Bog'liq ebooksclub.org Introduction to Satellite Communication Artech House Space Applications
particularly when the system is operated as a commercial business and requires
outside financing. The general trend toward higher insurance premiums for high-
risk kinds of coverage (not just for satellites) also has contributed to the cost. The
risks associated with launch have always been high, but a good commercial launch
record between 1970 and 1980 made the risks appear to be diminishing. Conse-
quently, launch insurance premiums during that decade were low enough to encour-
age satellite operators to insure not only their investment but expected revenues
as well. That removed most of the business risk from the satellite operator and
placed it in the hands of the major insurance underwriters, notably Lloyds of
London. With Lloyds now largely out of the market, satellite operators have
discovered a new breed of launch insurance underwriters who better understand
the nature of the game.
A recent trend is for satellite operators to receive partial claims when a satellite
can still provide a useful fraction of its design capability. This is one reason why
on-orbit life insurance rates have gone up.
12.4.1.4
TT&C Ground Facilities
As discussed at the beginning of this chapter, the investment cost of TT&C ground
facilities is tied primarily to the equipment block diagram and facilities layout. To
that must be added the fixed cost of providing the needed telecommunications
equipment associated with the ICN. It is a fairly straightforward matter to identify
all the equipment necessary to perform the TT&C functions as well as those
associated with system management. The buildings are designed so that the equip-
ment is properly housed and environmentally controlled. It is also important that
human factors be taken into account, since operations are conducted around the
clock throughout the life of the satellites.
The relative cost of implementing the ground facilities (indicated in Figure 12.3)
is small in comparison with that of any other element. Designing and implementing a
proper ground environment, therefore, is a wise measure, even considering the
extra cost in doing the job right. Placement of equipment for convenient access
and the provision of well-designed operator consoles and support software tend
to reduce personnel costs. It also results in more reliable operation of the satellites
themselves—the proper resolution of problems depends on the capability of the
people who staff the SCC and TT&C station.