I wonder if Google wil be more involved with Vint Cerf’s recent decision to join them…

ACM News Service

“The Interplanetary Internet”
IEEE Spectrum (08/05) Vol. 42, No. 8, P. 30; Jackson, Joab
Ambitious plans for future space exploration cannot be realized without an effective communications network to link Earth with its far-flung explorers, and all of NASA is in agreement that the ideal scheme would be an Internet that spans between planets. But the space agency is split over how this can be achieved: One research group supports the use of existing Internet software and Internet protocols, while the other says wirelessly communicating across vast distances with such tools is a practical impossibility. Both groups looked for ways to address the two biggest obstacles of interplanetary communications–delays caused by distance and the handing-off problems associated with the need to go through multiple ground stations. The first group engineered a demo of the space IP network concept on the ill-fated Columbia’s last flight, in which a file was transferred between the Goddard Space Flight Center and the shuttle across a distance of about 600 kilometers. But a team of scientists at the Jet Propulsion Laboratory (JPL) also worked on the problem, only to find that TCP could not be successfully modified for space travel. Their alternative solution is Delay Tolerant Networking (DTN), an architecture that moves data across networks by using routers that retain a copy of every packet of data sent at least until the next node in the network acknowledges receipt, thus guaranteeing that no data is lost even if a node is offline. This scheme not only ensures that data reaches its destination, but it can improve robot explorers’ efficiency by requiring them to hang onto data only until it is received by the first node. The Goddard group’s concern is that a DTN model would be more costly and less capable because it eschews reusable, commercially developed Internet hardware and software.