The Indian Space Research Organisation[a] (ISRO; /ˈɪsroʊ/) is the national space agency of India, headquartered in Bangalore. It operates under the Department of Space (DOS) which is directly overseen by the Prime Minister of India, while the Chairman of ISRO acts as the executive of DOS as well. ISRO is India's primary agency performing tasks related to space-based applications, space exploration and the development of related technologies. It is one of six government space agencies in the world which possess full launch capabilities, deploy cryogenic engines, launch extraterrestrial missions and operate large fleets of artificial satellites.[b]The Indian National Committee for Space Research (INCOSPAR) was established by Jawaharlal Nehru under the Department of Atomic Energy (DAE) in 1962, on the urging of scientist Vikram Sarabhai, recognising the need in space research. INCOSPAR grew and became ISRO in 1969, within DAE. In 1972, the government of India set up a Space Commission and DOS, bringing ISRO under it. The establishment of ISRO thus institutionalised space research activities in India. It since then has been managed by DOS, which governs various other institutions in India in the domain of astronomy and space technology.ISRO built India's first satellite, Aryabhata, which was launched by the Soviet Union in 1975. In 1980, ISRO launched satellite RS-1 onboard its own SLV-3, making India the sixth country to be capable of undertaking orbital launches. SLV-3 was followed by ASLV, which was subsequently succeeded by development of many medium-lift launch vehicles, rocket engines, satellite systems and networks enabling the agency to launch hundreds of domestic and foreign satellites and various deep space missions for space exploration.ISRO has the world's largest constellation of remote-sensing satellites and operates the GAGAN and NAVIC satellite navigation systems. It has sent two missions to the Moon and one to Mars.The agency's goals for the near future include expanding its satellite fleet, landing a rover on Moon, sending humans into space, development of a semi-cryogenic engine, sending more uncrewed missions to the Moon, Mars, Venus and the Sun, and deployment of more space telescopes in orbit to observe cosmic phenomena and space beyond the Solar System. Long-term plans include development of reusable launchers, heavy and super heavy launch vehicles, deploying a space station, sending exploration missions to the outer planets and asteroids and crewed missions to moons and planets.ISRO's programs have played a significant role in the socio-economic development of India and have supported both civilian and military domains in various aspects including disaster management, telemedicine and navigation and reconnaissance missions. ISRO's spinoff technologies also have found many crucial innovations for India's engineering and medical industries.
Global estimation of sea surface partial pressure of CO2 (pCO2) is becoming increasingly important in the context of global climate change and the associated environmental impacts occurring in various parts of the world’s oceans. In the present study, ISRO’s EOS-06 ocean color monitor (OCM-3) derived chlorophyll (Chl-a) data is utilized for estimating pCO2 variability over the global oceans. The analysis is carried out for a period of six months from April to August 2023. The recently developed multi-parametric nonlinear regression methodology is adopted in the present study to estimate the pCO2 distribution over the global ocean using satellite-derived sea surface temperature, salinity, and Chl-a. From the analysis, it is observed that the global oceanic pCO2 variability estimated from the present study substantiates that the pCO2 is high over the tropical region as compared to sub-polar and polar region. As a result of the dependency of pCO2 distribution on the upper ocean biological processes through photosynthesis, respiration, and calcification the global distribution of pCO2 also varies locally based on this. The Chl-a concentration is found to be high near the coastal regions, eastern Pacific Ocean and Polar regions. The pCO2 decreases near the high productivity Polar regions in response to the enhanced photosynthesis processes undergoing in these regions. Surface pCO2 is high ( 500 to 530 µatm) over the eastern and central Pacific Ocean as compared to the western region as upwelling occurs over the eastern Pacific Ocean which brings carbon rich water from the subsurface to the ocean surface. The pCO2 decreases from April to August over the Arctic and subarctic region as a result of an increase in Chl-a concentration.
Sambhar Lake ecosystem, India’s largest inland saline wetland ecosystem, has undergone siginificant hydrological and land-use changes in recent decades. The current study integrates remote sensing and geospatial analysis to assess land use/land cover (LULC), water extent seasonality, algal bloom patterns, and long-term wetland transitions in Sambhar Lake under 2 km buffer. LULC classification for the monsoon season of 2023 identified eleven classes, with water accounting for the largest share (24.7
In modern industries, optimizing machining parameters is crucial for product quality, efficiency, and cost-effectiveness. Conventional methods often fail in the machining of advanced materials like single crystal tungsten. This study presents a hybrid Bayesian network model to optimise wire electrical discharge machining (WEDM) parameters for single crystal tungsten, combining numerical and experimental analyses to enhance the fabrication process. The Bayesian model determines optimal values and permissible ranges for key WEDM process parameters, including pulse-on time, pulse-off time, arc-off time, wire feed rate, and gap voltage. Numerical simulation is carried out by the finite element method, indicating that single crystal tungsten has an ultimate tensile strength of 850 MPa with limited ductility, confirming its brittle nature. Subsequently, single crystal tungsten is fabricated under the optimised WEDM conditions determined by a hybrid Bayesian model and the numerically obtained ultimate compressive strength. Furthermore, comprehensive experimental analyses, such as X-ray diffraction, Laue diffraction, scanning electron microscopy, and X-ray fluorescence, are performed both before and after fabrication of a single crystal tungsten specimen to examine its crystallinity, microstructure, and compositional integrity. Overall, the experimental analysis demonstrates that optimised WEDM parameters, determined by a hybrid Bayesian network, are effective for fabricating single crystal tungsten and anticipated for critical technological applications.
Cloudbursts (Cb) are cataclysmic events occurring frequently over the Western Himalayas (WH) which are very difficult to predict mainly due to less understood microphysical processes. Since 2012, the frequency of cloudburst occurrences has increased notably in the Western Himalayas, so a comprehensive study to investigate this has been carried out with the help of CloudSat data for the period 2012–2016 and MERRA-2 reanalysis was used. This study suggests that Cb are mixed phase clouds supporting homogeneous nucleation of ice particles formed from large supercooled liquid particles. In contrast to the Indo-Gangetic Plain (Igp) monsoon clouds, the spread of the size spectrum for liquid and ice particles is broader for Cb clouds. Evidence of a positive correlation (0.66) between maxima of liquid and ice effective radius in case of Cb, as compared to negligible correlation for Igp, supports the hypothesis of homogeneous freezing of large liquid particles which may be responsible for intense precipitation. This study provides the first ever deep insight into the Cb systems in WH using satellite-radar data.
This study investigates the microstructural and mechanical effects of incorporating 1.5 wt
