Launch lessons: On ISRO’s satellite launch problem –

The loss of communication between the ground station and the Indian Space Research Organisation’s latest satellite after its launch on March 29 is deeply disappointing. ISRO’s mission aimed to place the communication satellite, GSAT-6A, in space. However, shortly after the second orbit-raising operation, the ground station lost track of the satellite on March 31, when it was on course for the final firing. Understanding why this happened is crucial. A launch operation can be simplified into the initial three stages, during which the satellite is boosted to different heights by the launch vehicle and then placed in a geosynchronous transfer orbit. This is an elliptical orbit into which a satellite is placed initially before being transferred into a geosynchronous orbit where it maintains a position above a fixed longitude. During each of these stages, a part of the rocket completes its role and disengages from the bulk. Then the satellite moves towards its final and desired orbit. The GSAT-6A was first raised to the elliptical orbit marked by the following parameters: its perigee, or point of closest approach to Earth, was 5,054 km; and its apogee, or point of farthest approach, was 36,412 km. This was followed up by a second orbit-raising operation on March 31. It was after this and during the third such operation that the ground station lost contact with the satellite. This is why it is being conjectured that the failure occurred because of a flaw outside the launch vehicle, the GSLV, perhaps from a short circuit or power glitch within the satellite itself. ISRO’s GSLV-F08 rocket carrying communications satellite GSAT-6A lifts off from the spaceport at Sriharikota on March 29, 2018.The last word has not been said on the mission, as ISRO officials continue to try to establish contact with the satellite. Yet, in complex scientific feats such as ISRO’s projects, there is no mission so devoid of a learning aspect to it that it is deemed a total failure. The GSLV has had several successes in the past, and this is its 12th flight. For instance, it was used to launch the advanced communication satellite, GSAT-6, in August 2015. GSAT-6A’s predecessor, GSAT-6, provides S-band services for two-way communications as in the case of mobile phones. The present mission, launched on March 29, was endowed with additional features, such as the high-thrust Vikas engine that gave it the capacity to carry a heavier payload. It had been reported that the mission would be a testing ground for ISRO’s next moon mission. Given this background, ISRO should be open about the specific learning points from this launch exercise. Space science is exciting not just for the experts, but to many outside the field. Therefore, it is important that the agency presents itself more openly to the world.



Meaning: Start or set in motion (an activity or enterprise).

Example: “The government is to launch a £1.25 million publicity campaign”

Synonyms: Set in motion, Get going.

On course

Meaning: Following the intended route.

Example: “He battled to keep the ship on course”


Meaning: Decisive or critical, especially in the success or failure of something.

Example: “Negotiations were at a crucial stage”

Synonyms: Pivotal, Critical.


Meaning: Separate or release (someone or something) from something to which they are attached or connected.

Example: “I disengaged his hand from mine”

Synonyms: Remove, Detach.


Meaning: Form an opinion or supposition about (something) on the basis of incomplete information.

Example: “Many conjectured that she had a second husband in mind”

Synonyms: Guess, Speculate.


Meaning: A mark, blemish, or other imperfection which mars a substance or object.

Example: “A flaw in the glass”

Synonyms: Defect, Blemish.


Meaning: A base from which spacecraft are launched.

Example: “Flight 152, the next launch from Europe’s spaceport, is scheduled to take place on 5 June”


Meaning: An achievement that requires great courage, skill, or strength.

Example: “The new printing presses were considerable feats of engineering”

Synonyms: Achievement, Accomplishment.


Meaning: Entirely lacking or free from.

Example: “Lisa kept her voice devoid of emotion”

Synonyms: Lacking, Without.


Meaning: Regard or consider in a specified way

Example: “The event was deemed a great success”

Synonyms: Regard as, Consider.

For instance

Meaning: As an example.

Example: “Take Canada, for instance”


Meaning: Provide with a quality, ability, or asset.

Example: “He was endowed with tremendous physical strength”

Synonyms: Provide, Supply.


Meaning: The part of a vehicle’s load, especially an aircraft’s, from which revenue is derived; passengers and cargo.

Example: “The truck is carrying a payload of 2,580 pounds”


Meaning: Present oneself formally as having arrived at a particular place or as ready to do something.

Example: “He had to report to the headmaster at 4 pm”

Synonyms: Arrive, Appear.