Gonets-D were the prototypes of a civilian derivate of the military Strela-3
satellite system. The Gonets system was offered to support international health
organizations to meet their global communications needs for the transfer of
medical data and records to remote sites.
The operational Gonets-D1 was to
be deployed in a constellation of 12 satellites consisting of 6 satellites in 2
orbital planes between 1996 and 1998. Each satellite had a single simultaneous
earth-space and space-earth channel. On-board storage was 12 Mbits of data, with
a transmission rate of 2.4 kbit/sec. Attitude control was achieved through
gravity-gradient stabilization. The electrical power system, provided by solar
cells and nickel-hydrogen batteries, provided an average 40 W for the payload
which was designed to operate for five years.
A partial D-1 constellation was completed and operated beyond the projected
dates of termination. The satellites were launched on Tsyklon-3
boosters, sharing the launch with Strela-3 satellites.
In the commercial variant, the satellites, known as Gonets (Messenger), were
capable of store-dump communications on 2-3 channels in the 2004-400 MHz band
with a transmitter output power of 10 W. Data transmission rates available
include 2.4 kbits/s, 9.6 kbit/s, and 64 kbit/s with an onboard storage capacity
of 8 Mbytes. A handheld user terminal (UT-P) resembles a cellular phone and
weighs only 1-3 kg. Finally the 250 kg Gonets were to be deployed at 1,350 km at
82.5 degrees, similar to the Strela-3
satellites, but distributed among six orbital planes for a total constellation
of 36 spacecraft. This infrastructure would ensure a mean communication waiting
time of less than 20 minutes with more than 80% probability.
