ISRO’s PSLV-C56 placed seven Singapore satellites into orbit in a picture-perfect launch on Sunday, marking its sixth successful blast-off this year and adding to the after glow of a hitch-free start to the Chandrayaan-3 mission just over two weeks ago. With this, Isro has so far launched 431 satellites belonging to 34 countries.
“In the midst of Chandrayaan 3 mission, Isro scales another landmark with the successful launch of PSLV-C56/DS-SAR,” minister of state for science and technology Jitendra Singh tweeted. The launch vehicle flew the seven payloads, including the radar imaging earth observation satellite DSSAR, to a 535-km circular orbit before the rocket’s upper stage was moved to a lower orbit to reduce its orbital life and mitigate space debris.
Around 21 minutes after PSLV lifted off, the rocket placed its primary payload – the 352kg DS-SAR. Over the next three minutes, the other six satellites, weighing a total of 70.5 kg, were injected into the orbit.
Chandrayaan on way to reach Moon
India’s third lunar mission, Chandrayaan-3, is only around six days away from reaching the lunar orbit with another important manoeuvre - that will see Isro slingshot the spacecraft towards Moon. The manoeuvre is expected to last between 28 and 31 minutes and onboard thrusters of the spacecraft will be fired when the spacecraft is at the closest point to Earth (perigee) and not when at the farthest point (apogee).
At present, the Chandrayaan-3 spacecraft is going around Earth in an elliptical orbit at a velocity ranging between 1km/second and 10. 3km/second. The velocity is highest (10. 3km/second) at perigee and lowest at apogee and while attempting the slingshot, the spacecraft will need to have a high velocity. The other reason is that its angle will have to change to travel towards Moon, which can be added if the operation is carried out at perigee.