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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 415 records · Page 23

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NASA NTRS1989

Semi-autonomous design concepts for a Mars rover

Studies of rover mobility and surface rendezvous for a Mars Rover/Sample Return (MRSR) mission have been performed. The objective of these efforts has been to identify and address the most challenging issues and develop the most promising design options for the rover mobility and navigation subsystems. A series of trade studies culminated in three candidate design concepts: a large, but otherwise conventional four-wheel drive vehicle; a sophisticated and agile six-legged walking vehicle; and a greatly simplified legged vehicle. This paper summarizes the key design features for these three concepts. For each design, the approaches to vehicle locomotion, sensing and navigation are discussed first. Timelines are developed for the adopted concepts of operation which constrain the range of the remaining parameters. Estimates of rover mass, volume, and power are provided, and performance is projected for vehicle range, terrain traversibility and navigation accuracy.

Spiessbach, Andrew J.↗

NASA NTRS1988

The CDAW-8 substorm event on 28 January 1983 - A detailed global study

A small, isolated substorm with an expansion phase onset at 0739 UT on January 28, 1983 was well observed by ground-based instrumentation as well as by low- and high-altitude spacecraft. Because of the comprehensive nature of the data coverage, including ISEE-3 identification of plasmoid signatures in the deep tail (about 220 earth radii) associated with the substorm, a detailed timeline of the growth, expansion, and recovery phases of the substorm can be provided. The plasma, energetic particle, and field signatures at ISEE-3 are considered within the framework of the near-earth data. Quantitative estimates of substorm energy input and output relationships are made for this case, and the timing and physical dimensions of the deep tail disturbance implied are evaluated by the global observations available.

Baker, D. N.↗

NASA NTRS1989

Increased efficiency of mammalian somatic cell hybrid production under microgravity conditions during ballistic rocket flight

The electrofusion of hybridoma cell lines under short-duration microgravity during a flight of the TEXUS 18 Black Brand ballistic sounding rocket at Kiruna, Sweden is reported. The fusion partners, growth medium, cell fusion medium, cell fusion, cell viability in the fusion medium, and postfusion cell culture are described, and the rocket, cell fusion chamber, apparatus, and module are examined. The experimental timeline, the effects of fusion medium and incubation time on cell viability and hybrid yields, and the effect of microgravity on hybrid yields are considered.

Schnettler, R.↗

NASA NTRS1989

The Space Station Freedom evolution-phase - Crew-EVA demand for robotic substitution by task primitive

Space Station Freedom represents a significant demand for automation and robotics services as substitutes for crew EVAs. Results are reported from a study aimed at identifying the demand for crew EVA and the crew-task primitive distributions derived for input to future robotic substitution studies. Generic EVA tasks are developed from historical EVA mission timelines, and a set of 70 task primitives defined. The generic task activities are partitioned into task setup, kernel, and tear-down, with standardized task times and frequencies. These standardized times are coupled with inputs from numerous mission data bases in a probabilistic simulation to obtain estimates of total crew-EVA task time demand by crew task primitive. The use of probabilistic model is found to be crucial for understanding, isolating, and addressing the large uncertainties in the EVA task kernels.

Smith, Jeffrey H.↗

NASA NTRS1989

Design of a final approach spacing tool for TRACON air traffic control

This paper describes an automation tool that assists air traffic controllers in the Terminal Radar Approach Control (TRACON) Facilities in providing safe and efficient sequencing and spacing of arrival traffic. The automation tool, referred to as the Final Approach Spacing Tool (FAST), allows the controller to interactively choose various levels of automation and advisory information ranging from predicted time errors to speed and heading advisories for controlling time error. FAST also uses a timeline to display current scheduling and sequencing information for all aircraft in the TRACON airspace. FAST combines accurate predictive algorithms and state-of-the-art mouse and graphical interface technology to present advisory information to the controller. Furthermore, FAST exchanges various types of traffic information and communicates with automation tools being developed for the Air Route Traffic Control Center. Thus it is part of an integrated traffic management system for arrival traffic at major terminal areas.

