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- N-1-3-020.22, "Science Knowledge Sharing", by Wendy D. White,
- <WWHITE%NAS.BITNET@vtvm2.cc.vt.edu>
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- In this column, we are exploring how information and communication
- technologies can be used by developing country scientists to share
- knowledge.
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- Several low-cost, computer-based technologies -- other than the
- Internet -- are available today to help scientists communicate. For
- example, they can use the services of low-earth-orbit satellites to
- communicate with colleagues around the world. These satellites weigh
- as little as 100-pounds and cost about $1 million to manufacture,
- compared to the $250 million it takes to manufacture a traditional
- satellite. Ground stations, which are personal computers linked to
- radios, provide access to the satellite.
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- Volunteers in Technical Assistance (VITA) has led the way in using
- this technology. Their "orbiting mailbox," a satellite-borne
- communications device, passes over earth at an altitude of 500 miles.
- Each orbit takes approximately 100 minutes so that every place on
- earth is within the satellite's "footprint" at least twice a day.
- When the satellite is in receiving distance over a ground station, the
- station uploads messages for storage in the satellite's memory and
- similarly downloads messages or computer files. The satellite will
- "store and forward" the new messages from the ground station to their
- destination.
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- Using this technology, SatelLife has recently launched a project to
- create a global health network. This project will link medical
- centers and health care providers throughout the world. The pilot
- project will include ground stations in five East African countries.
- Health professionals in the United States and Canada will participate
- by logging on to electronic mail networks linked to the North American
- gateway in Newfoundland.
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- The ground stations receive and transmit "packets" of digitized
- computer information as radio waves. Packet radio stations may be
- powered by batteries or solar cells. Thus, they have great potential
- applications in remote areas in developing countries where
- conventional grid power and telephones are unavailable. When packet
- radio is linked to such a low-earth-orbit satellite as the one used by
- VITA and SatelLife, it becomes a ground station for global
- communications. An entire station costs between $4,000 and $6,000:
- relatively cheap, especially considering that computers and radios can
- be used for other purposes when not linked to the satellite.
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- Use of the low-earth-orbit satellite is at the prototype stage;
- networks of operational satellites and ground stations will eventually
- be used by disaster relief and development organizations where rapid,
- accurate communications are required. Scientists, too, can use these
- networks to decrease their isolation.
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