While working with Aerospace to develop the NPP architecture documentation, NASA realized the Science Data Segment presented novel challenges in terms of ground system design and implementation. NASA asked Aerospace to suggest possible approaches for the Science Data Segment in early 2001. Based on initial architecture definition and requirements, Aerospace recommended an emerging technology known as grid computing (see sidebar, Grid Computing: An Overview). Because of the relative lack of maturity of this approach, Aerospace also recommended the development of a prototype implementation that would allow NASA to investigate key features as it moved to procure the full operational Science Data Segment. This prototype implementation was named the Advanced Data Grid.