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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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NASA NTRS2011

NASA's Space Launch System Progress Report

Exploration beyond Earth will be an enduring legacy for future generations, confirming America's commitment to explore, learn, and progress. NASA's Space Launch System (SLS) Program, managed at the Marshall Space Flight Center, is responsible for designing and developing the first exploration-class rocket since the Apollo Program's Saturn V that sent Americans to the Moon. The SLS offers a flexible design that may be configured for the MultiPurpose Crew Vehicle and associated equipment, or may be outfitted with a payload fairing that will accommodate flagship science instruments and a variety of high-priority experiments. Both options support a national capability that will pay dividends for future generations. Building on legacy systems, facilities, and expertise, the SLS will have an initial lift capability of 70 metric tons (mT) and will be evolvable to 130 mT. While commercial launch vehicle providers service the International Space Station market, this capability will surpass all vehicles, past and present, providing the means to do entirely new missions, such as human exploration of asteroids and Mars. With its superior lift capability, the SLS can expand the interplanetary highway to many possible destinations, conducting revolutionary missions that will change the way we view ourselves, our planet and its place in the cosmos. To perform missions such as these, the SLS will be the largest launch vehicle ever built. It is being designed for safety and affordability - to sustain our journey into the space age. Current plans include launching the first flight, without crew, later this decade, with crewed flights beginning early next decade. Development work now in progress is based on heritage space systems and working knowledge, allowing for a relatively quick start and for maturing the SLS rocket as future technologies become available. Together, NASA and the U.S. aerospace industry are partnering to develop this one-of-a-kind asset. Many of NASA's space centers across the country will provide their unique expertise to the Space Launch System endeavor. Unique infrastructure to be used includes the Michoud Assembly Facility for tank manufacturing, Stennis Space Center for engine testing, and Kennedy Space Center for processing and launch. As this panel will discuss, the SLS team is dedicated to doing things differently-from applying lean oversight/insight models to smartly using legacy hardware and existing facilities. Building on the foundation laid by over 50 years of human and scientific space flight--and on the lessons learned from the Apollo, Space Shuttle, and Constellation Programs-the SLS team has delivered both technical trade studies and business case analyses to ensure that the SLS architecture will be safe, affordable, reliable, and sustainable.

Singer, Joan A.↗

NASA NTRS1982

A NASTRAN model of a large flexible swing-wing bomber. Volume 2: NASTRAN model development-horizontal stabilzer, vertical stabilizer and nacelle structures

The NASTRAN model plans for the horizontal stabilizer, vertical stabilizer, and nacelle structure were expanded in detail to generate the NASTRAN model for each of these substructures. The grid point coordinates were coded for each element. The material properties and sizing data for each element were specified. Each substructure model was thoroughly checked out for continuity, connectivity, and constraints. These substructures were processed for structural influence coefficients (SIC) point loadings and the deflections were compared to those computed for the aircraft detail models. Finally, a demonstration and validation processing of these substructures was accomplished using the NASTRAN finite element program installed at NASA/DFRC facility.

Mock, W. D.↗

NASA NTRS1993

On eigensystem assignment with dissipativity constraints

Stability of the closed-loop system is of vital importance when controller synthesis is being performed using a reduced order model of the open-loop plant. For passive systems such as flexible space structures, closed-loop stability is often ensured by low-authority dissipative controllers using collocated and compatible sensors and actuators. This paper considers the problem of eigensystem assignment for flexible structures using constant-gain output feedback, under the dissipativity constraints requiring that the gain matrices be nonnegative definite. A novel method is developed in which a sequential procedure is used to assign one complex-conjugate pair of closed-loop eigenvalues in each step. At each step, an iterative technique is employed for generating a nonnegative definite gain matrix that assigns a new pair while keeping the previously assigned pairs unchanged. This method can assign up to m closed-loop system eigenvalues, where m is the number of control inputs. A numerical example of damping enhancement for a large flexible structure is presented to demonstrate the approach.

Maghami, Peiman G.↗

NASA NTRS1972

Lunar roving vehicle thermal control system.

A thermal control system was incorporated into the Lunar Roving Vehicle (LRV) to maintain temperature sensitive components within appropriate temperature limits during the translunar transportation phase, lunar surface operation, and quiescent periods between lunar traverses. This paper describes the thermal control system and discusses its thermal characteristics during all phases of operation. The basic concept is a passive system which stores internally generated energy during operation with subsequent radiation to space. The external environments are regulated by selected radiative surface finishes. Multi-layer insulation blankets, space radiators, flexible thermal straps, and fusible mass heat sinks were designed to control the temperatures of the electronic components.

