S6-S10: Flashcards
Mechanism Subsystems
Thermal, Propulsion, Communication, Payload, Orbit Control, Power
Space Mechanism Special Constraints?
No commissioning or maintenance, zero tolerance for mechanical failure, harsh and multiple environments, limitations on materials.
Two functions of One-shot Devices?
Hold something in place before or after deployment and assist in a predetermined movement.
Separation systems important parameters?
Axial force, lateral (shear) force, bending moment, force flux.
What are the mechanisms for deployable structures?
Telescopic boom, rolled tape, hinge and torsion spring, Lattice mast.
Solar array deployment components?
Hinges, latch up mechanism, hold-down mechanism.
Modes of operation for Intermittently Operated Mechanisms?
Steady-state pointing, re-pointing, tracking.
What are the actuator options for mechanisms?
Motor, springs, piezoelectric, shape-memory actuator.
Draw the design methodology graph.
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Material properties?
Specific strength, specific stiffness, fatigue life, thermal characteristics, availability, cost.
Al-Li alloy properties?
Lower density and higher stiffness than standard Al-Li.
Al-Be properties?
Lower density, higher stiffness, similar manufacturing processes, toxic to machine.
Mg alloy properties?
High specific strength, poor corrosion and fatigue properties.
Titanium properties?
High strength, low density, expensive, difficult to machine.
Important Fiber Characteristics?
Good tensile strength, low stiffness, low cost.
