April 2007 Issue

  April 2007
Journal of the IEST

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Complete Tech Talk articles and technical papers’ abstracts (full text by individual sale or subscription)

Photo caption: NASA Goddard Space Flight Center was asked by the National Highway Traffic Safety Administration to test the rollover resistance of sport utility vehicles.

The April issue of the Journal of the IEST offers technical papers as well as complimentary Tech Talk articles. Also in the issue is the original technical paper written by the student who won the Robert N. Hancock Memorial Scholarship provided by IEST. Subjects include sport utility vehicle rollover testing, the Mars Rover environmental test program, the contamination control program for the Hubble Space Telescope, USP 797 compliance, a test method to measure surface cleanliness, IEST-RP-CC012: Considerations in Cleanroom Design, a study on the operational modal analysis of aluminum beams, ISO 14644-5: Operations, a virtual remaining life assessment method for electronic hardware, and the disconnect between environmental testing and aging, long-lived vehicles.

The following three Tech Talk articles in the April 2007 issue of the Journal of the IEST are accessible free of charge (access Journal of the IEST).

ISO 14644-5 Offers a One-stop Guide to Cleanroom Operations
Anne Marie Dixon, Cleanroom Management Associates, Inc.

After a cleanroom has been built, validated, and certified, the daily operation of that facility is an ongoing task to ensure that the products manufactured or tested in the cleanroom meet quality standards and customer expectations. Cleanroom managers can turn to ISO 14644-5: Cleanrooms and associated controlled environments—Part 5: Operations for information on requirements and protocols for minimizing contamination risks that would compromise quality. This article will review the major provisions of the International Standard.

Updated IEST-RP-CC012 a ‘Must Read’ for Cleanroom Planners and Designers
A Journal of the IEST interview with Michael A. Fitzpatrick

IEST is in the final stages of revising a Recommended Practice (RP) that explores the factors to consider in the design of cleanroom facilities and provides a framework to establish performance criteria. Cleanroom designers, constructors, owners, and users will find IEST-RP-CC012.2: Considerations in Cleanroom Design “an essential first stop” in the design process, says Mike Fitzpatrick, Chair of IEST Working Group CC012, which developed the document. This article will explore highlights of the updated material.

Interpreting USP 797: Compounding Sterile Pharmaceuticals

In January 2004, US Pharmacopeia (USP) issued USP Chapter 797, Pharmaceutical Compounding: Sterile Preparations, the industry’s first set of enforceable standards governing sterile compounding practices. In May 2006 USP released proposed revisions that clarify requirements for facility design and environmental control. The new guidelines require compounded sterile preparations (CSPs) to be processed in a cleanroom environment. USP currently is reviewing extensive public comments regarding potential difficulties in complying with the requirements. This article will summarize the regulations and related issues.

The Effect of Tamarisk on Biodiversity and Soil Salinity in Western Colorado Ecosystems - Winner of the 2007 Robert N. Hancock Memorial Scholarship for the best original technical paper written by a student on a topic in the fields of science or engineering (not peer reviewed).
Scott Distel, Mesa State College

The April 2007 issue of the Journal of the IEST also contains peer-reviewed technical papers related to the fields of contamination control; design, test, and evaluation; and product reliability. IEST members and Journal of the IEST subscribers have full access to technical papers in the current issue as well as a 20-year archive of papers and articles. Others may obtain full-text abstracts of peer-reviewed technical papers and have the option to purchase individual papers (access Journal of the IEST).

Sport Utility Vehicle Rollover Test
William V. Chambers, ManTech-Space Systems, Aerospace Technology Applications Center

The National Highway Traffic Safety Administration (NHTSA) approached NASA to evaluate vehicle rollover resistance using the High Capacity Centrifuge facility. Testing was planned for six different sport utility vehicles (SUV). Previous methods for simulating rollover conditions were considered to be not indicative of the true driving conditions. A more realistic gradual application of side loading could be achieved by using a centrifuge facility. A unique load measuring lower support system was designed to measure tire loading on the inboard tires and to indicate tire liftoff. This lower support system was designed to more closely emulate actual rollover conditions. Additional design features were provided to mitigate potential safety hazards.

Environmental Test Program for the Mars Exploration Rover Project
Terry C. Fisher and Paul L.VanVelzer, Jet Propulsion Laboratory, California Institute of Technology

On June 10 and July 7, 2003, NASA launched two spacecraft from Cape Canaveral, Florida, for 6-month flights to the Red Planet, Mars. The two Mars Exploration Rover spacecraft landed safely on the planet on January 3 and 24, 2004. Prior to the successful launch, both of the spacecraft were involved in a comprehensive test campaign that included development, qualification, and protoflight test programs. Testing was performed to simulate the environments associated with launch, interplanetary cruise, landing on the planet, and Mars surface operations. Unique test requirements included operating the spacecraft while the chamber pressure was controlled to simulate the descent to the planet from deep space, high-impact landing loads, and rover operations on the surface of the planet at 8 Torr and -130 °C (-202 °F). This paper will present an overview of the test program that included vibration, pyroshock, landing loads, acoustic noise, thermal-vacuum, and solar simulation testing at the Jet Propulsion Laboratory (JPL) Environmental Test Laboratory facilities in Pasadena, California.

