What went wrong with the ISRO launch of SSLV?

What went wrong with the ISRO launch of SSLV?

Subject : Science and Technology

Section: Space Science

Context: On August 7, ISRO got ready for the first developmental flight of the SSLV-D1/EOS-2 mission. The launch took place from the Satish Dhawan Space Centre at Sriharikota. The Small Satellite Launch Vehicle (SSLV) D1/EOS-2 mission, was carrying two satellites — the Earth Observation Satellite-2 (EOS-2) which weighed about 135 kg and AzadiSAT which weighed about eight kg. The mission aimed to place the EOS-2 in a circular low-Earth orbit at a height of about 350 km above the Equator and inclined at an angle of 37 degrees. The initial part of the story was successful with the launch vehicle operating smoothly. However, the mission failed to place the satellites in their required orbits, and the satellites, as they were already detached from the launch vehicle, were lost.

Why do we need to develop an SSLV when we have successfully used PSLV and GSLV?

• The PSLV (Polar Satellite Launch Vehicle) and GSLV (Geosynchronous Satellite Launch Vehicle) are quite powerful and can carry huge loads.
• To place an Earth Orbiting Satellite in a low Earth orbit, one does not need such power horses.
• The SSLV can easily carry small-to-medium loads from 10 kg to 500 kg. It is less expensive.
• The three stages being powered by solid fuel is another advantage. Solid fuel is easier to handle, whereas handling the liquid propellants used in the PSLV and GSLV is more complex.

What is the difference between circular and elliptical orbits?

• Mostly objects such as satellites and spacecrafts are put in elliptical orbits only temporarily. They are then either pushed up to circular orbits at a greater height or the acceleration is increased until the trajectory changes from an ellipse to a hyperbola and the spacecraft escapes the gravity of the Earth in order to move further into space — for example, to the Moon or Mars or further away.
• Satellites that orbit the Earth are mostly placed in circular orbits. One reason is that if the satellite is used for imaging the Earth, it is easier if it has a fixed distance from the Earth. If the distance keeps changing as in an elliptical orbit, keeping the cameras focused can become complicated.