Spaceflight Insider

India launches nation’s first space observatory into orbit

Polar Satellite Launch Vehicle takes off from Satish Dhawan ISRO image posted on SpaceFlight Insider

Photo Credit: ISRO

The Indian Space Research Organisation (ISRO) successfully launched a set of seven satellites, including the country’s first-ever space observatory on Monday, Sept. 28. Liftoff occurred at 12:30 a.m. EDT (04:30 GMT) from the First Launch Pad (FLP) of the Satish Dhawan Space Centre (SDSC) in Sriharikota, India. The mission, designated PSLV-C30, employed the Indian Polar Satellite Launch Vehicle (PSLV) for the thirty-first time in the booster’s history.

The mission lasted about 25 minutes and 32 seconds when all the seven satellites separated from the launch vehicle. After lift-off, the PSLV rocket climbed vertically, gradually losing its ground-lit strap-on solid rocket boosters, which are used to augment the thrust provided by the first stage. Then, about 1 minute and 52 seconds into the mission, the vehicle’s first stage separated. After the second and third stage separation, the launch vehicle continued its ascent to a targeted altitude of about 404 miles (650 km), where the satellites were deployed.

Fully integrated PSLV-C30 core stage with strap-ons at the mobile service tower.

Fully integrated PSLV-C30 core stage with strap-ons at the mobile service tower. Photo Credit: ISRO

The most important passenger of the mission is likely the Indian Astrosat spacecraft. It is the country’s first dedicated astronomical satellite that will be used for the simultaneous multi-wavelength observations of various celestial objects.

Astrosat will be used to observe the universe in the optical, ultraviolet, low and high energy X-ray regions of the electromagnetic spectrum. Whereas most other, similar satellites are capable of observing a narrow range of wavelength band.

Multi-wavelength observations made using Astrosat can be further extended with coordinated observations using other spacecraft and ground-based observations. All major astronomical Institutions and some universities in India will participate in these observations.

“The capability to cover the full spectrum of wavelength simultaneously is the unique feature of Astrosat,” said Mylswamy Annadurai, the director of ISRO’s Satellite Centre in Bengaluru.

The spacecraft will also estimate the magnetic fields of neutron stars. It will study star birth regions and high energy processes in star systems lying beyond our galaxy. Astrosat is also capable of detecting new, briefly bright X-ray sources in the sky.

The space observatory has a lift-off mass of about 1.5 metric tons. After injection into low-Earth orbit (LEO), the two solar array of the satellite were automatically deployed in quick succession. The spacecraft control center at the Mission Operations Complex (MOX) of ISRO Telemetry,  and Command Network (ISTRAC) at Bangalore will manage the satellite during its 5-year mission life.

“Astrosat is not the first of its kind but is the best so far. It is the best all-rounder in the world. It is a one-stop shop for studying astronomical sources,” said Varun Bhalerao, Post-Doctoral Fellow at the Pune-based Inter-University Centre for Astronomy and Astrophysics (IUCAA).

Five of Astrosat’s payloads are chosen to facilitate a deeper insight into the astrophysical processes occurring in various types of astronomical objects that constitute our universe.  These payloads rely on the visible, Ultraviolet and X-rays coming from distant celestial sources. The most prominent of Astorsat’s instruments is probably the UVIT (Ultraviolet Imaging Telescope), a tool capable of observing the sky in the visible, near ultraviolet and far ultraviolet regions of the electromagnetic spectrum.

Besides Astrosat, the PSLV-C30 mission has also delivered six maritime observation satellites into orbit, these included the Indonesian LAPAN-A2, Canadian ExactView 9 and four Lemur spacecraft for the California-based Spire company.

LAPAN-A2 weighs in at approximately 167 lbs. (76 kg) and is a Microsatellite launched for the National Institute of Aeronautics and Space-LAPAN located in Indonesia. It has been developed to provide maritime surveillance services using the Automatic Identification System (AIS). LAPAN-A2 will support Indonesian amateur radio communities for disaster mitigation as well as carry out Earth surveillance activities. It will do so using video as well as digital cameras.

ExactView 9 – also called NLS-14 – is a nanosatellite produced by the Space Flight Laboratory at the University of Toronto Institute for Advanced Studies (SFL, UTIAS) in Canada. It is a maritime monitoring nanosatellite using the next generation AIS system. The satellite has a mass of 31 lbs (14 kg).

Astrosat during a pre-launch test in a clean room.

Astrosat during a pre-launch test in a clean room. Photo Credit: ISRO

Four Lemur nanosatellites were also a part of the PSLV’s payload. These spacecraft are non-visual remote-sensing satellites, focusing primarily on global maritime intelligence through vessel tracking via the AIS system, and high fidelity weather forecasting using GPS Radio Occultation technology. The four satellites, together, weigh about 62 lbs (28 kg).

The four-stage PSLV booster is India’s most reliable launch vehicle. It has been in service for more than twenty years and has been used to launch various satellites for some of the country’s most historic missions, such as the Chandrayaan-1, Mars Orbiter Mission (MOM), Space Capsule Recovery Experiment and Indian Regional Navigation Satellite System (IRNSS). The rocket has delivered more than 40 satellites to space for 19 countries. PSLV is capable of lofting up to 3.25 metric tons to LEO and about 1.42 metric tons to geosynchronous transfer orbit (GTO).

The rocket uses an Earth-storable liquid rocket engine for its second stage, known as the Vikas engine, developed by the Liquid Propulsion Systems Centre. The third stage of the PSLV is a solid rocket motor that provides the upper stage’s high thrust after the atmospheric phase of the mission. The fourth stage is comprised of two Earth-storable liquid fueled engines.

The 144 ft. (44 meters) tall XL version of the PSLV, used in Monday’s launch, is the upgraded version of the rocket in its standard configuration. It is boosted by more powerful, stretched strap-on boosters. The vehicle, with a mass of 320 tons at lift-off, uses larger strap-on motors (PSOM-XL) to achieve higher payload capability. PSOM-XL uses larger 1-meter diameter, 44 ft. (13.5 m) length motors, and carries 12 metric tons of solid propellants instead of the nine metric tons that were used on an earlier configuration of the PSLV.

The PSLV rocket in its XL configuration was launched for the first time on Oct. 22, 2008, when it sent India’s Chandrayaan-1 lunar probe toward the Moon. Monday’s successful launch is the 10th flight of the PSLV-XL booster.

The PSLV-C30 mission marked India’s fourth launch this year. The ISRO plans to conduct two more launches by the end of 2015. The next mission is currently scheduled to take place in December when another PSLV rocket will deliver the TeLEOS-1 Earth-observation satellite for Singapore.

PSLV-C30 launch of Astrosat

PSLV-C30 launch of Astrosat. Photo Credit: ISRO


Tomasz Nowakowski is the owner of Astro Watch, one of the premier astronomy and science-related blogs on the internet. Nowakowski reached out to SpaceFlight Insider in an effort to have the two space-related websites collaborate. Nowakowski's generous offer was gratefully received with the two organizations now working to better relay important developments as they pertain to space exploration.

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