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Jesse Leitner

Publications and source records attributed to Jesse Leitner.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

Modernizing NASA's Risk Classification System

NASA's risk classification system dates back to an era when every new NASA space mission was a one-of-a-kind build, and the only way to obtain reliability was as a by-product through a combination of reliability analyses, extensive and stringent quality requirements, and extensive testing. Originally, there were very limited commercial capabilities to develop systems to work reliably in space, so NASA considered its own homegrown approach the only recipe for success. This approach involved very detailed and prescriptive piece-part controls and no reliance on (and to some extent a rejection of) any type of commercial practices. Often risk was considered to be the lowest when NASA had the maximum amount of control and prescription, and the highest when commercial practices were largely employed, and these principles drove risk classification in the agency. Over time, however, commercial capabilities grew, and many products became standardized and commercialized, while the agency maintained its tried-and-true approach, paying little attention to the evolution of the commercial sector. In fact, the commercial sector was developing systems that have direct, proven reliability, established over time, while NASA still maintained the approach to ignore the reality of the commercialized aspects of standard products, label them as high risk, and attempt to change them to align with the agency's piece-part control practices. A table of mission classification vs lifetime for missions launched after 2000 indicates no correlation between lifetime and classification, with the few exceptions involving missions that have very limited objectives and no valid purpose to continue after they were met. This paper steps through some of the key historical elements in risk classification and NASA's overall approach to assurance, and presents some elements being brought forward to modernize the approach and take advantage of the growing capability in the commercial sector.

risk↗
NASA NTRS2022

Assessment of Aggregate Risk for JWST

This presentation communicates the aggregate assessment of risk performed for the James Webb Space Telescope prior to shipping the observatory to the launch site.

JWST↗
NASA NTRS2022

How NASA decided Webb was ready: Inside the risk assessment

Every do-it-yourselfer knows how hard it can be to declare a project complete. Will another turn of the bolt or brushstroke make things better or worse? That was roughly the choice NASA faced a year before the Dec. 25 launch of the James Webb Space Telescope. Would more testing close more technical risks in the nearly $10 billion project or create new ones? In the end, NASA decided against more testing. NASA’s Jesse Leitner and Tupper Hyde describe the assessment they performed.

JWST↗
NASA NTRS2022

Assurance of Electronic Parts for Aerospace System Reliability: Past, Present, and Future

Over the last two to three decades, the balance of influence within the electronics industry has shifted decisively towards the consumer electronics and information technology products, away from the defense or aerospace markets. This shift towards the commercial markets has changed certain ground rules in the electronics industry. Reliance of the aerospace industry, in particular, on components from supply chains dedicated to other products, or cross-vertical product integration, creates a supply web and introduces significant risks that are not necessarily present for volume-driven electronic products. Many of the unique risks in the aerospace industry emanate from the key characteristics of this industry. Although selection and usage of commercial electronics in NASA flight hardware is possible at a comparable (and in many cases lower) level of risk to that of employing parts that are screened to military or NASA specifications, for a large majority of flight projects it is difficult to distinguish the difference in on-orbit performance or reliability for parts screened at any level, or commercial parts that have no additional screening performed by the government. This paper identifies several bases for establishing context and developing unique or alternative approaches for successful parts selection and application within NASA and across the commercial space community.

electronic parts↗
NASA NTRSDate not supplied

SMD Class D standard MAR

Overview presentation for a streamlined Class D mission assurance requirements document developed by an Agency-wide team for NASA Science Mission Directorate

SMA↗
NASA NTRSDate not supplied

Phasing in COTS EEE parts in NASA

A number of activities within NASA and the space community, as well as growing technology needs and supply chain changes have accelerated the need to expand the use of COTS parts within NASA. While the use of COTS has been formally institutionalized and deemed acceptable for Class D space missions and those with greater tolerance for risk, there is still a lack of understanding of how to most effectively use COTS in such high risk-tolerance missions, and no apparent path towards broad use in missions with much less tolerance for risk. However, the reality is that the fundamental limitations of technology associated with the military specification system combined with the need to fly newer technologies in upcoming flagship robotic missions and human space flight missions will ultimately demand a more expansive use of COTS. The infinite nature of COTS gives rise to numerous challenges in the selection, acceptance, testing, and usage of COTS when reliable operation is essential. This presentation will highlight some of the current artifacts of a NASA Engineering and Safety Center (NESC) study on the use of COTS parts, as well as many of the historical through current facts about parts assurance within Agency to provide a path forward for reliable use of COTS for a range of space applications and risk postures.

