Russian future projects

366$94 Adv.SpaceRw. Vol. 17,No. 415, pp.(ar5)35944/5

Pergamon

0273~1177(95)00@0-1

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RUSSLAN FUTURE PROJECTS V. N. Oraevsky and V. V. Fomichev

ABSTRACT A preliminary results of the CORONAS-I which is the fist spacecraft of the CORONAS mission are presented in figures. The project of a system of spacecrafts for the continuous rno~t~~~ of the solar phenomena at the whole snrface of the Sun and obtaiuing three-dimention images (tomo~aphy) of solar fo~ati~ are proposed.

CORONAS MISSION The CORONAS missions began in March 2 1994, when the first of three orbiters, CORONAS-I, was launched. The second satellite, CORONAS-F, and the third one are scheduled in 1996 and 1998, respectively. The mission is intended for the study energy transfer from solar euterior, solar flare processes and its influence to Earth’s magnetosphere including: energy transfer from the solar interior to surface and subsequent release in the solar flare events; explosive flare processes on the Sun; characteristics of solar cosmic rays, exit conditions, their propagaitons in the IMF and effects of the Earth’s magnetoshere; developing the theory of flares and te~ques

of forecasting their geophysical effects;

The satellite was set into a polar orbit with altitude of about 500 km and the inclination of about 83” . It is quasisynchronous to asssure recurrence of the 20d periods when orbit is outside the Earth shadow. The base for the future satellites of CORONAS missions is orbiter CORONAS-I.

The Study Team V. Oraevsky, V. Fomichev, V. Klepikov, A. Stepanov, S. Pulinets, I. Prutensky, R. Gorgutsa, Yu. Zhugzhda, N. Lebedev, I. Kopaev, R. Gorgutsa (Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences (I2~AN}). I. Sobelman, I. Zhitnik (P. N. Lebedev Physical Institute of the Russian Academy of Sciences). E. Mazets, G. Kocharov (A. F. Ioffe Physical Technical Institute of the Russian Academy of Sciences). P. Svidsky, A. Nusinov, T. Kazachevskaya {Institute of Applied Geophysics, Moscow). M. Panasyuk, S. Kuznetsov, C. Rumin, A. Podorol’sky (Institute of Nuclear Physics Moscow State University). R. Kostyk (Main Astronomical Observatory, Kiev). 2. Klos, A. Kiraga (Space Research Center Polish Academy of Sciences).

V. N. Oraevsky and V. V. Fomichev

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Ja. Silvestr (Central Astronomical Iustitute of Polish Academy of Sciences). K. Kudela (Institute of Experimental Physics of the Slovakian Academy of Sciences). C. Fisher (Astronomical Institute of Czechian Academy of Sciences). “SYSTEM”

PROJECT

Solar and solar-terrestrial studies carried out for many years suffer essential limitations imposed by the fact that all systematic observations have been made from a single point (from the Earth or its neighborhood). The principal shortcomings are: The lack of full survey - we are absolutely unaware of what is coming about on the back side of the Sun; observations at an acute angle near the limb are inefficient; the structure of the polar regions is practically unknown. Flat pattern -

we cannot obtain a three-dimensional pattern of any feature in the Sun.

Blind zone - some fundamental events of solar activity, such as large-scale mass ejections (transients), that strongly affect the entire system of Sun-Earth relations, are invisible against the bright solar disk while moving straight to the Earth. These limitations on the study and monitoring of the sole space object that profoundly affects the Earth and the human life are the more deplorable that technical facilities to overcome them have been available for some time now.

Scientific Tasks Establishing of a system of continuous full survey of the Sun and its environment would promote solution of many vital problems such as prediction and monitoring of geophysical effects of solar activity in the Sun-Earth system (A), as well as the problems of solar and heliospheric physics as a whole (B). Some of the principal problems are as follows. (A) Prediction and Monitoring of GeoefFective Phenomena. Monitoring and prompt diagnostics of short-term effects (O-3 days) of all geoeffective solar events, including those that occur on the back side of the Sun, e.g. flares behind the western limb that strongly affect conditions on the Earth and in its environment. Working out of an algorithm for solar activity prediction with a lead of 3 to 20 days. This problem remains unsolved because no feature on the Sun can be now observed for more than 14 days running. Forecasting of recurrent events. Full survey of transients (including those moving straight to the Earth) forecasting purposes.

for geomagnetic

The problem of convergence of the field lines in coronal holes with approach to prediction of the solar wind velocity. (B) Solar and Heliospheric Physics l

Constructing of a full evolution pattern (evolutionary tracks) of active regions from birth to death (l-27 days or more). AR present-day models of active features on the Sun with lifetimes exceeding 100 days have been obtained by matching the data for different regions, because continuous observations for more than 14 days are impossible.

