ISRO to make commercial use of multiple burn technology

CHENNAI: Indian space agency ISRO on Monday will, for the first time, be making commercial use its own multiple burn technology while launching eight satellites — five foreign and three domestic — in different orbits, said a senior official.

Multiple burn technology is switching off and switching on rocket’s engine in space.

Vikram Sarabhai Space Centre (VSSC) director K Sivan also said that the 48 and half hour countdown for the launch of Indian rocket Polar Satellite Launch Vehicle (PSLV) that would carry the eight satellites is progressing smoothly at the rocket port Sriharikota in Andhra Pradesh.

“We will be using the the of a multiple burn technology for the first time for launching satellites. Earlier we switched off and switched on the fourth stage (engine) of PSLV to test the technology,” said Sivan.

He said the first time the multiple burn technology was first tested by ISRO while flying its PSLV rocket on December 16, 2015 and in June 2016, the technology was again demonstrated.

About the challenge to be faced on Monday, Sivan said: “After cutting off the engine, its condition should be brought to such a stage that it could be restarted again. The next challenge is to controlling the engine and bringing it so as to eject the remaining satellites into a different orbit.”

He said the rocket has GPS aided navigation system so that data generated by the rocket’s inertial navigation system and the one provided by the former will be blended so as to erase and errors and to generate a precise data.

On Monday, a 320-tonne PSLV rocket will put its main cargo the 371 kg SCATSAT-1 — for ocean and weather related studies — into a 730-km polar sun synchronous orbit, 17 minutes into the flight. The remaining seven satellites will be placed in a 689-km polar orbit nearly two hours later.

These include five foreign satellites: three from Algeria (Alsat-1B 103kg, Alsat-2B 117kg, Alsat-1N 7kg), and one each from Canada (NLS-19, 8kg) and US (Pathfinder-44kg). The two other Indian satellites are: Pratham (10kg) built by Indian Institute of Technology-Bombay and Pisat (5.25 kg) from PES University, Bengaluru and its consortium.

After putting into orbit SCATSAT-1, the rocket’s fourth stage or the engine will be shut down and would be restarted and cut off one hour 22 minutes twice after the rocket blast off from Sriharikota.

Two hours and 11 minutes into the flight the fourth stage will be restarted.

Four minutes later all the seven satellites would be put into their intended orbit.

Sivan said the long time gap between the cutting off of the engine and its restart is not an issue.

The PSLV rocket is engine rocket powered liquid fuel alternatively.

According to ISRO, SCATSAT-1 is a continuity mission for Oceansat-2 scatterometer to provide wind vector data products for weather forecasting, cyclone detection and tracking services to the users. a four stage/ by solid and