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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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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS2024

The Effects of Peel Ply on the Damage Tolerance Characteristics of the Space Launch System (SLS) Payload Adapter Fitting (PAF)

A payload adaptor fitting (PAF) has been manufactured at NASA’s Marshall Space Flight Center (MSFC) in support of the Space Launch System (SLS) program. This structure is essentially a large cone made up of eight curved “lobes” that are joined together to form the cone. The lobes were manufactured via automated fiber placement (AFP). The PAF will carry predominantly compressive loads thus compression strength will be the focus of this study. The lobes are sandwich structure made with aluminum honeycomb core and carbon/epoxy face sheets. The lobes will be inserted into metallic rings at the top and bottom of the cone to form the full cone. Both front and back exterior surfaces of each lobe have a plain weave fabric placed at ±45⁰ to the vertical direction to help prevent fiber “breakout” during drilling. The face sheet of each lobe is thickest at the top and plies are dropped as the cone reaches the main acreage in the bottom section of the cone. The entire structure used resin impregnated peel ply that, once removed, supplies a good bonding surface for secondary bonding steps. The peel ply can be removed either directly after cure, or just before any bonding operation. Since foreign object impact can occur to the structure at any time during its life, damage tolerance of the PAF structure both with and without peel ply needed to be addressed because a previous study, albeit with limited data, showed some significant differences in damage tolerance whether the peel ply was present or not [1]. A literature search showed no results for comparing impact damage on composite laminates with and without peel ply. Load versus deflection of impact curves, visual damage, dent depth, damage as ascertained by thermography and cross-sectional microscopy were evaluated as part of the damage resistance of the structure. Compression After Impact (CAI) was performed to assess damage tolerance. The impact tests were conducted on representative specimens both with and without the peel ply present.

Sandwich Structure↗
NASA NTRSDate not supplied

SLS Block-1B USA Separation Analysis and Requirements Evaluation Using the CLVTOPS Toolchain

Ensuring that rocket stage separation events provide positive clearance is critical to avoid loss of mission or crew. NASA's Marshall Space Flight Center (MSFC) has developed a cutting-edge toolchain to address this type of problem and it was used to set abstracted impulse requirements on, and to analyze the results of, the in-space separation event of the Universal Stage Adapter (USA) and the Exploration Upper Stage (EUS) of NASA's Space Launch System (SLS) Block-1B configuration. The toolchain is used as a hardware simulation to confirm positive body-to-body clearance during the separation event. It is also used to create a requirements-space simulation, which helps inform requirements as the hardware design matures.

Zach Muscha↗
NASA NTRS2018

Adjustments and Uncertainty Quantification for SLS Aerodynamic Sectional Loads

This paper presents a method for adjusting sectional loads to match target values for integrated force and moment coefficients. In a typical application, the sectional load profile for one flight condition is calculated from Computational Fluid Dynamics (CFD) while the integrated forces and moments are measured in a wind tunnel experiment. These two methods do not generally result in identical predictions, and this leads to an inherent inconsistency between different data products. This paper aims to provide a procedure to remove that inconsistency. A sectional load profile for a launch vehicle splits the rocket into slices along its length and calculates the aerodynamic loading on each slice, which leads to a one-dimensional aerodynamic load profile that is used for structural analysis. Adjusting sectional loads, also known as line loads, is a nontrivial matter due to several consistency constraints. For example, the adjusted sectional normal force profile must be consistent with both the integrated normal force and pitching moment. To avoid such inconsistency issues, this paper presents a method using a Proper Orthogonal Decomposition (POD) to generate basis functions to adjust the sectional load profiles. As a corollary, this correction method enables the creation of an uncertainty quantification for sectional loads that is consistent with the dispersed integrated force and moment database and its uncertainty quantification. Several extensions to this technique, such as applying the method to the surface pressures, are considered.

Quantification↗
NASA NTRS1985

Primate Experiments on SLS-1

Experiments to study how certain body systems are affected by the space environment are described. These experiments are to be conducted on space shuttle flights. How weightlessness affects two body systems of primates are the prime concern. Thermoregulation and fluid and electrolyte homeostasis are the two systems concerned. The thermoregulation project will provide data on how body temperature and circadian rhythms are affected in a weightlessness environment and the homeostasis in fluids and electrolyte levels will address the problem of body fluid shifts.