Davis, Thomas J.↗

NASA NTRS1990

Payload crew utilization for spacelab missions

Planned payload crew utilization on Spacelab mission are analyzed to establish trends and guidelines. The study included missions that have flow to date as well as those in planning. Available data were analyzed on the basis of four major timeline iterations that occur during mission design. Data were categorized and assessed by crewmember, flight day, and mission. Based on the results of this analysis, it was recommended that for the Requirements Review and Preliminary Design Review iterations the maximum utilization per shift should be 75 percent for the Payload Specialist (PS) and 65 percent for the Mission Specialist (MS); and for the basic and final iterations, the maximum utilization shift should be 85 percent for the PS and 75 percent for the MS. Additional recommendations include limiting the amount of activity during the first two shifts whenever possible and establishing a common set of guidelines for the calculations of crew utilization.

Ibrahim, K. Y.↗

NASA NTRS1989

Combustion process science and technology

An important and substantial area of technical work in which noncontact temperature measurement (NCTM) is desired is that involving combustion process research. In the planning for this workshop, it was hoped that W. Serignano would provide a briefing regarding the experimental requirements for thermal measurements to support such research. The particular features of thermal measurement requirements included those describing the timeline for combustion experiments, the requirements for thermal control and diagnostics of temperature and other related thermal measurements and the criticality to the involved science to parametric features of measurement capability including precision, repeatability, stability, and resolution. In addition, it was hoped that definitions could be provided which characterize the needs for concurrent imaging as it relates to science observations during the conduct of experimentation.

Hale, Robert R.↗

NASA NTRS1990

Interactions between the Space Station and the environment: A preliminary assessment of EMI

A review of the interactions between proposed Space Station systems/payloads and the environment that contribute to electromagnetic interference was performed. Seven prime sources of interference have been identified. These are: The Space Station power system; active experiments such as beam injection; ASTROMAG; ram and wake density gradients; pick up ions produced by vented or offgassed clouds; waves produced by current loops that include the plasma and structure; arcing from high voltage solar arrays (or possible ESD in polar orbit). This review indicates that: minimizing leakage current from the 20 kHz power system to the structure; keeping the surfaces of the Space Station structure, arrays, and radiators nonconducting; minimizing venting of payloads or systems to non-operational periods; careful placement of payloads sensitive to magnetic field perturbations or wake noise; and designing an operational timeline compatible with experiment requirement are the most effective means of minimizing the effects of this interference. High degrees of uncertainty exist in the estimates of magnitudes of gas emission induced EMI, radiation of 20 kHz and harmonics, ASTROMAG induced interference, and arc threshold/frequency of the solar array. These processes demand further attention so that mitigation efforts are properly calibrated.

Murphy, G. B.↗

NASA NTRS1989

Design of a Lunar Farside Observatory

The design of a mantendable lunar farside observatory and science base is presented. A farside observatory will allow high accuracy astronomical observations, as well as the opportunity to perform geological and low gravity studies on the Moon. The requirements of the observatory and its support facilities are determined, and a preliminary timeline for the project development is presented. The primary areas of investigation include observatory equipment, communications, habitation, and surface operations. Each area was investigated to determine the available options, and each option was evaluated to determine the advantages and disadvantages. The options selected for incorporation into the design of the farside base are presented. The observatory equipment deemed most suitable for placement on the lunar farside consist of large optical and radio arrays and seismic equipment. A communications system consisting of a temporary satellite about the L sub 2 libration point and followed by a satellite at the stable L sub 5 libration point was selected. A space station common module was found to be the most practical option for housing the astronauts at the base. Finally, a support system based upon robotic construction vehicles and the use of lunar materials was determined to be a necessary component of the base.

