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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 NTRS2008

Supersonics Project: Airport Noise Technical Challenge

This presentation gives an overview of the work being done under the Airport Noise Technical Challenge portion of the Supersonics Project in the Fundamental Aeronautics Program. The objective of the Challenge is to provide technology (e.g. low noise nozzle concepts) and engineering tools required for a viable supersonic aircraft. To accomplish this we have activities divided into Prediction, Diagnostics, and Engineering elements. Each of the tasks reviewed here have potential applications to work being done at other flight regimes and other aircraft and are of interest to the Acoustics Technical Working Group.

Bridges, James E.↗
NASA NTRS2009

Hubble Servicing Challenges Drive Innovation of Shuttle Rendezvous Techniques

Hubble Space Telescope (HST) servicing, performed by Space Shuttle crews, has contributed to what is arguably one of the most successful astronomy missions ever flown. Both nominal and contingency proximity operations techniques were developed to enable successful servicing, while lowering the risk of damage to HST systems, and improve crew safety. Influencing the development of these techniques were the challenges presented by plume impingement and HST performance anomalies. The design of both the HST and the Space Shuttle was completed before the potential of HST contamination and structural damage by shuttle RCS jet plume impingement was fully understood. Relative navigation during proximity operations has been challenging, as HST was not equipped with relative navigation aids. Since HST reached orbit in 1990, proximity operations design for servicing missions has evolved as insight into plume contamination and dynamic pressure has improved and new relative navigation tools have become available. Servicing missions have provided NASA with opportunities to gain insight into servicing mission design and development of nominal and contingency procedures. The HST servicing experiences and lessons learned are applicable to other programs that perform on-orbit servicing and rendezvous, both human and robotic.

Goodman, John L.↗
NASA NTRS2009

The Elephant in the Room: Biomedical Challenges for Long Duration Lunar Habitation

This slide presentation reviews 4 biomedical challenges that are involved in long duration lunar habitation: dust, radiation, hypogravity and synergistic effects. The first two of these challenges are reviewed with more in-depth information. The dangers of dust relate to the particle deposition in the lungs. The dangers of radiation are related to the permissible exposure limit (PEL) and the Risk of Exposure Induced Death (REID), a statistical approach pegged to a single radiation effect: Death from cancer directly attributable to the exposure. There has been a realization that radiation is more harmful than predicted. This is demonstrated by showing the change in the recommended career dose limits, have changed between 1989 and 2000.

Logan, James S.↗
NASA NTRS2009

Aerodynamic Challenges for the Mars Science Laboratory Entry, Descent and Landing

An overview of several important aerodynamics challenges new to the Mars Science Laboratory (MSL) entry vehicle are presented. The MSL entry capsule is a 70 degree sphere cone-based on the original Mars Viking entry capsule. Due to payload and landing accuracy requirements, MSL will be flying at the highest lift-to-drag ratio of any capsule sent to Mars (L/D = 0.24). The capsule will also be flying a guided entry, performing bank maneuvers, a first for Mars entry. The system's mechanical design and increased performance requirements require an expansion of the MSL flight envelope beyond those of historical missions. In certain areas, the experience gained by Viking and other recent Mars missions can no longer be claimed as heritage information. New analysis and testing is re1quired to ensure the safe flight of the MSL entry vehicle. The challenge topics include: hypersonic gas chemistry and laminar-versus-turbulent flow effects on trim angle, a general risk assessment of flying at greater angles-of-attack than Viking, quantifying the aerodynamic interactions induced by a new reaction control system and a risk assessment of recontact of a series of masses jettisoned prior to parachute deploy. An overview of the analysis and tests being conducted to understand and reduce risk in each of these areas is presented. The need for proper modeling and implementation of uncertainties for use in trajectory simulation has resulted in a revision of prior models and additional analysis for the MSL entry vehicle. The six degree-of-freedom uncertainty model and new analysis to quantify roll torque dispersions are presented.

