ISRO just launched an earth observation satellite along with 30 foreign satellites: What you need to know

By Elton Gomes

The Indian Space Research Organisation (ISRO) successfully launched its rocket Polar Satellite Launch Vehicle (PSLV-C43) carrying India’s earth observation Hyper-spectral Imaging Satellite (HysIS), and 30 foreign satellites from Sriharikota at 9:57:30 am on November 29. The satellite was launched from the Satish Dhawan Space Centre (SDSC) at Sriharikota.

During the 112-minute-long mission — one of the longest for ISRO — the PSLV-C43 initially delivered India’s HysIS into 645 km sun-synchronous polar orbit 17 minutes 19 seconds after the launch. Thereafter, the PSLV-C43 injected 30 foreign satellites into their intended orbit. 1 hour and 49 minutes after lift off, the last satellite was injected into its designated orbit.

ISRO chief K. Sivan and several other scientists at the space agency broke into cheers as the earth observation satellite reached the sun-synchronous polar orbit.

However, during the launch, scientists had to restart the fourth stage engine twice so that the 30 co-passenger satellites could be placed. An official said that the fourth stage engine was cut off after HysIS got separated at an altitude of 636.3 kilometres.

The PSLV rocket has emerged as ISRO’s workhorse after successfully launching satellites into a variety of orbits. In a period of 25 years, the PSLV spacecraft has launched 53 Indian and 269 international customer satellites from 28 countries.

Through its accomplishments, the spacecraft has established itself in the international commercial launch market as one of the most cost-effective launch vehicles for primary, as well as, co-passenger satellites.

What is the hyperspectral imaging satellite?

HysIS, or the hyperspectral imaging satellite, weighs 380 kg, is an earth observation satellite built around ISRO’s Mini Satellite-2 (IMS-2) bus. It will be primarily used to take photographs of the Earth in multiple frequencies.

The data from the satellite will be used in several fields such as agriculture, forestry, soil survey, geology, coastal zones, inland water studies, environmental studies, and in detecting pollution from industries.

HysIS’ primary mission HysIS is to study the earth’s surface in visible, near infrared, and shortwave infrared regions of the electromagnetic spectrum. It will also be used by the military for surveillance purposes.

India tested hyperspectral imaging earlier when ISRO launched an 83 kg IMS1 experimental satellite in 2008, and later in the Chandrayyan-1 mission in the same year. However, this is the first time a full-fledged hyperspectral imaging satellite has been launched.

How does HysIS work?

HysIS collects and processes information from the entire electromagnetic spectrum and enables distinct identification of objects, materials, or processes on the earth – HysIS does this by reading the spectrum for each pixel of a scene from space.

The payloads

HysIS, which can see in 55 spectral or colour bands from 630 km above the ground, carries two payloads. One to capture images in the visible near-infrared (VNIR) range of the light spectrum, and the other payload to capture images in the shortwave infrared (SWIR) range. HySIS has been designed to last five years while serving ISRO.

The other satellites

The 30 commercial satellites, including one micro and 29 nano satellities, are from eight countries. The satellites have a combined weight of 261.5 kg.

For the first time, satellites from Australia, Colombia, Malaysia, and Spain have been flown in an Indian rocket.

The 30 satellites include 23 from the US, and one each from Australia, Canada, Colombia, Finland, Malaysia, Netherlands, and Spain. These smaller companions are a mix of satellites that would be engaged in earth observation, communication, Internet of things (IoT), and scientific experiments from various countries.

All the 30 satellites will be placed in a 504-km orbit by PSLV-C43. These satellites have been commercially contracted for launch through Antrix Corporation Limited, ISRO’s commercial arm.

ISRO’s future plans

According to media reports in June, the Union Cabinet chaired by Prime Minister Narendra Modi had approved the continuation of the Polar Satellite Launch Vehicle and Geosynchronous Satellite Launch Vehicle Mark-III programmes – which are worth more than Rs 100 billion. The cabinet also approved the funding of 30 operational flights.

The operationalisation of PSLV has made India self-reliant in terms of launching capability of satellites for earth observation, disaster management, navigation, and space sciences.

News agency PTI, in November, reported that ISRO had made elaborate plans ahead of the new year. The space agency has lined up 10 missions before January 2019, ISRO chief K. Sivan said. ISRO also plans to launch 22 missions in 2019, while targeting to launch 50 missions in the next three years. The Chandrayaan 2 and the Aditya L-1 mission to the sun will be some of ISRO’s biggest projects to watch out for in 2019.


Elton Gomes is a staff writer at Qrius

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