ISRO will launch EOS-05 aboard GSLV-F17, the 19th flight of the Geosynchronous Satellite Launch Vehicle, from Sriharikota's Second Launch Pad. EOS-05, also called GISAT-1A, will be India's first imaging satellite from geostationary orbit, stationed at roughly 36,000 km altitude. It will provide near-real-time imagery every 30 minutes, with priority-target revisits as short as five minutes. The mission revives ISRO's GISAT programme after GISAT-1 failed to orbit during the GSLV-F10 launch in August 2021.

Most Earth observation satellites operate in Low Earth Orbit (LEO), typically 400–800 km altitude, where they pass over a given location only once every few hours or days. This periodic coverage limits their utility for monitoring fast-moving events like cyclones or floods. EOS-05 changes that equation by operating from geostationary orbit at ~36,000 km, where the satellite's orbital period exactly matches Earth's rotation, keeping it fixed over the Indian subcontinent continuously.

This persistent watch capability — imagery every 30 minutes, or every 5 minutes for priority zones — transforms Earth observation from a snapshot service into near-real-time surveillance. Applications span weather forecasting, agricultural monitoring, disaster management (cyclones, floods, forest fires), and strategic observation.

Technically, geostationary imaging is harder than LEO imaging. The satellite must resolve surface features from nearly 100 times the altitude of a typical LEO satellite, demanding extremely sensitive optics, precise pointing, and thermal stability.

The GISAT series is ISRO's answer to this challenge. GISAT-1 (EOS-05's predecessor) was lost in August 2021 when GSLV-F10's cryogenic upper stage failed to ignite. EOS-05/GISAT-1A thus carries both scientific and programmatic significance — it is ISRO's second attempt to establish continuous geostationary Earth imaging, a capability that major space powers have deployed but India has not yet operationalised.

For UPSC, note the distinction: GSLV (not PSLV) is the launch vehicle, the orbit is geostationary (not LEO or SSO), and the unique selling point is persistent regional coverage rather than global revisit.