Schoenenberger, Mark↗
NASA NTRS2009

Apollo 13 Guidance, Navigation, and Control Challenges

Combustion and rupture of a liquid oxygen tank during the Apollo 13 mission provides lessons and insights for future spacecraft designers and operations personnel who may never, during their careers, have participated in saving a vehicle and crew during a spacecraft emergency. Guidance, Navigation, and Control (GNC) challenges were the reestablishment of attitude control after the oxygen tank incident, re-establishment of a free return trajectory, resolution of a ground tracking conflict between the LM and the Saturn V S-IVB stage, Inertial Measurement Unit (IMU) alignments, maneuvering to burn attitudes, attitude control during burns, and performing manual GNC tasks with most vehicle systems powered down. Debris illuminated by the Sun and gaseous venting from the Service Module (SM) complicated crew attempts to identify stars and prevented execution of nominal IMU alignment procedures. Sightings on the Sun, Moon, and Earth were used instead. Near continuous communications with Mission Control enabled the crew to quickly perform time critical procedures. Overcoming these challenges required the modification of existing contingency procedures.

Goodman, John L.↗
NASA NTRS2009

Technology Transfer Challenges: A Case Study of User-Centered Design in NASA's Systems Engineering Culture

The Upper Stage (US) section of the National Aeronautics and Space Administration's (NASA) Ares I rocket will require internal access platforms for maintenance tasks performed by humans inside the vehicle. Tasks will occur during expensive critical path operations at Kennedy Space Center (KSC) including vehicle stacking and launch preparation activities. Platforms must be translated through a small human access hatch, installed in an enclosed worksite environment, support the weight of ground operators and be removed before flight - and their design must minimize additional vehicle mass at attachment points. This paper describes the application of a user-centered conceptual design process and the unique challenges encountered within NASA's systems engineering culture focused on requirements and "heritage hardware". The NASA design team at Marshall Space Flight Center (MSFC) initiated the user-centered design process by studying heritage internal access kits and proposing new design concepts during brainstorming sessions. Simultaneously, they partnered with the Technology Transfer/Innovative Partnerships Program to research inflatable structures and dynamic scaffolding solutions that could enable ground operator access. While this creative, technology-oriented exploration was encouraged by upper management, some design stakeholders consistently opposed ideas utilizing novel, untested equipment. Subsequent collaboration with an engineering consulting firm improved the technical credibility of several options, however, there was continued resistance from team members focused on meeting system requirements with pre-certified hardware. After a six-month idea-generating phase, an intensive six-week effort produced viable design concepts that justified additional vehicle mass while optimizing the human factors of platform installation and use. Although these selected final concepts closely resemble heritage internal access platforms, challenges from the application of the user-centered process provided valuable lessons for improving future collaborative conceptual design efforts.

Quick, Jason↗
NASA NTRS2009

Multiwavelength Challenges in the Fermi Era

The gamma-ray surveys of the sky by AGILE and the Fermi Gamma-ray Space Telescope offer both opportunities and challenges for multi wavelength and multimessenger studies. Gamma-ray bursts, pulsars, binary sources, flaring Active Galactic Nuclei, and Galactic transient sources are all phenomena that can best be studied with a wide variety of instruments simultaneously or contemporaneously. From the gamma-ray side, a principal challenge is the latency from the time of an astrophysical event to the recognition of this event in the data. Obtaining quick and complete multiwavelength coverage of gamma-ray sources of interest can be difficult both in terms of logistics and in terms of generating scientific interest.

Thompson, D. J.↗
NASA NTRS2009

Technology Challenges and Opportunities for Very Large In-Space Structural Systems

Space solar power satellites and other large space systems will require creative and innovative concepts in order to achieve economically viable designs. The mass and volume constraints of current and planned launch vehicles necessitate highly efficient structural systems be developed. In addition, modularity and in-space deployment/construction will be enabling design attributes. While current space systems allocate nearly 20 percent of the mass to the primary structure, the very large space systems of the future must overcome subsystem mass allocations by achieving a level of functional integration not yet realized. A proposed building block approach with two phases is presented to achieve near-term solar power satellite risk reduction with accompanying long-term technology advances. This paper reviews the current challenges of launching and building very large space systems from a structures and materials perspective utilizing recent experience. Promising technology advances anticipated in the coming decades in modularity, material systems, structural concepts, and in-space operations are presented. It is shown that, together, the current challenges and future advances in very large in-space structural systems may provide the technology pull/push necessary to make solar power satellite systems more technically and economically feasible.

