Liquid Apogee Motor

An Liquid Apogee motor (LAM) refers to a rocket motor which is used to provide thrust to bring the satellite or spacecraft into desired orbit.

It is regularly employed on artificial satellites or spacecrafts destined for a geostationary orbit or Moon's orbit (Chandrayan

1) or Mars (MoM) orbit.

How it works: The carrier rocket would only be able to launch the satellite into an elliptical orbit after that the satellite must then provide thrust to reach a geostationary orbit (or Moons orbit, Mars orbit). This is typically done with a fixed onboard Liquid Apogee Motor (LAM).

When the satellite reaches its orbit's apogee position, the LAM is ignited, transforming the elliptical orbit into a circular orbit, while at the same time bringing the inclination to around zero degrees, thereby accomplishing the insertion into the desired orbit. This process is called an "apogee kick".

ISRO's first liquid rocket motor (LAM), developed in the early eighties

Fuel: LAM develops 45-kg thrust and uses monomethyl hydrazine and a nitrogen tetroxide as propellants and pressurized helium gas is used to force the propellants into the combustion chamber.

Uses: The LAM has since been used in over two dozen missions to boost communication, weather and navigation satellites into geo-synchronous orbit.

The LAM-thruster combination was also adopted for the Chandrayaan-1 lunar orbiter mission and the Mars Orbiter Mission (MOM).

Eg. Liquid Motor (LM) on MOM: MOM features a modified version of the LAM called the Liquid Motor (LM), or the 440-Newton Liquid Engine. It was used to raise the orbit of the MOM and propel it on a Trans-Mars trajectory. It has been fired seven time so far and will next be used to slow MOM dow