New Delhi, Sep 22 (ANI): ISRO's Mars Obiter Mission will face a crucial test on Monday when the main liquid engine of the spacecraft which has been dormant for 10 months will be fired at around 2:30 pm for a very short duration of four seconds. Scientist CB Devgan explaining about this test said that if the engine works today, then probably it will work on 24th when it is fired for a longer duration into an orbit around mars. He added that if they are successful in their maiden attempt, then India will be the first country to do so.