• delta v
• green propellants
• Hydrazine
• Hydrogen Peroxide
• rocket
• upper stage

Space Technology is the backbone of modern technological advancements. With sustainable development goals in place for the Space Sector, there is a dire need to focus on technologies which are safer and cost friendly to promote young and small-scale companies to contribute.
Upper Stages play a vital role in delivering and dispensing missions into orbit, to ensure meeting the needs of the modern day requirements there is immense research and development being done.
The major concern for the Propulsion industry is the use of toxic propellants especially Hydrazine. Green Propellants are the way forward. Their effects when compared to the toxic propellants are low and are favorable for low cost rapidly developing propulsion systems.
Selection of Hydrogen Peroxide as the Green Propellant in consideration to replace Hydrazine. With reasonable performance parameters an attempt made to theoretically replace Hydrazine for the monopropellant and bipropellant engines of Fregat Upper Stage which would affect the total mass of the system, giving new requirements for payload to be carried by the proposed Green Fregat Upper Stage. For the main engine Hydrogen Peroxide based bipropellant combination has been used a reference for design parameters of the new main engine.
Adequate results have been obtained which increase the confidence in the selected Green Propellants and are a basis for research and development in design and mission analysis for the proposed Green Upper Stages of future.