Passage to a Ringed World - NASA's History Office

100 PASSAGE TO A RINGED WORLD
The Probe carries two redundant
S-band transmitters, each with its own
antenna. The telemetry in one link is
delayed by about four seconds with
respect to the other link, to prevent
data loss if there are brief transmission
outages. Reacquisition of the
Probe’s signal by the Orbiter would
normally occur within this interval.
Concluding Remarks
The design of the Cassini–Huygens
spacecraft is the end result of extensive
trade-off studies that considered
cost, mass, reliability, durability, suitability
and availability of hardware.
To forestall the possibility of mechanical
failures, moving parts were eliminated
from the spacecraft wherever
feasible. Early designs that included
articulating instrument scan platforms
or turntables were discarded in favor
of body-fixed instruments whose
pointing will require rotation of the
entire spacecraft.
Tape recorders were replaced with
solid-state recorders. Mechanical gyroscopes
were replaced with hemispherical
resonator gyroscopes. An
articulated Probe relay antenna was
discarded in favor of using the highgain
antenna to capture the Probe’s
signal.
Spacecraft engineers, both those
who designed and built the hardware
and those who will operate
the spacecraft, relied heavily on
extensive experience to provide a
spacecraft design that is more sophisticated,
reliable and capable than
any other spacecraft ever built for
planetary exploration. Because of
that care in design, the Cassini–Huygens
spacecraft will be far easier to
operate and will return more science
data about its targets than any prior
planetary mission!