Archive · 4 Sep 2026
ISRO’s ‘Naughty Boy’ Boosts EOS-05 Orbit, Saving Propellant
ISRO launched a rocket called GSLV-F17 carrying the EOS-05 satellite.
The rocket is sometimes nicknamed the “Naughty Boy” because it had failures early in its history.
This time, it worked better than expected.
It placed the satellite higher than planned in space.
EOS-05 is designed to watch India continuously from a very high orbit.
It can provide information about weather, disasters, infrastructure and regional surveillance.
Because the rocket did more of the work, the satellite may need less of its own fuel.
The saved fuel could help EOS-05 operate for longer.
ISRO launched the GSLV-F17 rocket from Sriharikota early on 4 September, carrying the EOS-05 satellite.
The rocket placed EOS-05 into a geosynchronous transfer orbit with a 171-kilometre perigee, 31,026-kilometre apogee and 19.28-degree inclination.
The mission document had expected an initial orbit with a 28,934-kilometre apogee, meaning the satellite reached about 2,092 kilometres higher than planned.
EOS-05 will use its onboard propulsion to reach and circularise at an altitude of about 36,000 kilometres above the equator.
The higher-than-expected orbit may reduce fuel use and potentially extend the satellite’s operational life beyond the typical five-to-seven-year range.
- Who
- The Indian Space Research Organisation launched the GSLV-F17 rocket carrying the EOS-05 satellite.
- What
- The launch placed EOS-05 into a higher-than-planned geosynchronous transfer orbit.
- When
- Early on 4 September; the article describes it as ISRO’s first successful launch of 2026.
- Where
- The rocket launched from Sriharikota, India.
- Why
- EOS-05 is intended to provide continuous observation of India and nearby regions for weather, disaster, infrastructure and surveillance needs.
- Rocket
- GSLV-F17
- Satellite
- EOS-05 earth observation satellite
- Actual transfer orbit
- 171-kilometre perigee, 31,026-kilometre apogee and 19.28-degree inclination
- Planned apogee
- 28,934 kilometres, according to the mission document
- Final operating altitude
- About 36,000 kilometres above the equator
- Expected benefit
- Reduced onboard propellant use and potentially longer operational life
- Typical mission life
- Earth observation satellites generally operate for five to seven years, according to the article