ISRO Spaceflight

🚨 GSLV performs better than expected, EOS-05 mission life likely to increase! 🔥

GSLV-F17 was supposed to place EOS-05 into a transfer orbit with an apogee of 28,934 km. However, GSLV's cryogenic third stage performed better than expected, achieving an apogee of 31,026 km!

Being a Geostationary satellite, EOS-05 would ideally be launched into an elliptical 170 × 35,786 km Geostationary Transfer Orbit (GTO), from where it would use its own propellant and thrusters to raise its perigee and eventually enter a circular Geostationary Orbit (GEO).

However, at 2,367 kg, EOS-05 is heavier than the 2,250 kg maximum mass GSLV can deliver to GTO.

Therefore, for this mission, GSLV's third stage was made to fire until all propellant is exhausted (burn to depletion), sending the satellite the furthest it could.

ISRO had estimated an apogee of 28,934 km i.e. lower than GTO altitude, hence the term Sub-GTO. EOS-05 would then use its own propulsion system to raise its apogee to GTO altitude before continuing its journey to GEO.

But GSLV achieved an apogee +2,092 km higher than expected!
This means EOS-05 will need to use less of its own propellant to reach GTO, leaving more propellant available once it reaches GEO.

This extra propellant can then be used for stationkeeping and attitude control, likely extending EOS-05's planned 10-year mission life!

Vehicle cleared for launch ✅️
Automatic Launch Sequence initiated ✅️
Rocket on internal power 🔳

#GSLVF17 | #ISRO

Vehicle cleared for launch ✅️
Automatic Launch Sequence initiated 🔳
Rocket on internal power 🔳

#GSLVF17 | #ISRO