Semi Cryogenic Technology for Gaganyaan: RSTV - In Depth

Semi Cryogenic Technology for Gaganyaan RSTV –Download PDF Here

Rajya Sabha TV programs like ‘The Big Picture’, ‘In Depth’ and ‘India’s World’ are informative programs that are important for UPSC preparation. In this article, you can read about the discussions held in the ‘In Depth’ episode on “Semi Cryogenic Technology for Gaganyaan” for the IAS exam.

Anchor: Teena Jha


India’s strategic partner Russia has offered its Semi Cryogenic engine technology and critical components for the Gaganyaan project.


  • In 2018, India’s first manned space mission was announced by Prime Minister Narendra Modi in his Independence Day speech.
  • Gaganyaan will be the Indian crewed orbital spacecraft intended to be the basis of Indian Human Space Flight Program.
  • With Gaganyaan, India will become only the 4th country after Russia, the USA and China to send humans to space.
  • It will be ISRO’s next big project after the anticipated soft landing of Chandrayaan 2 on the lunar
  • The target is to launch it before the 75 year celebration of India’s independence.
  • Before the manned mission scheduled for December 2021, two unmanned tests will be carried out in December 2020 and July 2021.
  • ISRO’s indigenous mission will be assisted by few other countries in selecting and training astronauts.
  • According to ISRO, a budget of Rs 10,000 Cr. has been set aside for putting the infrastructure in place.
  • It is described as a national mission than an ISRO mission.

The Spacecraft:

  • The spacecraft will take 3 Indian astronauts, who will be known as ‘vyomnauts’ (in Sanskrit ‘vyom’ means space.
  • It will circle the earth for 7 days from a distance of 300-400 km.
  • It will be launched by India’s biggest rocket GSLV Mk 3 from Sriharikotta.
  • The 7 ton spacecraft will orbit the earth at an altitude of 400km for up to 7 days.
  • ISRO has developed most of the critical technology needed for the mission.
  • Its service module will be powered by two liquid propellant engines.
  • It will have life support and environmental control systems.
  • It will be smaller than the current Russian and Chinese ones or NASA’s Apollo or the planned Orion
  • But it will be slightly larger than the U.S Gemini
  • ISRO Telemetry Tracking and Command Centre in Peenya will monitor it round the clock.

Crew Module:

  • The crew module is a twin walled sealed structure that recreates earth like conditions.
  • It will be equipped with Emergency Mission Abort and Emergency Escape System.
  • The crew escape system is an emergency system to help the crew pull away from the launch vehicle when the mission has to be aborted. It can be done at the 1st and 2nd stage of the rocket.
  • Crew escape system ensures that the crew module gets advance warning if anything goes wrong with the rocket.
  • It pulls the crew module away to a safe distance and can be landed either on sea or on land with parachutes.

Development of the Project:

  • Preliminary studies and technological development started in 2006 itself under the generic name ‘orbital vehicle’.
  • The plan was to design a simple capsule similar to the Mercury class spacecraft with an endurance of about 1 week in space.
  • It was initially designed to carry 2 astronauts and to land on water upon re-entry.
  • The design was finalised in
  • A full-fledged training facility will be set up at Bangalore for training the astronauts.

Russian Support for Gaganyaan:

  • Russia has offered Semi Cryogenic engine technology and critical components for the human space capsule. Agreements will be signed soon in this regards.
  • ISRO Chairman K Sivan revealed that the technology will be transferred under the ‘Make in India’ programme so that the engines can be made in India.
  • The two countries have already signed a deal for the training program of astronauts.
  • Based on an agreement between ISRO and Glavcosmos, a subsidiary of Russia’s state run space corporation Roscosmos, four Indians will be trained at the Yuri Gagarin Cosmonauts Centre.
  • The Russian agency will select, test and qualify the trainees in collaboration with the state run Institute of Medical and Biological Problems, Russia.
  • India is also negotiating with Russia for the supply of space suits, crew seats and windows.
  • Recently, National Security Advisor Ajit Doval and Roscosmos Director General discussed matters related to Rocket Aerodynamic Test, Piloted Vehicle and Crew Rescue System for the Indian mission.
  • Upcoming top level meetings at the Eastern Economic Forum in Vladivostok, Russia, may include further discussions on piloted flight, satellite navigation and engine technology.