Russian Future Pmjeds 0

Correct

helioseismology

to discriminate l

The problem

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of the full sphere of the Sun. (The full sphere pattern

between some oscillation

is necessary

modes).

of solar wind from polar regions.

(This task would require observations

high

above the ecliptic). A coronal streamer Estimation

- is it a flat or a three-dimensional

of the longitudinal

their mass and structure a three-dimensional l

extent

of coronal

and to find out whether

This will allow us to specify

a coronal transient

is an expanding

This list is far from complete.

of the source surface field taking into account However it shows that the problems

for the progress in the principal

a global international

A joint effort of all interested

arc,

institutions

such a system,

and analyze the enormous

ensure the use of world experience

above are critical

sciences will, sooner or later, face the necessity survey of the Sun.

both inside the country,

and operate

polar corrections.

physics.

system of full three-dimensional

be required to design, establish, to process

mentioned

areas of solar and solar-terrestrial

It is obvious that developing solar and terrestrial

observations,

transients.

feature or a bubble.

More precise determination

of creating

feature.

and at international

to ensure ground-based

bulk of the obtained

in designing and operating

spacecraft

data.

level will support

Cooperation

and onboard

of will

equipment

for solar observations. The System of Spacecrafts IZMIRAN located

proposes

a space system for regular

at different position

full survey of the Sun and that the former case, the spacecraft overlap.

Depending

from O,f120”

problem,

and l-3

analysis

the spacecraft

to 0, f90”

are not altogether

for three-dimensional

would have large overlapping

the problem

of

identical.

In

-

they must

angles should vary, e.g. analysis (in this case,

zones). by at least one out-of-ecliptic

at a height no less than 40 - 45’ above the ecliptic.

The system should be designed for long operation. around the solar maximum; Instruments

At worst, it should operate

for several years

at best, it should be permanent.

and Data Processing

The efficiency of the system will rather rely on new disposition of the instruments. tested

in the latter

position

This system located in the plane of ecliptic should be supplemented spacecraft

of 3 satellites

It should be noted that

fields of view must be complementary,

for the fuIl survey program l-2

orbit.

of three-dimensional

on the particular

the pairs of satellites

full survey of the Sun, consisting

angles in the Earth

This means that instruments

in space experiments

increase the reliability

can be used to promote

the program,

to reduce

novelty

and abroad and the cost and to

of the system.

The whole set of scientific equipment ray and UV wavelength

will allow us to obtain the images of the Sun in optical,

ranges, integral measurements

(from radio to r-rays), Detailed specification

in space, than on technical

already existing in the country

in situ measurements

X-

of emission in a wide range of wavelengths

of plasma parameters.

of the payload is under development

and is open to discussion.

Stages of Mounting An important of spacecraft

advantage

of the proposed program

is put into orbit.

system can provide interesting

is that the work may start before the whole set

At the very first stage (as soon as the first vehicle is launched) information

to the following stages, this information

the

of both scientific and applied value. When proceeding

should be taken into account

to change the composition,

w93(52

V. N.Omevsky and V.

V. Fomichev

characteristics and working regimes of instruments, as well as to correct the experimental program. Thus, we shall be able to combine a gradual development of global monitoring of the Sun and part of the heliosphere with speedy acquisition of preliminary data. The Study Team Scientific investigators: V. Oraevsky, V. Fomichev, V. Obridko, R. Gorgutsa. (Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation Academy of Sciences (IZMIRAN)).

of the Russian

SummarY We propose a space system for regular full three-dimentional survey of the Sun, consisting of 3 satellites located at different position angles in the Earth orbit, supplemented by at least one out- of-ecliptic spacecraft. The scientific equipment will allow us to obtain the images of the Sun in optical, X-ray and UV wavelength ranges, integral measurements of emission in a wide range of wavelengths, in situ measurements of plasma parameters. The system may be mounted step-by-step and at the very first stage (as soon as the first vehicle is launched) the system can provide interesting information of both scientific and applied value.