Designing Electronic Card Packages Against Shipping Shock

In optimizing packaging design, the product’s fragility is qualified by a protype undergoing quantitative and qualitative tests that rely heavily on past knowledge and experiments. By the addition of finite element analysis (FEA), the product’s fragility can be obtained in the initial stages of product design with material characterization and simulation. FEA can predict Gs on the product as well as examine the strains, which interpret product failure more easily in the design stage. To incorporate FEA, first the foam material was measured at various strain rates under compression. Next a shipping package containing an Al block with consistent density was dropped at different heights—610 mm (24”), 915 mm (36”), and 1067 mm (42”)—to confirm the methodology. An I/O book was packaged for the final demonstration incorporating FEA with an electronic card package. In an electronic card package, the electronic assemblies are sensitive to strains on the system board. If the strains on the board are high, the assemblies’ solder connections to the board could be damaged and result in a defect during shipment. The simulations’ predicted Gs and board strains were compared to experimental drop testing results at 610 mm (24”) and 915 mm (36”). The simulation results for each sensor location were within reasonable approximation of the experimental results, verifying that FEA could be used in the initial design stages to predict the accelerations and strains for packaging development in parallel to the product design.

Strategies for the Control of Visible Particles in Sterile Devices

Currently, limited guidance is available for the contamination control of visible particles for the manufacture of sterile devices; thus, a comprehensive guidance is warranted. Sterile devices require stringent control of visible particulates to ensure proper functionality, performance assurance of sterility, reliability, patient safety, efficacy, and product quality. This paper outlines practical and science-based strategies to prevent/minimize visible particle contamination from non-process related extrinsic and process related intrinsic sources. Witness plates are proposed as a comprehensive strategy for the real time detection of visible particles, sources of extrinsic and intrinsic visible particles, and methods to identify particle types. Implementing the control measures described herein, which include air ionization units for the control and neutralization of static charges, would maximize device yield and quality, thus reducing rework and leading to increased profitability. Installing validated air ionization systems at appropriate manufacturing and processing locations, storage, product transfer areas, and gown-up rooms can significantly reduce visible particle contamination accumulation, dispersion, and yield losses. Implementing effective material transfer practices can further minimize the risk of introduction of unwanted particles and particle dispersion within classified areas. Also described are additional control measures, such as material systems and supply chain controls, good facility design, gowning practices, manufacturing equipment and tool controls, and manual visual inspections which would further contribute to the overall reduction of particle burden. Crucial elements of an effective particle removal process are the dry and wet cleaning processes and the facility surveillance program. Process-product-particle traceability matrices can serve as effective tools to promptly identify trends and reduce device conformity defects. For this paper, the meaning of the term particle only includes particulates and particulate matter. Microbial contamination control approaches, including facility decontamination, are outside the scope of this paper.

Contamination Analyses of ISS Vehicle Visits

The SAGE III Contamination Monitoring Package detects the contamination environment in the immediate vicinity of the payload using eight Thermoelectric Quartz Crystal Microbalance sensors that telemeter continuous beat frequency measurements to the ground. The single greatest source of contamination measured to date was the SpaceX Cargo Dragon, whose outgassed contaminants chemisorbed to the gold electrodes of the sensors. This paper contains results from the mission’s first three years, including the signals observed from every visible visiting vehicle, the measured effects on the overall payload, and learned lessons to consider for future ISS or TQCM missions.

Use of the Velocity Intensity Spectrum to Characterize Transient Data

This paper introduces and develops the Velocity Intensity Spectrum as an analytical tool for examining transient data in the frequency domain. The Velocity Intensity Spectrum is then compared with three common alternatives: the Shock Response Spectrum, the Pseudo Velocity Spectrum, and the lesser-known Shock Intensity Spectrum, upon which it is based. The various techniques are applied to an experimental data set and compared and discussed in a practical manner.

Update of ISO Technical Committee 209 Cleanrooms and Associated Controlled Environments

International Organization for Standardization (ISO) Technical Committee (TC) 209’s first meeting was held in November 1993.The focus was on cleanrooms and controlled environments and the activities within cleanrooms. The TC has moved in recent years to generic operations documents such as a systematic approach for procuring disposables and particle deposition rate monitoring to improve the quality of products manufactured in a cleanroom. ISO stresses development of standards with requirements to support sustainability. A recently published standard on energy management in a cleanroom supports that need. ISO has a range of publication formats with different rigor in balloting to reduce document development being considered by the TC. ISO/TC 209 begins its third decade taking a more integrated approach to standardization with the goal of responding to the needs of industry.

