Isro to launch Astrosat to study the skies - The Times of India
MANGALORE: Indian Space Research Organisation (ISRO) is in the process of launching Astrosat to study the skies over India and thereby give a great contribution from India to the study of astronomy, said K Radhakrishnan, secretary, department of space, and chairman, space commission and ISRO. Astrosat will be launched aboard a PSLV in 2015, will have six instruments and can be described as a multi wave length observatory in space.
Delivering the 32nd annual convocation address of Mangalore University here on Monday and giving an insight into ISROs future space programmes, Radhakrishnan said earth observation capabilities too is high on ISROs agenda with plans afoot to study objects 0.25 metres on the ground with satellites that are 500-600kms in space. "We will use heavy high powered satellites for this," he said. Studying the skies too will be taken up with Astrosat.
This satellite will have ultra-violet, visible and x-ray instruments. It is getting ready now, he said, adding that the satellite will be integrated by 2015. The instruments that will be used on board Astrosat are being built by several institutions across India including the Tata Institute of Fundamental Research, Mumbai, the Indian Institute of Astrophysics, Bangalore, and at ISRO itself, Radhakrishnan noted adding this is a joint effort of various institutions.
Dwelling on two critical missions that ISRO embarked upon in recent past, Radhakrishnan said, in November last Mars orbiter spacecraft embarked on a journey towards Mars, making it the first Made In India object to leave the Earth's sphere of influence. The Mars orbiter is on course for its arrival near Mars on September 24, 2014, he said adding that the crucial operation of reducing its velocity and placing it around Mars will take place then.
The successful flight test of cryogenic stage in the beginning of this year is another milestone in space programme. Noting the success as result of hard work of teams for two decades and development of a host of test facility and infrastructure, Radhakrishnan said nearly 850 wind tunnel tests and 45 ground tests were conducted before proceeding for flight. Several hard technical and managerial decisions had to be arrived at for its success, he noted.
Astrosat - Wikipedia, the free encyclopedia
Astrosat is India's first dedicated astronomy satellite and is scheduled to launch on board the PSLV in 2014.[1]
After the success of the satellite-borne Indian X-ray Astronomy Experiment (IXAE), which was launched in 1996, the Indian Space Research Organization (ISRO) approved (in 2004) further development for a full fledged astronomy satellite: Astrosat. It was originally hoped to be launched about 2008/9.[2]
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 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), near UV (180-300 nm), far UV (130-180 nm), soft X-ray (0.3-8 keV and 2-10 keV) and hard X-ray (3-80 keV and 10-150 keV) regions of the electromagnetic spectrum.
Launch date2015 (planned)
Launch siteSatish Dhawan Space Centre
Launch vehiclePSLV-XL
Mission length5 years
Mass1,650 kg (3,640 lb)
Type of orbitNear-equatorial
Orbit height650 km (400 mi)
Orbit period5 years
WavelengthMulti-wavelength
Instruments
UVITUltraViolet Imaging Telescope
SXTSoft X-ray telescope
LAXPCX-ray timing and low-resolution spectral studies
CZTIHard X-ray imager
Mission[edit]
Artist's conception of a binary star system with one black hole and one main sequence star
Astrosat will be a proposal-driven general purpose observatory, with main scientific focus on:
The mission would also study near simultaneous muti-wavelength data from different variable sources. In a binary system, for example, regions near the compact object emit predominantly in X-rays, the accretion disc emitting most of its light in the UV/optical waveband, whereas the mass of the donating star is brightest in the optical band.
The observatory will also carry out:
Payloads[edit]
The scientific payload has a total mass of 750 kg and contains six instruments.
The Ground Command and Control Centre for Astrosat will be located at ISAC, 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. The satellite is capable of gathering 420 gigabits of data every day that can be down loaded in 10 to 11 orbits visible at Tracking and Data receiving center of ISRO in Bangalore.[citation needed] A third 11-meter antenna at the Indian Deep Space Network (IDSN) was operational in July 2009 to track Astrosat.
