A small but powerful engine Liquid Apogee Motor is vital to ISRO’s Plans to Place the Aditya Spacecraft in a halo orbit at Lagrangian Point L1.

It is Developed by Liquid Propulsion systems centre.

LAM has played an important role in missions including Mars Orbiter Mission, Mangalyaan and more recent Chandrayan -3.

LAM engines are used for orbital adjustments manoeuvres of satellites and spacecraft in orbit.

The ISRO is planning to launch the mission using a Polar Satellite Launch Vehicle (PSLV-XL) on September 2.

Once the Aditya spacecraft exits the earth’s sphere of influence and heads toward its destination — the Lagrangian Point L1 which is 1.5 million km away — the LAM will shut down for the best part of the four-month journey.

The propulsion system of the spacecraft comprises the 440 Newton LAM engine plus eight 22 Newton thrusters and four 10 Newton thrusters which will be intermittently fired.

The big challenge before the ISRO is restarting LAM at the precise moment for ‘braking’ the spacecraft as it closes in on its destination and nudging it into the desired halo orbit at L1.

“The propulsion module system on Aditya-L1 is identical to the one used on Chandrayaan-3.

The LAM engine is similar.

Its propellant combination (mono-methyl hydrazine (MMH) and MON3 (MON, short for mixed oxides of nitrogen) too is the same.

Its volume is different, hence propellant tank sizes are also different

About 1.5 million kilometres from the earth between it and the sun is L1, one of the five Lagrangian points or ‘equilibrium points’ in the sun-earth system.

Lagrangian points, also known as Lagrange points or libration points, are specific positions in space where the gravitational forces of two large bodies, such as the Earth and the Moon or the Earth and the Sun, produce enhanced regions of attraction and repulsion.

These points were discovered by Italian-French mathematician Joseph-Louis Lagrange in the late 18th century and have since been studied and utilized for various purposes in space exploration and astronomy.

There are five Lagrangian points in a two-body system like Earth and the Moon. They are labeled L1 through L5.

L1: Located between the two bodies and along the line connecting their centers, the L1 point experiences the gravitational pull of both bodies in a way that it maintains a nearly constant distance from both.

This point has been used for missions such as the Solar and Heliospheric Observatory (SOHO) to study the Sun.

Explain the Lagrangian points.