India has successfully launched a spacecraft to the Red Planet - with the aim of becoming the fourth space agency to reach Mars.
The Mars Orbiter Mission took off at 09:08 GMT from the Satish Dhawan Space Centre on the country's east coast.
The head of India's space agency told the BBC the mission would demonstrate the technological capability to reach Mars orbit and carry out experiments.
The spacecraft is set to travel for 300 days, reaching Mars orbit in 2014.
If the satellite orbits the Red Planet, India's space agency will become the fourth in the world after those of the US, Russia and Europe to undertake a successful Mars mission.
In order for the MOM to embark on the right trajectory for its 300-day, 780-million km journey, it must carry out its final orbital burn by 30 November.
Some observers are viewing the launch of the MOM, also known by the informal name of Mangalyaan (Mars-craft), as the latest salvo in a burgeoning space race between the Asian powers of India, China, Japan, South Korea and others.
Prof Andrew Coates, from University College London's Mullard Space Science Laboratory, told BBC News: "I think this mission really brings India to the table of international space exploration. Interplanetary exploration is certainly not trivial to do, and [India] has found some interesting scientific niches to make some measurements in."
Those niche areas include searching for the signature of methane (CH4) in the Martian atmosphere, which has previously been detected from Martian orbit and telescopes on Earth. However, Nasa's Curiosity rover recently failed to find the gas in its measurements of atmospheric gases.
CH4 has a short lifetime in the Martian atmosphere, meaning that some source on the Red Planet must replenish it. Intriguingly, some 95% of atmospheric methane on Earth is produced by microbes, which has led some to propose the possibility of a biosphere deep beneath the Martian surface. But the gas can be produced by geological processes too, most notably by volcanism.
Definitive conclusions are likely to be elusive, but the spacecraft's Methane Sensor for Mars (MSM) instrument will aim to make measurements and map any potential sources of methane "plumes".
The spacecraft will also examine the rate of loss of atmospheric gases to outer space. This could provide insights into the planet's history; billions of years ago, the envelope of gases around Mars is thought to have been more substantial.
At $72m (£45m), the mission is comparatively cheap, but some commentators have still questioned whether a country with one of the highest rankings for childhood malnutrition in the world should be spending millions on a mission to the Red Planet.
In one sense, India was left in a quandary because of the failure of its most powerful launcher, the first choice to loft the MOM into orbit. It meant the country's space agency could no longer fire the satellite directly out of Earth's atmosphere.
As a fuel-saving alternative, the spacecraft will circle Earth in an elliptical orbit for nearly a month, building up the necessary velocity to break free from our planet's gravitational pull.
The formal name for the route MOM will take to Mars is a "Hohmann Transfer Orbit". The spacecraft takes advantage of a favourable planetary alignment, carrying out six small engine burns over November to lift it to a higher orbit before a final burn sends it off on an interplanetary trajectory.
The difficulty of visiting the Red Planet will not be lost on Indian officials; just under half the total attempts to reach Mars have succeeded. But Prof Coates said the planned mechanics for getting to Mars were on a sound footing, and that the probe stood a good chance as long as its engines fired correctly.
Those who defend India's current direction in space exploration say the technological development required to mount this mission could indirectly benefit the country's other activities, including poverty reduction.
Nisha Agrawal, chief executive of Oxfam in India, told the BBC: "India is home to poor people but it's also an emerging economy, it's a middle-income country, it's a member of the G20. What is hard for people to get their head around is that we are home to poverty but also a global power.
"We are not really one country but two in one. And we need to do both things: contribute to global knowledge as well as take care of poor people at home."
K Radhakrishnan, chair of the Indian Space Research Organisation (Isro), told the BBC's India Business Report: "Why India has to be in the space programme is a question that has been asked over the last 50 years. The answer then, now and in the future will be: 'It is for finding solutions to the problems of man and society.'
He added: "A great revolution has taken place over these last 50 years in the country by a meagre expenditure that has been put into the space programme."
Mr Radhakrishnan played down talk of a race between China and India in space, commenting: "We are not in a race with anybody, but I would say we are in a race with ourselves. We need to excel, we need to improve, and we need to bring new services."
But a successful launch would allow India to surge ahead of regional rival China, at least in the exploration of Mars. China's Yinghuo-1 spacecraft was to have reached Martian orbit in late 2012. But it was piggybacked on the Russian Phobos Grunt spacecraft, which became stranded in low-Earth orbit shortly after launch in November 2011.
The MOM was to have been launched as early as 28 October, but rough weather in the Pacific forced officials to postpone lift-off.