By Parveen Kaswan:
It is believed that astronomy is as old as human presence. All through history man has been constantly inquisitive about space and far-off stars. The creation of the telescope supported him enormously, which is an instrument that aids in the perception of far-off objects. Distinctive kinds of the telescope were utilized in relying upon the part of electromagnetic range needed to see Radio, X-ray, Infrared, Visible light etc.
On 12th October 2015, the Indian Space Research Organisation (ISRO) tweeted a mesmerising image of Crab Nebula which is one of the brightest hard X-ray sources in the sky. The tweet marked a new scientific achievement; India is now just the fourth nation to have this sort of lookout in orbit. Space-based observatories are similar to a major telescope fitted on a satellite rotating around the earth in a settled orbit, and making observations in the unfathomable universe. Our own ASTROSAT, which India launched on 28th September is gazing the far off stars. According to ISRO, now “Astrosat would be looking at some of the black hole sources/candidates like GRS 1915+105, Cygnus X-1, Cygnus X-3 during the month of November.”
It is a well-known fact that earth is surrounded by a layer of atmosphere and this layer can possibly square X-Ray, Infrared and Ultraviolet beams. It can likewise distort/twist Microwaves and Visible light which has an immediate effect on the picture quality of ground-based telescopes. In spite of the fact that some of these issues can be rectified by setting observatories on higher elevations, furthermore utilising technological advances like adaptive optics, but they still have their limits. Additionally even space-based radio and visible light telescopes are complementary in nature to their earth based counterparts. As a space-based telescope won’t be affected by climatic twists furthermore by simulated or artificial lights, it will give us sharp pictures of space and remote cosmic systems.
Though they have their particular problems, confronted by any earth circling a satellite, these sort of observatories at some point need essential rectification additionally which is very much a mind-boggling mission. And they have their own particular mission period if the refuelling part is not a part of the project.
Hubble telescope, the space observatory named after astronomer Edwin Hubble, is the best case which was operationalised in 1990 and now gives high-resolution pictures of outer space and galaxies. Its observation has also helped in unravelling the riddles of the universe and determining the rate of expansion after the Big Bang.
Indian ASTROSAT dispatch was initially planned in 2005, and then in 2010, lastly it was activated in 2015. The reason for delay was mainly technical in nature. The considerable thing about this venture is that its very participatory in nature as nearly 10 noteworthy research institutions including ISRO, TIFR, BARC, Raman Research Institute, Canadian Space Agency and so forth are a part of it. The objective includes “to measure the magnetic fields of neutron stars and understand high energy processes that occur in binary and extragalactic systems.”
The observatory is now rotating in an equatorial near earth, in a 650 km orbit with five instruments on board, covering Visible, near Ultraviolet, far Ultraviolet, soft X-ray and hard X-ray regions of electromagnetic spectrum. According to ISRO, it will study ‘astrophysical objects ranging from the nearby solar system objects to distant stars, to objects at cosmological distances; timing studies of variables ranging from pulsations of the hot white dwarfs to active galactic nuclei with time scales ranging from milliseconds to few hours to days.’
After some exceptionally successful ‘Technology Demonstrator’ missions like MOM and Chandrayaan, it is time that we pay attention to some scientific activities too. Astrosat mission gives an adequate extension to India for presenting itself as a major contender for the space market pie, which is worth 400 billion dollars. ‘Indian Remote Sensing’ system is today the world’s largest constellation of satellites in civilian use which is also a good source of income for ISRO. Its application is used in the socio-economic development of the country, from agriculture to town planning and from geology to marine fisheries.
Such feats are required to tap into Asian and African space markets by providing cost effective and reliable services. It is high time that India should also look beyond the horizon, deep into space, and Astrosat is a right step in the right direction.