The article covers the concept and historical aspects of development of automated space stations
Luna-16
,
Luna-17
, and
Venera-7
, which for the first time in the world successfully completed ...outstanding scientific programs. They opened the way for the world scientific community to study the Moon and the planets of the Solar System, providing invaluable experience for the development of the next-generation space missions.
The eROSITA X-ray telescope on SRG Predehl, P.; Andritschke, R.; Arefiev, V. ...
Astronomy and astrophysics (Berlin),
03/2021, Letnik:
647, Številka:
A1
Journal Article
Recenzirano
Odprti dostop
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the primary instrument on the Spectrum-Roentgen-Gamma (SRG) mission, which was successfully launched on July 13, 2019, from the ...Baikonour cosmodrome. After the commissioning of the instrument and a subsequent calibration and performance verification phase, eROSITA started a survey of the entire sky on December 13, 2019. By the end of 2023, eight complete scans of the celestial sphere will have been performed, each lasting six months. At the end of this program, the eROSITA all-sky survey in the soft X-ray band (0.2–2.3 keV) will be about 25 times more sensitive than the ROSAT All-Sky Survey, while in the hard band (2.3–8 keV) it will provide the first ever true imaging survey of the sky. The eROSITA design driving science is the detection of large samples of galaxy clusters up to redshifts
z
> 1 in order to study the large-scale structure of the universe and test cosmological models including Dark Energy. In addition, eROSITA is expected to yield a sample of a few million AGNs, including obscured objects, revolutionizing our view of the evolution of supermassive black holes. The survey will also provide new insights into a wide range of astrophysical phenomena, including X-ray binaries, active stars, and diffuse emission within the Galaxy. Results from early observations, some of which are presented here, confirm that the performance of the instrument is able to fulfil its scientific promise. With this paper, we aim to give a concise description of the instrument, its performance as measured on ground, its operation in space, and also the first results from in-orbit measurements.
Information about the purpose, orbital parameters, and composition of the Arktika-M satellite, the characteristics of the HGHC-VE onboard heliogeophysical hardware system is given. The results of ...measuring fluxes of charged particles and calculating their orbital spectra are presented.
The results of the testing and operation of the Arktika-M highly elliptical orbit hydrometeorological space system are presented. The advantages of highly elliptical orbits, the main characteristics ...and tasks of the Arktika-M No. 1 satellite payload are considered. The description is given of the ground-based segment and resulting information products required to solve problems for the benefit of socioeconomic development of northern Russia.
This article describes the results of the
Phobos 2
interplanetary mission, launched in 1988, and presents some prospective scenarios for studying near-Mars space, including the return of regolith ...samples from Mars’ natural satellites. It also presents a tentative design of an interplanetary station aimed at solving these problems and discusses its possible scientific payloads.
Astronomical Roentgen Telescope – X-ray Concentrator (ART-XC) is the hard X-ray instrument with grazing incidence imaging optics on board the Spektr-Roentgen-Gamma (SRG) observatory. The SRG ...observatory is the flagship astrophysical mission of the Russian Federal Space Program, which was successively launched into orbit around the second Lagrangian point (L2) of the Earth-Sun system with a Proton rocket from the Baikonur cosmodrome on 13 July 2019. The ART-XC telescope will provide the first ever true imaging all-sky survey performed with grazing incidence optics in the 4–30 keV energy band and will obtain the deepest and sharpest map of the sky in the energy range of 4–12 keV. Observations performed during the early calibration and performance verification phase as well as during the ongoing all-sky survey that started on 12 December 2019 have demonstrated that the in-flight characteristics of the ART-XC telescope are very close to expectations based on the results of ground calibrations. Upon completion of its four-year all-sky survey, ART-XC is expected to detect approximately 5000 sources (~3000 active galactic nuclei, including heavily obscured ones, several hundred clusters of galaxies, ~1000 cataclysmic variables and other Galactic sources), and to provide a high-quality map of the Galactic background emission in the 4–12 keV energy band. ART-XC is also well suited for discovering transient X-ray sources. In this paper, we describe the telescope, the results of its ground calibrations, the major aspects of the mission, the in-flight performance of ART-XC, and the first scientific results.
