**Last modified:***Sunday, 10 July 1994***Source code: mace-domain.lisp****List of other known theories**

The Simplified MACE Model. MACE is a satellite design.The model is composed of three major subsystems: structure, attitude control unit, and pointing systems. The structure is a flexible segmented tube, or bus, about 1.5 meters long. The bus is divided into four polycarbonate tubular struts, with each strut threaded into two cubic aluminum nodes. Each face of any particular node has fittings for attaching a strut or other instruments.

The attitude control unit is a single torque wheel mounted to the node at the center of the bus. A single-axis rate gyroscope package is attached on the opposite side of the center node to provide inertial attitude information. When the gyro indicatea that the structure is rotating, the wheel will be accelerated or decelerated, preventing the structure from spinning out of control during experiments.

High precision single-axis pointing mechanisms are mounted on either end of the bus. These gimbals will slew payloads to conduct pointing and tracking tests. Each payload contains a single-axis rate gyro package, giving the gimbal mechanism access to the payload's inertial position and allowing the payloads to be pointed independent of bus orientation. Each gimbal can point its payload roughly within a 120 degree included angle, that is, each payload can move +-60 degrees away from vertical, in two directions.

To conduct active control experiments, a plain strut can be easily swapped for a segment fitted with piezoelectric actuators. The replacement strut can have various cross sections, giving freedom to the type of active control desired for a particular experiment. The total weight of the system is projected at about 60 pounds.

The main intent is to be able to point or track with one of the payloads while the other payload is also moving. Any slewing gimbal will transmit vibration through the bus, affecting the performance of the opposite payload. With this test article, we can examine various methods for suppressing the bus vibration in order to increase the overall pointing and tracking performance of the individual gimbals.

Components-With-ConstraintsMechanical-ComponentsUnary-Scalar-Functions

**No theories include Mace-Domain.**

AlphaBuslengthDelta-1Delta-2Gimbal-1-AngleGimbal-1-TorqueGimbal-2-AngleGimbal-2-TorqueWheel-AngleWheel-TorqueXY

Actuator-BaseBus-AssyGimbal-1Gimbal-1-BaseGimbal-1-PlatformGimbal-2Gimbal-2-BaseGimbal-2-PlatformGroundPayload-1Payload-2Planar-MaceTorque-WheelTorque-Wheel-Assy

**The following constants were used from included theories:**

******defined as a***function***in theory***Kif-Numbers********defined as a***function***in theory***Basic-Matrix-Algebra********defined as a***function***in theory***Physical-Quantities********defined as a***function***in theory***Scalar-Quantities********defined as a***function***in theory***Tensor-Quantities********defined as a***function***in theory***Unary-Scalar-Functions****-***defined as a***function***in theory***Kif-Numbers****-***defined as a***function***in theory***Basic-Matrix-Algebra****-***defined as a***function***in theory***Physical-Quantities****-***defined as a***function***in theory***Tensor-Quantities****Applied-Torque***defined as a***function***in theory***Mechanical-Components****Arity***defined as a***function***in theory***Frame-Ontology****Basis.Vec***defined as a***function***in theory***Tensor-Quantities****Documentation***defined as a***relation***in theory***Frame-Ontology****Domain***defined as a***relation***in theory***Frame-Ontology****Dot***defined as a***function***in theory***Tensor-Quantities****Function***defined as a***class***in theory***Kif-Relations****Has-Parameter-Slot***defined as a***relation***in theory***Components-With-Constraints****Instance-Of***defined as a***relation***in theory***Frame-Ontology****Mechanical-Component***defined as a***class***in theory***Mechanical-Components****Orientation***defined as a***function***in theory***Simple-Geometry****Parameter-Slot-Of***defined as a***relation***in theory***Components-With-Constraints****Position***defined as a***function***in theory***Simple-Geometry****Range***defined as a***relation***in theory***Frame-Ontology****Reference-Frame***defined as a***function***in theory***Mechanical-Components****Reference-Point***defined as a***function***in theory***Mechanical-Components****Scalar-Quantity***defined as a***class***in theory***Scalar-Quantities****Simple-Rotation***defined as a***function***in theory***Simple-Geometry****Subcomponent-Of***defined as a***relation***in theory***Component-Assemblies****Time-Quantity***defined as a***class***in theory***Unary-Scalar-Functions**

**All constants that were mentioned were defined.**

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