Russia’s Role in India’s Space Program:

  • Russia is one of the world leader in space technology and one among the few countries, such as France, Germany, Israel, U.S.A etc. who have assisted substantially in India’s space program.
  • Cooperation in space program remains one of the main pillars in the strategic partnership between India and Russia.
  • It has emerged as a key area in the high technology sector.
  • ISRO and Soviet Academy of Sciences signed a contract to launch India’s first national satellite, Aryabhata-1 in 1975.
  • USSR provided satellite launch facility and consultation on design and construction while India undertook the production of the satellite.
  • In 1979 and 1981, the partnership continued for the launch of Bhaskara 1 and 2
  • Rakesh Sharma, the first Indian to travel to space was carried by the Russian space vehicle Soyuz T-11.
  • In 1988 and 1991, Soviet Vostok rocket launched India’s imaging satellites in spite of the fact that India had developed its own satellite launch vehicle in 1987.
  • By the early 1990s, India became self-reliant in delivering its satellites into orbits through the Polar Satellite Launch Vehicle (PSLV).
  • In 1992, India signed an agreement with Russia for transfer of engine technology for the launching of geostationary satellites.
  • But, the US had concerns over triggering an arms race in the region and violation of Missile Technology Control Regime (MTCR).
  • In 1994, the deal was renegotiated but with no transfer of technology.
  • Instead 7 Russian made engines were transferred from Russia to India to be used in GSLV Mk 1 launcher.
  • India’s entire cryogenic program got delayed because of the issue.

Post USSR Partnership:

  • After the dissolution of the USSR, Russia continued the USSR policy of assisting India in the space domain.
  • In 2004, New Delhi and Moscow signed 2 agreements:
  • The Inter-Governmental Umbrella Agreement for Cooperation In Outer Space For Peaceful Purposes and
  • The Inter Space Agency Agreement for GLONASS (Global Navigation Satellite System, the Russian version of GPS).
  • But, both the agreements couldn’t be materialised.
  • In 2011, agreement was reached to grant Inter Military Preferential Access for positioning data under GLONASS.
  • The two countries also negotiated cooperative measures under GLONASS and Chandrayaan 2

Russian Cryogenic Technology:

  • Russia had transferred Cryogenic technology also to India.
  • Original Russian technology was not much useful for ISRO but, India reverse engineered and improved it.
  • Patterned on Russian engines, India successfully tested its cryogenic technology in GSLV Mk 2 in 2014.
  • In 2015, ISRO and Roscosmos signed a MoU for expanding cooperation on space exploration and use of outer space for peaceful purposes.

Cooperation in Recent Years:

  • In the 2016 BRICS summit at Goa, India and Russia reaffirmed the commitment to pursue the immense potential for cooperation in outer space to advance socially useful applications and scientific knowledge.
  • In his recent visit to India, Russian President Vladimir Putin signed an agreement on joint activities in the human space flight program.
  • The importance of mutually beneficial cooperation in outer space and enhancing the cooperation on exploration and use of outer space for peaceful purposes were also emphasised.
  • Dialogues are under way for the setting up of ground stations in each other’s land to enhance the accuracy of satellite navigation systems.
  • Russia will set up one at Bengaluru and India’s NAVIC station will be set up at Moscow.

Cryogenic Technology:

  • Rocket engines need enormous thrust to escape Earth’s gravitational pull.
  • Hydrogen and Oxygen that produce a good thrust are found in gaseous form on earth.
  • However, sending huge tanks of gas in a rocket is an impossible task.
  • In Cryogenic engines, fuel, oxidiser or both are stored as liquefied gases at very low temperatures (-253OC) to maintain the liquid state.
  • These are usually prepared for the upper stages or the last stage.
  • Cryogenic fuels such as liquid hydrogen are used because ordinary fuel can’t be used in space due to an absence of environment that support combustion.

