NASA has required the excellent quality ground-based TT&C services offered by the Near Earth Network (NEN) since the inception of Agency flight missions in 1958. The NEN's resources continuously evolve to meet the changing communication needs of the missions it supports. The NEN emerged from a series of communications networks with a rich history of enabling space flight mission success.

NASA implemented its first ground-based communications network-the Manned Space Flight Network (MSFN)-in the 1960s. The MSFN was a worldwide communications network with stations primarily located at low-latitudes to support the Mercury, Gemini, and Apollo Programs. During this same decade, NASA also acquired responsibility for DOD's Minitrack system, evolving it into the Satellite Tracking and Data Acquisition Network (STADAN) to support an emerging class of satellites requiring enhanced communications.

During the 1970s, NASA merged the MSFN and STADAN, forming the Spaceflight Tracking and Data Network (STDN) to support the communications needs of manned and unmanned spacecraft missions. During the next few decades, NASA decommissioned and commissioned STDN stations in response to the Agency's communications needs. NASA expanded the STDN in the 1980s to provide crucial support to the Shuttle while the Agency developed the Space Network (SN), which eventually enabled a reduction in the number of ground stations as the SN became operational. 

In the 1990s, NASA required ground-based stations to provide communications support for a series of high-data-rate science missions in low-Earth orbit primarily due to the Agency's Mission to Planet Earth (MTPE) initiative. The communications needs of these spacecraft required the addition of several ground stations in Earth's polar regions. In addition, mission support requirements changes enabled  the closure of certain equatorial sites. As a result, NASA transformed the STDN into a set of stations initially called the Ground Network (GN), and more recently renamed as the NEN. Furthermore, NASA began to utilize an emerging set of commercial TT&C stations to supply services for flight missions. 

Today, the NEN utilizes a diverse set of resources to provide high quality services at the lowest cost to supported flight missions. Current NEN resources include globally located NASA-owned orbital tracking systems, commercial orbital tracking stations, NASA partner stations, a scheduling system, and test systems. A key enabler to providing low cost services is the NEN Project's unique business practice of carefully blending the use of a large commercial and international provider base with NASA-owned assets to fulfill the changing needs of the NEN-supported mission communications requirements.

The NEN Project pioneered the practice of procuring commercial TT&C services on a large scale. This allowed the NEN Project to achieve geographical diversity without having to develop NASA assets worldwide.  It also minimized Project risk. However, The Project employs NASA-owned assets to provide support to missions with unique communications requirements, such as the Shuttle. Currently, the NEN provides apprximately half of its services using commercial and partner providers, and Project goals include furthering this business model to maximize efficiencies between commercial providers and NASA systems and stations.

The NEN provides TT&C services to missions identified in NASA's Space Communications Mission Model (SCMM), supporting pre-flight, launch, orbital, landing, and post flight activities. NEN customers include NASA's Science, Space Operations and Exploration Systems Mission Directorates, as well as other government agencies, international civilian space agencies, and commercial entities. Primary NEN Project activities involve achievement of the Project's operational requirements, mission safety, and the maintenance, sustainment, and improvement of NEN systems. The Project also periodically conducts upgrade and/or development efforts to ensure that NASA meets its commitments to missions identified in the SCMM. NEN development and upgrade activities involves development or procurement of new systems designed to meet upcoming customer requirements, or replacement of aging or obsolete equipment with state-of-the-art systems to ensure network proficiency and availability.