Environmental Engineering Reference
In-Depth Information
that adapt to new conditions, create new responses, or employ state-of-art
methodologies such as state modeling, case-based reasoning, or neural nets
should be hosted within an appropriate agent.
6.1.9 Diagnostic Science Instrument Commanding
If a SI experiences an anomaly within its hardware or embedded software, it
will be necessary to downlink diagnostic data to the ground for analysis. In
that event, as the SI or spacecraft platform may even be in safemode at the
time, it is necessary to provide a “bullet-proof” capability for ground control to
retrieve that diagnostic data, or even send troubleshooting commanding to the
SI to generate additional information needed to solve the problem. To provide
ground control a direct route to the SI for these purposes, the associated
diagnostic SI commanding should also reside within the FSW backbone.
6.1.10 Engineering Data Storage
Just as communications with ground control could be fully autonomous and
handled by Remote Agents (both on the spacecraft and in the ground's lights-
out control center), so too could management of science data collected in the
course of an observation. On the other hand, the main purpose of engineering
housekeeping data is to support fault detection in realtime onboard, as well
as anomaly investigations post facto on the ground. To support these ground
control efforts, which at times are critical to spacecraft H&S, the backbone
should control storage and management of these data.
6.2 Remote Agent Functionality
The Remote Agents have the responsibility for achieving science mission ob-
jectives. They are event-driven, independent modules that operate as back-
ground tasks, which in some flight hardware architectures would be distributed
among multiple processors. These mission-support agents are expected to ne-
gotiate among themselves and cooperate to accomplish higher level goals. For
example, they might strive to achieve optimal science observing eciency by
coordinating the efforts of individual Remote Agents (potentially distributed
between the flight and ground systems) responsible for data monitoring and
trending, science and engineering calibration, target planning and scheduling,
and science data processing.
To ensure the viability of the spacecraft, the FSW is designed such that
individual Remote Agents can unexpectedly terminate functioning without
impacting the FSW backbone. To isolate the agents from the backbone, an
executive agent controls agent communication with the backbone. The band-
width available for agent-to-backbone “conversations” is limited, so as not