Lessons Learned from the Hubble Space Telescope (HST) Contamination Control Program
Patricia A. Hansen, Jet Propulsion Laboratory, California Institute of Technology; Jacqueline A. Townsend and Randy J. Hedgeland, NASA/Goddard Space Flight Center

Over the past two decades, the Hubble Space Telescope (HST) contamination control program has evolved from a ground-based integration program to a space-based science-sustaining program. The contamination controls from new-generation scientific instruments and orbital replacement units were incorporated into the HST contamination control program to maintain scientific capability over the life of the telescope. Long-term, on-orbit scientific data has shown that the contamination controls implemented for the instruments, servicing mission activities (Orbiter, astronauts, and mission), and on-orbit operations successfully protected the HST from contamination and the instruments from self-contamination.

A Test Method for Measuring Surface Cleanliness with Respect to Nonviable Liquid Contaminants
Lori Shaffer, Kimberly-Clark Corp.

In cleanroom environments, minimization of surface contamination is critical. As contaminants can be trapped in liquid droplets, the ability of a substrate to remove liquid from a surface is crucial to maintaining the cleanliness of a cleanroom. The focus of this paper is a test method designed to measure the cleaning efficiency of a substrate under various wiping conditions. The intent is to utilize this method to determine the effectiveness of a given cleaning procedure.

Operational Modal Analysis of Aluminum Beams
S. Rudroju, A. Gupta, and S. Yandamuri, Department of Mechanical Engineering, Northern Illinois University

Natural frequencies obtained by modal analysis are important to engineers interested in predicting the dynamic behavior of structures. Traditional modal analysis involves impact testing or shaker testing, where response signal and input force are measured to obtain the transfer function. However, for large structures, input excitation force measurement may be difficult, if not impossible. Large structures may be subjected to ambient excitation; operational modal analysis, also known as output-only modal analysis, has been used for extracting modal parameters of these types of structures. The main advantage of operational modal analysis is that no artificial excitation is needed, and the analysis is based on measurements of only the output data of the system. Operational modal analysis tests are performed under the actual operating conditions of the system without any change of boundary conditions; the tests use the ambient loads as input and thus do not interfere with the normal functioning of the system. In this study, six aluminum beams of different configurations (beams with and without cuts of various lengths) were used for conducting experiments. Results based on impact test, shaker test, and operational modal analysis are presented.

Virtual Remaining Life Assessment of Electronic Hardware Subjected to Shock and Random Vibration Life Cycle Loads
Sony Mathew, Diganta Das, Michael Osterman, and Michael Pecht, Center for Advanced Life Cycle Engineering (CALCE), University of Maryland; Robin Ferebee, NASA Marshall Space Flight Center; Joseph Clayton, BD Systems Inc.

This study presents a physics-of-failure-based virtual remaining life assessment method for assessing the remaining life of an electronic circuit card. The approach is then demonstrated through a case study of a circuit card assembly in the Space Shuttle solid rocket booster. Using thermal and mechanical stress damage models, the accumulated damage in the circuit card due to the life cycle environment loads on the card was calculated. Based on the amount of damage accumulated, the remaining life of the circuit card was estimated.

The Disconnect Between Environmental Testing and Aging, Long-Lived Vehicles
Hank Caruso, L-3 Communications, Titan Group

Traditional laboratory test strategies and methodologies are structured to identify and correct product defects that occur relatively early in the life of a product. Issues associated with aging, long-lived vehicles, such as aircraft, involve degradation mechanisms that may not be thoroughly investigated in the test laboratory with current test approaches. Long-lived vehicles (platforms) do not experience end of life in the same way that an electronic sub-element might. Rather than being retired, an aging platform may undergo repeated cycles of renovation and upgrades. As a result, every platform element may be expected to perform far beyond the limits of its contractually defined lifetime. Extrapolations of Aging Effects (EAEs) could provide program personnel with forewarnings of potential aging platform issues. MIL-STD-810F and North Atlantic Treaty Organisation (NATO) Standardization Agreement (STANAG) Allied Environmental Conditions And Test Publication (AECTP) 600 offer tools to assist in developing EAEs. Significant changes in acquisition practices will be needed to take advantage of these opportunities.

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