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SSLV-D1 Pioneer: A Walk to the Future? ; By Subhadip Mondal

Updated: Sep 20, 2022

Image Courtesy : IANS

Article 35/2022


The SSLV-D1 pioneer of the small satellite launch vehicle (SSLV) was launched from the Satish Dhawan Space Centre, Sriharikota, on August 07, 2022. The concerned vehicle was carrying the payload of an Earth Observatory Satellite (EOS) and AzaadiSAT. The EOS-02 is a Microsat 2A version of satellite, and it is based on its predecessor Microsat-TD 1. Microsat 2A have a payload of Mid-wavelength infrared (MWIR) and Long-wavelength infrared (LWIR) with 6 m ground resolution and a life span of 10 months.

Despite the launch being unable to fulfil its mandate, it has still changed the course of the Indian Space Research Organization’s (ISRO) trajectory. The layout of the new track can be analysed from two contexts: one from the perspective of the utility of a small satellite and the other from the prospect of the vehicle.

Small Satellite

As the course of modern warfare is changing, the importance of space technologies is increasing. The satellite has assumed the role of boasting the Command, Control, Computers Communications, and Intelligence, Surveillance and Reconnaissance (C4ISR) capabilities of the army. Depending upon the weight, satellites whose weight lies between 0.001 to 180 kg are referred to as small satellites 2. From 2500 to 5400kg, satellites fall in the medium to extremely heavy category.

The small satellites (SmSAT) can be used for specific purposes, whereas medium or heavy category satellites carry multiple payloads. This difference has its proclivities. Two or three Tracking and Data Relay Satellites in Geostationary Orbit located suitably over a country provide a way to extend the coverage ofISR assets over a large part of the earth 3. But, this has its shortcomings. First, the revisit time for the stationary orbit satellites is the same as that of the earth’s rotation period. But the places that are strategically important from the military perspective require a revisit time with minimal lapse. Second, since the number of satellites is limited and the altitude of these satellites is high, latency remains on the higher edge 4. This could have an important repercussion, especially during military operations. Third, countries have developed their anti-satellite system (ASAT), so their state-of-the-art space devices are under constant intimidation. These gaps can be plugged in using small satellites.

SmSAT carries target-specific payloads, bringing down the cost of production of such satellites. This can be passed on in the form of mass production of such satellites, which make it conducive to perish and replacement. Small satellites are placed in the Lower Earth Orbit (LEO); this reduces the temporal resolution.

SmSAT can utilise a single band frequency, like the X-band. The army uses the concerned band for its surveillance purpose. So, a constellation of X-band-based SmSAT is helpful for the military to continue surveillance over a ‘Region of Interest’ (RoI) with less latency and a revisit time of a few hours. So far, India doesn’t have a satellite with a similar frequency capability, so having such capacity will be crucial for Indian military services.

India has dedicated military use satellites, i.e. GSAT-7 (Rukmini used by Navy) and GSAT-7A (Angry Bird operated by Airforce). If it is complemented with the constellation of specific use SmSAT, then it would be a game changer in regions like the Line of Actual Control (LAC) and the Indian Ocean Region (IOR). Even though China has ASAT, this will not have a more significant impact on the constellation of SmSAT, primarily for two reasons. First, none of the SmSAT wouldn’t be a primary satellite, and none would be a cost-driven satellite, so they can quickly be replenished. Second, the ASAT can target a single target at one time, so it wouldn’t be able to perish the work of the whole constellation in one go. In other words, the result of the constellation will remain conducive even under active threat.

