Automation and Robotics in the German Space Program – Unmanned on-Orbit Servicing (OOS) & the TECSAS Mission
- Paper number
IAC-04-IAA.3.6.2.03
- Author
Mr. Bernd Sommer, Deutsches Zentrum fur Luft und Raumfahrt e.V. (DLR), Germany
- Year
2004
- Abstract
This paper deals with what we believe to be a here-to-fore unexplored low-earth-orbit-based optic-fiber-communication system. Starting with an assumption that a "circum-terra" conductive ring can be deployed in the LEO (see A “LEO ARCHIPELAGO” T M , Symposium D.3), an entire communication system is proposed that would complement existing terrestrial networks and thereby improve global connectivity.
The experimental stage of the LEO-ring system (prior to deployment of the full fiber-optic ring) would involve testing and development of the control and stability of the ring structures and of the ring-based solar-power and communication systems. The initial operational phase of the communication system would be the LEO deployment of a near-equatorial, circum-terra, optic fiber (paired with, and connected to, the conductive fiber) along with perhaps hundreds of small phased-array-communications and RF-signal-transfer antennas. The LEO-earth connection would be through the microwave phased-array antennas with interconnectivity between these mini-broadcast stations via the optic fiber. These antenna sub-systems are stabilized by, and powered from, the conductive ring. The inter-station fiber links are far superior to any laser or microwave inter-satellite links.
When reliable links between the equatorial-optic-fiber ring and the terrestrial-optic-fiber cables are successfully established, initial cash inflow would begin. The space environment would perhaps allow the use of bare optic-fibers (without cladding) or, at least, thin-clad fibers (without any sheath), thereby reducing their weight and packing volume (and thereby launch and deployment costs).
The communication system would grow with the successive deployment of inclined-orbit rings above fixed ground points (higher-LEO, earth-synchronous rings). Specific rings, catering mainly to the earthquake-prone regions like Japan or to highly-populated regions like India and China, would be such examples. Unmanned robots capable of deploying the fibers and repairing damage to the system would also be deployed in LEO. A LEO fiber-optic cable would be safe, relative to submarine optic-fiber cables. The deployment, maintenance, and repair of this communication system would be economical compared to that pertaining to trans-oceanic cables or GEO constellations (and would not exhibit the communications time-delay of the latter). Successful development of this communications system could provide the cash flow for parallel growth of LEO mass-lifter and solar-power systems.
The advantages, options, and economics of the proposed LEO optic-fiber / microwave communication system over existing terrestrial- and space-communication systems (of similar functionality) are dealt with in the paper.
- Abstract document
- Manuscript document
IAC-04-IAA.3.6.2.03.pdf (🔒 authorized access only).
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