The NASA Jet Propulsion Laboratory uses software developed by Vint Cerf in an approach called disruption-tolerant networking to transmit dozens of space images to and from a NASA science spacecraft located about 20 million miles from Earth. The first deep-space communications network modeled on the Internet, DTN is expected to be used on a variety of upcoming space missions.
It took 10 years, but legendary Vint Cerf, who is widely credited as one of
the scientific founders of the Internet, has helped reach yet another Internet
milestone: the first deep-space communications network modeled on the Internet.
NASA announced Nov. 18 that engineers from NASA's JPL (Jet Propulsion
Laboratory) used software that Cerf helped develop over 10 years called DTN
(disruption-tolerant networking) to transmit dozens of space images to and from
a NASA science spacecraft located about 20 million miles from Earth.
"This is the first step in creating a totally new space communications
capability, an interplanetary Internet," Adrian Hooke, team lead and
manager of space-networking architecture, technology and standards at NASA,
said in a statement.
NASA began a month-long series of DTN demonstrations in October, using the
which is on a two-year mission to Comet Hartley 2, as a Mars
data-relay orbiter. The tests are the first in a series of planned
demonstrations of DTN. NASA eventually hopes to use DTN on a variety of
upcoming space missions.
According to NASA, the Interplanetary Internet could allow many new types of
space missions such as complex assignments involving multiple-landed, mobile
and orbiting spacecraft. DTN could also allow reliable communications for
astronauts on the surface of the moon.
"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
DTN sends information using a method that differs from the normal Internet's
TCP/IP communication suite, which Cerf
co-designed. Unlike TCP/IP on Earth, the DTN
does not assume a continuous end-to-end connection. In a typical TCP/IP
design, if a destination path can't be found, the data packets are not
With DTN, on the other hand, 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 means that information does not get lost
when no immediate path to the destination exists. Eventually, the information
is delivered to the end user.
"There are 10 nodes on this early interplanetary network," said
Scott Burleigh, JPL's 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
For the next round of testing, a NASA-wide
demonstration using new DTN software loaded on board the International Space
Station is scheduled to begin in summer of 2009.