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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 91 records · Page 5

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NASA NTRS1975

Space Processing Applications - The new challenge

The impact of Skylab Space Processing Applications experiments upon ground based research laboratory capabilities is discussed. The findings of a few selected space processing Skylab experiments are summarized and explained. The objectives of the ASTP space processing experiments are summarized. NASA's plans for use of sounding rockets for space processing experiments are outlined briefly. The integration of NASA's Space Processing Program into an active planning effort for use of Shuttle is reviewed.

Montgomery, B. O.↗

NASA NTRS2000

Molluscan engrailed expression, serial organization, and shell evolution

Whether the serial features found in some molluscs are ancestral or derived is considered controversial. Here, in situ hybridization and antibody studies show iterated engrailed-gene expression in transverse rows of ectodermal cells bounding plate field development and spicule formation in the chiton, Lepidochitona cavema, as well as in cells surrounding the valves and in the early development of the shell hinge in the clam, Transennella tantilla. Ectodermal expression of engrailed is associated with skeletogenesis across a range of bilaterian phyla, suggesting a single evolutionary origin of invertebrate skeletons. The shared ancestry of bilaterian-invertebrate skeletons may help explain the sudden appearance of shelly fossils in the Cambrian. Our interpretation departs from the consideration of canonical metameres or segments as units of evolutionary analysis. In this interpretation, the shared ancestry of engrailed-gene function in the terminal/posterior addition of serially repeated elements during development explains the iterative expression of engrailed genes in a range of metazoan body plans.

Non-NASA Center↗

NASA NTRSDate not supplied

Identification of Risks to Eva Created By Ambient Lighting Conditions at the Lunar South Pole

In the coming years, NASA’s Artemis Campaign intends to return humans to the Moon, both to explore and to establish a permanent human presence. The targeted landing and habitation sites are near the Lunar South Pole (LSP). Compared to the middle latitudes where the Apollo landings occurred, the sun at the LSP is consistently low in the sky, creating a much more challenging visual experience. The NASA Engineering & Safety Center (NESC) is working to characterize the extremes in ambient illumination that astronauts will encounter at the LSP, and to help programs characterize the lighting systems and glare protection that will be required to conduct safe surface operations. This paper will describe the LSP natural environments, and efforts to simulate that visual experience. It will also explain the risks derived from the lighting environment for the mission goals currently planned, and the kinds of new capabilities both in simulation techniques and in surface equipment that will be required to support those mission goals.

Identification of Risks↗

NASA NTRS1991

Autonomous space processor for orbital debris

The development of an Autonomous Space Processor for Orbital Debris (ASPOD) was the goal. The nature of this craft, which will process, in situ, orbital debris using resources available in low Earth orbit (LEO) is explained. The serious problem of orbital debris is briefly described and the nature of the large debris population is outlined. The focus was on the development of a versatile robotic manipulator to augment an existing robotic arm, the incorporation of remote operation of the robotic arms, and the formulation of optimal (time and energy) trajectory planning algorithms for coordinated robotic arms. The mechanical design of the new arm is described in detail. The work envelope is explained showing the flexibility of the new design. Several telemetry communication systems are described which will enable the remote operation of the robotic arms. The trajectory planning algorithms are fully developed for both the time optimal and energy optimal problems. The time optimal problem is solved using phase plane techniques while the energy optimal problem is solved using dynamic programming.

Ramohalli, Kumar↗

NASA NTRS1991

Mission and Safety Critical (MASC) plans for the MASC Kernel simulation

This report discusses a prototype for Mission and Safety Critical (MASC) kernel simulation which explains the intended approach and how the simulation will be used. Smalltalk is chosen for the simulation because of usefulness in quickly building working models of the systems and its object-oriented approach to software. A scenario is also introduced to give details about how the simulation works. The eventual system will be a fully object-oriented one implemented in Ada via Dragoon. To implement the simulation, a scenario using elements typical of those in the Space Station, was created.

Source record↗

NASA NTRS2001

Launcher Systems Development Cost: Behavior, Uncertainty, Influences, Barriers and Strategies for Reduction

This paper will report on the activities of the IAA Launcher Systems Economics Working Group in preparations for its Launcher Systems Development Cost Behavior Study. The Study goals include: improve launcher system and other space system parametric cost analysis accuracy; improve launcher system and other space system cost analysis credibility; and provide launcher system and technology development program managers and other decisionmakers with useful information on development cost impacts of their decisions. The Working Group plans to explore at least the following five areas in the Study: define and explain development cost behavior terms and concepts for use in the Study; identify and quantify sources of development cost and cost estimating uncertainty; identify and quantify significant influences on development cost behavior; identify common barriers to development cost understanding and reduction; and recommend practical, realistic strategies to accomplish reductions in launcher system development cost.