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NASA NTRS1990

In-space construction and dynamics of large space structures

The types of equipment and structures that will be required to construct very large spacecraft in space are discussed. One of the basic issues that must be resolved is the appropriate mix of humans and machines in the construction process. While the use of robots offers the potential for reducing the number of extra-vehicular activity (EVA) hours required for particular construction operations, the availability of humans greatly increases the reliability of complex construction tasks. A hybrid system is described which makes the best use of man and machine to provide a highly reliable and versatile construction approach. Such a system will provide an efficient method for constructing large spacecraft until fully automated, robotic devices can be perfected. Details are given on an extensive ground test program which was designed to evaluate and demonstrate large spacecraft construction. A discussion is presented on the use of the Space Station Freedom, or an appropriate derivative, as a construction facility. Finally, a construction scenario and assembly timelines are presented for constructing a 20-meter-diameter high precision reflector.

Mikulas, Martin M., Jr.↗

NASA NTRS1990

Mesoscale Lightning Experiment (MLE): A view of lightning as seen from space during the STS-26 mission

Information on the data obtained from the Mesoscale Lightning Experiment flown on STS-26 is provided. The experiment used onboard TV cameras and a 35 mm film camera to obtain data. Data from the 35 mm camera are presented. During the mission, the crew had difficulty locating the various targets of opportunity with the TV cameras. To obtain as much data as possible in the short observational timeline allowed due to other commitments, the crew opted to use the hand-held 35 mm camera.

Vaughan, O. H., Jr.↗

NASA NTRS1990

The FIFE information system

A description is given of the FIFE (First ISLSCP Field Experiment) information system, which was developed to serve FIFE investigators as a tool for designing the experiment and for organizing and manipulating the complex data set. Fulfilling these functions on an experiment-driven timeline led to abandoning the classical sequential development paradigm of software engineering in favor of a more responsive and broadly based approach. The design, development, and operation of the information system supporting the experiment had to be flexible and under direct day-to-day control of scientist/users. Because of the organization around scientific requirements, the system was able to incorporate diverse data types in a systematic way as they became available, to add scientific rigor by identifying data gaps at an early stage, and to provide real-time quality assurance. These factors are important for designing and building future databases and long-term information systems to support interdisciplinary scientific research.

Strebel, Donald E.↗

NASA NTRS1990

A global view of lander-to-orbiter communications accessibility for a Mars Global Network Mission

Given the mission objective to deploy a number of small landers to the surface of Mars at various latitude/longitude locations, it is of interest to obtain a global perspective of the communications link geometry between the landers and a data relay orbiter. Specifically, the question to be answered is what is the total time interval over one Martian day (1 sol) that a lander at any given latitude and longitude can communicate data to the orbiter. Results should be obtained for more than one elevation angle constraint (lander antenna design issue), and also for several time points into the mission since the orbiter's periapsis location moves under the influence of Mars' oblateness perturbation. Such information is presented in terms of global contour maps of available communications time per sol summed over all orbiter pases on that day. Global data of this type complements more detailed local site data such as communications range and elevation vs time per pass. Communications time contour maps are included here for sol grids of 180, 232, 318, 361, and 404 corresponding to orbiter periapsis latitudes of 35 S, 90 S, equatorial, 45 N, and 90 N. For each of these days, there is a map for both a 15 deg and 45 deg minimum elevation constraint on the lander-to-orbiter line of sight. The jagged appearance of the contour lines is due to computational resolution in interpolating between a finite number of latitude/longitude grid points. Although the contours should really be smooth, the general information content is represented by the lower resolution maps shown here. An example of the tabulated, finite-grid data points is also given. Communication with all sites is possible at the 15 deg elevation constraint, at times only for several minutes per sol but more generally for a much longer time up to 14 hours per sol. Significantly less time is available with a 45 deg elevation constraint, and at certain times in the mission some localized regions of the planet are inaccessible. Still, one may conclude that the reference orbit selection will support a more than adequate communications link through the mission timeline with landers emplaced at any desired location on Mars.