Elliott, R. G.↗

NASA NTRS1982

Quiet Short-Haul Research Airplane (QSRA) model select panel functional description

The QSRA, when equipped with programmable color cathode ray tube displays, a head up display, a general purpose digital computer and a microwave landing system receiver, will provide a capability to do handling qualities studies and terminal area operating systems experiments as well as to enhance an experimenter's ability to obtain repeatable aircraft performance data. The operating systems experiments include the capability to generate minimum fuel approach and departure paths and to conduct precision approaches to a STOLport runway. The mode select panel is designed to provide both the flexibility needed for a variety of flight test experiments and the minimum workload operation required by pilots flying into congested terminal traffic areas.

Watson, D. M.↗

NASA NTRS1984

A degree of controllability definition - Fundamental concepts and application to modal systems

Starting from basic physical considerations, this paper develops a concept of the degree of controllability of a control system, and then develops numerical methods to generate approximate values of the degree of controllability for any linear time-invariant system. In many problems, such as the control of future, very large, flexible spacecraft and certain chemical process control problems, the question of how to choose the number and locations of the control system actuators is an important one. The results obtained here offer the control system designer a tool which allows him to rank the effectiveness of alternative actuator distributions, and hence to choose the actuator locations on a rational basis. The degree of controllability is shown to take a particularly simple form when the dynamic equations of a satellite are in second-order modal form. The degree of controllability concept has still other fundamental uses - it allows one to study the system structural relations between the various inputs and outputs of a linear system, which has applications to decoupling and model reduction.

Viswanathan, C. N.↗

NASA NTRS1985

Inertial energy storage for advanced space station applications

Because the NASA Space Station will spend approximately one-third of its orbital time in the earth's shadow, depriving it of solar energy and requiring an energy storage system to meet system demands, attention has been given to flywheel energy storage systems. These systems promise high mechanical efficiency, long life, light weight, flexible design, and easily monitored depth of discharge. An assessment is presently made of three critical technology areas: rotor materials, magnetic suspension bearings, and motor-generators for energy conversion. Conclusions are presented regarding the viability of inertial energy storage systems and of problem areas requiring further technology development efforts.

Van Tassel, K. E.↗

NASA NTRS1988

OMV docking simulator

The Boeing Orbital Maneuvering Vehicle (OMV) Docking and Proximity Operation System (DAPOS) was completed. The system constructed involves the use of four separate processors. Appropriate software was developed that drives each of these four processors. The hand controller logic coordinates all the activities in the control station, and communicates with the OMV mathematical model. The state vector generated by the model is in turn transmitted to the control station as well as the POLY 2000 (via the ALCYON host computer) for real time graphics generation. The OMV characteristics are stored in a data file which may be easily updated and modified without disturbing the software, thereby making the system very flexible. The current system supports two types of hand controllers. The system was flown by several volunteers, some of whom are airplane pilots. A user manual is also enclosed.

Teoh, W.↗

NASA NTRS1997

Effect of Pressure Gradients on Plate Response and Radiation in a Supersonic Turbulent Boundary Layer

Using the model developed by the author for zero-pressure gradient turbulent boundary layers, results are obtained for adverse and favorable pressure gradients. It is shown that when a flexible plate is located in an adverse pressure gradient area, it vibrates more than if it were in a favorable pressure gradient one. Therefore the noise generated by the plate in an adverse pressure gradient is much greater than that due to the plate in a favorable pressure gradient. The effects of Reynolds number and boundary layer thickness are also analyzed and found to have the same effect in both adverse and favorable pressure gradient cases. Increasing the Reynolds number is found to increase the loading on the plate and therefore acoustic radiation. An increase in boundary layer thickness is found to decrease the level of the high frequencies and therefore the response and radiation at these frequencies. The results are in good qualitative agreement with experimental measurements.