Shaw, Eric J.↗

NASA NTRS2007

Implementation of a Collision Probability Prediction Technique for Constellation Maneuver Planning

On March 22, 2006, the Space Technology 5 (ST5) constellation spacecraft were successfully delivered to orbit by a Pegasus XI, launch vehicle. An unexpected relative motion experienced by the constellation after orbit insertion brought about a problem. Soon after launch the observed relative position of the inert rocket body was between the leading and the middle spacecraft within the constellation. The successful planning and execution of an orbit maneuver that would create a fly-by of the rocket body was required to establish the.formation. This maneuver would create a close approach that needed to conform to predefined collision probability requirements. On April 21, 2006, the ST5 "155" spacecraft performed a large orbit maneuver and successfully passed the inert Pegasus 3rd Stage Rocket Body on April 30, 2006 15:20 UTC at a distance of 2.55 km with a Probability of Collision of less than 1.0E-06. This paper will outline the technique that was implemented to establish the safe planning and execution of the fly-by maneuver. The method makes use of Gaussian distribution models of state covariance to determine underlying probabilities of collision that arise under low velocity encounters. Specific numerical examples used for this analysis are discussed in detail. The mechanics of this technique are explained to foster deeper understanding of the concepts presented and to improve existing processes for use in future constellation maneuver planning.

Concha, Marco a.↗

NASA NTRS1972

The Role of the Manufacturer in Air Transportation Planning

The role of the aircraft manufacturer in the airline industry is considered. The process is illustrated by using a fictitious airline as an example--that is, a case study approach with Mid-Coast Airways serving as the example. Both in slide form and with supporting papers, a brief history of the airline, a description of its route structure and a forecast based on econometric analysis are presented. Once the forecast rationale is explained, information outlines the requirements for additional aircraft and the application of new aircraft across the system using alternative fleet plan options. The fleet plan is translated into financial summaries which indicate the relative merit of alternative aircraft types or operating plans.

Mackenzie, J.↗

NASA NTRS1982

Selection of frequencies for deep-space telecommunications

The procedures used by the Jet Propulsion Laboratory to select and recommend frequencies to be used for deep space telecommunications are explained. The frequency selection process described deals only with the potential for radio frequency interference between deep space telecommunication links. Channel plans based on bandwidth, hardware implementation, and frequency ratio considered are used. The channel selection process is based on calculations and analysis of interference-to-signal power ratios as a function of time for each possible pair of missions. The modes of interference and the interference protection ratio are explained, and the interference analysis procedure described. Equations used in calculating the downlink and uplink interference analyses are presented.

Degroot, N. F.↗

NASA NTRS1984

Overview of materials processing in space activity at Marshall Space Flight Center

An overview of activities involving the Space Transportation System (STS), now in the operational phase, and results of some of the current space experiments, as well as future research opportunities in microgravity environment, are presented. The experiments of the Materials Processing in Space Program flown on the STS, such as bioseparation processes, isoelectric focusing, solidification and crystal growth processes, containerless processes, and the Materials Experiment Assembly experiments are discussed. Special consideration is given to the experiments to be flown aboard the Spacelab 3 module, the Fluids Experiments System, and the Vapor Crystal Growth System. Ground-based test facilities and planned space research facilities, as well as the nature of the commercialization activities, are briefly explained.

Williams, J. R.↗

NASA NTRS1991

Shuttle-C auxiliary propulsion system certification approach and low-cost evolution concepts

Shuttle-C provides NASA with a heavy-lift cargo capability that is a low-cost derivative of the current Space Shuttle. This system can deliver 80,000 to 140,000 pounds of payload to low earth orbit within 4 years of authority to proceed. Shuttle-C will share th existing Shuttle launch facilities at Kennedy Space Center (KSC). The Shuttle-C vehicle incorporates an auxiliary propulsion system (APS) which provides separation from the external tank (ET), orbit circularization, on-orbit attitude hold, and deorbit capability. The APS is derived from the Shuttle orbiter aft reaction control system (ARCS) and orbital maneuvering system (OMS) with the objective of achieving minimum life cycle cost for this expendable vehicle. The resulting APS system will be described, its plan for a minimum-cost flight certification utilizing a cold-flow test program explained, and low-cost evolution by component design modification and part substitution presented.

Harsh, M. George↗

NASA NTRS2021

ATTRACTOR: Autonomy Teaming and TRAjectories for Complex Trusted Operational Reliability

Autonomous systems (AS) are crucial to realizing the vision of new, complex transportation modes, such as advanced air mobility (AAM) and urban air mobility (UAM). A chief barrier to induction of AS into aviation is insufficient understanding of AS reliability in time-critical and safety-critical environments—an obstacle to certification. ATTRACTOR is aimed at building a basis for certification of classes of autonomous cyber-physical-human systems (CPHS) via establishing metrics and models of trustworthiness and trust in multi-agent team interactions, analyzable trajectories, explainability of computational algorithms (explainable artificial intelligence, or XAI), and persistent modeling and simulation, in the context of missions planning and operation. By “building a basis for certification,” we mean acquiring an understanding of when a system is trustworthy and developing computable means to estimate trustworthiness and trust in order to eventually inform functional requirements that contribute to certification. The outcomes are applicable not just to aviation but to all domains that rely on autonomous systems.