 Cryogenic Technology and Semi Cryogenic Technology- a Comparison: 

Parameters Cryogenic Technology Semi Cryogenic Technology
Fuel used Liquid hydrogen Refined kerosene
Oxidiser used Liquid oxygen Liquid oxygen
Temperature required by Fuel Very low (-253OC) Normal
Heaviness of Fuel Comparatively heavier Lighter
Space required Comparatively more Lesser
Advantages a) Easier to transport.

b) More density and hence more thrust can be produced in smaller burning time.

c) More thrust makes it possible to carry more weight and take that weight into a higher orbit.


a) Can carry more weight to a higher altitude.

b) Despite being a lighter fuel kerosene combined with oxygen gives a higher thrust.

c) More propellant can be carried in the fuel compartment as Kerosene needs lesser space

d) Payload can be increased since the weight of fuel will come down by around 500kg.

e) Engine is more powerful, environmentally friendly and cost effective.

f) Under deep throttle, we can go from 27% to 105% and work with much higher operability.


Status in India Used in Vikas engine of GSLV (With 3 stages; solid, liquid and cryogenic respectively). SCE 200 is being developed.

                 Semi Cryogenic Engine 200 (SCE 200):

  • Semi Cryogenic technology is very important for India’s space program to move to the next level. With Russia’s assistance India might be able to achieve it faster.
  • ISRO plans to commission a Semi Cryogenic Engine 200 (SCE 200).
  • In 2009, the project was approved at a sanctioned cost of 1798 Cr.
  • It is being developed by the Liquid Propulsion Systems Centre.
  • It uses liquid oxygen and RP1 kerosene in an oxidiser rich staged combustion cycle.
  • 200 denotes the power (200 tons).
  • However, the throttle can go from 60% to 105% only.
  • The initial target of 2014 was postponed and now ISRO is planning to flight test the engine in
  • Its purpose is to power the Unified Launch Vehicle (ULV), the Reusable Launch Vehicle (RLV) and the future GSLV Mk 3 rockets.

Challenges in a Manned Mission:

  • Satellites launched by ISRO are meant to remain in space even after their life is over. Even the Chandrayaan and Mangalyaan are not meant to return to earth.
  • But, a manned spacecraft need to return with the astronauts inside it.
  • For a spacecraft to re-enter atmosphere, it needs to withstand very high temperature created by friction, and hence special parameters are required.
  • Astronauts need special physical and mental training.
  • Re-entry needs to be carried out at a very precise speed and angle.
  • Recovery of the module after it lands in land or water need to be done promptly.

Crew Module Atmospheric Re-entry Experiment:

  • In 2014, ISRO successfully tested an experimental crew module that came back to earth from an altitude of 126km in space.
  • It re-entered the atmosphere at a height of 80km and landed in the sea near the Andaman and Nicobar islands.

Challenges for astronauts:

  • The astronauts will have to adapt to the change in gravitational field.
  • The change in gravity affects hand-eye and head-eye coordination.
  • Bones may lose minerals adding to the risk of osteoporosis related fractures.
  • Lack of exercise and improper diet make them lose muscle strength and cause develop vision problems.
  • Travelling in the rocket involves change of 0 to 29000 km/Hr. speed in less than 30 minutes.
  • Despite the many inbuilt safety features, rockets may disintegrate in the launch phase itself.
  • The systems can’t be tested in actual operating environments.
  • Once they are in space, astronauts will receive over 10 times more radiation than what people are subjected to on earth.
  • It can cause cancer, nervous system damage and trigger nausea, vomiting, and anorexia and fatigue.
  • Without pressure, human blood heats up.
  • Despite the training, behavioural issues may crop up due to isolation leading to depression, fatigue, sleep disorders and psychiatric disorders.
  • Space vehicles needs an atmosphere like earth and adequate supply of oxygen along with comfortable temperature and humidity levels.


The assistance from Russia will help India in realising faster, the dream of taking humans to space.

Also, See:

Read previous RSTV articles here.

Semi Cryogenic Technology for Gaganyaan RSTV –Download PDF Here

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