Belvin, W. Keith↗
NASA NTRS2009

Life Support Systems Microbial Challenges

This presentation reviews the current microbial challenges of environmental control and life support systems. The contents include: 1) Environmental Control and Life Support Systems (ECLSS) What is it?; 2) A Look Inside the International Space Station (ISS); 3) The Complexity of a Water Recycling System; 4) ISS Microbiology Acceptability Limits; 5) Overview of Current Microbial Challenges; 6) In a Perfect World What we Would like to Have; and 7) The Future.

Monsi C Roman↗
NASA NTRS2009

Challenges with Deploying and Integrating Environmental Control and Life Support Functions in a Lunar Architecture with High Degrees of Mobility

Visions of lunar outposts often depict a collection of fixed elements such as pressurized habitats, in and around which human inhabitants spend the large majority of their surface stay time. In such an outpost, an efficient deployment of environmental control and life support equipment can be achieved by centralizing certain functions within one or a minimum number of habitable elements and relying on the exchange of gases and liquids between elements via atmosphere ventilation and plumbed interfaces. However, a rigidly fixed outpost can constrain the degree to which the total lunar landscape can be explored. The capability to enable widespread access across the landscape makes a lunar architecture with a high degree of surface mobility attractive. Such mobility presents unique challenges to the efficient deployment of environmental control and life support functions in multiple elements that may for long periods of time be operated independently. This paper describes some of those anticipated challenges.

Bagdigian, Robert M.↗
NASA NTRS2009

Vibration Challenges in the Design of NASA's Ares Launch Vehicles

This paper focuses on the vibration challenges inherent in the design of NASA s Ares launch vehicles. A brief overview of the launch system architecture is provided to establish the context for the discussion. Following this is a general discussion of the design considerations and analytical disciplines that are affected by vibration. The first challenge discussed is that of coupling between the vehicle flight control system and fundamental vibrational modes of the vehicle. The potential destabilizing influence of the vibrational dynamics is described along with discussion of the typical methods employed to overcome this issue. Next is a general discussion of the process for developing the design loads for the primary structure. This includes quasi-steady loads and dynamic loads induced by the structural dynamic response. The two principal parts of this response are the gust induced responses of the lower frequency modes and the buffet induced responses of the higher frequency modes. Structural dynamic model validation will also be addressed. Following this, discussions of three somewhat unique topics of Pogo Instability, Solid Booster Thrust Oscillation, and Liquid Rocket Engine Turbopump Rotordynamic Stability and Response are presented.

Ryan, Stephen G.↗
NASA NTRS2009

The Status of the Mock LISA Data Challenges

For the last four years, many gravitational-wave researchers around the world have participated in the Mock LISA Data Challenges (MLDCs), a program to demonstrate and encourage the development of LISA data-analysis capabilities, tools and techniques. In this poster, we present a summary of the results of MLDC 3, which was completed in 2009. During MLDC 3, 27 participants from 15 institutions successfully analyzed data sets that included Galactic binaries, coalescing spinning massive black holes, extreme-mass-ratio inspirals, cosmic-string cusp bursts and a stochastic gravitational-wave background. We also describe the technical and scientific challenges that will be addressed by future MLI)Cs, starting with MLDC 4, which is currently in progress.

Baker, John↗
NASA NTRS2010

Challenges and Lessons Learned From Resurrecting a Legacy Research Flight Controller

Resurrecting the legacy Inner Loop Thrust Vectoring research flight controller to investigate the tail shock region brought unique challenges. This report documents these challenges and lessons learned from a stability and controls perspective. The flight test approach for flight envelope expansion and probing tests, as well as limited flight test results, are presented. Recent advances in sonic boom reduction technology have contributed to a resurgent interest in civilian supersonic cruise flight. These advances have focused only on fore body shaping, however, and little, if any, experimental flight data are available to develop and validate design tools for the tail shock region. In January of 2009, the NASA Dryden Flight Research Center completed research flights to investigate the tail shock region of a highly modified F-15 aircraft by probing the shock waves around it, using another F-15 aircraft. To adjust the lift distribution and plume shape, a decade-old research flight controller from the Inner Loop Thrust Vectoring project was required. To investigate the tail shock region, the lift distribution was changed by adjusting the canard position, and the plume shape was changed by adjusting the nozzle area and thrust vectoring.