Current status[edit]
April 2009 : Scientists from Tata Institute of Fundamental Research (TIFR) have completed the developmental phase of complex science payloads and have begun integrating them before delivery of the 1,650 kg satellite Astrosat. A payload from RRI (Raman Research Institute) is under development, awaiting delivery. The challenges in the design of payloads and Attitude Control System have been overcome and in a recent review committee meeting, it was decided that the delivery of the payload to ISRO satellite Centre will begin from the middle of 2009 and continue till early 2010 to enable the launch of ASTROSAT in 2010 using ISRO workhorse PSLV.[6]
Two of the instruments were harder than expected to complete. "The satellite’s soft x-ray telescope proved to be a huge challenge that took 11 years..."[2] As of April 2012, the launch has been rescheduled to 2014.[1]
Participants[edit]
The Astrosat project is a collaborative effort of a growing list of research institutions. The current participants are:
Payloads
MANGALORE: Indian Space Research Organisation (ISRO) is in the process of launching Astrosat to study the skies over India and thereby give a great contribution from India to the study of astronomy, said K Radhakrishnan, secretary, department of space, and chairman, space commission and ISRO. Astrosat will be launched aboard a PSLV in 2015, will have six instruments and can be described as a multi wave length observatory in space.
Delivering the 32nd annual convocation address of Mangalore University here on Monday and giving an insight into ISROs future space programmes, Radhakrishnan said earth observation capabilities too is high on ISROs agenda with plans afoot to study objects 0.25 metres on the ground with satellites that are 500-600kms in space. "We will use heavy high powered satellites for this," he said. Studying the skies too will be taken up with Astrosat.
This satellite will have ultra-violet, visible and x-ray instruments. It is getting ready now, he said, adding that the satellite will be integrated by 2015. The instruments that will be used on board Astrosat are being built by several institutions across India including the Tata Institute of Fundamental Research, Mumbai, the Indian Institute of Astrophysics, Bangalore, and at ISRO itself, Radhakrishnan noted adding this is a joint effort of various institutions.
Dwelling on two critical missions that ISRO embarked upon in recent past, Radhakrishnan said, in November last Mars orbiter spacecraft embarked on a journey towards Mars, making it the first Made In India object to leave the Earth's sphere of influence. The Mars orbiter is on course for its arrival near Mars on September 24, 2014, he said adding that the crucial operation of reducing its velocity and placing it around Mars will take place then.
The successful flight test of cryogenic stage in the beginning of this year is another milestone in space programme. Noting the success as result of hard work of teams for two decades and development of a host of test facility and infrastructure, Radhakrishnan said nearly 850 wind tunnel tests and 45 ground tests were conducted before proceeding for flight. Several hard technical and managerial decisions had to be arrived at for its success, he noted.
Astrosat - Wikipedia, the free encyclopedia
Astrosat is India's first dedicated astronomy satellite and is scheduled to launch on board the PSLV in 2014.[1]
After the success of the satellite-borne Indian X-ray Astronomy Experiment (IXAE), which was launched in 1996, the Indian Space Research Organization (ISRO) approved (in 2004) further development for a full fledged astronomy satellite: Astrosat. It was originally hoped to be launched about 2008/9.[2]
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 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), near UV (180-300 nm), far UV (130-180 nm), soft X-ray (0.3-8 keV and 2-10 keV) and hard X-ray (3-80 keV and 10-150 keV) regions of the electromagnetic spectrum.
Launch date2015 (planned)
Launch siteSatish Dhawan Space Centre
Launch vehiclePSLV-XL
Mission length5 years
Mass1,650 kg (3,640 lb)
Type of orbitNear-equatorial
Orbit height650 km (400 mi)
Orbit period5 years
WavelengthMulti-wavelength
Instruments
UVITUltraViolet Imaging Telescope
SXTSoft X-ray telescope
LAXPCX-ray timing and low-resolution spectral studies
CZTIHard X-ray imager
Mission[edit]
Artist's conception of a binary star system with one black hole and one main sequence star
Astrosat will be a proposal-driven general purpose observatory, with main scientific focus on:
- Simultaneous multi-wavelength monitoring of intensity variations in a broad range of cosmic sources
- Monitoring the X-ray sky for new transients
- Sky surveys 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
The mission would also study near simultaneous muti-wavelength data from different variable sources. In a binary system, for example, regions near the compact object emit predominantly in X-rays, the accretion disc emitting most of its light in the UV/optical waveband, whereas the mass of the donating star is brightest in the optical band.
The observatory will also carry out:
- Low to moderate resolution spectroscopy over wide energy band with the primary emphasis on studies of X-ray emitting objects
- Timing studies of periodic and aperiodic phenomenon in X-ray binaries
- Studies of pulsations in X-ray pulsars
- QPOs, flickering, flaring, and other variations in X-ray binaries
- Short and long term intensity variations in AGNs
- Time lag studies in low/hard X-rays and UV/optical radiation
- Detection and study of x-ray transients.[4]
Payloads[edit]
The scientific payload has a total mass of 750 kg and contains six instruments.
