Common Bulkhead Tank Design for Cryogenic Stage of an Indian Launch Vehicle

Indian Space Research Organization (ISRO) has been advancing in space technology with its cost-effective techniques. Currently, ISRO, in its cryogenic stages, uses truss type intertank structure, which induces large concentrated loads at the truss interfaces. As a remedial measure, works on closed intertank are being carried out by them, but this configuration will considerably increase the launch vehicle mass compared to truss type. Therefore, after a thorough literature survey, a Common bulkhead (CBH) tank seemed to be the best solution to the aforementioned problem. Detailed research on sandwich-type CBH has been carried out in this paper with the motivation of saving mass and height in launch vehicles. Suitable core and facesheet material were selected. A novel foam-filled honeycomb core is suggested in this work. Several comparisons in various CBH dome designs were carried out to reach for the best possible configuration and composition that can be used. MATLAB®, SolidWorks®, and ANSYS® were used in parallel for all computations dealing with design and analysis. A mass saving of approximately upto 490 kgs and a height reduction of upto 1.755 m was obtained with the final selected configuration with respect to the current GSLV configuration. These savings can add extra payload capacity to ISRO launch vehicles in their future missions.

Atmospheric Lightning as Essential Climate Variable (ECV) and Its Availability Over India Using NRSC/ISRO Lightning Detection Sensor Network

Atmospheric lightning is an outcome of extreme complex physical processes occurring in the atmosphere. Cloud-to-ground (CG) lightning is considered as a natural disaster. Understanding the importance of CG lightning and implication of the lightning phenomena, Global Climate Observing System (GCOS), world meteorological organization, in its report in the year 2016, introduced the lightning as an Essential Climate Variable (ECV). The present report uses the Lightning Detection Sensor Network (LDSN) established by the National Remote Sensing Centre, Indian Space Research Organization over India to generate the Lightning ECV. A use case of these ECVs are also showcased for an event in Bihar, India, when 42 deaths were reported at locations with large number of CG occurrences.

IRNSS/NavIC: Indigenous Indian Satellite Navigation Programme

India has a vibrant space programme, and over years has successfully operationalized communication and remote sensing satellites for the benefit of the country. In order to achieve self-reliance in satellite-based navigation service over Indian region, Indian Space Research Organization (ISRO) has initiated the NavIC (Navigation with Indian Constellation) Programme. NavIC is developed to give PNT (Position, Navigation and Time) services for users over Indian region and its neighbourhood with positional accuracy of 20 m and 10 Nano seconds time accuracy. It provides navigation services to Indian landmass and also it extends its service to 1500 km beyond the geopolitical boundary. This paper provides the overview about the IRNSS and its salient features.

Establishment of lightning detection sensors network in India: retrieval of essential climate variables and vulnerability mapping

A network of 25 lightning detection sensors (LDS) has been established by National Remote Sensing Centre (NRSC), Indian Space Research Organization (ISRO). In the present network, sensors are located in the north-east, east coastal, central and southern locations of India. Geo-location of the lightning occurrences is estimated using time of arrival algorithm. Thus obtained lightning occurrences have been used to derive climate variables (ECVs) and to understand the vulnerable regions. We carry out overlay analysis on a Geographical Information System (GIS) platform on the monthly aggregate number of CG flash occurrences to identify the vulnerable Indian states during July 2019 to November 2020. We note that December-January reported the least number of cloud-to-ground (CG) flash occurrences while, August-September were the months with most number of CG flash occurrences. We also note that during the period under the scrutiny in this report, Chattisgarh, Jharkhand, Odisha, Maharashtra and Madhya Pradesh states recorded the most number of CG lightning flash occurrences.

THE LOST INDIAN CHANDRAYAAN 2 LANDER VIKRAM AND ROVER PRAGYAAN FOUND INTACT IN SINGLE PIECE ON THE MOON

The Lunar Lander Vikram of the Moon Mission Chandrayaan 2 of the Indian Space Research Organization (ISRO) lost communication with the Lunar Orbiter and the mission control nearly 2.1 kms above the lunar surface during its landing on the Moon on 7th September, 2019. The exact location and the sight of the lost lander and rover are still elusive. We present here the exact location and first images of the lander Vikram and rover Pragyaan sighted on the lunar surface. It is evident from the processed images that the lander was intact and in single piece on landing away from the scheduled site and its ramp was deployed to successfully release the rover Pragyan on to the lunar surface. This contradicts earlier reports that the lander was disintegrated into small pieces and debris which were scattered far away from the proposed landing site.

