Previous Lecture Next Lecture Home Classes Contact Lecture 5: Interface Verification and Testing For additional details, refer to the appropriate Interface Definition Documents (IDD) for the carrier of interest: Middeck IDD: http://shuttlepayloads.jsc.nasa.gov/data/PayloadDocs/PayloadDocs.htm Spacehab IDD: http://www.boeing.com/nosearch/sh_verification/ ISS IDD http://stationpayloads.jsc.nasa.gov/J-reference/documents/ssp57000E.pdf EXPRESS IDD: SSP 52000-IDD ERP Payload Safety: NASA JSC PSRP (Payload Safety Review Panel) http://jsc-web-pub.jsc.nasa.gov/psrp/ Toxicology: NASA JSC Toxicology http://www.jsc.nasa.gov/toxicology/ Station Documents: http://stationpayloads.jsc.nasa.gov/J-reference/ Document Tree Testing / Interface Verifications Functional Testing Nominal Systems Functionality / Complex system interactions / experiment-facility interaction Environmental compatibility (temperature, vacuum, acceleration/microgravity, radiation) Off-nominal responses (safety, backup/redundancy, overheat, overpressure, communication loss, etc.) Science Verifications Science compatible with Spaceflight Operational Environment ? – Sanity Check ! Science in hardware validation ? Procedure / protocol verifications / science return (preparation - launch to landing – analysis) Compatibility verifications (bio-compatibility, operational constraints, sensitivity, environment: atmosphere, pressure, temperature, microgravity) Interface Verification Interface Verifications - verify proper function and connectivity between experiment and facility (connectors, power, data, video, fluids, ...) Test Requirements: http://jsc-web-pub.jsc.nasa.gov/psrp/docs/7002.pdf Structural Compatibility Vibrational Loads – “shake test” Acceleration (launch, landing, crash) – analytical, centrifuge Eigenfrequencies – analytical, “shake test” Microgravity disturbance - testAcoustics: Acoustic Emissions Acoustic Susceptibility Containment – depressurization: Vented Container - Vent Rate Analysis Sealed Container – Structural Integrity under combined loads (pressure + temperature, etc.) 1. Nominal Ops 2.0 psi/min Repressurization/Depressurization 2. Contingency (other than Bailout) 9.0 psi/min Depressurization/Repressurization 3. Emergency Bailout Requirements: Payloads located within the crew compartment area shall be designed to meet the following depressurization requirements in order to insure they will not present a hazard to the crew or to the Orbiter which could jeopardize crew survivability or impede crew egress during emergency bailout procedures: Initial (Max) 15.2 PSIA / Final (Min) 3.95 PSIA / Max Depressurization Rate 24.0 PSI/Minute Human factors Push-off (kick-ff): 125 lbf over 4”x4” area (foot) Max. Limits of necessary force to actuate / manipulate Electrical Compatibility Connector (pins=unpowered, sockets=powered, recessed), Pin Assignments Signal / power / interface compatibility (voltage, softstart, baud rate, data format, ....) Wire Size Analysis / Fusing (fire / over-heat) Power Draw (current limit) , Energy consumption (fuel / battery limit) Electromagnetic Compatibility EMC: Electromagnetic Emissions / Interference (EMI) Electromagnetic Susceptibility Batteries – stored energy, hazardous electrolytes, toxic combustion products (Lithium batteries). Materials Utilization: Flammability (MIUL) note: 30% O2 (pre-breath prior to EVA) or 100% O2 (EVA suit) changes flammability characteristics Offgas / Toxicity (MIUL): SMAC: Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants SWEG: Spacecraft Water Exposure Guidelines for Selected Waterborne Contaminants Corrosion (MIUL) Materials Compatibility (safety: containment, corrosion, science: biocompatibility)Experimental Fluids / Samples: Toxicity (health of astronauts) Restricted materials (example: alcohol) Ionizing radiation (isotope markers) Thermal Compatibility Heat Rejection Max. / Min allowable temperatures (touch, bare skin) Condensation Safety Verification Payload Safety at JSC: http://jsc-web-pub.jsc.nasa.gov/psrp/ Flight Safety – Payload Safety Review Panel (PSRP) Ground Safety – Ground Safety Review Panel (GSRP) OSHA, lab safety, handling, pressure, electric, hoisting,..... Science Verification Flight Access: Late Launch / Early Retrieval • Space Life Sciences: load as late as possible: limited shelf life: L-24 hrs. • Retrieve as early as possible: typically within 4 hrs. of landing. • Sample preparation: unique facilities on site (KSC), sample shipment (safety limitations) • Sample retrieval: backup landing sites • Sample preservation: ISS cargo flight delay / on-orbit duration Flight Phases • Launch/Landing: limited heat rejection / limited power availability / outlets (reduce power / unpowered; passive experiments) • EVA mission reduced pressure = reduced heat rejection / hotter environment Crew Access – Automation vs. Crew Operated • Detailed planning for schedule, resources, timeline, procedures (nominal and off-nominal)• Shuttle: first and last mission day very busy or debilitating (space sickness) ISS: docked operations very busy (loading/unloading) • Sleep, eat, house-keeping, scheduling, delays due to trouble-shooting; weekend ‘off’ • Inaccessibility of astronaut / intermediate layers of bureaucracy • Complex operations: safety, interfaces etc. – limited flexibility Materials Compatibility Testing / ‘experience’ • Biocompatibility 1. Offgassing (internal, external, biogenically produced/accumulating in sealed environment) 2. Contamination (heavy metals in solution, cleaning agents, fungus / bacteria) 3. Corrosion by-products 4. Related resources: Biocompatibility: Assessment of Medical Devices and Materials. 5. Humans / Animals: better characterized than plants; 6. Tighter Sealed Environment – potential accumulation / concentration. • Materials Compatibility 1. Corrosion (exposure duration, temperature, concentration) 2. Electrochemical, Oxidation, Stress Corrosion 3. Cleaning / Sterilization processes (temperature, pressure, chemicals/solvents) 4. Materials Compatibility examples: http://www.coleparmer.com/techinfo/ChemComp.asp http://www.rtpcompany.com/info/guide/resistance.htm http://www.upchurch.com/TechInfo/ChemSelect.asp Toxicological Assessment: http://www.jsc.nasa.gov/toxicology/ Assessing and documenting the health hazards of specific potential contaminants of