Countdown begins for tomorrow's GSLV-F17/EOS-5 mission, first in 7 months
Chennai, Sep 3 (UNI) The 27.5 hour countdown for the launch of Earth Observation Satellite (EOS-05) by the heavylift home grown GSLV rocket, began at the spaceport of Sriharikota shortly before midnight last night.
"The countdown started at 2325 hrs last night and is progressing smoothly", ISRO sources told UNI on Thursday.
The GSLV-F17/EOS-05 Mission launch will take place at 0255 hrs early tomorrow morning and during the countdown, propellant filling operations would be carried out in the three-stage vehicle", the Space Agency said.
The launch, from the Second Launch Pad, would end a seven month long break since the failure of the PSLV-C62 mission in January this year.
Nearly five years after the August 21, 2021 unsuccessful GISAT-1 mission by GSLV-F10 due to a glitch in the cryogenic upper stage, ISRO will hurl into space the EOS-05 spacecraft, also known as GISAT-1A. It will be India's first ever imaging satellite to operate from the Sub-Geosynchronous Transfer Orbit (GTO), using the heavy lift launch vehicle GSLV-MkII.
In a social media post, ISRO wrote"EOS-05, a state-of-the-art Earth observation spacecraft, is India's first-ever imaging satellite from Geosynchronous orbit". Usually most of the Earth observation satellites are placed in Low Earth Orbit. .
The EOS-05 will be launched by GSLV-F17, the 19th flight of India's Geosynchronous Satellite Launch Vehicle (GSLV), and the configuration of GSLV-F17 Payload Fairing is 4 m dia Ogive (composite) version.
"The 51.7 m tall GSLV-F17, with a lift off mass of 420.5 tonnes ,will place the EOS-05 satellite into a Sub-GTO. After the lift off,
the 2,367 kg spacecraft, with a mission life of 10 years, will be injected into the Sub-GTO with a perigee of 170 km and an apogee of 28,934 km with an inclination of about 19.28 Deg (with plus or minus one) to the equator.
EOS-05 is designed to capture detailed images of the Earth and provide data for monitoring and other applications that require regular observation of the land and environment. It aims to improve the existing remote sensing capabilities and GISATs are designed to image
in multi-spectral and hyper-spectral bands to provide near real-time pictures of large areas of the country, under cloud-free conditions,
at frequent intervals which is, selected field image in every 5 minutes and entire Indian landmass image every 30 minutes at 42 metres (138 ft) spatial resolution.
EOS-05 is a replacement for GISAT-1A, which was lost in an unsuccessful mission in 2021 -- after the cryogenic upper stage of the rocket failed to ignite due to malfunctioning of a valve that led to insufficient pressure in the liquid hydrogen tank -- and the proposed mission will be closely watched following the twin two successive failures of PSLV mission in 2025 and early 2026.
ISRO has ventured into the mission after temporarily pausing launches to investigate the causes of the setbacks involving the launch vehicle. The failures had raised concerns, making the GSLV-F17/EOS-05 mission particularly significant as the space agency seeks to reinforce confidence in its launch programme. The satellite is expected to strengthen India's capabilities in Earth imaging.
The mission woud mark yet another significant step in India's expanding space-based Earth observation programme and its efforts to deploy increasingly advanced satellite systems for national applications.
UNI GV 0930
