Astrosat - India's first Space Observatory | Telugu
It was huge day for Indian Astronomy 0n 28 Sep 2015, when Astrosat was launched. It was India's first observatory in space. Normally we have telescopes on land which are easier to build. However most of high frequency light is stopped by our atmosphere. It is great for living beings on earth; otherwise we will all die due to radiation exposure. But not so good for astronomers and so to study high energy radiation emitted in space we need to have observatory and telescopes in space.
Astrosat was placed in orbit by PSLV XL, a 4 stage with 6 strap on motors. PSLV weighed 320 tons, when it started and was as high as a 15 storied building. The satellite itself weighs 1.5 tons, equivalent to the weight of a car and is 2m in height. So to put 1kg in orbit we need 150 kg of rocket + fuel.
PSLV delivered Astrosat in the orbit at speed of 7.5 km/s in 23 mins. However most of the altitude was covered of 650 km was covered in 16.
A 7.5 km/s speed of Astrosat is 200 times Shatabdi Express, the fastest train in India.
The stages of PSLV keep dropping at different heights and finally the 4th stage rocket delivers it in almost circular orbit. The orbit is almost parallel to equator, inclined at an angle of 6 degrees. At this distance it goes around the earth every 97 minutes Or 15 times a day.
Astrosat orbit is 99% circular with just 1% elliptical eccentricity. This was done by achieving a precise rocket speed such that gravitational force of earth is equaled by the centrifugal force. If the speed is more the orbit will become more and more elliptical till it escapes the gravity of earth and flies away in space. (GMeMs/R^2 = Msv^2/R)
Astrosat is powered by solar panels providing 1.5KW of power. This is the same power as a geyser we use in the bathrooms.
AstroSat has an antennae operating at 8Ghz band and transmits data 105Mbs. Whenever it passes over the two receivers at ISSDC Byalalu near Bangalore, we can send commands to AstroSat and receive the data that Astrosat has collected. The contact remains alive for about 3 minutes. So total amount of data that can be received is about 4.7GB, the size of a full HD movie.
We spent 178 crores of rupees excluding the cost of delivery to space for the satellite. Is it worth it?? Well you decide.
If you want to find what is wrong in our bodies, doctors use various cameras, ultrasound, xray, infra red by which they can get correct picture of our body. Similarly to find out what is going on in the universe we need to look at light emitted by objects. The objects emit light, not just in visible range but from gamma rays, x-rays to ultraviolet, visible, infrared up to microwaves and radio waves. So to observe all these radiations we need different telescopes in space.
And this what Astrosat with is 5 cameras bundled in one does for us. So we can see monitor all the wavebands simultaneously by pointing at the same object.
The 5 cameras are...
UVIT : Ultra-Violet Imaging Telescope
LAXPC : Large Area X-ray Proportional Counter
SXT : Soft X-ray Telescope
CZTI : Cadmium-Zinc-Telluride Imager
SSM : Scanning Sky Monitor
These cameras provide information regarding binary star system, neutron stars, black holes, star birth regions etc.
And if we think about money we burn crackers worth Rs. 10,000 corers on Diwali.
Astrosat is the culmination of painstaking years of work of scientists from 5 Indian institutes ISRO, TIFR, IIA, PRL, RRI and IUCAA. The analysis and discoveries are to follow when Astrosat starts delivering data in 6 months.
This work is supported by IUCAA (www.iucaa.in) and TATA Trust (http://www.tatatrusts.org/) and (www.tata.com/aboutus/sub_index/Tata-trusts)
TATA Trust: Education is one of the key focus areas for Tata Trusts, aiming towards enabling access of quality education to the underprivileged population in India. To facilitate quality in teaching and learning of Science education through workshops, capacity building and resource creation, Tata Trusts have been supporting Muktangan Vigyan Shodhika (MVS), IUCAA's Children’s Science Centre, since inception. To know more about other initiatives of Tata Trusts, please visit www.tatatrusts.org
Credits:,Ashok Rupner, Manish Jain, Pradnya Pujari, Shivaji Mane, Jyoti Hiremath, Arvind Gupta, Vidula Mhaiskar
Dubbed in Telugu by Sri Prakash Vidyaniketan