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At least 289 records · Page 16

The Orion Exploration Flight Test Post Flight Solid Particle Flight Environment Inspection and Analysis

Orbital debris in the millimeter size range can pose a hazard to current and planned spacecraft due to the high relative impact speeds in Earth orbit. Fortunately, orbital debris has a relatively short life at lower altitudes due to atmospheric effects; however, at higher altitudes orbital debris can survive much longer and has resulted in a band of high flux around 700 to 1,500 km above the surface of the Earth. While large orbital debris objects are tracked via ground based observation, little information can be gathered about small particles except by returned surfaces, which until the Orion Exploration Flight Test number one (EFT-1), has only been possible for lower altitudes (400 to 500 km). The EFT-1 crew module backshell, which used a porous, ceramic tile system with surface coatings, has been inspected post-flight for potential micrometeoroid and orbital debris (MMOD) damage. This paper describes the pre- and post-flight activities of inspection, identification and analysis of six candidate MMOD impact craters from the EFT-1 mission.

Miller, Joshua E.↗

Advanced in In Situ Inspection of Automated Fiber Placement Systems

Automated Fiber Placement (AFP) systems have been developed to help take advantage of the tailorability of composite structures in aerospace applications. AFP systems allow the repeatable placement of uncured, spool fed, preimpregnated carbon fiber tape (tows) onto substrates in desired thicknesses and orientations. This automated process can incur defects, such as overlapping tow lines, which can severely undermine the structural integrity of the part. Current defect detection and abatement methods are very labor intensive, and still mostly rely on human manual inspection. Proposed is a thermographic in situ inspection technique which monitors tow placement with an on board thermal camera using the preheated substrate as a through transmission heat source. An investigation of the concept is conducted, and preliminary laboratory results are presented. Also included will be a brief overview of other emerging technologies that tackle the same issue. Keywords: Automated Fiber Placement, Manufacturing defects, Thermography

Juarez, Peter D.↗

Post-Test Inspection of NASA's Evolutionary Xenon Thruster Long-Duration Test Hardware: Discharge and Neutralizer Cathodes

The NEXT Long-Duration Test is part of a comprehensive thruster service life assessment intended to demonstrate overall throughput capability, validate service life models, quantify wear rates as a function of time and operating condition, and identify any unknown life-limiting mechanisms. The test was voluntarily terminated in April 2014 after demonstrating 51,184 hours of high-voltage operation, 918 kg of propellant throughput, and 35.5 MN-s of total impulse. The post-test inspection of the thruster hardware began shortly afterwards with a combination of non-destructive and destructive analysis techniques, and is presently nearing completion. This presentation presents relevant results of the post-test inspection for both discharge and neutralizer cathodes.

Lifetime↗

Status of the Post Flight MMOD Inspection Campaign for the SpaceX Cargo Dragon

The SpaceX Cargo Dragon has been flying supply missions for NASA to the International Space Station (ISS) since 2012. At the time of this writing, SpaceX has completed 14 missions to ISS with each returning to Earth via water landing. After each mission, a team from the NASA Johnson Space Center performs an inspection of the exterior surfaces of the Cargo Dragon spacecraft for hypervelocity impact damage features. Data from these inspections are collected into a database that includes impact feature dimensions as well as the location on the vehicle. Additional details on the type and size of particle that produced the damage site are pro-vided when sampling data and definitive spectroscopic analysis results are available. Observation data can be compared with impact estimates from risk assessment codes as a check on the micro-meteoroid and orbital debris (MMOD) environment predictions.

Hyde, James L.↗

Advanced Inspection System: Integrating Robotic Configurations & Controls

The Advanced Inspection System (AIS) promotes the ability to perform field inspections and repairs remotely by operator command. The robotic system is required to be a fully autonomous operation, managed by computer execution of scripts with limited user control. AIS is a complex yet intriguing challenge in which various goals must be reached to achieve complete autonomy. The first steps to building such a system require human computer interactions and computer simulations for testing and verification. Such applications include the use of a wireless video game controller via Bluetooth Technology and the use of Leap Motion, a gesture based motion controller which can be used to manipulate robotic arm movements. Utilizing the Robotic Operating System (ROS) environment, these applications, in accordance to developing a 3D simulation of the system, will provide a foundational test bed for AIS development.