The RadioAstron ground-space interferometer provides the highest angular resolution achieved now in astronomy. The detection of interferometric fringes from quasars with this angular resolution on ...baselines of 100–200 thousand km suggests the brightness temperatures which exceed the Compton limit by two orders of magnitude. Polarimetric measurements on ground-space baselines have revealed fine structure testifying to recollimation shocks on scales of 100–250 μas and a helical magnetic field near the base of radio emission in BL Lacertae. Substructure within a the scattering disk of pulsar emission on interferometer baselines (from 60000 to 250000 km) was discovered. This substructure is produced by action of the interstellar interferometer with an effective baseline of about 1 AU and the effective angular resolution of better than 1 μas. Diameters of scattering disks were measured for several pulsars, and distances to diffusing screens were evaluated. The ground-space observations of sources of the maser radiation in lines of water and hydroxyl have shown that the maser sources in star-forming regions remain unresolved on baselines, which considerably exceed the Earth diameter. These very compact and bright features with angular sizes of about 20–60 μas correspond to linear sizes of about 5–10 million km (several solar diameters).
—The execution of a soft landing of an unmanned spacecraft on Mars’ surface requires implementation of several technically challenging flight phases. The final one is an active braking using a ...steerable thrust jet engine. In this article we present an analysis of the flight environment before and during active braking, specify the composition of technical means for motion control, present one of the possible braking profiles, a sequence of the active braking modes, algorithms for guidance and control, and mathematical simulation results.
—Performing a soft landing of an unmanned spacecraft on Mars’ surface requires implementation of several technically challenging flight phases. The final one is an active braking with the use of a ...steerable thrust jet engine. In this article we present an analysis of the flight environment before and during of active braking, specify the composition of technical aids for motion control, overview one of the possible braking profiles, sequence of the active braking modes, algorithms of guidance and control, and mathematical simulation results.
SRG X-ray orbital observatory Sunyaev, R.; Arefiev, V.; Babyshkin, V. ...
Astronomy and astrophysics (Berlin),
12/2021, Letnik:
656
Journal Article
Recenzirano
The orbital observatory Spectrum-Roentgen-Gamma (SRG), equipped with the grazing-incidence X-ray telescopes Mikhail Pavlinsky ART-XC and eROSITA, was launched by Roscosmos to the Lagrange L2 point of ...the Sun–Earth system on July 13, 2019. The launch was carried out from the Baikonur Cosmodrome by a Proton-M rocket with a DM-03 upper stage. The German telescope eROSITA was installed on SRG under an agreement between Roskosmos and the DLR, the German Aerospace Agency. In December 2019, SRG started to perform its main scientific task: scanning the celestial sphere to obtain X-ray maps of the entire sky in several energy ranges (from 0.2 to 8 keV with eROSITA, and from 4 to 30 keV with ART-XC). By mid-June 2021, the third six-month all-sky survey had been completed. Over a period of four years, it is planned to obtain eight independent maps of the entire sky in each of the energy ranges. The sum of these maps will provide high sensitivity and reveal more than three million quasars and over one hundred thousand massive galaxy clusters and galaxy groups. The availability of eight sky maps will enable monitoring of long-term variability (every six months) of a huge number of extragalactic and Galactic X-ray sources, including hundreds of thousands of stars with hot coronae. In addition, the rotation of the satellite around the axis directed toward the Sun with a period of four hours enables tracking the faster variability of bright X-ray sources during one day every half year. The chosen strategy of scanning the sky leads to the formation of deep survey zones near both ecliptic poles. The paper presents sky maps obtained by the telescopes on board SRG during the first survey of the entire sky and a number of results of deep observations performed during the flight to the L2 point in the frame of the performance verification program, demonstrating the capabilities of the observatory in imaging, spectroscopy, and timing of X-ray sources. It is planned that in December 2023, the observatory will for at least two years switch to observations of the most interesting sources in the sky in triaxial orientation mode and deep scanning of selected celestial fields with an area of up to 150 square degrees. These modes of operation were tested during the performance verification phase. Every day, data from the SRG observatory are dumped onto the largest antennas of the Russian Deep Space Network in Bear Lakes and near Ussuriysk.
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