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The fact that the small bodies as Comets and asteroids have been submitted to a very weak evolution turn them into witness materials of the early stages of formation of the solar system. After the successful multi—spacecraft missions to the Halley comet a great interest is focusing now on asteroids. The soviet mission to Phobos, launched in July 1988 is a peculiar opportunity to study such a small body which could reasonably be a capturated asteroid. The peculiarity is also in the very low and very slow flyby that can be performed in the case of Phobos ; it has been taken advantage of that to use methfds of active remote chemical analysis derived from the laboratory techniques SIMS and LAMMA

The technical model of the LIMA-D/PHOBOS experiment has been used for laser-ionization studies at IKI, Moscow. Nd- YAG-laser and TOF-type mass-spectrometer were used to obtain mass-spectra of several elements, metals, natural minerals, and artificial minerals. The mass resolution of the experiment seems to be stable and accurate enough even to separate isotopes from each other. Accuracy of the composition determination and other topics concerning this method will be discussed.

The rocket experiment ZARNITZA-2 on artificial electron beam injection in the ionosphere was carried out on September 11, 1975. Great attention was paid to the study of phenomena occurring in the near-rocket region. The results of the experiment are discussed in terms of a beam plasma discharge.

The paper presents some results obtained when a beam of electrons (energy 2 to 3.5 keV, current 0.2 to 0.4A) was injected from aboard the rocket at 100 to 150 km. At the moments the beam was injected perturbations of the near-rocket region are observed with a cross-section of about 500 m, it is much larger than the region over which the injected beam is extended. The appearance of the above region can be explained by the interaction of accelerated ions with the surroundings; the ions are generated during the positive rocket charge neutralization owing to discharge mechanisms. It is confirmed by direct measurements of the rocket potential which is about 2 kV near the apogee.

Measurements from the Ducma dust counter and mass analyzer on the Vega spacecraft are compared with those from the SP-1 sensor on the same spacecraft. It is shown that the sequence of pulses recorded by the SP-1 instruments show deviations from a random distribution. Some of the nonrandom sequences observed by SP-1 are in the same time intervals as the clusters observed by the Ducma instrument. The results support the analysis of Ducma data which showed highly structured variations of dust intensity through the coma and large fluxes of low mass particles extending to great distances beyond the coma (Simpson et al., 1986).

This paper describes two rocket experiments “Aelita” with high power lithium plasma injection. The results of onboard magnetometer, massspectrometer, photometer, plasma, corpuscular and ground radar measurements are given. Dynamics and structure of plasma formation are discussed.

Dust-impact PUMA mass-analysers aboard the spacecrafts VEGA-1 and VEGA-2 allow to conduct the first direct measurements of mass spectra of comet Halley’s dust envelope particles with masses higher than 10 -17 g [1,2]. The analysis of spectra measured by the PUMA instruments showed that unindentified peaks in this spectra could be associated with very small particles (mass 10-17–10-20 g).

The PORCUPINE sounding rocket project provided the opportunity to study the dynamics of an artificially injected plasma beam in the near-Earth space. The structure of the plasma beam, its propagation across the magnetic field as well as the resulting wave phenomena will be discussed.

In this paper different active remote sensing methods are discussed which can be appleid to investigate the composition of minor solar bodies. Methods using ion, laser and electron beams are treated in detail.

Venera-Halley mission is to be launched to Venus in Dec. 1984. It will fly by Venus in June 1985. Separation of the cometary probe and Venera descend module will take place at that time. The gravitational swing-by at Venus will provide the encounter with the Halley comet in March 1986. The remote sensing of the inner coma (TV-imagery, spectrometry in the region from 1200 A to 12 μm, polarimetry) and of the nucleus, direct measurements of dust fluxes, dust composition, plasma and magnetic field are planned in the framework of multinational cooperation.

The nucleus of P/Halley rotates as a slightly asymmetric top, the orientation of the rotation axis (i.e., the orientation of the angular momentum vector) is 1 = 39°, b = −54° in the ecliptic system. The error zone is a cone about this axis with a half opening angle of 15°. In the rotation of an asymmetric top the rotation axis is not fixed rigidly to the body; this means that while the nucleus rotates about the axis with the short period of 2.2 +/−.05 days, its long axis “nods” periodically with the long period of 7.4 +/−.05 days. The amplitude of the “nodding” is about 14° +/− 3° in both directions relative to a plane perpendicular to the rotation axis.

The Phobos mission represents a new type of scientific program having multiple scientific goals including investigation of Phobos, Mars, the Sun and interplanetary medium. The Phobos investigations will be made from very close distances approximately 5Cm from the surface. Important scientific goals are to obtain TV images of the surface, active and passive studies of its chemical and mineralogical composition, its physical properties and other experiments. Experiments are planned which will probe, by means of radiophysical methods, the properties of the Phobos surface down to depths of 20Cm. Also planned are sounders onboard the spacecraft having a number of scientific experiment which will measi~ire ~he physical.paramete~sQf Phol?os. ~The goals of the planned Mars investigation include ionospheric investigations, studies of the atmospheric aerosol component and dynamical atmospheric phenomena. A number of experiments will study the physics of the Sun, including its corona and upper chromosphere, solar oscillation, solar flares activity and solar constant determination. The investigation of the interplanetary medium includes studies of the solar wind, interplanetary shock waves, solar cosmic ray propagation and cosmic gamma bursts.

The quasilinear theory of MHD waves excitation by cosmic rays accelerated at a front of supernova shock has been constructed. It is shown that the energetic particles excite the waves propagating from the shock front, the intensity and the spectrum of these waves is obtained. The role of nonlinear Landau damping in the formation of such spectrum has been analysed. The diffusive scattering length of the high energy particles in the preshock region has been calculated and it is shown with the help of these formulae that the effective Fermi acceleration at the shock front is possible upto the values of the relativistic factor = 10 4 - 10 5 . The injection mechanism for cosmic rays acceleration has been proposed. It is based on stochastic Fermi acceleration of the thermal plasma by MHD waves excited in the preshock region. Different possibilities for wave phase velocity dispersion needed for stochastic Fermi acceleration are analysed, those are the excitation of the oblique magnetosonic waves as well as the excitation of parallel Alfven waves propagating in opposite directions. The distribution function of the suprathermal particles accelerated by MHD waves is obtained, the cosmic rays density as well as the lower boundary of their energy spectrum realised in the proposed mechanism are also calculated.