Wlodarczyk, Stephan J.↗

In-situ Inspection of Reflowable-Interface Composite Joints During Cure in an Autoclave

In structural bonds, the interface between adherend and adhesive is nearly two-dimensional making it susceptible to minute quantities of contamination, which can cause weak bonds. Regulatory organizations such as the Federal Aviation Administration (FAA) often require redundant load paths in secondary-bonded, primary-structures to alleviate concerns with bonded performance. Under NASA’s Convergent Aeronautics Solutions (CAS) project, the Adhesive Free Bonding of Composites (AERoBOND) project is investigating reformulated aerospace epoxy-matrix resins to enable reflow and diffusion of the resin at the joint interface during a secondary bonding and cure process. The reflow and intermixing of the matrix resin during assembly can eliminate the material discontinuity at the interface, thereby removing the dependence of bond performance on adhesion at a nearly two-dimensional boundary. AERoBOND process development has evaluated a multitude of parameters including the materials used, the stoichiometric offset of the epoxy resins, time and temperature of cure, and thickness of each ply. Without in-situ process monitoring, the condition of a test article is unknown until mechanical testing is completed. This presentation describes the use of an in-situ ultrasonic inspection system to monitor the joining of two composite parts assembled using the AERoBOND technique. This work quantifies the elimination of the interface by measuring the wave reflection, or lack thereof, at the joint throughout the cure cycle. In addition, the results indicate when reflow and cure of the epoxy resin at the joint occurred. By using the recently developed in-situ inspection with a mobile ultrasonic transducer, localized results can be obtained across a large portion of the joint with high resolution.

Tyler B Hudson↗

In-situ Inspection of Reflowable-Interface Composite Joints During Cure in an Autoclave

In structural bonds, the interface between adherend and adhesive is nearly two-dimensional making it susceptible to minute quantities of contamination, which can cause weak bonds. Regulatory organizations such as the Federal Aviation Administration (FAA) often require redundant load paths in secondary-bonded, primary-structures to alleviate concerns with bonded performance. Under NASA’s Convergent Aeronautics Solutions (CAS) project, the Adhesive Free Bonding of Composites (AERoBOND) project is investigating reformulated aerospace epoxy-matrix resins to enable reflow and diffusion of the resin at the joint interface during a secondary bonding and cure process. The reflow and intermixing of the matrix resin during assembly can eliminate the material discontinuity at the interface, thereby removing the dependence of bond performance on adhesion at a nearly two-dimensional boundary. AERoBOND process development has evaluated a multitude of parameters including the materials used, the stoichiometric offset of the epoxy resins, time and temperature of cure, and thickness of each ply. Without in-situ process monitoring, the condition of a test article is unknown until mechanical testing is completed. This presentation describes the use of an in-situ ultrasonic inspection system to monitor the joining of two composite parts assembled using the AERoBOND technique. This work quantifies the elimination of the interface by measuring the wave reflection, or lack thereof, at the joint throughout the cure cycle. In addition, the results indicate when reflow and cure of the epoxy resin at the joint occurred. By using the recently developed in-situ inspection with a mobile ultrasonic transducer, localized results can be obtained across a large portion of the joint with high resolution.

Tyler B Hudson↗

In-situ Inspection of Reflowable-Interface Composite Joints During Cure in an Autoclave

In structural bonds, the interface between adherend and adhesive is nearly two-dimensional making it susceptible to minute quantities of contamination, which can cause weak bonds. Regulatory organizations such as the Federal Aviation Administration (FAA) often require redundant load paths in secondary-bonded primary-structures to alleviate the inability to certify bonded performance. To address this issue, the NASA Convergent Aeronautics Solutions (CAS): Adhesive Free Bonding of Composites (AERoBOND) project is investigating reformulated aerospace epoxy-matrix resins to enable reflow and diffusion of the resin at the joint interface during a secondary bonding and cure process. The reflow and intermixing of the matrix resin during assembly can eliminate the material discontinuity at the interface, thereby removing the dependence of bond performance on adhesion at a nearly two-dimensional boundary. AERoBOND process development has evaluated a multitude of parameters including the materials used, the stoichiometric offset of the epoxy resins, time and temperature of cure, and thickness of each ply. Without in-situ process monitoring, the condition of a test article is unknown until mechanical testing is completed. This paper describes the use of an in-situ ultrasonic inspection system to monitor the joining of two composite parts assembled using the AERoBOND technique. This work quantifies the interface by measuring the wave reflection, or lack thereof, at the joint throughout the cure cycle. In addition, the results indicate when reflow and cure of the epoxy resin at the joint occurred. By using the recently developed in-situ inspection method with a mobile ultrasonic transducer, localized results can be obtained across a large portion of the joint with high resolution.

Tyler B Hudson↗

High Resolution Computed Tomography Inspection of Components Uncovers Root Causes of Vexing Failure Mysteries

During testing of actuators for fight programs, failures have occurred that required closure with an understanding of the root cause of the failure. For some InSight project actuators, intermittent changes of the winding resistance of the motors during temperature changes was extremely baffling. It was critical to determine the cause of the intermittent characteristic because the actuators were stock from a previous program and the company that provided the motors was no longer in business. Using an X-Ray Computed-Tomography (CT) method, the exact source of the intermittent failure was determined and completely understood – at dimensions of less than 20 microns. In another case, after the completion of an actuator’s life-test-to-failure, inspection was required to determine the source of the failure. The size of the actuator (10 mm diameter) required destructive means to get to the interior of the actuator for inspection, risking the loss of the source of the failure. Using CT imaging, the exact source of the failure was determined.

