| Summary
Enhanced formation flying (EFF) technology, for onboard
autonomous constellation and formation flying control,
will enable a large number of spacecraft to be managed
with a minimum of ground support. The result will be a
group of spacecraft with the ability to detect errors
and cooperatively agree on the appropriate maneuver to
maintain their desired positions and orientations. The
EFF technology is applicable to any mission class, be
it low-Earth or Deep Space, that desires to fly multiple
satellites autonomously while gaining the added benefit
of enabling science and reducing mission operations costs.
The EO-1 EFF technology features flight software that
is capable of autonomously planning, executing, and
calibrating routine spacecraft maneuvers to maintain
satellites in their respective constellations and formations.
The EO-1 mission formation flying requirement is that
the spacecraft fly only 1 minute (450 km) behind Landsat
7 in the same ground track and maintain the separation
within 2 seconds. This close separation enables EO-1
to observe the same ground scene through the same atmospheric
region so that paired scene comparisons can be made.
Unique features of the EFF technology include an innovative
use of fuzzy logic decision making capabilities and
natural language scripting to resolve multiple conflicting
constraints and to enable algorithm updates without
software changes; flight wrapper that interfaces directly
with the command and data handling subsystem for input
and output; multiple operating modes to allow execution
control; generic closed-loop formation flying control
algorithms that are applicable to many missions; and
a modular architecture design that is flexible enough
to control execution of multiple and varying algorithms
from several partners. |