EEE parts↗
NASA NTRSDate not supplied

Quality Practices for Highly-Constrained Projects

The presentation provides guidance and recommendations for the implementation of quality practices for space system development projects that have constraints, such that the full suite of traditional or "best" standard practices cannot be applied.

Streamlined quality↗
NASA NTRSDate not supplied

Inherited Items Process 2.0

This presentation describes the process at NASA GSFC for SMA acceptance of inherited products.

inherited items↗
NASA NTRSDate not supplied

Risk Classification Modernization

NASA’s risk classification system dates back to an era when every new NASA space mission was a one-of-a-kind build, and the only way to obtain reliability was as a by-product through a combination of reliability analyses, extensive and stringent quality requirements, and extensive testing. Originally, there were very limited commercial capabilities to develop systems to work reliably in space, so NASA considered its own homegrown approach the only recipe for success. This approach involved very detailed and prescriptive piece-part controls and no reliance on (and to some extent a rejection of) any type of commercial practices. Often risk was considered to be the lowest when NASA had the maximum amount of control and prescription, and the highest when commercial practices were largely employed, and these principles drove risk classification in the agency. Over time, however, commercial capabilities grew, and many products became standardized and commercialized, while the agency maintained its tried-and-true approach, paying little attention to the evolution of the commercial sector. This presentation introduces GSFC’s new approach at risk classification, which includes classification of components and full spacecraft, as well as of constellations of spacecraft.

risk↗
NASA NTRSDate not supplied

SMA for Highly Constrained Projects

This is a collection of presentation elements into a consolidated presentation on overall safety and mission assurance practices for highly constrained projects, such as Class D, 7120.8, or Do No Harm.

Jesse Leitner↗
NASA NTRSDate not supplied

Risk Classification Modernization

NASA’s risk classification system dates back to an era when every new NASA space mission was a one-of-a-kind build, and the only way to obtain reliability was as a by-product through a combination of reliability analyses, extensive and stringent quality requirements, and extensive testing. Originally, there were very limited commercial capabilities to develop systems to work reliably in space, so NASA considered its own homegrown approach the only recipe for success. This approach involved very detailed and prescriptive piece-part controls and no reliance on (and to some extent a rejection of) any type of commercial practices. Often risk was considered to be the lowest when NASA had the maximum amount of control and prescription, and the highest when commercial practices were largely employed, and these principles drove risk classification in the agency. Over time, however, commercial capabilities grew, and many products became standardized and commercialized, while the agency maintained its tried-and-true approach, paying little attention to the evolution of the commercial sector. This presentation introduces GSFC’s new approach at risk classification, which includes classification of components and full spacecraft, as well as of constellations of spacecraft.

risk↗
NASA NTRSDate not supplied

Risk-Based SMA and Modernizing Risk Classification at GSFC

In 2014, in response to a large volume of feedback from industry, the science community, and internal to Goddard Space Flight Center (GSFC), GSFC’s Safety and Mission Assurance (SMA) Directorate began a transition to a risk-based implementation of SMA, departing from its longstanding practice of being primarily driven by a mostly static set of Mission Assurance Requirements. The transition started out with a pilot project involving risk-based acceptance of bare-printed circuit boards that was enormously successful, continued through a complete organizational transformation in 2015, and culminated with the baselining of formal Risk-Based SMA policy in 2016. In this presentation we will describe the risk-based SMA concept, segue into how it shapes a modernization of risk classification that GSFC has rolled out, and provide results from the original pilot project for risk-based SMA, involving the printed circuit board assurance process.

Jesse Leitner↗