Frendi, Abdelkader↗

NASA NTRS2003

A Tabletop Tool for Modeling Life Support Systems

This paper describes the development plan for a comprehensive research and diagnostic tool for aspects of advanced life support systems in space-based laboratories. Specifically it aims to build a high fidelity tabletop model that can be used for the purpose of risk mitigation, failure mode analysis, contamination tracking, and testing reliability. We envision a comprehensive approach involving experimental work coupled with numerical simulation to develop this diagnostic tool. It envisions a 10% scale transparent model of a space platform such as the International Space Station that operates with water or a specific matched index of refraction liquid as the working fluid. This allows the scaling of a 10 ft x 10 ft x 10 ft room with air flow to 1 ft x 1 ft x 1 ft tabletop model with water/liquid flow. Dynamic similitude for this length scale dictates model velocities to be 67% of full-scale and thereby the time scale of the model to represent 15% of the full- scale system; meaning identical processes in the model are completed in 15% of the full- scale time. The use of an index matching fluid (fluid that matches the refractive index of cast acrylic, the model material) allows making the entire model (with complex internal geometry) transparent and hence conducive to non-intrusive optical diagnostics. So using such a system one can test environment control parameters such as core flows (axial flows), cross flows (from registers and diffusers), potential problem areas such as flow short circuits, inadequate oxygen content, build up of other gases beyond desirable levels, test mixing processes within the system at local nodes or compartments and assess the overall system performance. The system allows quantitative measurements of contaminants introduced in the system and allows testing and optimizing the tracking process and removal of contaminants. The envisaged system will be modular and hence flexible for quick configuration change and subsequent testing. The data and inferences from the tests will allow for improvements in the development and design of next generation life support systems and configurations.

Ramachandran, N.↗

NASA NTRS2009

Flexible Packaging Concept for a Space Suit Portable Life Support Subsystem

Neither the Shuttle Extravehicular Mobility Unit (EMU), the space suit currently used for space shuttle and International Space Station (ISS) missions, nor the Apollo EMU, the space suit successfully used on previous lunar missions, will satisfy the requirements for the next generation Constellation Program (CxP) lunar suit. The CxP system or Constellation Space Suit Element (CSSE) must be able to tolerate more severe environmental and use conditions than any previous system. These conditions include missions to the severely cold lunar poles and up to 100 Extravehicular Activity (EVA) excursions without ground maintenance. Much effort is focused on decreasing the mass and volume of the Portable Life Support Subsystem (PLSS) over previous suit designs in order to accommodate the required increase in functionality. This paper documents the progress of a conceptual packaging effort of a flexible backpack for the CSSE PLSS. The flexible backpack concept relies on a foam protection system to absorb, distribute, and dissipate the energy from falls on the lunar surface. Testing and analysis of the foam protection system concept that was conducted during this effort indicates that this method of system packaging is a viable solution.

Thomas, Gretchen↗

NASA NTRS2010

Airspace Systems Program: Next Generation Air Transportation System, NextGen Systems Analysis, Integration and Evaluation Project: Project Plan - Version 1.0

The key objectives of the NASA ASP are to: Improve mobility, capacity efficiency and access of the airspace system. Improve collaboration, predictability, and flexibility for the airspace users. Enable accurate modeling and simulation of air transportation systems. Accommodate operations of all classes of aircraft. Maintain system safety and environmental protection. In support of these program objectives, the major goal of the NextGen-SAIE Project is to enable the transition of key capacity and efficiency improvements to the NAS. Since many aspects of the NAS are unique to specific airport or airspace environments, demand on various parts of the NAS is not expected to increase equally as system demand grows. SAIE will provide systems level analysis of the NAS characteristics, constraints, and demands such that a suite of capacity-increasing concepts and technologies for system solutions are enabled and facilitated. The technical objectives in support of this goal are the following: Integration, evaluation, and transition of more mature concepts and technologies in an environment that faithfully emulates real-world complexities. Interoperability research and analysis of ASP technologies across ATM functions is performed to facilitate integration and take ASP concepts and technologies to higher Technology Readiness Level (TRL). Analyses are conducted on the program s concepts to identify the system benefits or impacts. System level analysis is conducted to increase understanding of the characteristics and constraints of airspace system and its domains.

