Prostate Specific Antigen Public Service Announcement Post Shakedown Availability Port Support Activity Principal Staff Assistant Probabilistic Safety Assessment Problem Statement Analyzer Professional Services Automation Public Service Agreement Pressure Switch Assembly Pacific Science Association Payload Support Avionics Power Servo Amplifier Power Servo Assembly Pressure Sensitive Adhesive Pressure Swing Adsorption probabilistic safety analysis Probe Support Avionics Product Safety Association prostate-specific antigen Protected Service Area Payload Service Area Personnel Support Activity phase shift analysis Pipeline Safety Act Pisum sativum agglutinin Point of Service Activation Polysilicon Self-Aligned Portfolio Systems Acquisition Post-Sleep Activity