November 7, 2020 8:40:02 am
The PSLVC49 carries # E0S01 and nine international customer satellites at First Launch Pad in Sriharikota. (Twitter / @ isro)
India will send its first space mission in nearly a year with the launch of EOS-01, a ground-observing satellite, on Saturday afternoon. The EOS-01, along with nine satellites from foreign countries, would be launched by a PSLV rocket shortly after 3 pm.
This will be ISRO’s first mission since the launch of RISAT-2BR1, another Earth observation satellite similar to EOS-01, on December 11 last year. After that, ISRO also sent the GSAT-30 communications satellite into space in January this year, but that was done using an Ariane rocket launched from French Guiana.
Thereafter, the ISRO launch schedule was completely derailed by the coronavirus epidemic. ISRO had planned more than 20 satellite launches in fiscal year 2020-21, including high-profile missions such as Aditya L1, the first exploratory mission to Sun, and unmanned Gaganyaan, the precursor to India’s first manned space flight. Half of the planned launches were those of Earth observation satellites like the one to be sent today.
New nomenclature
EOS-01 is just another Radar Imaging Satellite (RISAT) that will work alongside RISAT-2B and RISAT-2BR1 launched last year. EOS-01 was initially named RISAT-2BR2, and was supposed to be the third in the constellation of three spacecraft intended to provide a 24-hour, all-weather service for high-resolution imaging.
With EOS-01, ISRO is moving towards a new naming system for its Earth observation satellites which have so far been named thematically, according to the purpose for which they are intended. For example, the Cartosat series of satellites were intended to provide data for land surveying and mapping, while the Oceansat satellites were intended for observations over the sea. Some series INSAT, Resourcesat, GISAT, Scatsat, and some others are Earth observation satellites, with different names depending on the specific jobs assigned to them or the different instruments they use to do their work.
Mapping and monitoring of land and forests, mapping of resources such as water or minerals or fish, meteorological and climatic observations, soil assessment, and geospatial contour mapping are performed using satellite observation satellites. the earth.
Before the release of EOS-01. (Twitter / @ isro)From now on, it seems, all Earth observation satellites would be called the EOS series.
Radar images
EOS-01, like its cousins RISAT-2B and RISAT-2BR1, uses synthetic aperture radars to produce high-resolution images of the earth. One big advantage that radar images have over optical instruments is that they are not affected by weather, clouds or fog, or lack of sunlight. It can produce high-quality images in all conditions and at all times.
Depending on the wavelength of the electromagnetic radiation used by the radar, different properties on the ground can be captured in the image. For example, a low wavelength signal can capture tree cover or vegetation, while a higher wavelength signal can penetrate even dense tree cover to observe the contours of the land below.
EOS-01, and its RISAT siblings, use X-band radars that operate at low wavelengths and are considered the best for monitoring the urban landscape and imaging agricultural or forest lands. According to ISRO, EOS-01 is intended for applications in agriculture, forestry and disaster management support. Radar images are also considered immensely useful for military requirements.
New rocket
For the launch of EOS-01, ISRO would use a new variant of its PSLV rocket that had been flown only once before, in January last year, when it had put the Microsat-R satellite into orbit. This Microsat-R was the one that was shot down in March last year in India’s first anti-satellite test, a demonstration of its ability to hit an enemy satellite orbiting in space.
This PSLV variant is not wasted after placing your satellite in orbit. Instead, the last stage of the rocket, the one left after the satellite separates, can acquire its own orbit and be used as an orbital platform for other instruments on board to conduct experiments in space. In effect, the fourth stage acts like one more satellite, with a useful life of about six months.
For the PSLV, this would be Flight 51. Only two of its launches have been unsuccessful.
Of the nine foreign satellites being carried on the mission, four are from the United States and Luxembourg, while another is a technology demonstrator from Lithuania.
© The Indian Express (P) Ltd
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