Exactly at 10am IST, the 44.4-metre, 320-tonne polar satellite launch vehicle’s XL variant (PSLV-XL) blasted off the first launch pad at the rocket port in Sriharikota, around 80km from Chennai.
Besides Astrosat, the rocket carries six other foreign satellites.
Astrosat is the country’s first dedicated multi-wavelength space observatory that will help in understanding the universe.
India will cross the half-century milestone once it successfully injects the six foreign satellites into their intended orbit.
India has so far launched 45 foreign satellites for a fee.
In 2008, Isro had launched 10 satellites in one go including India’s Cartosate-2A satellite.
Now, Isro will be launching seven satellites for the third time in its history.
The PSLV-XL version is a four-stage rocket with six strap-on motors for additional thrust during the initial phase of the flight.
The first and third stages are powered by solid fuel while the second and fourth stages are powered by liquid fuel which will be filled during the countdown.
Apart from fuelling up the engines, all the systems would be checked and rechecked during the countdown.
The rocket is carrying India’s Astrosat weighing 1,513 kg, apart from four from the US and one each from Indonesia and Canada.
The PSLV is carryi g a total payload of 1,631 kg during this mission.
Just over 22 minutes into the flight, the rocket will eject Astrosat at an altitude of 650 kms above the earth.
Soon after, six other satellites will be put into orbit and the whole mission will come to an end in just over 25 minutes.
Astrosat, with a life span of five years, will observe the universe through optical, ultraviolet, low and high energy X-ray components of the electromagnetic spectrum, whereas most other scientific satellites are capable of observing through a narrow wavelength band, the agency said.
The Indonesian 76 kg LAPAN-A2 is a micro-satellite from the National Institute of Aeronautics and Space, meant for providing maritime surveillance using automatic identification system (AIS), supporting Indonesian radio amateur communities for disaster mitigation and carrying out earth surveillance using video and digital camera.
The 14-kg NLS-14 (Ev9) of Space Flight Laboratory, University of Toronto Institute for Advanced Studies, is also a maritime monitoring Canadian nano satellite using the next generation AIS.
The remaining four LEMUR nano satellites from Spire Global Inc., San Francisco, US, are non-visual remote sensing satellites, focusing primarily on global maritime intelligence through vessel tracking via AIS and high fidelity weather forecasting using GPS radio occultation technology, the Isro said.