Complex sentence: MISSEs 3 and 4 also served an educational purpose, it flew approximately 8 million basil seeds that were given to children for science experiments, in order to stimulate interest in space science.
Split into simpler sentences: MISSEs 3 and 4 also served an educational purpose. They flew approximately 8 million basil seeds that were given to children for science experiments, in order to stimulate interest in space science.