GSLV-F17/GISAT-1A Launch (Space Sector)
GSLV-F17/GISAT-1A Launch (Space Sector)
Why In News:
GISAT-1A, also designated EOS-05, an Earth observation satellite is scheduled to be launched aboard GSLV-F17 on 4 September 2026 from the Satish Dhawan Space Centre, Sriharikota.
GISAT-1A (EOS-05) and GSLV-F17 Mission
The mission is expected to end a nearly seven-month launch gap following the PSLV-C62/EOS-N1 mission failure in January 2026.
GISAT-1A is a replacement for GISAT-1 (EOS-03), which was lost in the GSLV-F10 mission failure in August 2021 due to an anomaly involving the cryogenic upper stage.
The satellite is designed for a mission life of around 10 years and aims to provide high-frequency imaging of the Indian landmass.
Unlike conventional low-Earth-orbit Earth observation satellites, GISAT-1A is designed for operation from a geosynchronous orbit, enabling frequent observation of the same broad geographical region.
Geostationary Imaging and Applications
A geostationary satellite orbits above the equator at an altitude of approximately 35,786 km and has an orbital period equal to Earth's rotation, allowing it to remain apparently fixed over a particular longitude.
GISAT-1A's geosynchronous configuration enables repeated and near-continuous observation of the Indian region, unlike polar-orbiting satellites that pass over a location periodically.
High-frequency imaging is particularly useful for disaster monitoring, agricultural assessment, forestry, weather-related observation and rapid detection of changes on the Earth's surface.
Launch Vehicles and Institutions
Satish Dhawan Space Centre (SDSC), Sriharikota: India's principal spaceport, located in Andhra Pradesh, with multiple launch facilities including the Second Launch Pad.
Geostationary vs Geosynchronous: Every geostationary satellite is geosynchronous, but a geosynchronous orbit need not be geostationary; geostationary satellites must have a circular equatorial orbit and appear fixed over one point on Earth.
PSLV vs GSLV
Primary Purpose
PSLV: Primarily launches satellites into Polar and Sun-Synchronous Orbits (SSO).
GSLV: Primarily designed to place heavier satellites into Geosynchronous Transfer Orbit (GTO).
Payload Capacity
PSLV: Can carry approximately 1.75 tonnes to Sun-Synchronous Polar Orbit (SSO) and is mainly used for Earth-observation, remote-sensing, navigation and scientific satellites.
GSLV Mk II: Can carry approximately 2.25 tonnes to Geosynchronous Transfer Orbit (GTO) and is primarily used for launching heavier communication and meteorological satellites.
Propulsion Technology
PSLV: Uses a combination of solid and liquid propulsion stages.
GSLV: Uses solid, liquid and cryogenic propulsion, with an indigenous cryogenic upper stage.
Key Applications
PSLV: Known as ISRO’s workhorse, with a strong record of launching diverse satellites, including Earth-observation and navigation satellites.
GSLV: Strengthens India’s capability to launch heavy geosynchronous satellites and reduces dependence on foreign launch vehicles.