ISRO had organized a National meeting on Aeronomy research to discuss the importance and prospect of space-based in-situ observation of the Earth’s upper atmosphere to study the space-weather effects, with the theme ‘Science of Near-Earth Space & Applications’, on May 10, 2022, in virtual mode. The meeting was attended by representatives of several ministries of the Government of India, academicians and scientists from several reputed academic institutions.

Introducing the theme, during the inaugural session, Shri Shantanu Bhatwadekar, Scientific Secretary, ISRO, explained that ‘Aeronomy’ refers to the physics and chemistry of the Earth’s upper atmosphere, which directly feels the wrath of the space weather events. In the near-Earth environment, the space weather is governed by the eruptive phenomena from the Sun, which affect the ionosphere-thermosphere system severely, and the perturbation percolates to the lower altitudes depending on the intensity of the solar events. In this context, Scientific Secretary, ISRO mentioned that the DISHA-H&L mission, a twin Aeronomy mission conceptualized by ISRO, comprising two satellites, one at high (DISHA-H, at inclination greater than 85 degrees) and the other one at low (DISHA-L, at an inclination of about 25 degrees) inclination orbits, simultaneously orbiting the Earth at an altitude of ~400 km. He mentioned that DISHA is an acronym for ‘Disturbed and Quiet time Ionosphere-Thermosphere systems at High Altitudes’. The twin satellites, he informed, with the identical set of scientific instruments, will capture the latitudinal and longitudinal effects of the space weather events on the Earth’s upper atmosphere.

Shri S. Somanath, Chairman, ISRO / Secretary, DOS, inaugurated the meet. During his inaugural address, he emphasized the necessity of bringing out the societal benefit of the proposed DISHA H&L mission. He mentioned that the proposed DISHA H&L mission will provide valuable scientific insight into the effect of space weather events on Earth’s upper atmosphere, which, in turn, will help in the modelling of the ionosphere-thermosphere system in terms of its response to the space weather events. The model will not only be a valuable scientific contribution towards the understanding of the Sun-Earth connection but also be a tool for several applications that are susceptible to the space weather events. He solicited the active participation of the academia, institutes and ministries to build a strong user-base for this mission.

Prof. Pallam Raju, Dean, Physical Research Laboratory, an autonomous body within the Department of Space, made a presentation on the DISHA H&L concept, the parameters to be investigated, and the scientific instruments.

The meeting, apart from several lectures from academia and institutes, witnessed a panel discussion on ‘Science of Near-Earth space and its applications’, which was attended by the senior officials nominated by the Department of Telecommunication, Ministry of Civil Aviation, Ministry of Power, Ministry of Earth Sciences, Department of Science & Technology, Ministry of Electronics and Information Technology and Ministry of Information and Broadcasting. The panelists deliberated the importance of such space-based Aeronomy missions with relevance to the respective ministries. Discussions spun the domains of the disruption of radio-wave propagation affecting communication and navigation infrastructure during severe space-weather events, the need for coupling the ionosphere-thermosphere model and atmospheric model to build a holistic model to assess the effects of space weather events on the atmosphere, passenger health in aviation sector during polar flights, the importance of the Aeronomy study on the air navigation services, need for parallel/super-computing facilities for high spatial-temporal modelling of the Sun-Earth coupling system will better accuracy, to name a few. Ministry representatives offered collaborative support to take this endeavor forward.

Dr. Tirtha Pratim Das, Director, Science Programme Office, moderated the inter-ministerial panel discussion. He mentioned that DISHA H&L is just an initial step towards the building of the space infrastructure towards achieving self-reliance in modelling and managing space weather events. Fullfilling this goal necessitates drawing a long-term plan covering many solar cycles, which, in turn, requires a programmatic approach, with the confluence of the wisdom and active participation of the relevant ministries. Once Aditya-L1 heliophysics observatory is in orbit and study the causes of the space weather events, DISHA H&L will studies the effects. The ground-based observations of the ionosphere and the Sun will complement the space-based observations. Thus, DISHA H&L will add to the space and ground-based infrastructure for achieving a better understanding of the space weather effects, which will eventually lead to better planning for the protection of the space and ground-based assets.

The event was live-streamed to the ISRO website, and the ISRO social media platforms.The recording of the meet can be viewed on Youtube/ISRO Official