature sensors and an external radiator. The DS-MT and DS-MG variants used an offset heat exchanger with an external radiator.

The antennae suite included four rod antennae, five ribbon antennae, and one slot antenna. The spacecraft had no attitude control with the exception of the aerodynamically-oriented DS-MO. The mass of the spacecraft was between 47 kg and 321 kg. Net mass of the research equipment was between 4.5 kg and 44 kg. The active life in orbit was from 10 to15 days, dictated by the payload's power consumption from the batteries (except for the DS-P1 solar-powered radar target series) .Ground control and reception of data were via the Soviet military's ground tracking, command, and control network.

The success of the initial DS-series satellites resulted in an increased demand for low-cost small satellite missions to conduct scientific research. By 1962 the number of projects assigned to KB Yuzhnoye became so great that it was decided to transfer some satellite development projects to other design bureaus (the Meteor weather satellite to Yosifiyan at the VNIIEM State Scientific and Research Institute of Electromechanics in April 1962; the Tsiklon navigation satellite to Reshetnev at OKB-10 in August 1962; and the Yantar reconnaissance satellite to Kozlov in June 1967). Even then, to cope with the wide assortment of missions being assigned, it was necessary to design an improved universal satellite bus for the more demanding missions.

A requirements document from the Academy of Sciences of the USSR stated the need for such satellites with capabilities beyond those of the initial DS series. Preliminary Design for the DS-U was completed in 1963. Yuzhnoye proposed an improved DS-U common bus produced in five primary variants:

• DS-U1: Unstabilized and battery-powered bus
• DS-U2: Unstabilized and solar-powered bus
• DS-U3: Sun-oriented and solar-powered bus
• DS-U4: Stabilized bus with a recoverable capsule. Cancelled in 1965 and never flown
• DS-U5: Stabilized bus with propulsion system for correction or maintenance of orbit. Cancelled in 1965 and never flown

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	DS-1	Technology test version of the original DS light satellite design. Primary mission was to test launch vehicle.
	DS-2	A decision was made after two unsuccessful launches of the DS-1 to create a simplified DS-2 spacecraft based on the equipment and structural elements of DS-1 spacecraft. The cylindrical section for mission avionics was completely omitted.
	DS-A1	Carried military experiments to test communications and navigation equipment needed for command and control of Soviet nuclear forces (later used on the Uragan navigation satellites). Also conducted operational monitoring of cosmic rays, radiation from nuclear tests, and natural and artificially-produced radiation belts.
	DS-K-8	Detected meteoroid flux in near-earth space and carried unspecified military research equipment.
	DS-P1	Prototype ABM radar target; supported developmental experiments for ABM systems.
	DS-MT	Payload developed by the VNIIEM to test electric gyrodyne orientation systems. Also studied variations in the intensity of cosmic rays.
	Omega	Early Cosmos satellite, evidently using the Yuzhnoye DS satellite bus. Payload developed by the VNIIEM to test electric gyrodyne orientation systems.
	DS-MG	Payload developed by VNIIEM to test electric gyrodyne orientation systems. Also studied magnetosphere of the earth.
	DS-P1-Yu	Development of systems for air defense and the control of outer space.
	DS-K-40	Development of systems for the later operational Tselina satellites.
	DS-U1-A	Studied the optical characteristics of the atmosphere. Radiation observatory; 8 telescopes.
	DS-U1-IK	Studies ionosphere of the earth; version used for Intercosmos international launches.
	DS-U2-M	Development tests of atomic clocks.
	DS-U2-V	Military technology development satellite - mission still classified.
	DS-U4-B	Light satellite with recoverable capsule for biological studies. Cancelled in 1965 and never flown.
	DS-U4-T	Light satellite with recoverable capsule for low gravity materials and technology studies. Cancelled in 1965 and never flown.
	DS-U5	Light satellite with propulsion for periodic correction of orbit. Cancelled in 1965 and never flown.
	DS-P1-I	Operational radar target for the ABM forces.
	DS-U1-G	Studied the relationship between variations in the upper atmosphere and solar activity.
	DS-U2-D	Studied charged particle flows.
	DS-U2-I	Studied the influence of the ionosphere on passing VLF radio waves.
	DS-U2-MP	Studied cosmic dust particles in near-Earth space.
	DS-MO	Used in development of aerodynamic systems for stabilization and orientation of spacecraft. Also carried military optical equipment experiments.
	DS-U3-S	Specialized orbital solar observatory for measuring solar rays in multiple spectral zones.
	DS-U1-Ya	Studied charged particle flows and cosmic rays.
	DS-U2-GF	Conducted heliophysical studies.
	DS-U2-GK	Conducted complex geophysical studies of the upper atmosphere. Air density, auroral investigations.
	DS-U3-IK	Measurements of the sun; used for Interkosmos launches. Payload included East European experiments to study solar UV, X-ray effects on upper atmosphere. Investigation of solar radiation and its effect on the atmosphere of the earth.
	DS-P1-M	Target for IS ASAT systems tests.
	DS-U1-R	Studied spectral range of the UF.
	DS-U2-IK	Studied charged particle flows and the ionosphere; version used for Intercosmos international launches. East European experiments studied protons, electrons, alpha particles.
	DS-U2-IP	Studied the ionosphere and charged particle flows.
	DS-U2-MG	Studied the Earth's magnetic poles.
	DS-U2-K	Studied charged particle flows and cosmic radiation.
	DS-U2-MT	Measured micrometeoroid impacts and gamma rays.
	GVM DS-U2-IK	Designation indicates a mass model of the DS-U2-IK (which studied charged particle flows and the ionosphere). However flown after the functional spacecraft's flights were completed.