The 44.4-metre tall trusted workhorse of the Indian Space Research Organization (ISRO) stood on its launchpad as its tanks were filled with fuel that will power the rocket over its four stages into space to insert the spacecraft into an Earth orbit. Final destination: Mars, the Red Planet, 400 million km and 300 days' journey away.
The actual launch operations on Tuesday will only involve about 43 minutes of rocket flight. But it is still set to be the longest initial flight for any launch in ISRO's history.
"If the rocket has to function and the vehicle is able to put the satellite into an orbit of 23,500 km-by-250 km, that is sufficient. There is a band 675 km plus or minus this number. Anywhere within that if it is put, it is a success," ISRO chairman K Radhakrishnan said of the expectations for the initial flight the first step in the long journey to Mars.
If all goes well on Tuesday, the next major test for the mission will come on November 30, when the spacecraft is scheduled to begin its journey to Mars: The trans Martian injection. And then again in September 2014, when it will inject the Mars orbiter into the Mars orbit.
The launch will involve 23 minutes of flight when the rocket will be visible to ISRO through its own ground station at Biak near Indonesia. The subsequent operations, during which the rocket will disengage the spacecraft and place it in a Earth orbit, will be tracked by special ship-borne terminals: Nalanda and Yamuna in the South Pacific Ocean.
The specific operations that the ship-borne terminals will monitor are the ignition of the fourth stage of the rocket at 33 minutes, and the separation of the satellite from the rocket at around 43 minutes. After the initial 23 minutes, the rocket will coast for about 10 minutes before the fourth stage ignition takes place.
"Up to 23 minutes of flight we can have visibility. Beyond that we don't have visibility. These ship terminals are placed in two positions in such way that the ignition of the fourth stage is seen and the separation of the satellite is seen. Immediately after the separation of the satellite we also have the deployment of the solar panel, which happens automatically based on the command stored in the spacecraft," the ISRO chairman said.
"It is a leap forward. It is a turning point for the country if we are able to accomplish this. Any progress we make in this is new learning. Any progress we make from then onwards is a learning for us," he said.
A 299-day journey of 400 mn km at a cost of Rs 450 cr
PSLV-C25 lifts off from Satish Dhawan Space Centre, Sriharikota, at 2.38 pm. In 42-min first phase of the flight, Mangalyaan will be put into a 248 km-by-23,000 km elliptical Earth Parking Orbit.
DEPARTURE: NOV 30
Leaves Earth in a direction tangential to Earth's orbit around the Sun. Encounters Mars tangentially to its orbit around the Sun. Trans-Martian injection of December 1 is most crucial part of mission, says ISRO.
MARS ORBIT INSERTION: SEP 21, 2014
Spacecraft reaches Mars's sphere of influence in hyperbolic trajectory; expected to be captured into planned orbit when it reaches Mars Periapsis. Nine earlier Mars missions have failed at this stage.
Only 21 of the 51 attempted Mars missions have been successful. Attempts by Japan in 1999 and China in 2011 failed.