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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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102 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

MLI Blanket Effective Emittance Variance and Its Effect on Spacecraft Propellant Line Thermal Control

Multi-Layer Insulation (MLI) blankets commonly employed for temperature control of spacecraft propellant lines consistently show large variances in their effective emittances. These variances are primarily due to workmanship, hence are hard to control or predict. Unfortunately, the variances are also the primary drivers of propellant line temperatures, thus leading to large predicted temperature uncertainties and increased risks to the success of space missions. JPL has gained significant knowledge of these variances from Mars spacecraft designs over more than two decades. This knowledge has led to improved analytical approaches to bound existing designs, emphasis on increased temperature visibility for design verification and model correlation, as well as methods for improving the robustness of propellant line thermal designs.

Miller, Jennifer R.↗
NASA NTRS2019

James Webb Space Telescope Optical Telescope Element / Integrated Science Instrument Module (OTIS) Cryogenic Vacuum Test Part II: Thermal Analysis

The James Webb Space Telescope (JWST), set to launch in early 2019, is currently undergoing a series of system-level environmental tests to verify its workmanship and end-to-end functionality. As part of this series, the Optical Telescope Element and Integrated Science Instrument Module (OTIS) Cryo-Vacuum (CV) test, the most complex cryogenic test executed to date by NASA, was completed in 2017 at the Johnson Space Center's Chamber A facility. The OTIS CV test was intended as a comprehensive test of the integrated instrument and telescope systems to fully understand its optical, structural, and thermal performance within its intended flight environment. Due to its complexity, extensive pre-test planning was required to ensure payload safety and compliance with all limits and constraints. A comprehensive thermal analysis campaign was undertaken to predict the behavior of the test payload during its transition to cryogenic temperatures and back to ambient, and exhaustive preparations for off-nominal scenarios were studied due to the increased possibility of unanticipated events during the 100-day test length. This current four-part online course for the NASA Engineering and Safety Center (NESC) Academy gives a thorough overview of the multiple years of preparation executed by hundreds of individuals to ensure the success of the JWST OTIS CV Test. Part I will introduce the major components of James Webb and specifically the OTIS CV Test thermal architecture. Part II will encompass the extensive thermal analysis performed to prepare for the test. Part III will talk about the preparations for off-nominal events: what analysis was done, and how steps were taken pre-test to anticipate unexpected circumstances and mitigate their impacts to hardware and test timeline. Part IV is a recap of the lessons learned from the thermal perspective for both the payload and ground support equipment (GSE) test conductors. It is hoped that the insight gained from the OTIS CV test campaign will benefit planning and execution for upcoming large cryogenic missions.

Testing↗
NASA NTRS2019

Heatshield for Extreme Entry Environment Technology (HEEET) Thermal Protection System (TPS)

Starting in 2013 and completing in 2019, the Heatshield for Extreme Entry Environment Technology (HEEET) project has been working to mature a 3-D Woven Thermal Protection System (TPS) to Technical Readiness Level (TRL) 6 to support future NASA missions to destinations with extreme entry environments such as Venus, Saturn, Uranus, Neptune and high-speed sample return missions to Earth. A key aspect of the project has been the building and testing of a 1-meter base diameter Engineering Test Unit (ETU) representative of what could be used for a Saturn probe. This paper provides a high-level overview of the HEEET project including manufacturing and testing of the ETU for structural model verification, establish system capability and verify manufacturing workmanship.

Extreme Entry Environment↗
NASA NTRS2019

Heatshield for Extreme Entry Environment Technology (HEEET) Thermal Protection System (TPS)

Over the last 5 years, the Heatshield for Extreme Entry Environment Technology (HEEET) project has been working to mature a 3-D Woven Thermal Protection System (TPS) to Technical Readiness Level (TRL) 6 to support future NASA missions to destinations with extreme entry environments such as Venus, Saturn, Uranus, Neptune and high speed sample return missions to Earth. A key aspect of the project has been the building and testing of a 1-meter base diameter Engineering Test Unit (ETU) representative of what could be used for a Saturn probe. This paper provides a high level overview of the HEEET project including manufacturing and testing of the ETU which has been subjected to mission relevant thermal and mechanical loads, to verify structural models, establish system capability and verify manufacturing workmanship.

