Astrosat

ASTROSAT is India's first dedicated astronomy satellite and is scheduled to launch in mid 2009.

After the success of the satellite-borne Indian X-ray Astronomy Experiment (IXAE), which was launched in 1996, the Indian Space Research Organization (ISRO) has approved further development for a full fledged astronomy satellite - ASTROSAT. A large number of leading astronomy research institutions in India and abroad are jointly building various instruments for the satellite.

Important areas requiring broad band coverage include studies of 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(AGN)with time scales ranging from milliseconds to few hours to days.

ASTROSAT is currently proposed as a multi-wavelength astronomy mission on an IRS-class satellite into a near-Earth, equatorial orbit by the PSLV. The 5 instruments on board cover the Visible (320-530 nm), NUV(180-300 nm), FUV(130-180 nm), Soft and Hard X-ray regimes (0.3 - 8 keV, 2 - 10 keV, 3 - 80 keV and 10 - 150 keV).

Objectives of ASTROSAT

* Multi-wavelength studies of cosmic sources
* X-ray timing, with response up to hard X-rays (~100 keV)
* Monitoring the X-ray sky for new transients
* Sky survey in the hard X-ray and UV bands
* Broadband spectroscopic studies of X-ray binaries, AGN, SNRs, clusters of galaxies and stellar coronae
* Studies of periodic and non-periodic variability of X-ray sources
* Monitoring intensity of known sources and detecting outbursts and luminosity variations

Participants

ASTROSAT project is a collaborative effort of a growing list of research institutions. The current participants are:

* Indian Space Research Organization
* Tata Institute of Fundamental Research, Mumbai
* Indian Institute of Astrophysics, Bangalore
* Raman Research Institute, Bangalore
* Inter-University Centre for Astronomy and Astrophysics, Pune
* Nuclear Research Laboratory, Bhabha Atomic Research Centre, Mumbai
* S.N. Bose National Centre for Basic Sciences, Kolkata
* Canadian Space Agency
* University of Leicester

To achieve the mission objectives, Astrosat will carry the following payloads:

# Large-Area Xenon-filled Proportional Counters (LAXPC)
# A Coded-mask Camera with Cadmium-Zinc-Telluride detector array (CZTI)
# A Soft-Xray imaging telescope with multi-foil Wolter optics and CCD detector (SXT)
# A Scanning X-ray Sky Monitor consisting of three one-dimensional coded mask cameras (SSM)
# Two 40-cm dia Ultraviolet Telescopes for Visible, NUV and FUV coverage (UVIT)
# A Charged particle monitor (CPM)

The total weight of all the instruments will be about 750 kg, and the weight of the entire spacecraft will be about 1650 kg. It will be launched by ISRO's PSLV from Satish Dhawan Space Centre at Sriharikota into a Low-Earth (altitude ~ 600 km) circular low-inclination (near-equatorial; < 8°) orbit.

Open observing time on ASTROSAT will start one year after launch, for which proposals will be invited from the astronomy community. The primary data archive for ASTROSAT will be located at the Indian Space Science Data Centre (ISSDC) near Bangalore, India.

The Ground Command and Control Centre for ASTROSAT will be located at ISTRAC, Bangalore, India. Commanding and data download will be possible during every visible pass over Bangalore. Ten out of 14 orbits per day will be visible to the ground station.

External links

* [http://meghnad.iucaa.ernet.in/~astrosat/ ASTROSAT website]