A muesli bar developed for ESA astronauts on the International Space Station made with Spirulina and goji berries. Spirulina, a cyanobacteria, occurs naturally in tropical lakes and has been harvested for food in South America and Africa for centuries. It is a complete protein containing all essential amino acids, and is now cultivated worldwide. Goji berry, or wolfberry, is the fruit of the Boxthorn bush (Lycium sp.), and is rich in vitamin C and other nutrients.