Aerospace Systems Research Group (ASReG)

SAFFIRE

Overview

The South African First Integrated Rocket Engine (SAFFIRE) is a paper design study started by ASReG on a modular and compact liquid propellant rocket engine. Rapid advances in pico-satellite technology have led to a growing interest in smaller launch vehicles that can rapidly deploy cubeSats to low Earth orbit (LEO) at low cost. For countries like South Africa, with fledgling satellite industries but no launch capacity, the outsourcing of payload delivery to foreign providers is costly and can also lead to unanticipated delays. This raises the question of whether South Africa should develop an indigenous commercial launch vehicle. 

The hypothetical small-sat launch vehicle, for which SAFFIRE is being developed, would consist of two stages, with adjusted nozzle design, for the second stage. The vehicle payload capacity is 75 kg to accommodate at least 15 cubeSats (including the auxiliary equipment needed to deploy them) to a target orbit of 400 km, sun-synchronous.  

SAFFIRE is designed to be a compact engine that can be utilised in multiple configurations for a variety of launch vehicles. One of the potential uses of the engine is to provide small-sat launch vehicle capabilities on the continent of Africa. 

Technical Specifications

  • 25 kN Thrust.
  • Propellant mass flow rate of 8.88 kg/s.
  • 50 bar Chamber Pressure.

Research

The study builds on previous work performed on the design and CFD analysis of a kerosene fuel pump by Smyth and Ritchings for a large rocket engine. An impeller test rig was designed and constructed by Philogene.

The work currently being developed for SAFFIRE includes:

  • An electrically driven Kerosene (RP-1) Fuel Pump
  • An electrically driven Liquid Oxygen (LOX) Oxidiser Pump
  • Impinging Jet Injector
  • Design and Performance Simulation of a Combustion Chamber
 
Conventional liquid rocket engines utilise turbopump (turbine and pump) technology to achieve the required mass flow rate and pressure rise of the propellants fed to the combustion chamber. SAFFIRE makes use of an electro-pump system which dispenses with the gas-driven turbine of a normal turbopump and replaces it with an electric drive system. This consists of two brushless DC motors and separate high density lithium-polymer battery banks to drive each pump. The flow rate and pressure rise specifications for the pumps were obtained from the required engine performance

SAFFIRE concept