The Indian Space Research Organisation (ISRO) tasted success in the small satellite launch vehicle segment on Friday, February 10, with its SSLV (Small Satellite Launch Vehicle) D2 rocket injecting three satellites into an intended circular orbit. This was months after the first mission failed to bring in the desired results. Buoyed by Friday's success, the agency said the launch has "set the tone" for its activities this year, dotted with a number of proposed Polar Satellite Launch Vehicles (PSLV) and Geosynchronous Satellite Launch Vehicle (GSLV) missions, among others.
The payloads launched by the SSLV D2 rocket on Friday included ISRO's earth observation satellite EOS-07. ISRO's first mission in 2023 and SSLV's August 2022 sequel saw a strange coincidence — a 9.18 AM launch, the same time the vehicle lifted off from the Satish Dhawan Space Centre on August 7, but could not deliver due to orbit anomaly and flight path deviation.
With the earlier SSLV not living up to the expectations, 'corrective measures' were put in place in its successor.
A relieved Chairman of ISRO S Somanath said SSLV in its second flight put the three satellites in the intended orbit accurately. "Congratulations to the space community of India. So we have a new launch vehicle, the small satellite launch vehicle SSLV. In its second attempt today, SSLV D2 has placed the EOS-07 satellite into the intended orbit very accurately. Along with EOS-07 two more satellites were placed in the required orbit. Janus-1 through NSIL (NewSpace India Ltd) and from ANTARIS and AzaadiSat through In-Space, realised by SpaceKidz," he said.
Recalling the rocket's flight, SSLV D1, Somanath said "we had a narrow miss of placing the satellite in the orbit because of the shortfall in velocity." He added, "And I am very happy to report that we have analysed the problems we faced in D1, identified the corrective actions, implemented (them) in a fast pace, qualified all of those new systems, went through a lot of simulations and studies to ensure that the vehicle will become a success this time. And I am very happy to see that the really intended model of the vehicle has been executed in reality in flight."
"We were aiming to put it in a 450 km orbit. We have very close apogee and perigee (relating to orbit distances)...inclination is a very small error only. This also shows that the new model of vehicle navigation system and electronics that we have incorporated in SSLV is doing very well," Somanath, also Secretary, Department of Space, added. "This is the inaugural launch of 2023. This will set the tone for the rest of the activities that are going to happen," this year, he said.
Mission Director S Vinod said the ISRO team made a "comeback" shortly after the August 7, 2022 launch. ISRO now has a new launch vehicle on offer for the launch vehicle community, he added.
"It is a momentous occasion for us, a proud occasion for ISRO that we now have a new launch vehicle to be offered to the launch vehicle community. The journey has traversed through its nascent phase of configuration, realisation, fabrication, testing analysis and finally it even had to overcome the COVID-19 phase."
With this launch, ISRO has accomplished the laid objective of SSLV, "that is to have a low-cost low turnaround time satellite which can offer launch on demand," he said.
Earlier, the 34-metre tall SSLV soared into clear skies at 9.18 AM, after a six-and-a-half-hour countdown, carrying with it the EOS-07, besides Janus-1 and AzaadiSAT-2 satellites. The rocket placed the satellites into the intended 450-km circular orbit after a 15-odd minute flight. EOS-07 is a 156.3 kg satellite which has been designed, developed and realised by ISRO. New experiments include mm-Wave Humidity Sounder and Spectrum Monitoring Payload. Janus-1, a 10.2 kg satellite, built by Antaris, USA is a technology demonstrator, smart satellite mission, ISRO said.
AzaadiSAT-2, weighing about 8.2 kg is a combined effort of about 750 girl students across India guided by Space Kidz India, Chennai. It aims to demonstrate amateur radio communication capabilities, measure radiation, among others, the space agency added. Somanath congratulated the girls behind the initiative.
According to ISRO, SSLV is capable of launching mini, micro or nano satellites in the 10-500 kg segment into the 500 km planar orbit. It caters to the launch of satellites to Low Earth Orbits (LEO) on a "launch-on-demand" basis. It provides low-cost access to space, offers low turn-around time and flexibility in accommodating multiple satellites, and demands minimal launch infrastructure, ISRO added. It is configured with three solid propulsion stages and a velocity terminal module.