GSLV-F17 / EOS-05 MISSION — INDIA’S GEO-IMAGING EARTH OBSERVATION CAPABILITY

GSLV-F17 / EOS-05 MISSION — INDIA’S GEO-IMAGING EARTH OBSERVATION CAPABILITY

1. Context

• ISRO successfully launched GSLV-F17 carrying EOS-05 on 4 September 2026 at 02:55 AM IST from the Satish Dhawan Space Centre, Sriharikota. (ISRO)
• The uploaded material correctly identifies the mission as an important comeback after recent launch setbacks.

2. What is EOS-05?

• EOS-05 is a state-of-the-art Earth Observation Satellite developed for imaging the Earth from geosynchronous altitude.
• ISRO describes it as India’s first imaging satellite from geosynchronous orbit. (ISRO)
• Its importance lies in providing repeated observation of the same broad geographical region.

3. Orbit of EOS-05

• GSLV-F17 initially placed EOS-05 into a Sub-Geosynchronous Transfer Orbit (Sub-GTO). (ISRO)
• The spacecraft subsequently uses onboard propulsion for raising and circularising its operational orbit.
• Geosynchronous satellites have an orbital period approximately equal to Earth’s rotation period.

4. Geosynchronous and Geostationary Orbits

• A geosynchronous orbit is one in which the satellite completes one revolution in roughly 24 hours.
• A geostationary orbit is a special circular geosynchronous orbit directly above the Equator, where the satellite appears fixed over one longitude.
• The standard geostationary altitude is about 35,786 km above Earth.

5. Advantage over Low Earth Orbit

• Most Earth-observation satellites in Low Earth Orbit provide high-resolution observations while repeatedly passing over different regions.
• A GEO-imaging satellite can continuously or frequently observe a very large area from nearly the same viewing geometry.
• It is therefore especially useful where rapid changes must be monitored repeatedly.

6. GSLV-F17 Launch Vehicle