PSLV-C40: A multipurpose mission

The liftoff of an Indian Polar Satellite Launch Vehicle on its first mission since an August 2017 launch failure. (credit: ISRO)

India’s space agency, ISRO, ended 2017 rather on a somber note with the failure of the Polar Satellite Launch Vehicle PSLV-C39 mission. On August 31, 2017, ISRO was forced to declare the mission a failure owing to a freak incidence. PSLV-C39 failed after the payload fairing did not separate during one of the legs of the launch sequence.

The payload fairing is meant to protect the satellite payload from the aerodynamic forces during initial phases of flight. After reaching a specific altitude, this fairing is no longer needed, and must separate. However, during the PSLV-C39 mission, which was carrying India’s navigational satellite IRNSS-1H, this did not happen and the satellite got stuck in the fourth stage of the rocket.

For many years, India’s space program has won various laurels because of the excellent services provided by the PSLV, a third-generation launch vehicle. From 1994 until June of 2017, it carried out 39 consecutive successful missions. Naturally, this failure during August 2017 mission was a big blow for both ISRO and India’s regional satellite navigational program. This failure required ISRO to take a four-month launch break.

However, 2018 brought the cheer back with the successful launch of PSLV-C40 mission. The success of the PSLV-C40 mission on January 12 has reassured ISRO that there is nothing wrong with their vehicle design.

From purely a technology perspective, PSLV-C40, which launched 31 satellites, could not be considered as some milestone mission. This mission carried India’s 100th satellite and, in that context, it has its own relevance. However, this mission should not be remembered only from the perspective of history and nostalgia.

Besides giving reassurance to the scientists of ISRO of their own capabilities, this launch lasted for two hours, the longest so far for ISRO. Normally, most of the PSLV launches last approximately for 20 minutes. However, this mission took an additional two hours because the mission sequence involved using multiple-burn technology, where the fourth stage was fired three additional times. The maximum altitude of 510 kilometers, which was reached during release of the first satellite (Cartosat 2) into the polar sun synchronous orbit, was reduced to 359 kilometers during these burns. As a predesigned part of a launch profile, the altitude was reduced for positioning the last remaining satellite, a microsatellite, during the mission’s end phase. The challenge was to restart the engine in a cold microgravity environment and to ensure that no impact takes place on the satellites owing to the heat generated during the restart.

This mission also strengthens India’s cartographic series satellite program. India has a unique geography and is impacted by both tropical and extratropical weather systems. For a country with such a varied terrain and weather, satellites have for many years played an important role in the management of land and water resources, crop management, and getting useful weather inputs. India has an exceptional track record in the arena of launching remote-sensing satellites.

India launched its first remote sensing satellite in 1988 under the Indian Remote Sensing (IRS) program. Also, having understood the nature of strategic inputs that remote sensing technology offers, India started upgrading its sensor technology. In 2001, ISRO launched a Technology Experimental Satellite (TES) that produced images with a resolution less than 1 meter. The first cartographic satellite, called Cartosat 1, was launched in 2005. The Cartosat 2 program started in 2007 and three satellites were launched through 2010. Three more Cartosat 2 satellites were launched before this launch. All these satellites have a resolution less than 80 centimeters and it is expected that India could develop the capability of around 30 centimeters resolutions for future launches.

Apart from the Cartosat satellite that was the main payload for this mission, 30 other smaller satellites (micro and nano) were launched. Of there, 28 were for the foreign customers, including Canada, Finland, South Korea, UK, USA, and France. It is interesting to observe that countried with their own launch capabilities are also looking at ISRO as a viable option. The confidence of these global customers in ISRO is heartening, particularly given the failure of the PSLV-C39 mission.

All in all, the relevance of PSLV-C40 mission is threefold: launching a cartographic satellite that is an important part of India’s civilian and strategic remote sensing architecture, successfully demonstrating the multiple-burn technology of the PSLV, and demonstrating the capabilities of the PSLV for the launch of small satellites to international customers.

During last two decades, ISRO has succeeded in establishing PSLV as a multipurpose vehicle. It is the same vehicle that has allowed ISRO to undertake successful missions to Moon and Mars, and also launch microsatellites and nanosatellites. For the last few years, ISRO has made conscious efforts to promote this vehicle as a suitable option for launch of small satellites. Demonstration of multiple-burn technology could be considered as one such step in that direction. The other step could be launch of 104 small satellites in one mission in early 2017. The multiple-burn technology has been used in some forms on some earlier missions. For example, on September 26, 2016, the PSLV-C35 launched eight satellites into two different orbits, with the main payload was in one orbit and remaining seven satellites in the other. Now, with this mission, ISRO has repeated that performance but with many more satellites.

Before this mission, ISRO had launched 209 satellites for international customers. Over the years, ISRO has succeeded in establishing itself as a reliable launching partner, particularly for small satellites. The nanosatellite (1–10 kilograms) and microsatellite (11–100 kilograms) market is showing major growth. The nanosatellite market is forecast for the highest growth coming few years. According to one report, “The nanosatellite and microsatellite market is projected to grow from an estimated USD 1.21 Billion in 2017 to USD 3.49 Billion by 2022, at a Compound Annual Growth Rate (CAGR) of 23.7% during the forecast period, from 2017 to 2022. The base year considered for the study is 2016.” This study clearly indicates that there is big launch market available for ISRO to grab.

Various agencies of ISRO are involved in designing, developing, and manufacturing satellites required for them. It also manufactures satellites for international customers. However, one area that ISRO and India’s private space industry needs to focus on is the field of small satellite manufacturing. Today, foreign customers ship their satellites to ISRO for launch. India needs to ensure that customers should be presented with an option for having their satellites also manufactured in India to their specifications. For this purpose, India needs to evolve a major ecosystem for manufacturing of small satellites. Now, the time has come for ISRO to focus simultaneously on both the satellite launch market and satellite manufacturing market.