NASA needs to transition to optical communication systems that would allow spacecraft to send high-definition video and other high data-rate products back to Earth — the kind of data that would overwhelm the radio frequency systems used today, said NASA Administrator Mike Griffin.

Speaking to an international conference of electronics experts Sept. 15 in Pasadena, Calif., Griffin outlined a new in-space communications architecture that gradually would replace the Deep Space Network that has served the U.S. space program since its inception in 1958.

"If the truth be told, the Deep Space Network is 50 years old, not 50 years young, and it is showing its age," Griffin said in a speech at the 33rd International Conference on Infrared, Millimeter and Terahertz Waves. The conference was held at the California Institute of Technology, which manages NASA's Jet Propulsion Laboratory — home to core elements of the Deep Space Network.

Griffin said NASA has spent "the past few years" defining a new communications architecture for future human spaceflight missions as well as Earth and space science programs. "We want an integrated, scalable communications network offering exponentially higher data rates," he said.

Designing a communications systems to meet the agency's needs for the next 50 years "will be no mean feat," he added. "We should not build simply to meet minimal requirements, but to enable qualitatively new capabilities."

To prepare for the challenges ahead, NASA has spent the last few years under Griffin consolidating the management and budget for the agency's space communications and navigation activities into a centralized organization.

"We used this approach in the old NASA Code O, and I believe it was a mistake to get rid of it," Griffin said. "We've re-established it within our Space Operations Mission Directorate."

By centralizing the management and systems engineering of the agency's previously separate Deep Space Network, Near Earth Network and Space Network, Griffin hopes to wring more from the agency's current communications budget. However, he said it will take more than centralized management to bring about the space communications network of the future.

"With our current budget, we can afford to operate and maintain the aging [Deep Space Network] or we can afford to build a new, integrated communications network. We cannot afford both," he said. "Thus, we must be more efficient with automation, commonality, and interoperability between the various communications networks, including those of our international partners, so that we invest the savings in building future capabilities."

Griffin said shifting to an optical communications network will enable "exponentially higher data rates" than now are possible with NASA's current systems.

"Rather than returning grainy images like those from the first moon landing, we will be able to stream high-definition video upon our return," he said.

To help bring about this future, Griffin said NASA will develop a medium-sized optical payload and pathfinder data relay satellite, although he did not say when. A NASA official said more specifics would be detailed in NASA's 2010 budget request, currently in work for release in early 2009.

Griffin, however, said the NASA demonstration mission would leverage the work of the National Reconnaissance Office on the GeoLITE satellite, a $130 million technology demonstrator that was launched on a nominal nine-year mission in 2001 aboard a Delta 2 rocket. Among GeoLITE's payloads was a laser communications experiment developed by the Massachusetts Institute of Technology's Lincoln Laboratory.

Griffin said in his speech that he has directed Ed Weiler, NASA's associate administrator for science, to identify spacecraft missions in formulation suitable for hosting optical communications demonstrations.

Griffin also told the audience NASA hopes to phase out the Deep Space Network's aging 70-meter antennas and replace them with smaller but more numerous Ka-band antennas.

NASA's 2008 budget included just over $300 million for space communications. About half that amount is dedicated to the purchase of new Tracking and Data Relay Satellites used by NASA to communicate with the space shuttle, international space station and other spacecraft in low Earth orbit.