Launch Vehicle

After multiple successful trials, the pioneer of the SSLV series, i.e. SSLV-D1, was plunged into space with an actual payload. This project incepted the coalesce of many path-breaking acts. First, the project laid the foundation for incorporating private players into space infrastructure. Second, SSLV helped India achieve the capacity of placing small loads in the LEO cost-effectively. Before SSLV, Polar Satellite Launch Vehicle (PSLV), Geosynchronous Satellite Launch Vehicle (GSLV) and GSLV Mk III have the LEO capacity. The LEO payload capacity of these vehicles is around 5,000 kg & 8,000 kg, respectively 5. Comparing GSLV with PSLV, the latter has a higher success rate while the other remains a challenge. So, before the SSLV, the Polar vehicle was the option to place satellites in the LEO. PLSV provides the opportunity of either placing multiple satellites in one go or piggybacking small satellites along with the primary satellite. As it has exhibited during the launch of PSLV-C37 which placed 104 satellites belonging to seven nations including India 6. In the present instance, despite India proving itself to be a promising uprising, it is far from achieving the global benchmark. The SSLV-D1 was based on solid propulsion and had three stages, i.e. 87 tonnes, 7.7 tonnes and 4.5 tonnes. All these stages achieved their target using a heterogeneous propellant-based thruster. This success story has opened the doors that would attract more private players to India’s space market, which intern will be able to generate billions of revenues. To put a number on the market share which India can tap into through similar initiatives, as per data from MarketsandMarkets the global small satellite market size is projected to grow to 7.1 billion USD by 2025 7.


India has deployed Heron drones in the LAC region. The drones connected with satellite helps fly those beyond visual range. A constellation of SmSAT will assist in deploying multiple drone missions simultaneously. This will be both cost-effective and withstanding fewer perished human lives.

The use of the SmSAT constellation for the IOR will not only corroborate the work of Rukmini and Angry Bird but would also buttress the efforts of the Information Fusion Centre – Indian Ocean Region (IFC-IOR). Besides this, the GSAT-7 has extended its planned mission duration, so it is high time to install a constellation.

Besides catering to the needs of National Security, India must also aid in capacity building of ISRO to attract private players, especially those who are in the business of providing satellite internet service. This is a booming market. In this context, SSLV stands more appealing than PSLV, as for SSLV the Government of India (GoI) had sanctioned ₹169 crores, 8 whereas in the 2021 budget GoI allocated 700 crore INR to New Space India Limited (NSIL) which executed the launch of PSLV-CS51 9.

The need of the hour for India is to formulate a “Space Doctrine” on similar lines of the US which would be a step in the right direction. This doctrine shall include provisions for collaboration between government agencies and private players. Such a vision will also help to lay the foundation, which allows earmarking a particular portion of the annual budget for this purpose. The recent launch established the foundation of a journey which could make India a dominant player in space, but it is the time which will decide whether New Delhi will be able to achieve it or not.

Keywords National Security, SSLV, GSAT, SmSAT

(Mr. Subhadip Mondal is a research officer at C3S. The views expressed in this article are those of the author and do not reflect the views of C3S.)


1 “Microsat-TD (Microsat 1).” Gunter's Space Page. Accessed August 16, 2022.

2 Bommakanti, Kartik. “Introduction.” Essay. In Strengthening the C4ISR Capabilities of India's Armed Forces: The Role of Small Satellites, 1–8. Delhi, Delhi: ORF, 2020.

3 Chandrashekar, S. “Capacities, Capabilities & Gaps - Space Based Support Services for C4ISR.” Essay. In Space, War & Security– a Strategy for India, 6167. Bengaluru, Karnataka: NIAS, 2015.

4 Ibid no ii; p – 5.

5 “Geosynchronous Satellite Launch Vehicle (Gslv).” ISRO. ISRO. Accessed August 16, 2022.

6 “PSLV-C37 Successfully Launches 104 Satellites in a Single Flight.” ISRO. Accessed September 1, 2022.

8 “ISRO Developing a SSLV with Private Participation, to Be Launched in Q1 of 2022.” mint, December 16, 2021.

9 Pti. “Department of Space Allocated Rs 13,949 Crore in Budget, Rs 4,449 Crore More than Fiscal 2020-21.” News18, February 1,2021.

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