Darpa Looks to Send the Internet Into Orbit

[Eugen Leitl]

http://www.wired.com/dangerroom/2009/10/darpa-looks-to-send-the-internet-into-orbit/

Darpa Looks to Send the Internet Into Orbit

    * By Noah Shachtman Email Author

    * October 27, 2009  | 

    * 11:34 am  | 

    * Categories: DarpaWatch

Therebve been satellites orbiting Earth for half a century. But getting
information to and from them is still a pain. Which is why Pentagon research
arm Darpa is looking to finally hook the orbiting spacecraft up with reliable
broadband connections. Itbs part of a larger movement to extend terrestrial
networks into space, and eventually build an bInterplanetary Internet.b In
the meantime, we might even get less-than-crappy satellite internet service b
if the project works out, of course.

Darpa recently issued a request for information about supplying bpersistent
broadband ground connectivity for spacecraft in low-Earth orbit.b The idea
would be to give these satellites a near-constant feed of b100 kbps or
higherb two-way connectivity, with end-to-end transmission latency of less
than a second. Unlike most Darpa projects, which are meant to pay off years
or decades in the future, this would be a near-term attempt. The agency wants
the system boperational in the 2012 to 2013 time frame.b

Brian Weeden, a former officer with U.S. Air Force Space Command and a
technical adviser with the Secure World Foundation, says Darpabs help would
be most welcome.

bThe protocol that the internet uses b TCP/IP b wasnbt really designed with
space in mind. For one, the delay times between nodes can be big. One way to
GEO [geosynchronous orbit] is 300 milliseconds at the speed of light, there
and back over half a second of built-in network lag before anything else adds
to it. Thatbs one reason why getting internet from satellites sucks right
now,b he tells Danger Room.

bIf you go lower than GEO, then of course satellites are always moving and
thus not always overhead. It would be a huge help to have a protocol that can
automatically store and forward packets when the satellite is present or
not,b Weeden adds.

For years, Darpa b which backed much of the early research into the internet
b has been working with other networking godfathers to put together an
binterplanetary internet.b

bWebre pretty used to it but the internet is actually a pretty revolutionary
construct. That you can drop a packet of data on it with only a starting and
destination address and it finds its way there without any directions is
pretty astonishing,b Weeden explains. bThe payloads on most satellites donbt
work that way b payload operators need to configure specific transponders for
specific users and applications. So part of this is trying to bring those
internet concepts of automatic routing and network config to satellite
constellations, and perhaps to make them extensions of the land-based
internet infrastructure.b

Darpabs deadline for ideas of how to pull it off is Nov. 5.