"ISRO's EOS-05 Becomes India's First Geo-Orbit Dedicated Imaging Satellite"
Geosynchronous Orbit (GSO)
Orbit with a 24-hour period; may be elliptical or inclined, tracing a figure-eight ground track.
Geostationary Orbit (GEO)
Circular GSO directly above the equator; satellite appears fixed over one point on Earth.
India's space programme has long pursued a dual mandate: civilian development and strategic self-reliance. The Kargil War (1999) was a turning point. The United States denied India access to GPS data over the conflict zone, exposing a dangerous dependence on foreign space-based infrastructure. This drove India to build its own navigation system, NavIC (Navigation with Indian Constellation), declared operational in 2018. The same strategic logic now extends to Earth observation. Until EOS-05, India relied on satellites in low or medium orbits for imaging, or on foreign geo-orbit assets for continuous regional surveillance. A dedicated imaging satellite in geosynchronous orbit changes this calculus fundamentally, giving India persistent, autonomous coverage of the subcontinent without depending on foreign platforms.
Understanding orbital mechanics is essential here. A Low Earth Orbit (LEO) satellite sits roughly 400–2,000 km above Earth and completes an orbit in about 90–100 minutes. It provides high-resolution images but can only observe a given location for a few minutes per pass. A Geostationary Orbit (GEO) satellite sits at approximately 35,786 km above the equator, matching Earth's rotation exactly, so it appears stationary over one point. A Geosynchronous Orbit (GSO) satellite also has a 24-hour orbital period but may be slightly inclined or elliptical, tracing a figure-eight ground track rather than remaining fixed. NavIC itself uses a hybrid of three GEO and four GSO satellites for exactly this reason: GEO provides fixed coverage, while GSO satellites improve geometry and visibility at higher latitudes. EOS-05 has been placed in a slightly elliptical GSO rather than a perfectly circular GEO, a deliberate design choice that UPSC has previously tested in the context of ISRO missions, the precise orbital parameters of a satellite, and whether 'first/only' claims about it are accurate, are exactly the kind of statement-based facts examiners have built questions around.
EOS-05 is ISRO's first Earth observation satellite placed in a geosynchronous orbit. It was launched by the GSLV F17 rocket, which carried the heaviest payload in the GSLV class's history. The satellite was initially placed in a sub-geostationary transfer orbit with a perigee of 171 km and an apogee of 31,000 km. Three successive orbit-raising manoeuvres, using the Liquid Apogee Motor (LAM) engine, progressively raised the perigee until the satellite settled into a near-circular geosynchronous orbit at approximately 34,903 km × 35,884 km.
The distinction between EOS-05's orbit and a true geostationary orbit matters for its imaging capability. A geostationary satellite is permanently fixed over one equatorial point, making it ideal for continuous monitoring of a fixed region. EOS-05's slightly elliptical geosynchronous orbit means it traces a small figure-eight path, but it remains close enough to stationary to provide near-continuous observation of the Indian subcontinent. …
With reference to 'Astrosat', the astronomical observatory launched by India, which of the following statements is/are correct?
1.Other than USA and Russia, India is the only country to have launched a similar observatory into space.
2.Astrosat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth.
Select the correct answer using the code given below.
Consider the following statements:
The Mangalyaan launched by ISRO
1.is also called the Mars Orbiter Mission
2.made India the second country to have a spacecraft orbit Mars after USA
3.made India the only country to be successful in making its spacecraft orbit the Mars in its very first attempt
Which of the statements given above is/are correct?
Why is Indian Regional Navigational Satellite System (IRNSS) needed? How does it help in navigation?
Consider the following statements about India's satellite navigation system NavIC:
1.Its development was directly motivated by denial of GPS access during the Kargil War.
2.The constellation consists of four satellites in Geostationary Orbit and three in Geosynchronous Orbit.
3.It provides coverage over India and approximately 1,500 km beyond its borders.
4.Second-generation NVS satellites added the L1 band for compatibility with commercial chipsets.
Which of the statements given above are correct?
Consider the following statements about EOS-05, launched by ISRO:
1.It is India's first Earth observation satellite placed in a geosynchronous orbit.
2.It was launched by the GSLV Mk III rocket, the heaviest in ISRO's launch vehicle fleet.
3.Its final orbit is slightly elliptical rather than a perfectly circular geostationary orbit.
4.It is intended to serve both weather forecasting and Indian Navy imaging requirements.
How many of the above statements are correct?
Which of the following correctly distinguishes a Geostationary Orbit (GEO) from a Geosynchronous Orbit (GSO)?
Match the following ISRO satellite series with their primary orbital regime:
Satellite Series — Orbital Regime
1.Cartosat series — P. Geosynchronous Orbit
2.EOS-05 — Q. Low Earth Orbit
3.NavIC (IRNSS) satellites — R. Hybrid GEO + GSO
Select the correct match:
With reference to the orbit-raising process used for ISRO's EOS-05 satellite, which of the following statements is/are correct?
1.The satellite was initially placed in a sub-geostationary transfer orbit with a perigee of 171 km.
2.The Liquid Apogee Motor (LAM) engine was used to raise the satellite's orbit progressively.
3.A single orbit-raising manoeuvre was sufficient to place EOS-05 in its final geosynchronous orbit.
Select the correct answer using the code given below:
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