Dave Stewart

Using Internet nodes and routers onboard satellites

An Internet router was integrated into the UK-DMC remote-sensing satellite as a secondary experimental payload. This commercial product has been orbiting in space for over three years. We describe the integration of the router and satellite and the successful on-orbit testing of the router, which took place using the Virtual Mission Operations Center (VMOC) application as part of a larger systems internetworking exercise. Placing this Cisco router in Low Earth Orbit (CLEO) onboard a small satellite is one step towards extending the terrestrial networking model to the near-Earth space environment as part of a merged space-ground architecture.

Large File Transfers from Space Using Multiple Ground Terminals and Delay-Tolerant Networking

Abstract-We use Delay-Tolerant Networking (DTN) to break control loops between space-ground communication links and ground-ground communication links to increase overall file delivery efficiency, as well as to enable large files to be proactively fragmented and received across multiple ground stations. DTN proactive fragmentation and reactive fragmentation were demonstrated from the UK-DMC satellite using two independent ground stations. The files were reassembled at a bundle agent, located at Glenn Research Center in Cleveland Ohio. The first space-based demonstration of this occurred on September 30 and October 1, 2009. This paper details those experiments.

Virtual Mission Operations of Remote Sensors With Rapid Access To and From Space

This paper describes network-centric operations, where a virtual mission operations center autonomously receives sensor triggers, and schedules space and ground assets using Internet-based technologies and service-oriented architectures. For proof-of-concept purposes, sensor triggers are received from the United States Geological Survey (USGS) to determine targets for space-based sensors. The Surrey Satellite Technology Limited (SSTL) Disaster Monitoring Constellation satellite, the United Kingdom Disaster Monitoring Constellation (UK-DMC), is used as the space-based sensor. The UK-DMC s availability is determined via machine-to-machine communications using SSTL s mission planning system. Access to/from the UK-DMC for tasking and sensor data is via SSTL s and Universal Space Network s (USN) ground assets. The availability and scheduling of USN s assets can also be performed autonomously via machine-to-machine communications. All communication, both on the ground and between ground and space, uses open Internet standards.