Dees, Ray A.↗
NASA NTRS2009

Software Health Management: A Short Review of Challenges and Existing Techniques

Modern spacecraft (as well as most other complex mechanisms like aircraft, automobiles, and chemical plants) rely more and more on software, to a point where software failures have caused severe accidents and loss of missions. Software failures during a manned mission can cause loss of life, so there are severe requirements to make the software as safe and reliable as possible. Typically, verification and validation (V&V) has the task of making sure that all software errors are found before the software is deployed and that it always conforms to the requirements. Experience, however, shows that this gold standard of error-free software cannot be reached in practice. Even if the software alone is free of glitches, its interoperation with the hardware (e.g., with sensors or actuators) can cause problems. Unexpected operational conditions or changes in the environment may ultimately cause a software system to fail. Is there a way to surmount this problem? In most modern aircraft and many automobiles, hardware such as central electrical, mechanical, and hydraulic components are monitored by IVHM (Integrated Vehicle Health Management) systems. These systems can recognize, isolate, and identify faults and failures, both those that already occurred as well as imminent ones. With the help of diagnostics and prognostics, appropriate mitigation strategies can be selected (replacement or repair, switch to redundant systems, etc.). In this short paper, we discuss some challenges and promising techniques for software health management (SWHM). In particular, we identify unique challenges for preventing software failure in systems which involve both software and hardware components. We then present our classifications of techniques related to SWHM. These classifications are performed based on dimensions of interest to both developers and users of the techniques, and hopefully provide a map for dealing with software faults and failures.

Pipatsrisawat, Knot↗
NASA NTRS2010

Aircraft Emergencies: Challenge and Response

Emergency and abnormal situations in aviation present flight crews with a number of challenges. Checklists are essential tools that have been developed to assist them to meet these challenges. However, in order for checklists to be most effective in these situations they must be designed with the operational and situational demands of emergencies and abnormal conditions in mind as well as human performance capabilities and limitations under high stress and workload.

Burian, Barbara K.↗
NASA NTRS2010

Workmanship Challenges for NASA Mission Hardware

This slide presentation reviews several challenges in workmanship for NASA mission hardware development. Several standards for NASA workmanship exist, that are required for all programs, projects, contracts and subcontracts. These Standards contain our best known methods for avoiding past assembly problems and defects. These best practices may not be available if suppliers are used who are not compliant with them. Compliance includes having certified operators and inspectors. Some examples of problems that have occured from the lack of requirements flow-down to contractors are reviewed. The presentation contains a detailed example of the challenge in regards to The Packaging "Design" Dilemma.

Plante, Jeannette↗
NASA NTRS2010

Present Challenges, Critical Needs, and Future Technological Directions for NASA's GN and C Engineering Discipline

The National Aeronautics and Space Administration (NASA) is currently undergoing a substantial redirection. Notable among the changes occurring within NASA is the stated emphasis on technology development, integration, and demonstration. These new changes within the Agency should have a positive impact on the GN&C discipline given the potential for sizeable investments for technology development and in-space demonstrations of both Autonomous Rendezvous & Docking (AR&D) systems and Autonomous Precision Landing (APL) systems. In this paper the NASA Technical Fellow for Guidance, Navigation and Control (GN&C) provides a summary of the present technical challenges, critical needs, and future technological directions for NASA s GN&C engineering discipline. A brief overview of the changes occurring within NASA that are driving a renewed emphasis on technology development will be presented as background. The potential benefits of the planned GN&C technology developments will be highlighted. This paper will provide a GN&C State-of-the-Discipline assessment. The discipline s readiness to support the goals & objectives of each of the four NASA Mission Directorates is evaluated and the technical challenges and barriers currently faced by the discipline are summarized. This paper will also discuss the need for sustained investments to sufficiently mature the several classes of GN&C technologies required to implement NASA crewed exploration and robotic science missions.

Dennehy, Cornelius J.↗
NASA NTRS2010

Multiwavelength Challenges in the Fermi Era

The gamma-ray surveys of the sky by AGILE and the Fermi Gamma-ray Space Telescope offer both opportunities and challenges for multiwavelength and multi-messenger studies. Gamma-ray bursts, pulsars, binary sources, flaring Active Galactic Nuclei, and Galactic transient sources are all phenomena that can best be studied with a wide variety of instruments simultaneously or contemporaneously. From the gamma-ray side, a principal challenge is the latency from the time of an astrophysical event to the recognition of this event in the data. Obtaining quick and complete multiwavelength coverage of gamma-ray sources of interest can be difficult both in terms of logistics and in terms of generating scientific interest.

Thompson, D. J.↗