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NASA NTRSDate not supplied

NASA's Moon to Mars Autonomous Habitat Status

NASA is developing a strategy for sending humans to the Mars vicinity, known broadly as the Moon to Mars (M2M) Campaign. A critical part of this campaign is the development of in-space and surface habitation systems capable of substantially extending human presence beyond Low Earth Orbit (LEO). Mars missions feature an in-space transit habitat capable of supporting crews of four on ~850-1200-day missions, including transit to and from Mars and time in Mars orbit. Surface and transit habitats are complex elements which must keep crewmembers healthy and productive in deep-space environments with limited resources, long rescue times in contingency situations, and communication delays; all within constrained mass, volume, and power budgets. These habitats provide crew both living and workspace as well as most of the resources needed to support crew life. For deep space habitats, automation needs to be employed due to latency and for significant amounts of time when the habitats are uncrewed. Automation of systems is possible in space applications, but there are limitations. Outside of the Earth’s (or any) magnetosphere, radiation environments are harsh to both the physical hardware and the software components. Radiation (charged particles and ionizing electromagnetic waves) degrades and damages the hardware and causes single event upsets (SEUs) in software. If the hardware is damaged, data can be lost, or control actions not made. For software, SEUs cause algorithms to result in different solutions, or incorrect commands to be sent out. This means that algorithms and hardware used for deep space systems are different than what is used on Earth. Radiation-tolerant hardware is generations behind the current state-of-the-art hardware. Recent NASA missions, such as James Webb Space Telescope, continue to rely on older technologies such as the RAD750 processor, and the most advanced processors are still single core and less than 1.5 GHz. There have been attempts to use higher performance processors, but these often take multiple mitigation steps to handle the radiation environments, which limits the processing power and/or throughput. Current techniques for radiation mitigation have been redundancies, voting, physical separation of hardware, encasing materials, under-clocking hardware, and more. Some radiation mitigation techniques do provide benefits such as having a redundant system to improve the probability that a system will be available when needed. Autonomous software systems will have fewer interactions with humans on deep space missions and therefore need to be able to handle more off-nominal conditions. Microgravity also complicates the autonomous aspects of the mission because autonomous systems are usually built from known deterministic states, but microgravity causes physical objects to shift and move changing the location an autonomous system placed the object. Not only does the software need to be reliable and deterministic, losing resources due to a software error is not only costly but detrimental to reputation. The combination of having lower performance hardware and having to be able to verify and deterministically run software and an ever-changing environment makes deep space autonomous systems more complicated. Multiple gaps have been identified including verification of autonomous software algorithms (including artificial intelligence and machine learning), higher performance processors (graphics and general purpose), high speed networks (onboard and transmissions), memory, power distribution, data security, and variations from these. These gaps need to be closed for more advanced systems to be deployed and reduce the size, weight, and power impacts on the habitats.

Scott B. Tashakkor↗
NASA NTRS1990

EnviroNET - A space environment data resource

This paper reviews the features of EnviroNET that make it a valuable space data resource. This computerized data base provides rapid access to the latest information on space debris and other space environments and spacecraft interactions of importance to the space community. Although originally conceived as an information resource for Space Shuttle users, EnviroNET has expanded into other areas including space debris and the near-earth environments of potential interest to the conference attendees.

Lauriente, Michael↗
NASA NTRS1982

STS payload retention system concept

A payload retention concept that may be utilized on Space Shuttle missions is investigated. This concept appears to embody all the desirable features for the very demanding requirements for space flight. Desirable features include light weight, low cost, high reliability, excellent load distribution, versatility, and insensitivity to critical alignment.

Clark, K. H.↗
NASA NTRS1989

Return to Space Mission: The STS-26 Crew Report

This videotape features footage from NASA's return to space flight after the 51-L accident. The videotape is narrated by the crew, and it includes the following: launch, landing, and the TDRS/IUS deployment.

Source record↗
NASA NTRS1985

Regenerative fuel cell systems for space station

Regenerative fuel cell (RFC) systems are the leading energy storage candidates for Space Station. Key design features are the advanced state of technology readiness and high degree of system level design flexibility. Technology readiness was demonstrated through testing at the single cell, cell stack, mechanical ancillary component, subsystem, and breadboard levels. Design flexibility characteristics include independent sizing of power and energy storage portions of the system, integration of common reactants with other space station systems, and a wide range of various maintenance approaches. The design features led to selection of a RFC system as the sole electrochemical energy storage technology option for the space station advanced development program.

Hoberecht, M. A.↗
NASA NTRS1981

MAGSAT science investigations

A preliminary magnetization model for the U.S. was produced from MAGSAT data. The double grid processing method resulted in a 100 km source spacing. While some spurious features are present in the map, much of the detail appears to be real. The determination of the optional source spacing for inversion of MAGSAT delta B data is in progress. A fine attitude vector data set was obtained for comparison with the theoretical vector field associated with the magnetization model.

