The word cryogenics comes from Greek word
kryos and means “the production of freezing
cold” the term is used today as a synonym for
the low-temperature state.
In physics, cryogenics is the study of the
production of very low temperature
(below −150 °C, −238 °F or 123 K) and the
behavior of materials at those temperatures .
A cryogenic rocket engine is a rocket engine that
uses a cryogenic fuel and oxidizer, that are the gases
which are liquefied and stored at very low
Rocket engines need high mass flow rate of both
oxidizer and fuel to generate a sufficient thrust.
Generally oxygen and low molecular weight
hydrocarbons are used as oxidizer and fuel pair.
The combination of liquid oxygen and liquid hydrogen
offers the highest energy efficiency for rocket engines
that need to produce large amounts of thrust.
The Russians were the first to reach into space.
Solid-fuel rocket engines were the first engines created by man.
All the current Rockets run on Liquid-propellant.
The United States was the first country to develop cryogenic rocket
They register their first successful flight in 1963 with RL-10 engine
and is still used on the Atlas V rocket.
Then The Japanese LE-5 engine flew in 1977 ,French HM-7 in 1979 ,
Chinese YF-73 in 1984 .
The Russians who put a first satellite and later a human in space,
successfully launched a rocket with a cryogenic engine in 1987.
India successfully launched cryogenic engine on 5th January 2014.
BRIEF HISTORY OF CRYOGENIC ENGINE
cooling and compressing gases into liquids, we can vastly
increase their density and make it possible to store them in
large quantities in smaller tanks.
super cooled gases are stored at the temperature lower
than their freezing point.
Nitrogen, hydrogen, oxygen, helium argon, neon, etc,
Liquid oxygen being the oxidizer and liquid hydrogen being
Liquid oxygen boils at 297oF and liquid hydrogen boils at
Thrust chamber or combustion chamber
Among them, the combustion chamber & the nozzle
are the main components of the rocket engine.
Components Of Cryogenic Rocket
DIFFERENT TYPES OF ROCKET
ENGINE POWER CYCLES
1. Gas Pressure Feed System
2. Gas – Generator cycle
3. Staged Combustion Cycle
Production & Manufacturing
The Indian cryogenic engine is produced by Godrej
and the Hyderabad-based MTAR Technologies
working together as a consortium.
Instead of ISRO first mastering the technology and
transferring it to industry, the two companies were
involved from the start and even the early prototypes
were built by them.
High Energy per unit mass:
Propellants like oxygen and hydrogen in liquid form
give very high amounts of energy per unit mass due to
which the amount of fuel to be carried aboard the rockets
Hydrogen and oxygen are extremely clean fuels. When
they combine, they give out only water. This water is thrown
out of the nozzle in form of very hot vapour. Thus the rocket is
nothing but a high burning steam engine
Use of oxygen and hydrogen as fuels is very
economical, as liquid oxygen costs less than gasoline.
The next generation of the Rocket Engines
All rocket engines burn their fuel to generate thrust . If any other
engine can generate enough thrust, that can also be used as a
There are a lot of plans for new engines that the NASA scientists
are still working with. One of them is the “ Xenon ion Engine”.
This engine accelerate ions or atomic particles to extremely high
speeds to create thrust more efficiently. NASA's Deep Space-1
spacecraft will be the first to use ion engines for propulsion.
There are some alternative solutions like Nuclear thermal rocket
engines, Solar thermal rockets, the electric rocket etc.
We are looking forward that in the near future there will be
some good technology to take us into space