Autonomy↗

NASA NTRS1982

Upward Mobility Program Handbook

This handbook contains the policy and program objectives of the NASA Upward Mobility Program. In addition it gives guidance regarding program planning, implementation, and evaluation and also describes the roles and responsibilities of key personnel responsible for the successful implementation of the program. The Federal Personnel Manual Chapter 720 explains the Federal Government's policy on upward mobility and is available from the installation personnel office upon request. This handbook is applicable to all NASA installations. Unless specifically limited, all responsibilities set forth in this plan for the Installation Personnel Director may be administered wholly or in part by the Personnel Director's designee. This handbook will be revised by page changes.

Source record↗

NASA NTRS1973

Hollow cathode restartable 15 cm diameter ion thruster

The effects of substituting high perveance dished grids for low perveance flat ones on performance variables and plasma properties within a 15 cm modified SERT II thruster are discussed. Results suggest good performance may be achieved as an ion thruster is throttled if the screen grid transparency is decreased with propellant flow rate. Thruster startup tests, which employ a pulsed high voltage tickler electrode between the keeper and the cathode to initiate the discharge, are described. High startup reliability at cathode tip temperatures of about 500 C without excessive component wear over 2000 startup cycles is demonstrated. Testing of a single cusp magnetic field concept of discharge plasma containment is discussed. A theory which explains the observed behavior of the device is presented and proposed thruster modifications and future testing plans are discussed.

Wilbur, P. J.↗

NASA NTRS2002

Expedition 5 Crew Interviews: Valery Korzun, Commander

Expedition 5 Commander Valery Kozun is seen during a prelaunch interview. He gives details on the mission's goals and significance, his role in the mission and what his responsibilities will be as commander, what the crew exchange will be like (the Expedition 5 crew will replace the Expedition 4 crew on the International Space Station (ISS)), the daily life on an extended stay mission, the loading operations that will take place, the experiments he will be conducting on board, and the planned extravehicular activities (EVAs) scheduled for the mission. Kozun discusses the EVAs in greater detail and explains the significance of the Mobile Base System and the Crew Equipment Translation Aid (CETA) cart for the ISS. He also explains at some length the science experiments which will be conducted on board by the Expedition 5 crew members. Korzun also touches on how his previous space experience on Mir (including dealing with a very serious fire) will benefit the Expedition 5 mission.

Source record↗

NASA NTRS1991

Architecting a mission plan for Lunar Observer

The present status of NASA's Lunar Observer study effort at JPL is discussed in the context of an ongoing 20-year series of studies focused on defining a robotic, low-altitude, polar-orbiting mission to the moon. The primary emphasis of the discussion is a review of the various systems-level factors that drive the overall architecture of the mission plan. Selected top-level project and science requirements are summarized and the current mission and science objectives are presented. A brief description of the candidate science instrument complement is included. Several significant orbital effects caused by the lunar gravity field are explained and the variety of trajectory and maneuver options considered for both getting to the moon and orbiting there are described. Several candidate mission architectures are outlined and the mission plans chosen for future study are described. Two mission options result: a single-spacecraft, single-launch scenario, and a multiple-spacecraft, multiple-launch concept.

Ridenoure, Rex W.↗

NASA NTRS1988

MOORE: A prototype expert system for diagnosing spacecraft problems

MOORE is a rule-based, prototype expert system that assists in diagnosing operational Tracking and Data Relay Satellite (TDRS) problems. It is intended to assist spacecraft engineers at the TDRS ground terminal in trouble shooting problems that are not readily solved with routine procedures, and without expert counsel. An additional goal of the prototype system is to develop in-house expert system and knowledge engineering skills. The prototype system diagnoses antenna pointing and earth pointing problems that may occur within the TDRS Attitude Control System (ACS). Plans include expansion to fault isolation of problems in the most critical subsystems of the TDRS spacecraft. Long term benefits are anticipated with use of an expert system during future TDRS programs with increased mission support time, reduced problem solving time, and retained expert knowledge and experience. Phase 2 of the project is intended to provide NASA the necessary expertise and capability to define requirements, evaluate proposals, and monitor the development progress of a highly competent expert system for NASA's Tracking Data Relay Satellite. Phase 2 also envisions addressing two unexplored applications for expert systems, spacecraft integration and tests (I and T) and support to launch activities. The concept, goals, domain, tools, knowledge acquisition, developmental approach, and design of the expert system. It will explain how NASA obtained the knowledge and capability to develop the system in-house without assistance from outside consultants. Future plans will also be presented.

Howlin, Katherine↗

NASA NTRS1972

Apollo portable life support system performance report

The performance of the Apollo portable life support system (PLSS) on actual lunar missions is discussed. Both subjective comments by the crewmen and recorded telemetry data are evaluated although emphasis is on the telemetry data. Because the most important information yielded by the PLSS deals with determination of crewman metabolic rates, these data and their interpretation are explained in detail. System requirements are compared with actual performance, and the effect of performance margins on mission planning are described. Mission preparation testing is described to demonstrate how the mission readiness of the PLSS and the crewmen in verified, and to show how the PLSS and the crewmen are calibrated for mission evaluation.

Carson, M. A.↗