Science & Technology
Source: The Indian Express
Why in News?
Recently, Indian Space Research Organisation's earth observation satellite EOS-04 and two small satellites (INSPIREsat-1 and INS-2TD) were successfully placed into the intended orbit by the PSLV-C52 rocket.
This launch was the 54th flight of the Polar Satellite Launch Vehicle (PSLV) rocket, and the 23rd of its most powerful XL-version that has six strap-on boosters.
What are Earth Observation Satellites?
Earth observation satellites are the satellites equipped with remote sensing technology. Earth observation is the gathering of information about Earth's physical, chemical and biological systems.
Many earth observation satellites have been employed on sun-synchronous orbit.
Other earth observation satellites launched by ISRO include RESOURCESAT- 2, 2A, CARTOSAT-1, 2, 2A, 2B, RISAT-1 and 2, OCEANSAT-2, Megha-Tropiques, SARAL and SCATSAT-1, INSAT-3DR, 3D, etc.
What are the Three Satellites Launched?
EOS-04 weighing 1,710 kg and with a mission life of ten years designed to provide high quality images under all weather conditions for applications such as Agriculture, Forestry and Plantations, Soil Moisture and Hydrology and Flood mapping.
It will complement the data from Resourcesat, Cartosat and RISAT-2B series of satellites that are already in orbit.
The first of these newly named satellites, EOS-01, launched in November 2020, is in orbit right now. EOS-02, a micro-satellite to be flown on a new launch vehicle called SSLV (Small Satellite Launch Vehicle) is yet to be launched, while launch of EOS-03 had ended in a failure in August, 2021.
It will be placed in a sun synchronous polar orbit of 529 km, is a radar-imaging satellite which would have made it a part of the RISAT series earlier.
In fact, it would replace the RISAT-1 which was launched in 2012 but has been non-functional for the last few years.
RISATs use synthetic aperture radars to produce high-resolution images of the land.
One big advantage that radar imaging has over optical instruments is that it is unaffected by weather, cloud or fog, or the lack of sunlight.
It can produce high-quality images in all conditions and at all times, making it suitable for surveillance.
INSPIREsat-1 is part of a constellation of satellites planned under the International Space Program in Research and Education (INSPIRE) involving the Small-spacecraft Systems and Payload Centre (SSPACE) at IIST, University of Colorado (US), Nanyang Technological University (NTU), Singapore, and National Central University (NCU), Taiwan.
Two scientific payloads on INSPIREsat-1, with a mass of 8.1 kg and mission life of one year, are aimed at improving the understanding of ionosphere (part of Earth’s upper atmosphere) dynamics and the sun's coronal heating processes.
INS-2TD is a technology demonstrator for the first India-Bhutan joint satellite that is scheduled to be launched in March, 2022.
The two countries had signed a space agreement last year, and its first outcome would be the launch of BhutanSat, or INS-2B, on a PSLV rocket in March, 2022.
The thermal imaging cameras of the INS-2TD are meant for earth observation purposes, like assessment of land and water surface temperature, and identification of forest and tree cover.
How many satellites does India have in space?
India currently has 53 operational satellites, of which 21 are earth observation ones and another 21 are communication-based.
Eight are navigation satellites, while the remaining three are science satellites.