Modernization of NASA Johnson Space Center’s Chamber A to support Cryogenic Vacuum Optical Testing of the James Webb Space Telescope (JWST)

NASA is the mission lead for the James Webb Space Telescope (JWST), the next of the “Great Observatories,” scheduled for launch in 2021. NASA is directly responsible for the integration and test (I&T) program that culminated in an end-to-end cryo vacuum optical test of the flight telescope and instrument module in Chamber A at NASA Johnson Space Center. Historic Chamber A is the largest thermal vacuum chamber at Johnson Space Center and one of the largest space simulation chambers in the world. Chamber A has undergone a major modernization effort to support the deep cryogenic, vacuum and cleanliness requirements for testing the JWST. This paper describes the upgrades to the Chamber A facility: Thermal Shrouds, Helium Refrigeration, Liquid Nitrogen System, High Vacuum System, Clean Airflow System, and Utilities.

Blind to Chemistry: Molecular Contaminant Films We Could Be Missing During Visual Inspections and the Potential Impact to System Performance

Throughout the assembly, integration, and test process, molecular contamination levels of space mission hardware are monitored to meet system performance requirements. Qualitatively, reflective surfaces and witness mirrors are continuously inspected for the visible presence of molecular contaminant films. Quantitatively, periodic reflectance measurements of witness mirrors indicate changes of mirror reflectivity over time due to the accumulation of molecular contaminant films. However, both methods only consider the presence of a contaminant film and not the molecular composition. Additionally, there is a risk that hardware may appear to be “visibly clean” even with a molecular contaminant film present on critical surfaces. To address these issues, experiments were performed to quantify the maximum molecular contaminant film that could be missed in visual inspections on witness mirrors with five different contaminants present. The corresponding changes in mirror reflectivity were modeled using the program STACK to determine the impact to space mission hardware performance. The results of this study not only show the criticality in considering the chemical make-up of molecular contaminant films on system performance, but also the need to recognize and understand the limitations of traditional visual inspection techniques on detecting molecular contaminant films.

Inter-comparison of environmental low-cost sensors on Arduino platform

Low-cost sensors for relative humidity, pressure, and ambient temperature have begun to be used regularly for different applications in which the measurement or control of systems or processes is required using an affordable technology. However, in most cases, reliable information about their performance, capabilities, and limitations is not available. In this work, we aim to establish a systematic comparison between different sensors widely used in conjunction with the Arduino platform, such as the DS18b20, DHT11, BMP180, and BME280 sensors. Laboratory and field trials were performed to determine linearity, accuracy, precision, resolution, response times, and response to loss of power. The results indicate that these devices, despite having a very low cost, can provide relatively reliable information, taking into account their manufacturing characteristics and the specific use required. In turn, this work offers useful information to choose the sensor that best suits a particular project.

TRANSIENT MULTI-DOF VIBRATION TESTING: ANALYTICAL AND EXPERIMENTAL DATA

The HYDRA facility is a very large 6-Degrees-of-Freedom (DoF) hydraulic shaker located in the European Space Research and Technology Centre of ESA in The Netherlands. It has been recently used as test platform to perform a number of innovative, 6-DoF experimental vibration runs with the aim of assessing more flight-representative ways to dynamically qualify a spacecraft, hence reducing the level of conservatism. This paper focuses on the methodology behind the definition of the injected profiles computed by launcher/spacecraft coupled loads analysis, the performance achieved by HYDRA and its state-of-the-art MIMO control system, how the experimental data compare to the simulation ones, and aims also at defining success criteria for 6-DoF transient testing.

Improved Techniques for Uniaxial and Multiaxial Vibration Test Profile Definition

This work aims to improve profile derivation methods for uniaxial and multiaxial vibration testing. Thereby, the focus is put on the inclusion and processing of phase information between the excitation axes. An inherent necessity is the availability of field data. Two existing methods are independently extended by additional phase information and an appropriate processing. The first method is the Fatigue Damage Spectrum for a uniaxial profile derivation. The second method is the enveloping technique for a multiaxial profile derivation. Both methods are theoretically discussed and then evaluated with a fatigue damage calculation of an exemplary structure.