National Aeronautics and Space Administration

Glenn Research Center

James Nessel

June 18, 2013

On Tuesday evening, the Space and Aeronautics Academies attended a presentation by James Nessel. James is an electronics engineer in the Antenna and Optics Systems Branch. Since joining NASA in 2005, he has analyzed the Ka band and antenna design for lunar communications.

The focus of the presentation was NASA’s space communication networks. The Academites learned about NASA’s different networks and their uses, including the Space Network, which provides communication to spacecraft in earth orbit through direct-to-ground communication and communication through the Tracking and Data Relay Satellite System, as well as the Deep Space Network, which communicates with interplanetary spacecraft. He described how three ground stations provide complete coverage of the universe.

James also spoke about the communication bands used to communicate with spacecraft, and how these have changed over the years. He discussed in particular use of the Ka band, and how it’s performance is affected by atmospheric attenuation and how it compares to traditional bands such as S-band. He also discussed how frequency blocks are sold off by the government to the private sector, creating challenges by forcing NASA to use a narrower and different spectrum. He also talked about ground stations and arrays, such as the Very Large Array.

To finish off the presentation, James discussed his path to working at NASA. He graduated from Arizona State University in 2004 with a Master’s degree, and is currently pursuing his PhD in an area related to his work at NASA. He discussed his recommendations on balancing education and employment. All in all, the aero and space academies gained much new knowledge from the presentation.