ISRO launches PSLV rocket carrying SCATSAT-1, 7 others
An Indian Polar Satellite Launch Vehicle (PSLV) rocket on Monday morning lifted off successfully with the country\'s weather satellite SCATSAT-1 and seven others.
Sriharikota (Andhra Pradesh): An Indian Polar Satellite Launch Vehicle (PSLV) rocket on Monday morning lifted off successfully with the country's weather satellite SCATSAT-1 and seven others.
The Indian Space Research Organisation (ISRO) will for the first time, be using its own multiple burn technology while launching eight satellites - five foreign and three domestic - in different orbits.
Multiple burn technology is the switching off and switching on of a rocket's engine in space mainly to launch satellites in different orbits.
The PSLV rocket standing 44.4 metre tall and weighing 320 tonne, tore into the morning skies at 9.12 a.m. with a growl breaking free of the earth's gravitational pull.
The rocket was ferrying eight satellites weighing around 665kg and will be put into orbit in two phases.
The PSLV's main cargo- the 371 kg SCATSAT-1 for ocean and weather related studies - will be put 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 around two hours and 15 minutes after the rocket's lift off.
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.
Around 16 minutes into the flight, the rocket's fourth state or the engine will be cut off and a minute later the weather satellite SCATSAT-1 will be put into orbit.
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.
The satellite carries Ku-band scatterometer similar to the one flown onboard Oceansat-2.
The mission life of the satellite is five years.
After slinging SCATSAT-1 into its orbit the rocket's fourth stage would be restarted after one hour 22 minutes into the flight and cut off around 20 seconds later.
Two hours and 11 minutes into the flight the fourth stage will again be restarted to be cut off one minute later.
Following that in three minutes all the seven satellites would be ejected putting an end to PSLV's longest mission till date.
The PSLV rocket is a four stage/engine rocket powered by solid and liquid fuel alternatively.
Vikram Sarabhai Space Centre (VSSC) director K. Sivan told IANS on Sunday that the long time gap between the cutting off of the engine and its restart is not an issue.
Sivan said the first time the multiple burn technology was first tested by ISRO while flying its PSLV rocket on December 16, 2015 and this June, the technology was again demonstrated.
About the challenge to be faced, 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.
By Venkatachari Jagannathan
