A Case for Waste Fraud and Abuse: Stopping the Air Force from Purchasing Spacecraft That Fail Prematurely
Affiliation
Failure AnalysisIssue Date
2011-10Keywords
TelemetryPrognostic
Failure Prediction
Failure Analysis
Diagnostic
Satellite Failure
Launch Vehicle Failure
Failure Analysis
Prognostic Analysis
Metadata
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Copyright © held by the author; distribution rights International Foundation for TelemeteringCollection Information
Proceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection.Abstract
Spacecraft and launch vehicle reliability is dominated by premature equipment failures and surprise equipment failures that increase risk and decrease safety, mission assurance and effectiveness. Large, complex aerospace systems such as aircraft, launch vehicle and satellites are first subjected to most exhaustive and comprehensive acceptance testing program used in any industry and yet suffer from the highest premature failure rates. Desired/required spacecraft equipment performance is confirmed during factory testing using telemetry, however equipment mission life requirement is not measured but calculated manually and so the equipment that will fail prematurely are not identified and replaced before use. Spacecraft equipment mission-life is not measured and confirmed before launch as performance is but calculated using stochastic equations from probability reliability analysis engineering standards such as MIL STD 217. The change in the engineering practices used to manufacture and test spacecraft necessary to identify the equipment that will fail prematurely include using a prognostic and health management (PHM) program. A PHM includes using predictive algorithms to convert equipment telemetry into a measurement of equipment remaining usable life. A PHM makes the generation, collection, storage and engineering and scientific analysis of equipment performance data "mission critical" rather than just nice-to-have engineering information.Sponsors
International Foundation for TelemeteringISSN
0884-51230074-9079
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STOPPING LAUNCH PAD DELAYS, LAUNCH FAILURES, SATELLITE INFANT MORTALITIES AND ON ORBIT SATELLITE FAILURES USING TELEMETRY PROGNOSTIC TECHNOLOGY(International Foundation for Telemetering, 2007-10)Telemetry Prognostics is Failure Prediction using telemetry for launch vehicle and satellite space flight equipment to stop launch failures, launch pad delays, satellite infant mortalities and satellite on orbit failures. This technology characterizes telemetry behaviors that are latent, transient, and go undetected by the most experienced engineering personnel and software diagnostic tools during integration and test, launch operations and on orbit activities stopping launch pad delays, launch failures, infant mortalities and on orbit failures. Telemetry prognostics yield a technology with state-of-the-art innovative techniques for determining critical on-board equipment remaining useful life taking into account system states, attitude reorientations, equipment usage patterns, failure modes and piece part failure characteristics to increase the reliability, usability, serviceability, availability and safety of our nation’s space systems.
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IP Fast Rerouting for Single and Multi-Link Failures(The University of Arizona., 2014)The resilience of networks is increasingly becoming crucial as the adoption of cloud- based computing and interactive multimedia applications accelerates. Advances in optical technologies are enabling these modern network applications. The optical backbone, however, remains vulnerable to several types of failures that can cause considerable data loss. Natural phenomena, unintentional cutting of cables, configuration errors, or sabotage can cause multiple simultaneous link failures in IP networks. To reap the benefits of modern network applications, the network must provide resilience guarantees. We develop three novel IP network fast reroute methods in this dissertation. First, we address the problem of guaranteeing single-link failure recovery, while simultaneously load balancing traffic with negligible increase in path length. Existing failure recovery methods do not load balance traffic, or when they do they significantly lengthen paths. We turn our attention next to the problem of guaranteeing recovery from multiple link failures. The second IP fast reroute method we propose guarantees packet delivery under arbitrary link failures, provided that the number of link failures is one less than the size of the minimum edge-cut. None of the existing fast reroute recovery methods guarantee recovery from more than two-link failures. As with all fast reroute methods, we only use pre-computed and pre-installed routing table entries, and a fixed-length packet header to recover packets in the fast data plane. Our third IP fast reroute method provides a stronger failure recovery guarantee. We guarantee the delivery of a packet, provided that the number of failed links is at most one less than the number of link-disjoint paths connecting the packet's source to its destination, even when the failures disconnect the network. Comprehensive evaluations in real- world network topologies demonstrate our methods' excellent path length performance. Our methods may be implemented in modern networks, including SDNs, to provide failure recovery guarantees while retaining packet delivery speeds.
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Evaluation of Satisfaction and Self-Efficacy of Veteran Patients with Heart Failure in a Group Clinic Setting(The University of Arizona., 2006)Objectives: To evaluate the group clinic patients’ visit satisfaction and self-efficacy assessments at baseline and six months after the implementation of the heart failure group clinic. Additional outcomes of interest included health service utilization and medication management. Methods: This study utilized a pre-experimental design to compare patients’ clinic visit satisfaction and self-efficacy assessments at baseline and six months. Demographic variables, diagnoses, vitals, health service utilization and medication management data were obtained retrospectively from the computerized patient record system (CPRS). Results: Eleven patients met the inclusion criteria, agreed to participate and completed the informed consent. Mean age was 64.1 years (± 11.28); 100% were male; 45.5% were white, not of Hispanic origin. Health service utilization could not be compared using the planned analysis because of the limited data available for this outcome. Medication management trends included titrating angiotensin-converting enzyme inhibitors (n=1), titrating beta-blockers (n=6), and converting from non-preferred HF medications to ACC/AHA guideline recommended agents (n=3). The mean self-efficacy score increased at follow-up when compared to baseline data (7.4 ± 1.7 versus 6.4 ± 2.7, respectively) with no statistical significance shown between the two groups (p=0.12). Additionally, the mean patient satisfaction score increased at follow-up when compared to the baseline scores (74.5 ± 12.3 versus 71.0 ± 15.1 respectively); however, data analysis revealed no statistical significance (p=0.50). Conclusions: Our study demonstrated trends suggesting improved patient satisfaction and improved self-efficacy with a group clinic model in veteran patients with heart failure. Group clinic settings have the potential to optimize HF medication management in the setting of enormous demand for VA healthcare services and limited financial resources.
