On September 28, 2015, Indian Space Research Organization (ISRO) conducted successful launch of PSLV-C30 launch vehicle carrying nation’s first astronomical satellite, ASTROSAT, and six small satellites in the interests of international customers from Satish Dhawan Space Centre.
The mission marked 31st launch for PSLV rocket family since 1993, 49th Indian orbital launch attempt since 1979, 10th launch of PSLV rocket in XL configuration, and 3rd PSLV launch this year.
ASTROSAT is India's first dedicated multi-wavelength space observatory. It will observe the universe in optical, ultraviolet, low and high energy X-ray wavebands. Multi-wavelength observations of ASTROSAT can be further extended with coordinated observations of other spacecraft and ground-based observatories. All major astronomy institutions and universities in India will participate in this project.
Weighting 1513 kg, the mission was launched into a 650 km orbit inclined at an angle of 6° to the equator. Five payloads were chosen to be installed on ASTROSAT in order to get a deeper insight into various astrophysical processes occurring with various astronomical objects in our universe:
- Ultraviolet Imaging Telescope (UVIT), capable to perform observations in visible, near ultraviolet and far ultraviolet regions of the electromagnetic spectrum;
- Large Area X-ray Proportional Counter (LAXPC), designed to study variations in the emission of X-rays from cosmic sources;
- Soft X-ray Telescope (SXT), designed for studying how the X-ray spectrum of 0.3-8 keV range coming from distant celestial bodies and how it varies with time;
- Cadmium Zinc Telluride Imager (CZTI), functioning in the X-ray region, extends capability of the satellite to sense X-rays of high energy in 10-100 keV range.
- Scanning Sky Monitor (SSM), intended to scan the sky for long-term monitoring of bright X-ray sources in binary stars, and for detection of sources that become bright in X-rays for a short duration of time.
Two of the payloads above were developed in collaboration with Canadian Space Agency (CSA) and University of Leiscester (UoL), UK.
Piggyback payloads for the ASTROSAT mission are the following:
- LAPAN A2 microsatellite of the National Institute of Aeronautics and Space (LAPAN) of Indonesia. Weighting 76 kg, it carries an AIS (Automatic Identification System) payload to identify ships in Indonesian waters, two video cameras for Earth observation, and a payload for disaster management by amateur radio communications;
- exactView 9 (EV 9) – part of exactEarth' AIS constellation to monitor ship movements through busy shipping channels and harbors and to provide information on global shipping movements. It weighs around 14 kg and is also known as NLS-14, since it was developed jointly with Canada's Space Flight Laboratory at the University of Toronto Institute for Advanced Studies.
- 4 Lemur satellites (Lemur-2 Joel, Lemur-2 Peter, Lemur-2 Jeroen, and Lemur-2 Chris), being an initial low-Earth orbiting constellation built by San Francisco-based Spire Global. These 3U CubeSats carry payloads for ship traffic tracking (SENSE AIS) and high fidelity weather forecasting using GPS Radio Occultation technology (STRATOS). Notably, Spire Global names Lemur-2 satellites after its own team members and each contributing to their mission.
PSLV family of Indian launchers currently has 3 configurations. These are PSLV, standard version of the rocket that has four stages and six strap-on boosters, PSLV-CA ('core alone') without strap-on boosters, and PSLV-XL, updated version of rocket's standard configuration boosted by more powerful, stretched strap-on boosters. Payload capacity of the most powerful PSLV-XL, used recently, is 1800 kg to a sun-synchronous orbit.PSLV-C30 mission was the fourth Indian space launch in 2015, after successful mission to orbit IRNSS-1D navigation satellite on March 28, launch of three DMC3, CBNT-1, and De-OrbitSail satellites on July 10 (both by PSLV launchers), and GSLV Mk II mission with GSAT-6 spacecraft on August 27. According to ISRO launch kit, LAPAN A2, ExactView 9 and 4 Lemur satellites have become 46-51st foreign spacecraft launched aboard a PSLV rocket.