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Date: Tue, 18 Nov 2008 13:14:53 -0800
From: NASA Jet Propulsion Laboratory <info@jpl.nasa.gov>
To: "sondheim@panix.com" <sondheim@panix.com>
Subject: NASA Tests First Deep-Space Internet






[NASA-NEWS-600-1172.GIF]

Rhea Borja 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
rhea.r.borja@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

Katherine Trinidad 202-358-1100
NASA Headquarters, Washington
Katherine.trinidad@nasa.gov

News Release: 2008-216                       November 18,
2008

NASA Tests First Deep-Space Internet

PASADENA, Calif. - NASA has successfully tested the first deep space
communications network modeled on the Internet.

Working as part of a NASA-wide team, engineers from NASA's Jet Propulsion
Laboratory in Pasadena, Calif., used software called Disruption-Tolerant
Networking, or DTN, to transmit dozens of space images to and from a NASA
science spacecraft located about more than 32 million kilometers (20
million miles) from Earth.

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

NASA and Vint Cerf, a vice president at Google, Inc., in Mountain View,
Calif., partnered 10 years ago to develop this software protocol. The DTN
sends information using a method that differs from the normal Internet's
Transmission-Control Protocol/Internet Protocol, or 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. The delay in sending or receiving data from
Mars takes between three-and-a-half to 20 minutes at the speed of light.

Unlike TCP/IP on Earth, the DTN does not assume a continuous end-to-end
connection. In its design, if a destination path can't be found, the data
packets are not discarded. Instead, each network node keeps custody of
the information as long as necessary until it can safely communicate with
another node. This store-and-forward method, similar to basketball
players safely passing the ball to the player nearest the basket, means
that information does not get lost when no immediate path to the
destination exists. Eventually, the information is delivered to the end
user.

"In space today, an operations team has to 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 JPL. "With standardized DTN, this can all
be done automatically."

Engineers began a month-long series of DTN demonstrations in October.
Data were transmitted using NASA's Deep Space Network in demonstrations
occurring twice a week. Engineers use NASA's Epoxi spacecraft as a Mars
data-relay orbiter. Epoxi is on a mission to encounter Comet Hartley 2 in
two years.

"There are 10 nodes on this early interplanetary network," said Scott
Burleigh of JPL, lead software-engineer for the demonstrations. "One is
the Epoxi spacecraft itself and the other nine, which are on the ground
at JPL, simulate Mars landers, orbiters and ground mission-operations
centers."

This month-long experiment is the first in a series of planned
demonstrations to qualify the technology for use on a variety of upcoming
space missions, said Jay Wyatt, manager of the Space Networking and
Mission Automation Program Office at JPL. In the next round of testing, a
NASA-wide demonstration using new DTN software loaded on board the
International Space Station is scheduled to begin next summer.

In the next few years, the Interplanetary Internet could enable many new
types of space missions. Complex missions involving multiple landed,
mobile and orbiting spacecraft will be far easier to support through the
use of the Interplanetary Internet. It could also ensure reliable
communications for astronauts on the surface of the moon.

The Deep Impact Networking Experiment is sponsored by the Space
Communications and Navigation Office in NASA's Space Operations Mission
Directorate in Washington. NASA's Science Mission Directorate and
Discovery Program in Washington provided experimental access to the Epoxi
spacecraft. The Epoxi mission team provided critical support throughout
development and operations.

JPL is managed for NASA by the California Institution of Technology in
Pasadena.

                                                      - end -





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