Environmental Engineering Reference
In-Depth Information
Formation flying concepts have been identified as the canonical means for
achieving very large apertures in the space environment. (It should be noted
that, as with other types of constellation mission, formation flying presents an
opportunity to create a synergistic system (e.g., an imaging system) where the
members of the group operate cooperatively to give rise to group capabilities
that no single platform could provide by itself. Further, as with other types
of constellation mission, the mission can be designed, in many cases, so that
the loss of a member leaves the remainder of the group functioning. In the
alternative mission design, based on using a single large spacecraft, the loss
of the spacecraft means losing the entire mission.)
In a representative formation-flying concept for an astronomical observa-
tory, the formation itself creates the effect of a large “instrument” whose
aperture can be changed along with range to target by maneuvering the
formation - which presents several issues in control:
•
Timing
•
Timing knowledge accuracy and synchronization
•
Positioning
•
Positioning and timing knowledge confidence
and these, in turn, raise issues of:
•
Performing inter-satellite communications
•
Relaying data
•
Commanding via a master control
Such control issues generally have no possible solution apart from an au-
tonomous mechanism (e.g., laser cross-links between the members of the for-
mation to permit minute, near-instantaneous relative position adjustments on
a scale measured by the diameter of an atomic nucleus), and for similar rea-
sons (inadequate ability of humans to deal with distant or rapidly occurring
phenomena), some level of autonomicity will be required for the system's sur-
vival and viability when, for example, the system experiences the effects of a
threat that was not predicted.
Autonomic satellite designs will make major contributions to resolving
these issues. Each design should be approached first from the viewpoint of
constellation architecture, considering the control options available.
9.5 Intelligent Agents in Space Constellations
For single-agent systems in domains similar to space, intelligent machine learn-
ing methods (e.g., reinforcement learners) have been successfully used and
could be used for single-spacecraft missions. However, applying such solu-
tions directly to multiagent systems often proves to be problematic. Agents
may work at cross-purposes, or have diculty in evaluating their contribu-
tion to achievement of the global objective, or both. Constellations based on
