MGX Minerals Inc has announced the preliminary magnesium fuel specification parameters for Mg/CO2-type rockets.
Mg/CO2-type rockets utilize powdered magnesium as a solid fuel and carbon dioxide (CO2) as an oxidant. The calculated specific impulse of powder rocket engines is higher than that of traditional propulsion systems.
By reducing the traditional propellant requirement for ascent from Mars, the engine size and mass of spacecraft may be reduced. With an atmosphere of 97% carbon dioxide, CO2 is readily available on Mars. And magnesium is one of the lightest known metal solid propellants.
READ: MGX Minerals says strategic review for space and nuclear metals is underway
In an Mg/CO2 propulsion system, the magnesium powder may be fed by a positive displacement fluidized-bed feed system, which includes a porous piston in a cylindrical tank. The piston pushes the powder, and the gas fluidizes the powder at the same time. Particle size distribution, particle shape, and the purity of the magnesium have been determined as the primary parameters.
MGX Minerals said it is focused on a high purity magnesium particle with a small particle size of fewer than 50 microns. The smaller the particles, the shorter the burning time, which is desirable for the complete burning of the fuel inside the combustion chamber, and the priority is to reduce the size of the fuel storage tank by using a higher density material.
The company said the characteristics of the feeding process are sensitive to the powder characteristics, such as the particle size distribution and the shape of the particles. In the feeding process, a lower density particle may be a positive factor. This will require a balanced final particle optimization that considers a preference for high-density magnesium particles balanced with a potential decrease in the feeding flow rate or creation of significant variation in pressure, deposition in the pre-burner, and overall efficiency. Both regular and irregular-shaped particles are being considered at this time.
MGX Minerals said the ignition, combustion, and performance of magnesium carbon-dioxide type rocket engines have been experimentally studied. The ignition temperature of magnesium particles of medium sizes in CO2 is about 960 kelvin (K). Although broad applications may exist for powder fuel rockets.
Contact the author: patrick@proactiveinvestors.com
Follow him on Twitter @PatrickMGraham