The Interhelioprobe mission aims to investigate the inner heliosphere and the Sun from close distances (up to 0.3 AU) and from out of the ecliptic plane (up to 30°). In this paper we present the relevance of the mission and its main scientific objectives, describe the scientific payload, ballistic scenario and orbits of the spacecraft. Possibilities of scientific cooperation with other solar and heliospheric space missions are also mentioned.

The energy spectra of electromagnetic field and plasma density in the 10−4 - 4×10−2 Hz frequency bands observed on Vega 1 behind bow shock are presented. It has been shown that the spectral maxima coincide with the cyclotron frequencies of cometary molecular ions.

Flux transfer events (FTEs) are common on the Earth's dayside low- and mid-latitude magnetopause, where they tend to occur for southward interplanetary magnetic field (IMF) orientations. Direct events exhibiting (+,-) bipolar signatures normal to the nominal magnetopause predominate at northern latitudes, whereas reverse events exhibiting (-,+) bipolar signatures normal to the nominal magnetopause predominate at southern latitudes. This paper reports Interball-1 magnetometer observations of reverse events on the high-latitude northern magnetopause and direct events on the high-latitude southern magnetopause. During one sequence of events, the sense of the bipolar signature normal to the nominal magnetopause reversed. In conjunction with the fact that most events occur when and where magnetosheath and magnetospheric magnetic field lie nearly antiparallel, the observations suggest that lobe events are generated locally on the high-latitude magnetopause.

It is shown that the ion-plasma method can be combined with the diffusion methods for the formation of complex heat- and corrosion-resistant coatings on blades of ЖC6У alloy. The complex method enables one to apply metal layers, for example, Ni–Cr–Zr, and to produce surface ceramic film based on fcc ZrO2. A version of the coating satisfied the imitative tests and, as a part of an article, the pilot-industrial tests.

The microhardness and corrosion resistance of 35–40-μm-thick vacuum–plasma coatings of Ti, Zr, Ti–TiN, or Zr–ZrN, which were applied to structural carbon steel substrates, were studied. The properties of the coatings were compared with those of a 12X18H10T-steel coating, which had been suggested as a corrosion-resistant coating. The corrosion resistance of both Ti and Zr coatings was found to be virtually unaffected by further applying a nitride surface layer. The coatings, in order of increasing corrosion properties, can be arranged in the sequence: Ti–TiN, Ti, 12X18H10T-steel, Zr, and Zr–ZrN. The question on the corrosion mechanism of the coatings was touched on.

The cause of damage in internal and external containers of the nozzle set of the first stage of the TV3-117 engine is shown to be the intercrystallite gas corrosion of the materials of which they are produced (alloy KhN38VT and steel 12Kh18N10T, respectively). It is shown that low-active circulating-gas aluminizing can be used for repairing the parts, increasing their high-temperature strength, and “curing” micro- and macrocracks.

The scheme of gas-abrasive wear test of turbine compressor blades under free vibration of blades, including at high temperatures, is proposed. The amplitude- and time-dependences of the wear rate of εν961-steel and BT8-alloy blades, having either with or without a (Ti,Zr)N coating, were compared. The coating's effectiveness is almost the same for both cases at 20°C, but at 150°C, it is lower for steel blades because of spalling the coating due to its deficient adhesion.

Ti-N three-layer vacuum-plasma coatings 50–60-μm thick deposited on VT3- and OT4-alloy turbine compressor blades by a high-energy technology were studied. The gas-abrasive wear resistance of the coatings on VT3 alloy was superior to those on OT4 alloy at 20°C, but inferior at 250°C. The coatings were not susceptible to climatic corrosion. Their cycle-temperature stability were higher on OT4 alloy.

Results for stator and rotor turbine-compressor blades (EI961-grade steel) coated with (Ti, Zr)N-based corrosion-resistant coatings and tested for corrosion, wear, and fatigue are presented. Thin Zr, Cr, and Sc interlayers sandwiched between the outer coating and the base metal and treatment with a perchloric acid solution improve the resistance to corrosion. Further improvement of the corrosion-resistance properties of the blades is achieved by combining low-temperature calorizing with ion-plasma sputtering.

The properties of compressor blades of a helicopter gas-turbine engine with an experimental ionplasma coating Zr−Cr−N, are compared to those with Ti−Zr−N basic composition. It is shown that, due to the structural properties, the experimental coatings make the blades more corrosion-resistant, and mitigate the dependence of their residual properties on the amplitude and the temperature of the preliminary vibrotempering.

Magnetic field variations, produced by field aligned currents during substorm on November 13, 1996 were investigated on the base of magnetic field measurements by the Interball-2 spacecraft. It is shown, that satellite observations are in a good agreement with magnetic field observations at ground level and with Iijima and Potemra model.

The effect of multiphase Ti(C,N) coatings-produced by ion-plasma spraying with subsequent activator-free diffusion carburizing-on the properties of turbine compressor blades, made of EI961 and BT8 alloys, was investigated. The suggested coating relative to TiN causes an increase in wear resistance by a factor of 1.3 and retains the set of chemical-mechanical properties. A similar treatment of the steel blades results in a drastic degradation of their corrosion resistance.

The dependences "wear resistance vs. temperature" of the compositions (sic)961 + (Ti, Zr)N and BT8 + (Ti, Zr)N were measured and the service life limit of the materials was estimated. The effects of free-vibrational amplitude and preliminary tempering temperature on residual wear resistance, corrosion fatigue, and yield strength were determined. Some essential differences in behavior between the steel and coated titanium blades were revealed.