THE MARS SCIENCE LABORATORY ENTRY, DESCENT, AND LANDING INSTRUMENTATION (MEDLI) IS AN INSTRUMENTATION SUITE…

Public award description

THE MARS SCIENCE LABORATORY ENTRY, DESCENT, AND LANDING INSTRUMENTATION (MEDLI) IS AN INSTRUMENTATION SUITE INSTALLED IN THE HEATSHIELD OF THE MARS SCIENCE LABORATORY S (MSL) ENTRY VEHICLE THAT WILL GATHER DATA ON THE ATMOSPHERE AND ON THE AEROTHERMAL, THERMAL PROTECTION SYSTEM (TPS) AND AERODYNAMIC CHARACTERISTICS OF THE MSL ENTRY VEHICLE DURING ENTRY AND DESCENT AT MARS PROVIDING ENGINEERING DATA FOR FUTURE MARS MISSIONS. MEDLI CONSISTS OF SEVEN INTEGRATED SENSOR PLUGS (MISP), WHICH ARE USED TO MEASURE THE TEMPERATURE WITHIN THE HEATSHIELD THERMAL PROTECTION SYSTEM (TPS), AS WELL AS THE RATE OF RECESSION OF THE ABLATING TPS. MEDLI ALSO INCLUDES SEVEN PRESSURE TRANSDUCERS TO MEASURE THE PRESSURE ON THE HEATSHIELD DURING THE MARS ENTRY WHICH TOGETHER FORM THE MARS ENTRY ATMOSPHERE DATA SYSTEM (MEADS). THE FINAL ELEMENT OF MEDLI IS THE SENSOR SUPPORT ELECTRONICS (SSE), WHICH IS USED TO COLLECT, DIGITIZE, AND THEN TRANSMIT THE TEMPERATURE AND PRESSURE DATA TO THE MSL SYSTEM. PYROSHOCK TESTING IS REQUIRED PER THE MSL ENVIRONMENTAL REQUIREMENTS DOCUMENT (MSL 223-0301 REV B). MEDLI IS USING THE PROTOFLIGHT (PF) TEST APPROACH WHICH REQUIRES 1 SHOCK/AXIS. THE TEST FACILITY WILL PROVIDE PYROSHOCK TESTING OF (1) A DESIGNATED MEADS PROTOFLIGHT ASSEMBLY UNIT, AND (2) AN SSE PROTOFLIGHT UNIT. THIS TEST PLAN DETAILS THE TEST OBJECTIVES AND REQUIREMENTS TO EVALUATE THE TEST ARTICLES ABILITY TO WITHSTAND THE PYROSHOCK ENVIRONMENTS ANTICIPATED DURING THE MSL MISSION. TESTING IS CURRENTLY SCHEDULED FOR MARCH, 2008 TIMEFRAME. THE PYROSHOCK TESTS SHALL BE COMPLETED WITHIN 7 BUSINESS DAYS OF RECEIPT OF THE TEST ARTICLES. 2.0 TEST OBJECTIVES THE PRIMARY TEST OBJECTIVE IS TO EVALUATE THE SURVIVABILITY OF THE MEADS AND SSE DESIGNATED PF TEST ARTICLES, WHILE OPERATING, WHEN EXPOSED TO PYROSHOCK LEVELS REPRESENTATIVE OF THOSE ENCOUNTERED DURING THE MSL MISSION. 3.0 TEST REQUIREMENTS 3.1 TEST CONDITIONS THE PROVIDED PYROSHOCK TESTING SHALL CONFORM TO THE NASA PYROSHOCK TEST CRITERIA (NASA-STD-7003). EACH TEST ARTICLE SHALL BE SUBJECTED TO A SYNTHESIZED SHOCK ONCE FOR PROTOFLIGHT IN EACH OF THREE ORTHOGONAL DIRECTIONS WITH THE TEST ARTICLES OPERATING. THE SYNTHESIZED SHOCK WAVEFORM SHALL MEET THE FOLLOWING CRITERIA: THE TIME HISTORY SHALL BE OSCILLATORY IN NATURE, AND THE PULSE SHALL DECAY TO LESS THAN 10% OF ITS PEAK VALUE WITHIN 20 MILLISECONDS. THE DESIRED MAXIMAX SHOCK RESPONSE SPECTRA (SRS) TEST LEVELS FROM THE (IOM 352G-KTL-0718) MSL DOCUMENT, ARE SHOWN IN TABLE 3.1.1. TABLE 3.1.1: MEDLI SHOCK REQUIREMENTS FREQUENCY, HZ LEVEL 100 30 G 100 1600 +10 DB/OCTAVE 1600 10,000 3000 G 3.2 TEST TOLERANCES THE MEASURED MAXI-MAX SHOCK RESPONSE SPECTRUM SHALL HAVE A MINIMUM RESOLUTION OF 1/6 OCTAVE FREQUENCY BAND AND BE CALCULATED USING A Q=10 (PER NASA-STD-7003). FOR A SHAKER TEST, THE SPECTRUM SHALL BE WITHIN +/- 3 DB OF THE SPECIFIED SHOCK SPECTRUM LEVEL. ABOVE 3000 HZ THE LOWER TOLERANCE (-3 DB) MAY BE ELIMINATED, IF THE TEST HARDWARE SHOCK SENSITIVE FREQUENCY IS FAR BELOW THIS FREQUENCY (SINCE WE HAVE MODES IN THE 100 S OF HZ, THIS IS THE CASE). FOR OTHER SHOCK-GENERATING APPARATUS, THE TOLERANCES SHALL BE WITHIN +/- 6 DB, BUT AT LEAST 50% OF THE SPECTRUM VALUES SHALL EXCEED THE NOMINAL VALUES. THE SYNTHESIZED SHOCK PULSE SHALL BE OSCILLATORY IN NATURE AND DECAY TO 10% OF ITS PEAK VALUE IN 20 MILLISECONDS. PRIOR TO MOUNTING FLIGHT HARDWARE, THE FACILITY SHOULD DEMONSTRATE THE REQUIREMENT AND TOLERANCES CAN BE MET WITH AN EQUIVALENT SIMULATED MASS.