Friedlander, Alan L.↗

NASA NTRS1991

Advanced technology needs for a global change science program: Perspective of the Langley Research Center

The focus of the NASA program in remote sensing is primarily the Earth system science and the monitoring of the Earth global changes. One of NASA's roles is the identification and development of advanced sensing techniques, operational spacecraft, and the many supporting technologies necessary to meet the stringent science requirements. Langley Research Center has identified the elements of its current and proposed advanced technology development program that are relevant to global change science according to three categories: sensors, spacecraft, and information system technologies. These technology proposals are presented as one-page synopses covering scope, objective, approach, readiness timeline, deliverables, and estimated funding. In addition, the global change science requirements and their measurement histories are briefly discussed.

Rowell, Lawrence F.↗

NASA NTRS1989

Flight Operations reunion for the Apollo 11 20th anniversary of the first manned lunar landing

The following major areas are presented: (1) the Apollo years; (2) official flight control manning list for Apollo 11; (3) original mission control emblem; (4) foundations of flight control; (5) Apollo-11 20th anniversary program and events; (6) Apollo 11 mission operations team certificate; (7) Apollo 11 mission summary (timeline); and (8) Apollo flight control team photographs and biographies.

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NASA NTRS1991

Costs and benefits of lunar oxygen: Engineering, operations, and economics

Oxygen is the most commonly discussed lunar resource. It will certainly not be the easiest to retrieve, but oxygen's fundamental place in propulsion and life support guarantees it continued attention as a prime candidate for early in situ resource utilization (ISRU). The findings are reviewed of recent investigation, sponsored by NASA-Ames, into the kinds of technologies, equipment, and scenarios (the engineering and operations costs) that will be required even to initiate lunar oxygen production. The infrastructure necessary to surround and support a viable oxygen-processing operation is explained. Selected details are used to illustrate the depth of technology challenges, extent of operations burdens, and complexity of decision linkages. Basic assumptions, and resulting timelines and mass manifests, are listed. These findings are combined with state-of-the-art knowledge of lunar and Mars propulsion options in simple economic input/output and internal-rate-of-return models, to compare production costs with performance benefits. Implications for three realistic scales of exploration architecture - expeditionary, aggressive science, and industrialization/settlement - are discussed. Conclusions are reached regarding the contextual conditions within which production of lunar oxygen (LLOX) is a reasonable activity. LLOX appears less useful for Mars missions than previously hoped. Its economical use in low Earth orbit hinges on production of lunar hydrogen as well. LLOX shows promise for lunar ascent/descent use, but that depends strongly on the plant mass required.

Sherwood, Brent↗

NASA NTRS1991

Resource envelope concepts for mission planning

Seven proposed methods for creating resource envelopes for Space Station Freedom mission planning are detailed. Four reference science activity models are used to illustrate the effect of adding operational flexibility to mission timelines. For each method, a brief explanation is given along with graphs to illustrate the application of the envelopes to the power and crew resources. The benefits and costs of each method are analyzed in terms of resource utilization. In addition to the effect on individual activities, resource envelopes are analyzed at the experiment level.

Ibrahim, K. Y.↗

NASA NTRS1990

The JOVE initiative - A NASA/university Joint Venture in space science

The JOVE (NASA/university Joint Venture in space science) initiative is a point program between NASA and institutions of higher education whose aim is to bring about an extensive merger between these two communities. The project is discussed with emphasis on suggested contributions of partnership members, JOVE process timeline, and project schedules and costs. It is suggested that NASA provide a summer resident research associateship (one ten week stipend); scientific on-line data from space missions; an electronic network and work station, providing a link to the data base and to other scientists; matching student support, both undergraduate and graduate; matching summer salary for up to three faculty participants; and travel funds. The universities will be asked to provide research time for faculty participants, matching student support, matching summer salary for faculty participants, an instructional unit in space science, and an outreach program to pre-college students.

Six, F.↗