TPS↗
NASA NTRS2010

Reliability of area array packages with 1500-2500 I/Os

This report first provides a literature survey for designing, manufacturing, and reliability test results for area array packages with 1500 to 2500 inputs/outputs (I/Os). It then presents test matrix on design, yield, and workmanship defects on assembly and environmental testing, including thermal cycle and mechanical drop-test evaluation results for FCBGA1704, FPBGA432, and PBGA676 I/Os packages assembled onto printed circuit/wiring boards (PCBs/PWBs). Finally, it summarizes lessons learned from test results for assembly and environmental testing along with optical, scanning electron microscopy (SEM), and x-ray photomicrographs showing damage progress.

Ghaffarian, Reza↗
NASA NTRS2018

Developing a Standard Test Program for CubeSats

Developers of CubeSats and other miniaturized satellites often lack the schedule and budget to devise and implement an extensive environmental test campaign. CubeSat projects have become increasingly common at Jet Propulsion Laboratory (JPL) over the past few years, revealing the need for a standard CubeSat test program to maximize the likelihood of mission success while meeting project cost and schedule constraints. In this paper, we describe our efforts to develop a general protoflight test program for CubeSats in low-Earth orbit (LEO) and compare this test program with a typical test program for non-CubeSat LEO satellites and instruments. We investigate the effectiveness of the CubeSat test program—both as a design and workmanship screen and as a standard needing minimal project-specific tailoring—and discuss potential areas for improvement.

Seal, Gabriella L.↗
NASA NTRS2018

Overview of the Mars 2020 Parachute Risk Reduction Activity

In 2012, the Mars Science Laboratory (MSL) landed safely on the surface of Mars using a supersonic Disk-Gap-Band (DGB) parachute, which was structurally qualified for flight via a subsonic wind tunnel test program. Results of the Low Density Supersonic Decelerators (LDSD) program have called into question the methodology and principles that form the foundation of the MSL subsonic test program. LDSD discovered that quasi-static subsonic proof loading a parachute via ground testing may not provide canopy stresses that sufficiently bound the stresses experienced during a rapid supersonic inflation at Mars. Additionally, deeper scrutiny of the materials and structural margins present in previously successful supersonic DGBs indicated that the MSL parachute flew with lowest margins of any previous parachute. These factors have increased the perceived risk of reusing a heritage MSL DGB parachute design with a subsonic test program for Mars 2020. To reduce this risk,a series of risk reduction steps were initiated starting in 2016. First, two parachute assemblies have been pursued in parallel: a Build-to-Print (BTP) MSL parachute, designed and manufactured by Pioneer Aerospace Corporation, which maintains the heritage of the successful MSL parachute, and a strengthened parachute, designed and manufactured by Airborne Systems North America, which uses higher strength materials throughout the parachute assembly but maintains the same overall size as the MSL parachute. Second, each parachute system was tested in a subsonic wind tunnel to examine the canopies in their fully inflated state and assess the workmanship of each canopy. Finally, full-scale parachutes from each vendor will experience at least one supersonic inflation at Mars relevant Mach numbers and atmospheric densities at Earth via a supersonic sounding rocket test campaign. This paper presents high-level details regarding the risk reduction strategy, the two candidate parachute configurations, the ground test program, and the supersonic flight test program, and brief results from each of the test programs.

