In view of the increasing number of science experiments being carried out in the Russian Segment of the International Space Station, there is a growing interest in the state of the environment where they are conducted, especially, in the contaminating effects of the external induced atmosphere. Sources of the induced atmosphere contamination are the off-gassing of non-metallic materials of the outer coatings, firings of control system thrusters and exhausts of various venting systems, as well as dust particles remaining on the external surfaces after launch from Earth, atmospheric aerosols and space dust. The paper presents results of measurements of molecular depositions on the sensors of quartz crystal microbalances that were used for evaluating contamination in the induced atmosphere of the first Soviet orbital stations Salyut-7 and Mir, as well as modules Pirs and Poisk of the Russian Segment of the International Space Station. The results of the experiments show a significant effect of lighting and thermal conditions of the contamination source and the quartz microbalance sensor on the measurement results. Key words: contamination, quartz crystal microbalance, orbital, external induced atmosphere.

The paper presents results of conceptual design studies to determine configuration of an electrically propelled upper stage (EPUS) – a space transportation stage (a space tug) with main engines based on electric propulsion powered by solar arrays. It addresses the problem of deploying a multi-plane orbital constellation of small spacecraft (SSC) using an electrically propelled upper stage. It proposes to change the SSC operational orbital planes based on the effect of the difference in precession rates between the parking and the working orbits owing to the effect of eccentricity in the Earth gravitational field. Requirements have been defined for the EPUS electrical propulsion system that take into account the need to operate it to offset the aerodynamic drag while waiting in the parking orbit for the SSC operational orbital plane to turn. It demonstrates the feasibility of employing four EPUS that use Stationary Plasma Thruster-type electric propulsion as their main engines and gallium arsenide solar arrays for deployment in a 600 km orbit in four planes an orbital constellation of 24 small spacecraft with a mass of ~250 kg each using one launch of a medium capacity launch vehicle of Soyuz-2.1b type. Key words: Electrically propelled upper stage, electric propulsion, small spacecraft, orbital constellation.

A brief review of existing (handheld cameras and spectrometers) and developed (hyperspectral and infrared equipment) means of the Russian segment of the ISS for remote sensing of the Earth is given. The problem of planning Earth observation sessions from the ISS in the framework of space experiments «Uragan», «Dubrava», «Scenario» using manual and stationary equipment is considered.

The paper discusses an integrated system for spacecraft rendezvous and docking using measurements from satellite navigation equipment combined with the optical final approach subsystem (OFAS) which generates high-precision relative position vector during final approach It addresses issues involved in designing an OFAS which has to operate in an environment exposed to sunlight and provides an estimate for the accuracy of the relative position measurements depending on the current range and OFAS configuration. Simulations have been run of the final approach involving simultaneous control for m the satellite navigation equipment and OFAS. It was shown that at the moment of initial contact the approach accuracy of 2–5 cm for relative position, and of 1 cm/s for velocity is achieved. Key words: spacecraft, navigation, rendezvous, docking, final approach, satellite navigation, optical sensor, TV camera, control, precision.

The paper presents results of unsolicited exploratory design studies done by the authors into the feasibility of developing for a super-heavy launch vehicle a single-stage oxygen-hydrocarbon acceleration/deceleration unit (ADU) with two liquid-propellant rocket engines 11D58M developed by RSC Energia, intended for insertion of manned spacecraft into lunar orbit, as well as for insertion of super-heavy spacecraft into geostationary orbit (including the orbital module high-apogee transfer profile using lunar gravity assist maneuver). It demonstrates that the single-stage ADU will have a number of important advantages over both a single-stage oxygen-hydrogen ADU and a functionally similar two-stage acceleration/deceleration system of an orbital module in the form of a tandem stack of an oxygen-hydrogen acceleration stage and correction and braking stage. To assure the start-ups of the main liquid propulsion system of the ADU, it proposes a new method for inertial propellant component phase separation in the tanks in zero-gravity environment using a pre-startup pre-programmed ullage separation turn maneuver of the orbital unit about its transverse axis of inertia. Key words: Integrated launch vehicle, launch vehicle, orbital module, upper stage, orbital transfer vehicle, acceleration/deceleration unit, ullage maneuver, liquid-propellant rocket engine.