NASA’s Disruption Tolerant Networking Challenge Series

Welcome to the NASA Disruption Tolerant Networking (DTN) project. DTN is an approach to computer network architecture that seeks to address the technical issues in heterogeneous networks that may lack continuous network connectivity. Examples of such networks are those operating in mobile or extreme terrestrial environments, or planned networks in space. Disruption may occur because of the limits of wireless radio range, sparsity of mobile nodes, energy resources, attack, and noise.

Project Background

NASA needs to integrate the ION Disruption Tolerant Networking (DTN) implementation of Bundle Protocol (BP) with Microsoft Outlook and Microsoft Exchange Server to support the transfer of astronaut email to/from the International Space Station (ISS).

Astronauts currently use Microsoft Outlook on the ISS connected to a Microsoft Exchange Server on the ground to send and receive email from ISS.  The current system operates over TCP/IP on links that are delayed and frequently disrupted due to ISS structural blockage and Tracking and Data Relay Satellite System (TDRSS) handovers.  The combination of delay and disruptions causes Microsoft Outlook to frequently have problems and become unusable, particularly when sending emails with large attachments, such as pictures or videos.

Check out this infographic that helps explain the NASA Astronaut Email Challenge

Two permanent DTN gateways will be available to support operations and payloads users on ISS starting in March 2015. The corresponding ground nodes will also be put in place.

The gateways are the nodes that all DTN traffic will hit before being transferred over the space-to-ground link. The network setup can be thought of as: [Exchange Server]<->[Ground DTN  Gateway]<->[Space DTN Gateway]<->[Microsoft Outlook Client]

These DTN assets will be utilized by Microsoft Outlook and Exchange Server to remedy the email problem that currently exists on ISS.

High Level Requirements

NASA needs a plug-in/extension for Outlook/Exchange Server that converts the TCP-based protocols used by Outlook (on-board the ISS) to communicate with an Exchange server (on Earth) to instead use the DTN Bundle Protocol. If a plug-in is not feasible, then any other type of mechanism or gateway application is sufficient.

Project Overview & Stats

This project launched in April, 2014 and was completed in June, 2015.

The project was completed using 12 challenges, and had 146 registrants from 42 different countries. The primary objective of the project was to integrate the ION Disruption Tolerant Networking (DTN) implementation of Bundle Protocol (BP) with Microsoft Outlook and Microsoft Exchange Server to support the transfer of astronaut email to/from the International Space Station (ISS).

In addition, the following requirements were met:

1. The solution includes both ends of the communication (client-side and server-side).
2. The DTN support code does not cause interference with other ground users that are using the same Exchange server without DTN.
3. The solution supports:
—–1. Unpredictable suspension of communication for up to 4 hours.
—–2. Unpredictable loss of data.
—–3. Round trip times on the order of .6 s – 1 s.
4. The solution utilizes the ION 3.2.0 API for all bundle transmission and reception.

Resources

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