Chen, Allen↗
NASA NTRSDate not supplied

NASA Space Launch System Completes Green Run Testing, Begins Assembly

NASA’s Space Launch System (SLS) Program is poised in 2021 to shift its focus to the launch site with the completion of its last major integrated hardware and software test. SLS is NASA’s evolvable super heavy-lift launch vehicle for deep space exploration. Using proven propulsion technologies, SLS will be the most powerful launch vehicle in the world. That capability translates not only into more mass and volume to destinations but also simplified payload design and mission operations and greater opportunity for mission success. These capabilities will be important for the Artemis program, NASA’s plan to return humans to the Moon to stay in a sustainable way in order to develop and test technologies and operations needed for human missions to Mars and other destinations. SLS will anchor the transportation leg of an innovative, sustainable program of lunar exploration with commercial and international partners as the first step of human exploration of deep space. While all major hardware and software efforts made significant progress in 2020 and 2021, the most visible was the Green Run test series of the Artemis I core stage conducted at NASA’s Stennis Space Center (SSC) on the B-2 test stand. The series validated core stage design, performance, workmanship, and readiness for shipment to NASA Kennedy Space Center (KSC) for final processing, integration and launch. The core stage provides the backbone for SLS’ main propulsion system, consisting of two five-segment solid rocket boosters and four RS-25 liquid hydrogen (LH2)/liquid oxygen (LOX) engines. SLS also includes an Interim Cryogenic Propulsion Stage (ICPS) that will insert the Orion crew spacecraft into a lunar trajectory.

John Honeycutt↗
NASA NTRS2021

A Study of Lessons and Experiences of NASA Centers in the Use of Commercial Off the Shelf (COTS) Electronics

The NASA Engineering and Safety Center (NESC) sponsored a Technical Assessment relating to the utilization of commercial-off-the-shelf (COTS) electrical, electronic, and electromechanical (EEE) parts in spaceflight systems at NASA Centers. The assessment had two primary goals. The first was to capture each NASA Centers’ current practices, best practices, lessons learned and Center-proposed recommendations on the use of COTS EEE parts and assemblies in critical ground support equipment (GSE). The second was to provide recommendations on the use of COTS, including a set of current best practices based on the Centers’ current and best practices and the NESC team’s discussions. One key achievement made by the assessment team was the characterization of the term Industry Leading Parts Manufacturers (ILPMs) as parts manufacturer with high volume automatic production facilities and which can provide documented proof of the technology, process and product qualification, and its implementation of the best practices for “zero defects” for parts quality, reliability and workmanship. The assessment concluded with numerous findings, takeaways and recommendations that will be discussed during this presentation.

commercial↗
NASA NTRSDate not supplied

BioSentinel Avionics Design Approach with COTS Parts

This presentation focuses on ARC's avionics design approach using Commercial Off-The-Shelf (COTS) parts for high-risk, high-reward missions. Examples of ARC's past missions in small spacecraft, nano-satellites, and Class D payloads are highlighted, emphasizing the benefits of COTS, such as wider selections, faster development schedules, and lower costs. The challenges and limitations of traditional Qualified Parts List (QPL) approaches are discussed, along with observations from ARC missions, which show that design and workmanship issues are more significant than component failures. Mitigations for radiation risks associated with COTS are proposed, emphasizing risk awareness, proper software and hardware design, and careful parts selection. The success of ARC's 30+ projects using COTS over the past 17 years underscores its viability for high-risk missions.

BioSentinel↗
NASA NTRSDate not supplied

Topics in Reliability

This talk will wind through the details of history of reliability in the agency, where things are today, and where we need to go tomorrow. It will provide many examples of reliability that are often discounted because they are not tied to some mantra from the past. Furthermore, it will separate us from the red herrings that are ever present based on the misuse of terms and practices in reliability. It will delve into several key subject matter areas that have long been considered the key reliability drivers, such as parts, printed circuit boards, radiation, and workmanship. Finally, it will highlight how the Center and Agency need to change our approach at learning lessons from past experiences to maintain a basis for reliability long into the future.

COTS↗
NASA NTRSDate not supplied

Proposed Reliability-Based Damage Tolerance Guidelines for Space Systems

Deterministic damage tolerance guidelines for highly reusable and efficiently designed launch systems can be challenging to meet and result in overly conservative assessments for tightly controlled manufacturing processes. Deterministic approaches may be unconservative when the structure is workmanship sensitive and there is a wide spread in fracture properties. Reliability-based damage tolerance assessments targeting a component reliability over the service life commensurate to mission risk posture is a promising alternative. Low production rates, short fleets, and lack of standards or guidance has slowed down widespread adoption of this method. Guidance for the robust application of reliability-based damage tolerance for space systems are proposed. These guidelines cover the treatment of uncertainty in damage tolerance analysis, the collection of data to develop probabilistic distributions, uncertainty propagation methods, and types of hardware.

Reliability-Based Damage Tolerance↗