VidBodh AcademyThe art and science of civil services preparation
Student login

Science and Technology › Space

हिन्दी — Read in Hindi

Launch vehicles, satellites and applications

India's launch vehicles and satellites and what they are used for: Earth observation, communication and navigation, and the launches of each year. Prelims has asked about the orbits of the Indian Regional Navigation Satellite System (IRNSS) satellites and the uses of Indian Remote Sensing satellites.

Foundation note: ISRO's launch vehicles and the orbits they serve

UPSC has asked

  • Prelims 2023: countries with their own satellite navigation system
  • Prelims 2018: the orbits of the IRNSS satellites
  • Prelims 2015: uses of Indian Remote Sensing satellites

All 4 articles shown; the 4 that changed from 1 July to 30 September 2026 are marked.Show only these

EOS-05

Copy link to EOS-05

Prelims and Mains

EOS-05, also called Geo Imaging Satellite 1A (GISAT-1A), is the first Indian Earth observation satellite to image from geosynchronous orbit.

Satellite orbit bands, not to scaleLow Earth orbit from 160 to 2,000 km, medium Earth orbit from 2,000 to 35,786 km, and geosynchronous orbit at about 35,786 km, where EOS-05 operates.Geosynchronous orbitAbout 35,786 km upOne orbit a day, matching Earth's spinCommunication, weather, now EOS-05Medium Earth orbit2,000 to 35,786 km upNavigation constellations,such as GalileoLow Earth orbit160 to 2,000 km upOne orbit every 90 to 120 minutesMost imaging satellites, the ISSEOS-05Earth

Closer to Earth. Finer detail, but a satellite races past and sees a place only briefly.

Farther from Earth. A wide region watched continuously, in coarser detail.

Not to scale. Altitudes as given in The Indian Express, 5 September 2026.

The satellite

  • It images chosen areas at frequent intervals for disaster monitoring, agriculture and forestry.
  • It replaces GISAT-1, lost in 2021 when the cryogenic upper stage of its GSLV failed to ignite.
  • What these satellites see feeds the Landslide Atlas of India, the monitoring of glacial lake outburst floods, and the National Database for Emergency Management 5.0.

Choosing an orbit

  • Which orbit a satellite is given decides what its pictures can show and how often they arrive, so the choice is made against what the images are for.
  • A satellite in low Earth orbit sees fine detail, but its revisit time runs to days.
  • A satellite in geosynchronous orbit watches one large region continuously, in coarser detail, and spends fuel on station keeping.
  • Only a satellite in geostationary orbit appears fixed in the sky, while other geosynchronous orbits trace a path across it over the day.

What changed

  1. 4 Sep 2026

    • A Geosynchronous Satellite Launch Vehicle (GSLV-F17) carried EOS-05 to orbit.

    PIB, 4 Sep 2026: Prime Minister hails the launch of GSLV-F17 carrying EOS-05 (opens in a new tab) · The Hindu, 5 Sep 2026

Background reading: The Indian Express, 5 Sep 2026: ISRO launches EOS-05: What are the different types of satellite orbits, and why do they matter? (opens in a new tab)

Everest and full-flow staged combustion

Copy link to Everest and full-flow staged combustion

Prelims and Mains

Everest is an 800 kN rocket engine built by a Bengaluru startup on the full flow staged combustion cycle, the demanding end of engine design.

  • The cycle an engine runs on decides how much of its propellant ends as thrust, and how hard the engine is to build.
  • Everest burns liquid oxygen and methane, a pair called methalox that leaves little soot.
  • The cycle throttles precisely and suits reusable rockets.

What changed

  1. 11 Aug 2026BriefA Bengaluru startup unveiled Everest, making India the fourth country with full flow staged combustion technology after Russia, the United States and China. The Hindu, 11 Aug 2026: What is the significance of India's first privately built FFSC rocket engine? (opens in a new tab)

Vikram-1

Copy link to Vikram-1

Prelims and Mains

LeadVikram-1: a private Indian rocket reaches orbitJuly 2026

Why in news

Vikram-1, built by Skyroot Aerospace of Hyderabad, lifted off from Sriharikota on 18 July 2026 and placed its payloads in low Earth orbit. It is the first privately built Indian rocket to reach orbit.

Background

  • Until 2020 only the Indian Space Research Organisation (ISRO) built and launched rockets in India.
  • The space reforms of 2020 opened the sector to private firms and set up IN-SPACe to authorise and support them.
  • A suborbital flight crosses into space and falls back. An orbital flight reaches the speed needed to stay in orbit, which is far harder.
  • Earlier private flights, Skyroot's Vikram-S in 2022 and Agnikul's Agnibaan in 2024, were suborbital.

The rocket

  • Vikram-1 is a four stage vehicle about 22 metres tall: three solid stages and a restartable liquid upper stage.
  • It can place about 350 kg in low Earth orbit, which makes it a small satellite launch vehicle.
  • Its airframe is carbon fibre composite, lighter than steel for the same strength.
  • Its liquid engine is 3D printed as a single piece, which removes the joints and seals where engines leak.

The flight

  • The mission, named Aagaman, placed six technology demonstration payloads in an orbit of about 450 km.
  • India is the third country, after the United States and China, whose private industry has reached orbit.
  • It was a developmental flight; two more are planned before commercial service.

Why it matters

  • The reforms had so far produced private satellites and applications; this adds launch capability.
  • Small satellites are the fastest growing part of the launch market, and a small rocket can launch them on demand.
  • It widens India's launch capacity beyond ISRO's own vehicles, at a time when India flies few launches a year.

What remains

  • A rocket becomes a business only with repeated, reliable flights.
  • India has no space activities law yet, so liability for damage by a private launch rests on policy and not statute.
  • Private firms still depend on ISRO's launch pads and test facilities.

The way forward

  • Pass a space activities law that settles licensing, liability and insurance.
  • Give private firms assured demand, through government launch contracts.
  • Complete the handover of the Kulasekarapattinam small satellite launch complex to a private operator, and open test facilities on the same terms.

Prelims facts

  • Vikram-1: Skyroot Aerospace, Hyderabad; four stages, three of them solid.
  • Mission Aagaman; launched from the first launch pad at Sriharikota.
  • Vikram-S (2022) and Agnibaan (2024) were suborbital.
  • India is the third country with private orbital launch, after the United States and China.

Open the lead on its own page

Vikram-1 is a four stage launch vehicle about 22 metres tall, built by Skyroot Aerospace of Hyderabad, with three solid stages and a restartable liquid upper stage called the Orbital Adjustment Module. It can place about 350 kg in low Earth orbit, or about 290 kg in a 500 km sun synchronous orbit. Its airframe is carbon fibre composite and its liquid engine is 3D printed as a single piece, which removes the joints and seals where conventional engines leak. Skyroot's Vikram-S (2022) and Agnikul's Agnibaan (2024) were suborbital flights, which cross into space without reaching the speed needed to stay in orbit.

What changed

  1. 18 Jul 2026LeadVikram-1: a private Indian rocket reaches orbit

Also filed elsewhere

  • India's first commercial Earth observation constellation · on Space policy, private sector and governance

    India's first fully commercial Earth observation constellation is a set of twelve satellites to be built, owned and operated by a private consortium by 2029 under IN-SPACe authorisation.

  • Indian Space Policy 2023 · on Space policy, private sector and governance

    The Indian Space Policy 2023 divides India's space work four ways and opens every activity, from building satellites to running launch sites, to non governmental entities.

Download a copy

Every article on this page, in full.