Quon, Leighton↗

NASA NTRS2019

NASA’s Space Launch System: Enabling a New Generation of Lunar Exploration

Following two decades of operational experience in low-Earth orbit (LEO), NASA has turned its focus once again to deep space exploration. The Agency is building the Space Launch System (SLS) to take astronauts and cargo to the Moon and send robotic spacecraft deep into the solar system. Offering unmatched performance, departure energy and payload capacity, SLS is designed to evolve into progressively more powerful configurations, enabling a new generation of human exploration of the Moon in preparation for future missions to Mars. The first build of the Block 1 vehicle is nearly complete for Exploration Mission-1 (EM-1), the first integrated flight of SLS and the Orion crew vehicle. EM-1 will send an uncrewed Orion to a distant retrograde lunar orbit in order to test and verify new systems, and along the way will deploy 13 6U-class CubeSats in deep space along the upper stage disposal trajectory after separation from Orion. The Agency’s current plans call for the first three missions on the SLS manifest to utilize the Block 1 vehicle in crew and cargo configurations. A more powerful evolved vehicle, Block 1B, will provide additional mass and volume performance using a new Exploration Upper Stage (EUS). Block 1B will lift 34 to 40 metric tons (t) to trans-lunar injection (TLI), depending on crew or cargo configuration. The Block 1B crew configuration will offer as much payload volume as industry-standard 5 m-diameter fairings to co-manifested payloads in a Universal Stage Adapter (USA). The Block 1B cargo variant will accommodate 8.4 meter-diameter fairings in 62.7-foot (19.1 meter) or 90-foot (27.4 meter) lengths. Adding smallsat secondary payloads to ride along with primary and co-manifested payloads on future flights may be possible, depending on mass margins. Leveraging a flight-proven, well-understood propulsion system, SLS’s flexible architecture, unmatched performance and expansive payload accommodations will open exciting new mission possibilities in deep space. Launches of habitat modules for NASA’s new Gateway lunar outpost, the next generation of robotic spacecraft to the far reaches of the solar system, large-aperture deep space telescopes, probes to interstellar space and the return of astronauts to the Moon are all possible with SLS.

Creech, Stephen D.↗

NASA NTRS1976

Development of weight and cost estimates for lifting surfaces with active controls

Equations and methodology were developed for estimating the weight and cost incrementals due to active controls added to the wing and horizontal tail of a subsonic transport airplane. The methods are sufficiently generalized to be suitable for preliminary design. Supporting methodology and input specifications for the weight and cost equations are provided. The weight and cost equations are structured to be flexible in terms of the active control technology (ACT) flight control system specification. In order to present a self-contained package, methodology is also presented for generating ACT flight control system characteristics for the weight and cost equations. Use of the methodology is illustrated.

Anderson, R. D.↗

NASA NTRS1977

Effects of simulated turbulence on aircraft handling qualities

The influence of simulated turbulence on aircraft handling qualities is presented. Pilot opinions of the handling qualities of a light general aviation aircraft were evaluated in a motion-base simulator using a simulated turbulence environment. A realistic representation of turbulence disturbances is described in terms of rms intensity and scale length and their random variations with time. The time histories generated by the proposed turbulence models showed characteristics which are more similar to real turbulence than the frequently-used Gaussian turbulence model. The proposed turbulence models flexibly accommodate changes in atmospheric conditions and are easily implemented in flight simulator studies.

Jacobson, I. D.↗

NASA NTRS1982

On the modelling and simulation of the dynamics and control of large flexible orbiting systems

This paper attempts to review the steps involved in the development of mathematical models that can be used to simulate the in-orbit dynamics of large flexible systems. The use of graph theoretic techniques can often be used to reduce the computational effort involved for calculating the eigenvalues of large ordered systems. Computer generated graphical techniques may provide additional insight into the understanding of elastic modal shape functions of complex systems. Finally the numerical techniques commonly used to develop shape and attitude control laws will be briefly reviewed.

Bainum, P. M.↗

NASA NTRS1984

A Method for Measuring the Effective Throughput Time Delay in Simulated Displays Involving Manual Control

The advent and widespread use of the computer-generated image (CGI) device to simulate visual cues has a mixed impact on the realism and fidelity of flight simulators. On the plus side, CGIs provide greater flexibility in scene content than terrain boards and closed circuit television based visual systems, and they have the potential for a greater field of view. However, on the minus side, CGIs introduce into the visual simulation relatively long time delays. In many CGIs, this delay is as much as 200 ms, which is comparable to the inherent delay time of the pilot. Because most GCIs use multiloop processing and smoothing algorithms and are linked to a multiloop host computer, it is seldom possible to identify a unique throughput time delay, and it is therefore difficult to quantify the performance of the closed loop pilot simulator system relative to the real world task. A method to address these issues using the critical task tester is described. Some empirical results from applying the method are presented, and a novel technique for improving the performance of GCIs is discussed.

Jewell, W. F.↗

NASA NTRS1987

Development of computerized analysis for solid propellant combustion (ISAP-2)

This report is an improvement of ISAP-1, SRB Vorticity-Acoustic Coupled Instability Analysis, September 1986. Included in this report are the automatic generation of all input data for grid configuration, boundary conditions for coupled acoustic and vortical field calculations, transformation of all dimensions to a parametric form, resulting in flexibility for the user to define the size of the problem (geometric configurations) with reduction in storage (15 to 65%) and computer run-time (50 to 75%). Additional research is required for the following areas: (1) turbulence effects; (2) nonlinear wave oscillations; and (3) chemistry upon combustion instability.

Chung, T. J.↗