Senior Design Team 3 Ron Capalbo, Brittany Russo, Matthew Holt, Elizabeth Keighley Sponsored By: NASA ESMD Senior Design Program & WANTS/NEEDS/CONSTRAINTS: Cost is a constraint; the prototype tester must cost less than or equal to $5,000. Size – Must fit on a bench top Repeatability- Repeatable, consistent results under the same parameters were required. Simplistic Operation- The tester must be operator independent Manufacturability- The tester should be able to be reproduced in a timely manner. BENCHMARKING Original Space Suit Dust JSC in Houston, TX Other Testers Researched Included: Mechanical Boot Tester RoTap Sieve Shaker (UD Geological Dept.) Bearing Testers Abrasion Testers Concept Selection & Design Details A modifiable tumbler was the concept chosen for this project because of its simplistic design and great modifiability. All components for assembly were able to be commercially ordered. The unique feature that separates the original tester from our design is the incorporation of interchangeable drums with varying internal geometries to achieve specific mechanisms. Final Drum Designs Nearly the entire lunar surface is covered in regolith. Regolith is highly detrimental to the spacesuit & therefore very problematic for an astronaut. PERFORMANCE GOALS Different drums were designed to target each of the defined mechanisms as well as randomness. Two of these drums were built within the scope of Senior Design. VIRTUAL To REAL-LIFE  The Randomizer Drum  The Impact Drum Final Machine Design Future Drum Design Ideas: The Abrasion Drum Geometry: circumscribed square within drum Allows sample to slide down each wall, maximizing friction force The Penetration Drum Ridged inner ring all the way around drum Creates vibratory cutting These preliminary designs will be handed to ILC for future development & fabrication. Geometry: Drum with 3 Different Sized Internal Baffles Allows the Material to Experience Differing Levels of All Mechanisms Geometry: 2 Parallel Planes Adhered to Walls of Drum Carries the sample to the top of the drum, and then drops it creating impact  Team 3’s Scope: To design and fabricate a fixture that can apply impact & mechanism randomness in a sand & aggregate- challenged environment to representative materials that provides repeatable, qualitative,& quantitative results. PROBLEM DEFINTION MetricsTarget Values Stress (Abrasion)Between 1-4 lbf/in. 2 Impact EnergyBetween 1-6 (lbf*ft)/in. 2 Time To Change Inputs<5 Hours Amount of Escaped Sand 0 Leakage Footprint of Test Fixture ft 3 Time for Complete Device Setup <8 Hours (Full Workday) VALIDATION TESTING Two Main Categories of Testing Were Performed: 1. HAND TESTS: A bucket filled with sand was placed on a force sensor plate. Various test fabrics attached to known weights were dropped into the sand. By doing this, we understood what kinds of force values were needed for different levels of damage. 2. TUMBLER TESTING Mass of the material, speed of the drum, and size of sand particles was altered during testing. By showing that the same damage occurred after like trials, the repeatability of our device was validated. Damage Scale: 1=Low, 5=Moderate, 10=High