Successful test flight of SSLV-D2 gives ISRO a new, low-cost rocket

The vehicle successfully placed its three payloads in circular orbits. EOS-07 is an ISRO satellite, while the other two – Janus-1 and AzaadiSAT-2 – were passenger satellites.

SSLV-D2 launch from Satish Dhawan Space Centre at Sriharikota | Photo: ANI

Bengaluru: With the successful test flight of the Small Satellite Launch Vehicle (SSLV-D2), a new class of rockets was officially launched by the Indian Space Research Organisation for low–cost, smaller satellites on 10 February at 0920 hours IST. The rocket is capable of delivering 500 kg to low Earth orbit or 300 kg to sun-synchronous orbit and performing multiple drop offs, as it did in this test flight.

The launch will enable easier access to space for on-demand launches. SSLV provides an extremely quick turnaround time, low–cost, fast launches, and minimal infrastructure requirements. It is expected to play a major role in the future launches of private commercial satellites, student and research satellites, and experimental satellites.

In its successful test flight, called SSLV-D2/EOS-07, the vehicle successfully placed its three payloads in circular orbits.

This rocket was launched from the Satish Dhawan Space Centre at Sriharikota and follows last year’s unsuccessful first test flight, where the rocket failed to place the three payloads in their designated orbits.

With the SSLV, and the existing Polar Satellite Launch Vehicle (PSLV), Geosynchronous Satellite Launch Vehicle (GSLV), and Launch Vehicle Mark-3 (LVM 3), ISRO now has multiple launch vehicles across the range of various types of payload cost, function, and sizes.

Flexible and low cost

SSLV can launch mini, micro, and nano satellites, which all weigh anywhere from 10 to 500 kg. 

It is a four–stage vehicle with all solid propulsion in the first three stages and liquid propulsion in the terminal stage known as the Velocity Trimming Module (VTM). The rocket is 34 metres high, 2 metres wide, and has a mass of 120,000 kg. 

The SSLV is designed to accommodate multiple satellites in a flexible manner with low costs and quick launches.

This mission injected its three satellites into their designated orbits, demonstrating successfully the in-flight performance of the rocket’s vehicle systems. 

The SSLV’s previous test flight, in August 2022, was unsuccessful because the terminal stage did not perform as expected, launching the payloads into a 356×76 km elliptical orbit rather than a 350 km circular orbit. Therefore, both satellites were “no longer usable.” 

The failure seemed to have occurred due to a faulty sensor. ISRO has since redesigned the launch vehicle with structural modifications. 

Payloads

The mission’s objective was to demonstrate the payload insertion capability of SSLV into the right orbit, launching three payloads in the process. One was an ISRO satellite, while the other two were passenger satellites. 

The EOS-07 is an earth observation satellite designed and built by the UR Rao Satellite Center (URSC), ISRO, Bengaluru. It weighs 156.3 kg and carries multiple instruments, including a mm-wave humidity sounder and a spectrum monitoring payload. 

The other customer payloads were Janus-1 and AzaadiSAT-2. 

Janus-1 is a 10.2 kg test satellite built by Antaris, USA. It is a 6U cubesat built on the Antaris platform, which is a software platform for space. It was designed and built within ten months with instruments from eight organisations in seven countries. It was manufactured by XDLINX Labs and Ananth Technologies. It is a low–cost mission that is set to demonstrate the efficiency of the Antaris platform. 

AzaadSAT-2 is a nano satellite, built by SpaceKidz India, Chennai. The 8.7 kg satellite was built by about 750 girl students from government schools across the country. It is an 8U cubesat, which are miniaturised satellites that are 10 cm cubes with eight of them stacked next to each other.

The satellite itself carries multiple sensors and instruments.

(Edited by Tarannum Khan)