A CRYSTALLISED REVIEW ON ROLE OF TECHNICAL HIGHER EDUCATION UNDER THE TENETS OF NEW EDUCATION POLICY

Since education leads to economic and social change, a well-defined and futuristic education policy is important for a country at school and college levels. By considering tradition and culture, different countries adopt different education systems and adopt different stages during their life cycle at the level of school and college education to make it successful. The Government of India recently announced its new Education Policy, based on the recommendations of an expert committee chaired by Dr. Kasturirangan, former president of the Indian Space Research Organization (ISRO). This paper presents and illustrates the effects of the NEP on higher technical education and provides recommendations for successful policy implementation.

Performance Analysis of Acquisition Algorithms for Navic

Indian Regional Navigation Satellite System (IRNSS), is an indigenous navigation system designed and developed by ISRO (Indian Space Research Organization).It is named as NavIC, Navigation with Indian Constellation by Indian Prime Minister. NavIC is designed to have seven satellite constellation that provides reliable position, navigation and timing services over India. The focal modules of NavIC receiver are acquisition, tracking and navigation unit. Among them, acquisition is the data processing unit for detecting satellite signals and their corresponding code phase and carrier frequency. In this paper, various acquisition algorithms like Serial search and Parallel Code Phase search algorithms are analyzed and compared with Cooley-Tukey FFT algorithm and sub-sampled Fast Fourier transform (ssFFT).The results obtained in MATLAB shows that the acquisition computation time for ssFFT based NavIC receiver is faster than parallel FFT acquisition and the Cooley-Tukey FFT IRNSS acquisition algorithm is faster and provides better code phase and carrier frequency values compared to serial search acquisition algorithm.

Estimation and Analysis of IRNSS Satellites Differential Code Biases using Real Data

IRNSS is a regional navigation system developed by the Indian Space Research Organization (ISRO) for precise position and navigation services over the Indian sub-continent. However, the IRNSS measurements are being affected by the many residuals or biases. Differential Code Biases (DCB) are very significant in the precise measurement of ionosphere Total Electron Content (TEC). In this paper, DCB of all available IRNSS satellites and receiver is derived from the pseudorange measurements of IRNSS on L5 and S-band signals. Results show that the estimated daily mean DCB of IRNSS satellites is in the range between -0.60 nanoseconds(ns) and 0.606 ns. Further, the receiver DCB is obtained as 7.904 ns.

Comparison of Oceansat-2 Scatterometer Wind Data with Global Moored Buoys and ASCAT Observation

The Oceansat-2 satellite was launched on 23 September 2009 by the Indian Space Research Organization (ISRO). In this study, the historic archived OSCAT wind vectors are compared with the global moored buoys’ wind observations, including the U.S. National Data Buoy Center (NDBC), the Tropical Atmosphere Ocean (TAO), the Pilot Research Moored Array in the Tropical Atlantic (PIRATA), the Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA), and Advanced Scatterometer (ASCAT) wind data in the same period of OSCAT by calculating the statistical parameters, namely, the root mean square error (RMSE), bias (mean of residuals), and correlation coefficient (R) between the collocated data. The comparisons with the global moored buoys show that the OSCAT wind vectors are consistent with buoys’ wind measurements. The average errors of the OSCAT wind vectors are 1.20 m/s and 17.7°. The analysis of the OSCAT wind vector errors at different buoy wind speeds in bins of 1 m/s indicates that the accuracy of the OSCAT wind speed first increases and then decreases with the increasing wind speed. The comparisons of OSCAT wind vectors and ASCAT wind vectors show that the average RMSEs of their differences are 1.27 m/s and 20.17°. In general, the accuracies of the OSCAT wind vectors satisfy the general scatterometer’s mission requirement and are consistent with ASCAT wind data. OSCAT wind vectors can be used in the global change study by the combination with other scatterometer data.

The Calibration of the UVIT Detectors for the ASTROSAT Observatory

The UVIT ultraviolet and visual band detectors and electronics for the ASTROSAT observatory were calibrated in the vacuum laboratory at the University of Calgary. This work was supported by the Canadian Space Agengy and carried out prior to integration with the UVIT optical assembly and the ASTROSAT spacecraft. The multiband (X-ray, ultraviolet and optical) ASTROSAT observatory was successfully launched by the Indian Space Research Organization on Sept. 28, 2015, with subsequent in-orbit verification and ongoing calibration activities. Here we discuss the current issues of calibrating the UVIT data, such as distortion corrections, and how the laboratory data is being used to address these issues.