- The UltraViolet Imaging Telescope (UVIT) - The UltraViolet Imaging Telescope will perform imaging simultaneously in three channels: 130-180 nm, 180-300 nm, and 320-530 nm. The field of view is a circle of ~ 28 arcmin diameter and the angular resolution is 1.8" for the ultraviolet channels and 2.5" for the visible channel. In each of the three channels a spectral band can be selected through a set of filters mounted on a wheel; in addition, for the two ultraviolet channels a grating can be selected in the wheel to do slitless spectroscopy with a resolution of ~100.
- Soft X-ray imaging Telescope (SXT)- The soft X-ray telescope on Astrosat will employ focussing optics and a deep depletion CCD camera at the focal plane to perform X-ray imaging in 0.3-8.0 keV band. The optics will consist of 41 concentric shells of gold-coated conical foil mirrors in an approximate Wolter-I configuration. The focal plane CCD camera will be very similar to that flown on SWIFT XRT. The CCD will be operated at a temperature of about −80 °C by thermoelectric cooling.
- The LAXPC Instrument - For X-ray timing and low-resolution spectral studies over a broad energy band (3-80 keV) Astrosat will use a cluster of 3 co-aligned identical Large Area X-ray Proportional Counters (LAXPCs), each with a multi-wire-multi-layer configuration and a Field of View of 1° × 1°. These detectors are designed to achieve (I) wide energy band of 3-80 keV, (II) high detection efficiency over the entire energy band, (III) narrow field of view to minimize source confusion, (IV) moderate energy resolution, (V) small internal background and (VI) long lifetime in space.
- Cadmium Zinc Telluride Imager (CZTI) - Astrosat will carry a hard X-ray imager in the form of CZTI. It will consist of a Pixellated Cadmium-Zinc-Telluride detector array of ~1000 cm2 geometric area. These detectors have very good detection efficiency, close to 100% up to 100 keV, and have a superior energy resolution (~2% at 60 keV) compared to scintillation and proportional counters. Their small pixel size also facilitates medium resolution imaging in hard x-rays. The CZTI will be fitted with a two dimensional coded mask, for imaging purposes. The sky brightness distribution will be obtained by applying a deconvolution procedure to the shadow pattern of the coded mask recorded by the detector.
- Scanning Sky Monitor (SSM) - The Scanning Sky Monitor will consist of three position sensitive proportional counters, each with a one-dimensional coded mask, very similar in design to the All Sky Monitor on NASA's RXTE satellite. The gas-filled proportional counter will have resistive wires as anodes. The ratio of the output charge on either ends of the wire will provide the position of the x-ray interaction, providing an imaging plane at the detector. The coded mask, consisting of a series of slits, will cast a shadow on the detector, from which the sky brightness distribution will be derived.
- Charged Particle Monitor (CPM) - A charged particle monitor (CPM) will be included as a part of Astrosat payloads to control the operation of the LAXPC, SXT and SSM. Even though the orbital inclination of the satellite will be 8 deg or less, in about 2/3 of the orbits, the satellite will spend a considerable time (15 – 20 minutes) in the South Atlantic Anomaly (SAA) region which has high fluxes of low energy protons and electrons. The high voltage will be lowered or put off using data from CPM when the satellite enters the SAA region to prevent damage to the detectors as well as to minimize ageing effect in the Proportional Counters.
The Ground Command and Control Centre for Astrosat will be located at ISAC, 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. The satellite is capable of gathering 420 gigabits of data every day that can be down loaded in 10 to 11 orbits visible at Tracking and Data receiving center of ISRO in Bangalore.[citation needed] A third 11-meter antenna at the Indian Deep Space Network (IDSN) was operational in July 2009 to track Astrosat.
Current status[edit]
April 2009 : Scientists from Tata Institute of Fundamental Research (TIFR) have completed the developmental phase of complex science payloads and have begun integrating them before delivery of the 1,650 kg satellite Astrosat. A payload from RRI (Raman Research Institute) is under development, awaiting delivery. The challenges in the design of payloads and Attitude Control System have been overcome and in a recent review committee meeting, it was decided that the delivery of the payload to ISRO satellite Centre will begin from the middle of 2009 and continue till early 2010 to enable the launch of ASTROSAT in 2010 using ISRO workhorse PSLV.[6]
Two of the instruments were harder than expected to complete. "The satellite’s soft x-ray telescope proved to be a huge challenge that took 11 years..."[2] As of April 2012, the launch has been rescheduled to 2014.[1]
Participants[edit]
The 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
- Bhabha Atomic Research Centre, Mumbai
- S.N. Bose National Centre for Basic Sciences, Kolkata
- Canadian Space Agency
- University of Leicester[7]
Payloads
Last edited:
