Why in news?
As AstroSat marked ten years in orbit on 28 September 2025, the Indian Space Research Organisation (ISRO) shared results from the mission and outlined plans for future space observatories. The anniversary drew attention to India’s capacity for multi‑wavelength astronomy.
Mission overview
AstroSat was launched on 28 September 2015 aboard a PSLV‑XL rocket. It is India’s first dedicated multi‑wavelength space telescope, designed to observe cosmic sources simultaneously in ultraviolet, optical and X‑ray bands. Instruments aboard AstroSat include:
- Ultraviolet Imaging Telescope (UVIT): Captures high‑resolution images in near‑ and far‑ultraviolet and visible light (130–530 nanometres).
- Soft X‑ray Telescope (SXT): Uses mirrors and detectors to study soft X‑ray sources (0.3–8 keV).
- Large Area X‑ray Proportional Counter (LAXPC): Measures time variability and spectra of X‑ray sources in the 2–80 keV range.
- Cadmium Zinc Telluride Imager (CZTI): Detects hard X‑rays (10–150 keV) and gamma rays; also capable of measuring polarisation.
- Scanning Sky Monitor (SSM): Scans the sky for transient X‑ray sources, enabling prompt follow‑up observations.
Scientific achievements
AstroSat has observed pulsars, black hole binaries, active galactic nuclei, supernova remnants, galaxy clusters and flare stars. Simultaneous multi‑wavelength observations have allowed astronomers to study cosmic explosions and variable sources in unprecedented detail. Data from AstroSat have been made available to scientists worldwide, fostering international collaborations.
Looking forward
ISRO is considering future missions, including an ultraviolet space telescope and a gravitational‑wave observatory. The success of AstroSat demonstrates that indigenous instruments can perform cutting‑edge science. Continuous investment in space science will inspire students and strengthen India’s standing in global astronomy.