N-1-3-020.22, "Science Knowledge Sharing", by Wendy D. White,
<WWHITE%NAS.BITNET@vtvm2.cc.vt.edu>


In this column, we are exploring how information and communication
technologies can be used by developing country scientists to share
knowledge.

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.

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.

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.

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.

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.