The development of auto-regenerative biological life support systems for men in Space will be based on photosynthetic organisms, such as higher plants and algae, providing edible material. In this work, Spirulina platensis grown in a continuous photobioreactor was used to design a process for its recovery and further treatment to be used as food. Two different possibilities are studied (liquid or dry food). In each case, different steps are considered in the design of the process and further characterised: cell harvesting, washing, pasteurisation and spry-drying. Special emphasis is made on biomass quality, both in terms of potential microbial contamination and changes in its composition during the different steps of the process. Cell harvesting was conducted with a net recovery of solids and water higher than 95% with a solids concentration factor about 20–30. Biomass quality was shown as satisfactory in all the treatments tested.