SINP scientists celebrate the 57-th anniversary of the first scientific instruments' space launch

The first space scientific instrument. It was developed and produced by SINP scientists. Photo by Oleg Barinov.

On November 3, 1957 SINP scientists launched scientific instruments to space for the first time in the world. The instruments were mounted onboard the second Earth's satellite. Onboard this satellite the first living being - dog Laika - was also launched to space.

Besides the scientific instruments developed by SINP scientists in order to measure cosmic rays intensity, the scientific complex onboard the second satellite also included a device for registration of UV and X-ray solar radiation, developed by the scientists of P.N.Lebedev Physical Institute.

The second satellite was launched to the orbit by means of two-stage launcher "R-7" ("Sputnik"). Maximum distance from the satellite to the Earth's surface was about 1670 km, minimum distance - 225 km. Turnaround time was about 100 minutes. Inclination of the satellite's orbit to the equatorial plane was 65 degrees. Chemical batteries provided power supply for the scientific instruments onboard the satellite during 7-10 days. Totally the satellite turned around the Earth over 2300 times and in April 1958 it burned up in the Earth's atmosphere.

Scientific instruments for the measurements of the cosmic rays intensity were developed under the guidance of the Academician Sergey Vernov. Yuri Logachev, now Professor, DSc., SINP Chief Scientist, was directly involved in the development and manufacturing of the instruments.

Yuri Logachev told us: "There were no scientific equipment onboard the first satellite, because of competition between the USSR and USA for the leadership in the launching of the first Earth's satellite. The purpose was to become the leader, let the satellite be very simple, but we'll be the first... Nobody knew about the development and spacecraft processing of the first satellite, besides narrow group, which did not include scientists. By this time our instrument was ready to be launched, and if Sergey Vernov knew about the first satellite launch, definetely, our instrument was launched onboard it."

There were two instruments, developed by SINP scientists, onboard the second satellite. Each weighted about 2.5 kg. There were the first instruments with electronics completely developed and assembled basing on semiconductors. It provided low weight and low power consumption. Information on the cosmic rays intensity was transmitted to the Earth by radiotelemetry channel while the satellite was passing over the USSR territory, i.e. near the perigee of its orbit, at the altitude of 250-500 km. Measured cosmic rays fluxes for all passes over the USSR territory, except one dated on November 7, 1957, were of reasoned values. There were the first measurements of cosmic rays at these altitude within wide range of longitudes and latitutdes. During the passage on November 7, 1957 both instruments detected increased counting rates for space particles. Later it was found out that the reason for it was precipitation of the electrons from the outer radiation belt of the Earth, discovered by SINP scientists by means of the third Soviet satellite in May 1958. The inner radiation belt was detected and discovered by scientific team of Van Allen during the experiments with instrument analogous to the first space instruments of SINP scientists, onboard the American satellites Explorer-1 and Explorer-2 in February-March 1958.

Shortly before the 57-th anniversary of the first studies of cosmic rays in space Yuri Logachev confided his ideas about the perspectives of the studies development in this direction to us:

"Cosmic rays are assumed to be separated to galactic and solar. Galactic cosmic rays come from far space, solar ones - from the Sun. Scientists of almost all advanced nations study cosmic rays.

Currently the most pressing challenge for the galactic cosmic rays concerns the studies of the most high-energy part of spectrum, which need huge ground-based plants or complicated and heavy instruments onboard the satellites. Both directions of studies are being successfully developed.

There are also a lot of detailed discussions on the colonization of the Mars and the Moon. Flights to the Mars are very long, a half a year is needed to reach it. The main problem here is to protect the cosmonauts from the radiation influence of the galactic and solar cosmic rays. It is practically impossible to protect the cosmonauts from the galactic cosmic rays, and it is also very difficult to shelter them from the powerful solar flare. The way to the Moon is not long, but if you stay on its surface you will face the same problems as during the flight to the Mars. Perspective of these flights is not near-term, but we need to start the development of the protection from space radiation just now. In this regard long-term prediction of powerful solar flares would be very useful, but our current knowledge is not enough for the development of such prediction. The maximum thing we can do now is to predict that there will not be powerful flares during the following 3-4 days basing on the specific disposition of active regions on the visage of the Sun.

Solar flares are very bright and quite often phenomena. The solar cosmic rays were the first to be studied onboard the satellites. Due to the absorption of the cosmic rays particles in the Earth's atmosphere the ground-based plants can detect only very powerful flares. The satellites allowed to expand our opportunities. Each solar flare, even rather small one, generate great amount of high-energy charged particles, and after the beginning of satellites era of space research the number of registered flares increased sharply. Today the catalogue of the solar proton events, developed by SINP scientists, includes over 500 events.

The particles propagate from the Sun to the Earth through the interplanetary medium, which influence on the particles, its energy and spatial distribution. If we know exactly the parameters of the interplanetary space, its particle composition, density, temperature, and foremost - the interplanetary magnetic field which "works traffic" of the charged particles, we can turn from the characteristics of the solar particles, measured near the Earth, to their characteristics near the Sun and in the source. Unfortunately, the orbits of almost all spacecrafts lay in the ecliptic plane (the plane of the Earth's rotation around the Sun - Ed.) and our knowledge about the latitudinal variations of heliospheric parameters are very constrained. We have small knowledge of specific characteristics of latitudinal variations of the solar wind, magnetic field, solar and galactic cosmic rays and other components of heliosphere. Till now there were only three passages of the Ulysses spacecraft in the inner heliosphere at the high latitudes at the distance over 1.5 a.u. from the Sun, during which essentially different values of heliospheric parameters were detected.

This problem is a perspective one due to its essential scientific interest, and it is quite available for the studies by relatively cheap instruments. It is possible to develop satellite of the Sun with a circular orbit with 1 a.u. radius and inclination of, for instance, 30 degrees to the ecliptic plane. In other words, solar satellite with the same orbit, as the Earth's one, but at an angle with ecliptic.
At this orbit the satellite will every year spend 4 months at the helio-latitudes about plus-minus 30 degrees and practically the same helio-longitude, as the Earth. The spacecraft and the Earth will move synchronously with the same period of 1 year. This orbit provide an opportumity for the latitudinal measurements of different parameters of the inner heliosphere. Total coverage of the Sun is about 40% during a long time period. Surely, the same measurements are needed to be conducted at the ecliptic plane, onboard one of the Earth's satellites out of its magnetosphere.

If the launch will be organized in Spring or in Autumn, inclination will be 7 degrees higher because of the inclination of the axis of the Sun to the ecliptic plane. I'll explain: the Earth crosses the plane of the solar equator at the beginning of June and at the beginning of December. During the first half of the year the southern hemisphere of the Sun faces the Earth, during the second half - the northern one. At the beginning of September and at the beginning of March inclination is the highest - plus-minus 7.25 degrees.

All measurements will be conducted during a long time period, which will cover both the quiet Sun periods and different active processes. During one year latitudinal distributions of heliospheric parameters will be measured during 13 solar revolutions over its axis. Till now there were only 2-3 latitudinal passages near the Sun.

Currently the orbit's inclination of 30 degrees is defined by the possibilities of our rocket technology. But we can have a stab at the larger inclination, if we use gravitational manoeuvres of the spacecraft during its passage near the Moon and the Earth. Success of this project will prompt the science and technology for the development of the orbits, which will at last allow us to get pictures of the solar poles".