Aochi, J.↗
NASA NTRS1991

The astronaut science advisor: Ground testing during SLS-1

The objective of the Astronaut Science Advisor (ASA) is the improvement of the scientific return of experiments performed in space. This is accomplished through the use of expert systems technology to encode the domain and experiment knowledge commanded by the principal investigator (PI) and make it available to the astronaut experimenters. The principal functions of the ASA include the following: capture, reduce, and archive experimental data; monitor data quality and help diagnose problems with equipment when experimental data is erratic or poor; identify and permit investigation of interesting data; and suggest protocol changes that would result in better utilization of remaining time.

Compton, Michael M.↗
NASA NTRS1991

Flight equipment supporting metabolic experiments on SLS-1

Five experiments in different aspects of human metabolism will be performed on Spacelab Life Sciences-1. Nine items of equipment from the Life Sciences Laboratory Equipment inventory will be used: the rack-mounted centrifuge, the hematocrit centrifuge, the low-gravity centrifuge, a body-mass measurement device, a urine monitoring system, the Spacelab refrigerator/freezer, the Orbiter refrigerator, an in-flight blood collection system, and a pocket voice recorder. In addition, each experiment will require some specialized equipment such as incubators and culture blocks for an immunology experiment, and tracers for a fluid and electrolyte experiment and a hematology experiment. The equipment for these experiments has been developed over many years, in some cases since the Skylab program in the early 1970s, and has been certified for use on the Space Shuttle.

Leach, Carolyn S.↗
NASA NTRS1990

Automated Spacelab Stowage Expert System for SLS missions

Issues related to the development of the Automated Spacelab Stowage Expert System (ASSESS) are examined including the problem domain, design, and status. The ASSESS concept is designed to configure stowage items into Spacelab lockers with an expert-system approach in which knowledge is available for every item and locker and for the complete heuristics. ASSESS employs the Knowledge Engineering Environment for development, and graphic displays present data on the items, lockers, and general system status. The automatic and manual modes are presented; the former provides the capability for an automatic solution to the stowage of a set of items into Spacelab lockers based on stowage heuristics defined and/or set by the user. The approach and heuristics algorithms are shown to permit the effective practical solution of NP-hard problems.

Kao, C. Y.↗
NASA NTRS1994

PI in the sky: The astronaut science advisor on SLS-2

The Astronaut Science Advisor (ASA, also known as Principal-Investigator-in-a-Box) is an advanced engineering effort to apply expert systems technology to experiment monitoring and control. Its goal is to increase the scientific value of information returned from experiments on manned space missions. The first in-space test of the system will be in conjunction with Professor Larry Young's (MIT) vestibulo-ocular 'Rotating Dome' experiment on the Spacelab Life Sciences 2 mission (STS-58) in the Fall of 1993. In a cost-saving effort, off-the-shelf equipment was employed wherever possible. Several modifications were necessary in order to make the system flight-worthy. The software consists of three interlocking modules. A real-time data acquisition system digitizes and stores all experiment data and then characterizes the signals in symbolic form; a rule-based expert system uses the symbolic signal characteristics to make decisions concerning the experiment; and a highly graphic user interface requiring a minimum of user intervention presents information to the astronaut operator. Much has been learned about the design of software and user interfaces for interactive computing in space. In addition, we gained a great deal of knowledge about building relatively inexpensive hardware and software for use in space. New technologies are being assessed to make the system a much more powerful ally in future scientific research in space and on the ground.

Hazelton, Lyman R.↗
NASA NTRS1992

SLS-1: The first dedicated life sciences shuttle flight

Spacelab Life Sciences 1 was the first space laboratory dedicated to life science research. It was launched into orbit in early June 1991 aboard the space shuttle Columbia. The data from this flight have greatly expanded our knowledge of the effects of microgravity on human physiology as data were collected in-flight, not just pre and post. Principal goals of the mission were the measurement of rapid and semichronic (8 days) changes in the cardiovascular and cardiopulmonary systems during the flight and then to measure the rate of readaptation following return to Earth. Results from the four teams involved in that research will be presented in this panel. In addition to the cardiovascular-cardiopulmonary research, extensive metabolic studies encompassed fluid, electrolyte and energy balance, renal function, hematology and musculoskeletal changes. Finally, the crew participated in several neurovestibular studies. Overall, the mission was an outstanding success and has provided much new information on the lability of human responses to the space environment.

Phillips, Robert W.↗