In the olden days, when we had a real space program, planetary missions were launched in pairs (mariner 6/7, Mariner 8/9, Viking 1/2 and Voyager 1/2), both for redundancy and to double the possible return. Mariner 8 was lost during launch, but it was only one-half of the Mariner 8/9 mission of a Mars orbiter.
In any event, I shall save my congratulations to ISRO until I see what data (if any) they get from their spacecraft.