Here's how ISRO's GISAT-1 satellite will add to India's space power

Here's how ISRO's GISAT-1 satellite will add to India's space power
GISAT 1 satellite preparing for launch at the Satish Dhawan Space Center in Sriharikota aboard the GSLV F10 rocketISRO

  • The GISAT-1 is India’s first geo imaging satellite.
  • It will be placed in geostationary orbit 36,000 above the Earth putting it out of range of most anti-satellite weapons.
  • Its geostationary position will also allow the GISAT-1 to send back real-time images of Indian terrain and borders around the clock.
The Indian Space Research Organisation (ISRO) is gearing up to launch its very first geo imaging satellite GISAT-1 into orbit on March 5. The primary objective of the satellite is to help India monitor natural hazards.

However, the GISAT-1 also serves a defensive purpose in a world where outer space, especially Earth’s orbit, is getting more competitive and gaining strategic importance. It’s a necessary requirement even as some experts believe that it may not be sufficient to meet the defence requirements for India’s national security, according to ORF.

Most satellites are placed in Low Earth Orbit — a height at which they can be knocked out by most anti-satellite weapons. Even though only four countries have demonstrated their anti-satellite capabilities, many more have untested systems in-store.

The GISAT-1 undercuts the risk of being blasted out of the sky since it goes above Low Earth Orbit to a height of 36,000 kilometres above the Earth’s surface, putting it out of range of known anti-satellite weapons.

Real-time surveillance
The GISAT-1 will also provide real-time images of the Indian terrain and its borders. Even though it can’t see through cloud cover, it will be India’s first satellite with the capability to scan the entire country every 30 minutes — day and night.

Normal remote sensing satellites in Low Earth Orbit need at least two to 24 days to send back high-resolution images of a particular area. This is because they’re locked a polar orbit. They need to complete a full orbit around the Earth in order to observe the same spot — and that takes time.

The GISAT-1 won’t have to face the same problem since it will be placed in a geostationary orbit around the Earth. This means that as the planet rotates, the satellite follows. At night, when there won’t be any light from the Sun, the satellite has infrared night vision and thermal imaging to see what’s happening on the ground.

The satellite has five multispectral cameras that are capable of scanning the entire country every 30 minutes at a spatial resolution of 50 meters. However, if a specific area has been selected, the satellite can general a field image as frequently as every five minutes.

This means that if a specific area along the border is being infiltrated, the GISAT-1 will be able to send back images of enemy lines with near real-time accuracy.

An ORF report points out that while GISAT-type satellites are key, India could also benefit from a constellation of small satellites that cater to the country’s military requirements. In comparison to heavy satellites, small satellites are easier to manufacture, handle and launch. Even though may take more time to send back images, high-resolution images are key to identifying and targetting possible threats.

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