ઉપગ્રહના ઓછા વજનનું કારણ છે

$Zero$ reaction force due to the satellite surface

Due to gravity all bodies are attracted towards the earth's centre and weight is due to gravity. It is the value of normal reaction exerted on the body by ground. Since a satellite is in a state of free fall along with the body, therefore, the normal reaction at any surface on the satellite is $zero.$