The Indian Space Research Organisation (ISRO) is launching a Polar Satellite Launch Vehicle (PSLV) this Tuesday (5 Nov 2013) from Satish Dhawan Space Center, Sriharikota, India, flying on the PSLV-C25 mission with Mars Orbiter Mission (MOM), informally called Mangalyaan onboard.
Looking through the mission objectives, it seems the scientific payload is of secondary nature and ISRO's primary objectives are limited to building the spacecraft, getting there, and communicating with the spacecraft by extending the India's Deep Space Network (the launch was delayed from late October to early November due to, I believe, one of the launch tracking ships not being able to get to Fiji in time because of a tropical storm in the Pacific Ocean).
BBC's interview with K. Radhakrishnan, chair of ISRO further emphasises main objectives:
Essentially in this Mars mission, which we are planning, the prime objective is to demonstrate India's capability to capture the Martian orbit and then to conduct a few meaningful scientific experiments.
Proto-flight model of the payloads for Indian Mars Mission (Source: PDF, 44th Lunar and Planetary Science Conference)
The spacecraft's 15 kg (33 lb) scientific payload still includes five instruments to conduct atmospheric, particle environment and surface imaging studies, with focus on establishing the presence of methane in the Martian environment. But all this sounds more like being a preliminary mission paving the way for future ISRO's missions to Mars, so it naturally begs the question:
What plans does ISRO have for future exploration of Mars? What are the India's Mars exploration campaign goals, which future missions are approved, in development, under consideration or on the drawing boards that are known to public?
Update: I see there's some confusion on where my question is coming from. This is not a non-researched question asking about what information is so far presented to the general public. To quote Dr. K. Radhakrishnan, Chairman of the Indian Space Research Organisation (ISRO) when asked about India's efforts to explore Mars:
Would India have an ongoing Mars programme or would the 2013 mission be a one-mission agenda? If not, then has ISRO developed any well articulated Mars agenda? Has ISRO started preparations for any missions for the launch windows in 2016 and 2018 respectively?
Of course, while exploring the launch opportunities in the year 2013, 2016 and 2018, we have also studied the possible launch opportunities, corresponding velocity requirements and payload capabilities for Orbiter missions to planet Mars beyond 2018 as well.
This statement has to have some grounds somewhere, in actual planned missions, draft proposals, and so on. A chairman of ISRO wouldn't be discussing future launch windows to Mars, if there wasn't a good reason for it. What are these reasons? In essence, what comes next, after Mangalyaan, for ISRO and their endeavors to explore the red planet?