Skyroot Vikram-1 vs ISRO PSLV: What is the difference?

India’s space sector is mostly dominated by the Indian Space Research Organisation (ISRO). After the privatisation of the Indian space sector in 2020, which opened the door for private enterprises and individuals to contribute to the country's space sector. 

It is marking a significant transformation like the successful launch of Skyroot Aerospace’s Vikram-1 following its successful maiden orbital flight (Mission Aagaman),

What does significance and impact of an achievement by a private rocket compared to ISRO’s Polar Satellite Launch Vehicle (PSLV)?  Although both are great examples of Indian engineering excellence but designed for different missions. 

ISRO's PSLV 

ISRO’s Polar Satellite Launch Vehicle (PSLV) is developed in the early 1990s. The PSLV is a medium-lift launch vehicle. It was built to give India independent access to space for remote sensing and communication satellites. It has helped ISRO launch its key missions such as Chandrayaan-1 and the Mars Orbiter Mission (MOM).

Skyroot's Vikram-1

Vikram-1 is a small and 3D-printed orbital-class commercial rocket. Developed by India’s private company Skyroot. It is named after the father of India’s space program Dr. Vikram Sarabhai. It is customized for the modern global commercial market to launch small satellite constellations.

Here are the key technology differences between the Both Vikram 1 and PSLV. 

Structural and Other Differences

• The PSLV-XL is a large-scale launch vehicle standing at 44.4 meters with a liftoff mass capacity of roughly 320 tonnes. 

• Vikram-1a small-scale launch vehicle with a height of 20–24 meters. 

• Vikram-1 cuts down structural unladen weight because it uses an all-carbon composite airframe which makes it light and efficient for small satellites. 

• Both rockets use a 4-stage propulsion system. However, they execute it differently:

• The PSLV utilises a mix of solid and liquid fuel systems. 

1. Its first stage (S139) is one of the largest solid boosters in the world. 

2. The second stage uses the famous liquid-fuelled Vikas engine.  

3. The third is solid 

4. and the fourth is a twin-engine liquid stage.

• Vikram-1 utilised solid fuel for its first three stages that is powered by its proprietary Kalam-1200, Kalam-250 and Kalam-100 motors.

• The final and fourth stage uses liquid propulsion powered by 4 x Raman-I engines. 

• Vikram-1 features 3D-printed liquid engines and modular avionics systems. While the PSLV relies on traditional, ultra-reliable aerospace manufacturing. 

• The PSLV is built to launch heavy gear or payloads. Its payload capacity ranges from 1,100 kg to 1,750 kg to Sun-Synchronous Polar Orbits (SSPO).

• Vikram-1 is designed for the small satellite market with a payload capacity of 300 kg to 350 kg for Low Earth Orbit (LEO). 

• Vikram-1 provides a dedicated taxi service by allowing companies to launch when and where they want.

• The PSLV is a complex and heavy launch vehicle. It takes weeks to prepare a launch in assembling, stacking and validating.

• Skyroot has designed Vikram-1 for rapid integration and minimal launch infrastructure. The rocket can be assembled and readied for flight in a fraction of the time. 

• Vikram-1 is a replacement for the PSLV. They represent a tag-team dynamic within India's growing space economy.

ISRO’s PSLV will continue to act as the institutional launcher for countries' heavy payloads for scientific explorations. Skyroot Aerospace Vikram-1 is built to cater to the hyper-fluid, fast-paced commercial micro-satellite market. India now has both an established transit system and a rapid-response local delivery fleet.