NASA Tests Interplanetary Internet

The Internet has entered the final frontier.

NASA has successfully tested the first deep space communications network modeled on the Internet, using it to transmit images to and from a spacecraft 20 million miles from Earth, it was announced on Tuesday.

"This is the first step in creating a totally new space communications capability, an interplanetary Internet," said Adrian Hooke, leader of the team that performed the feat and manager of space-networking architecture, technology and standards at NASA Headquarters in Washington, D.C.

NASA and Vint Cerf, a vice president at Google, in Mountain View, Calif., who is often called the father of the Internet, partnered 10 years ago to develop the software protocol used for space transmissions, called Disruption-Tolerant Networking, or DTN. The DTN sends information using a method that differs from the terrestrial Internet's Transmission-Control Protocol/Internet Protocol (TCP/IP) communication suite, which Cerf co-designed.

The Interplanetary Internet must be robust enough to withstand delays, disruptions and disconnections in space. Glitches can happen when a spacecraft moves behind a planet, or when solar storms and long communication delays occur. For instance, the delay in sending or receiving data from Mars takes between three-and-a-half to 20 minutes, even at the speed of light.

If a disruption occurs in the pathway along which the information travels, each node in the network will hang on to its information until it's safe to communicate, unlike our Internet on Earth, which just discards the data packets.

The new network could ease communication with distant spacecraft and enable new kinds of space missions.

"In space today, an operations team must manually schedule each link and generate all the commands to specify which data to send, when to send it, and where to send it," said Leigh Torgerson, manager of the DTN Experiment Operations Center at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "With standardized DTN, this can all be done automatically."

The DTN was tested during a month-long experiment in October, using NASA's Epoxi spacecraft (currently on a mission to encounter Comet Hartley 2 in two years) and nine other "nodes," all on the ground at JPL.

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