"FACETS system can point the satellite like traditional attitude control
systems, and in addition, its flywheels can provide power to spacecraft
payloads at levels as much as 10 times as a traditional battery-based
energy storage subsystem," said Dr. Brian Wilson, a Space Vehicles
Directorate electrical engineer working on the experiment. "The
frictionless magnetic bearings employed in the flywheel energy storage
subsystem give FACETS the ability to operate on-orbit for about twice as
long as a satellite using chemical batteries."
For decades, rotational disks (flywheels) have been employed as
spacecraft positioning devices, but have not extensively been considered
for power purposes. The success of the Flywheel Attitude Control, Energy
Transmission, and Storage (FACETS) system’s unique trial could change that
perspective.
"I’m definitely looking forward to demonstrating the combined energy
storage and attitude control capability of FACETS and showing the
feasibility of something that has never been done before," said Dr. Jerry
Fausz, FACETS program manager, AFRL’s Space Vehicles Directorate.
Completed in February 2006, the mini-Agile Multi-Purpose Satellite
Simulator (mini-
AMPSS) is a three-degree-of-freedom structure weighing over a ton.
Affixed on a pressurized air bearing, it serves as the testbed for the
FACETS units, which will be mounted on it. Built under contract with
Honeywell, the tri-flywheel arrangement will be used to store energy as
momentum, supplying power through an electromagnetic drive system. The
FACETS contains a device, similar to a car alternator, which will convert
rotational power into electricity to operate a spacecraft’s payloads. To
maintain a satellite’s attitude control, the system will also possess the
capability to change the flywheel speed and spin axis to point mini-AMPSS
in a different direction.
"The FACETS experiment represents the first full-scale, three
degree-of-freedom, mission-traceable, ground demonstration that introduces
the Air Force to this new concept of combined energy storage and attitude
control," said Dr. Wilson. "Our successful demonstration will mature the
technology through its adolescence. The excitement generated by this
groundbreaking demonstration could lead to a flight experiment, further
maturing the FACETS system. These are the first steps necessary in the
ultimate transition of the FACETS technology to military and commercial
customers in the greater aerospace community."
On the Web (links open in a new window):
Air Force Research Laboratory