Johnson, Michael R.↗

Machine Learning for Extravehicular Mobility Unit (EMU) Glove Inspections

The Extravehicular Mobility Unit (EMU) Glove Machine Learning Inspection project utilizes machine learning to expedite the inspection, analysis, and recommendation for continued use of space suit gloves post spacewalks. Today, ISS glove photos are individually reviewed by a team of experts to determine the conditions of space suit gloves. For this project the Microsoft Azure platform is used to perform Automated Machine Learning (AutoML) to detect issues with tagged images from previous Extravehicular Activities (EVA’s) to build a predictive model. The model analyzes a test image and deems the glove GO or NO-GO for additional EVA’s. The goal for this ML project is to decrease the time spent reviewing images by ground personnel and crewmembers in high frequency EVA locations such as the Moon and Mars. For destinations such as the Moon and Mars the goal is to give crew autonomy in determining glove conditions with limited support from Earth. This paper will outline the results to date and future work needed to expand the capability for in-situ recommendations.

EVA↗

Wire Rope Inspection Report Safety Division, Code 360

The purpose of this report is to review Federal Regulations, Voluntary Consensus Standards (VCS), and best practices associated with WRI requirements within the government and industry. This report provides an analysis to NASA Headquarters regarding the limited risks that wire ropes present to the Agency based on the interpretation of Section 29 CFR 1910.179 (m) of the Occupational Safety and Health Administration (OSHA) requirements that allow inspections of OHC wire rope based on the operational status of the crane. This report also provides details and recommendations for the reduction of personnel exposure to safety risk associated with working at heights while inspecting wire rope on inactive lifting devices.

Wire Rope↗

Ultrasonic Inspection During Autoclave Cure of Reflowable-Interface Composite Joints

In structural bonds, the interface between adherend and adhesive is nearly two-dimensional making the interface susceptible to minute quantities of contamination, which can cause weak bonds. Regulatory organizations such as the Federal Aviation Administration (FAA) often require redundant load paths in secondary-bonded primary-structures due to uncertainty in bond performance. To address this issue, the NASA Convergent Aeronautics Solutions (CAS): Adhesive Free Bonding of Composites (AERoBOND) project is investigating reformulated aerospace epoxy-matrix resins to enable reflow and diffusion of the resin at the joint interface during a secondary bonding and cure process that can eliminate the material discontinuity at the interface. Implementing in-situ process monitoring enables assessing the bond quality during processing rather than waiting for post-fabrication mechanical testing to be completed. In this paper, an in-situ ultrasonic inspection system is used to monitor the joining of three composite laminates assembled using the AERoBOND technique. For each panel, the amplitude of the wave reflection at the joint was measured throughout the cure cycle. The results indicate the timing and extent of reflow and cure of the epoxy resin at the joint. Factors indicating end of cure were ascertained and a metric was developed to qualitatively predict acceptable mode-II fracture toughness based on the ultrasonic amplitude at the joint line during cure. In addition, since the inspection system scans an area of the joint, high-resolution localized results can be obtained across the joint.

Tyler B Hudson↗

Agency Additive Manufacturing (AM) Certification Support Team (AACT) Risk Reduction – Safe Life Category: Fracture Control Framework for Un-inspectable Fracture Critical AM Parts

The NASA Engineering and Safety Center (NESC) was requested to support the development of a governing philosophy to provide a consistent and systematic approach for fracture control certification of additive manufacturing (AM) hardware that cannot be reliably inspected. The overall goal of the NESC assessment was to make progress toward a framework for general certification of un-inspectable fracture critical AM hardware and toward approaches for evaluating risks associated with these components. This report contains the results of the assessment.

Additive Manufacturing↗

2023 Land Use Control Inspections Report

2023 Land Use Control (LUC) Inspections Report for John F. Kennedy Space Center (KSC), Florida. This letter report documents the quarterly LUC inspections the KSC Remediation Group conducts at Remediation Sites. No LUC findings occurred in 2023. A Corrective Action to address arsenic-impacted soil at the KSC Child Development Center was performed in July 2023. This letter report provides a summary and documents the field activities for that Corrective Action. Copies of the formal LUC Implementation Plans (LUCIPs) for 71 Remediation Sites at KSC are presented in this letter report. For the Remediation Sites that do not have formal LUCIPs, the report documents that informal LUCs that the Remediation Group has implemented at these sites.

Christopher Adkison↗