Source record↗
NASA NTRS1991

The Jade File System

File systems have long been the most important and most widely used form of shared permanent storage. File systems in traditional time-sharing systems, such as Unix, support a coherent sharing model for multiple users. Distributed file systems implement this sharing model in local area networks. However, most distributed file systems fail to scale from local area networks to an internet. Four characteristics of scalability were recognized: size, wide area, autonomy, and heterogeneity. Owing to size and wide area, techniques such as broadcasting, central control, and central resources, which are widely adopted by local area network file systems, are not adequate for an internet file system. An internet file system must also support the notion of autonomy because an internet is made up by a collection of independent organizations. Finally, heterogeneity is the nature of an internet file system, not only because of its size, but also because of the autonomy of the organizations in an internet. The Jade File System, which provides a uniform way to name and access files in the internet environment, is presented. Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Because of autonomy, Jade is designed under the restriction that the underlying file systems may not be modified. In order to avoid the complexity of maintaining an internet-wide, global name space, Jade permits each user to define a private name space. In Jade's design, we pay careful attention to avoiding unnecessary network messages between clients and file servers in order to achieve acceptable performance. Jade's name space supports two novel features: (1) it allows multiple file systems to be mounted under one direction; and (2) it permits one logical name space to mount other logical name spaces. A prototype of Jade was implemented to examine and validate its design. The prototype consists of interfaces to the Unix File System, the Sun Network File System, and the File Transfer Protocol.

Rao, Herman Chung-Hwa↗
NASA NTRS2000

Cryocoolers for Space

This paper presents Cryocoolers for Space in viewgraph form. The topics include: 1) U.S. Cryocoolers for 4 to 6 Kelvin; 2) Turbo Brayton Cryocooler-Features; 3) HST/NICMOS (Hubble Space Telescope/Near Infrared Camera and Multiobject Spectrometer) 75 Kelvin Cryocooler; 4) Turbo-Brayton Cryocooler-NGST Design; and 5) Two-stage Sorption J-T Cryocooler.

Castles, Stephen↗
NASA NTRS1986

Early thermal profiles and lithospheric strength of Ganymede from extensional tectonic features

The early thermal profiles and the lithospheric stability and strength of Ganymede are quantitatively determined on the basis of brittle lithosphere thickness estimates derived from the width and spacing of extensional tectonic features, together with lithospheric strength envelopes for ice. Plots of the brittle and ductile yield stress vs. depth for the icy lithosphere of Ganymede exhibit a linear increase in brittle strength with depth to a maximum at the brittle-ductile transition that is followed by an exponential decrease in ductile yield stress with depth. The results obtained imply that the thermal gradient and lithospheric strength have varied laterally by factor as great as 5, and that Ganymede underwent cooling in a highly inhomogeneous fashion with lateral thermal anomalies. The present analysis furnishes reasons for the stability of large cratered terrain remnants.

Golombek, Matthew P.↗
NASA NTRS1993

Space Biology and Medicine: Space and Its Exploration - Volume I

Perhaps one of the greatest gifts that has been given to the people of the world in the last few hundred years has been an emerging sense of the place of our planet and its inhabitants within the context of the vast universe. Our knowledge of the rest of the universe has not come quickly, nor was the process of attaining it only recently begun; however, the unprecedented acceleration of that process has benefitted from a fundamental new aspect of our species that has only manifested itself in the last 30 years or so, the ability to travel in space. Before the space age, the Universe was studied only through observations from the Earth. All that has changed with the beginning of the space age. Machines built by humans have flown to all but one of the nine planets that revolve around our Sun, have ventured billions of miles from the Earth and looked back, and have landed on three other worlds. Spacecraft in orbit around the Earth have viewed the sky at a vast number of electromagnetic wavelengths, detecting the shape of the galaxy and the universe, and even measuring the remnants of the universe's beginning. Human explorers have ventured forth, first for short stays in orbit, then, later, walking upon the Moon and living for long periods in space. As they did so, billions of people on the Earth came to view the Earth in a fundamentally different way, not just as the familiar day to- day backdrop for their lives, but as a small oasis suspended in the night sky above an alien landscape. It is this new view of the Earth that is the true gift of space exploration. Space exploration has at once given us a new perspective on the value of our world, and a new perspective from which to understand how it operates. It has shown us that the Earth is by far the most precious place in the solar system in terms of supporting human life, while revealing that other destinations may still be compelling. The exploration of space has at once become a challenge for humanity to overcome and a path to our common future. But for humanity to embark on this path, we need to understand ourselves in a new environment. As such, an understanding of the biological consequences of and opportunities in space flight is essential. In this, the first volume of a joint U.S./Russian series on space biology and medicine, we describe the current status of our understanding of space and present general information that will prove useful when reading subsequent volumes. Since we are witnesses to the beginning of a new era of interplanetary travel, a significant portion of the first volume will concentrate on the physical and ecological conditions that exist in near and outer space, as well as heavenly bodies from the smallest ones to the giant planets and stars. While space exploration is a comparatively recent endeavor, its foundations were laid much more than 30 years ago, and its history has been an eventful one. In the first part of this volume, Rauschenbach, Sokolskiy, and Gurjian address the "Historical Aspects of Space Exploration" from its beginnings to a present-day view of the events of the space age. The nature of space itself and its features is the focus of the second section of the volume. In the first chapter of the part, "Stars and Interstellar Space," the origin and evolution of stars, and the nature of the portions of space most distant from Earth are described by Galeev and Marochnik. In Chapter 2, Pisarenko, Logachev, and Kurt in "The Sun and Interplanetary Space" bring us to the vicinity of our own solar system and provide a description and discussion of the nearest star and its influence on the space environment that our Earth and the other planets inhabit. In our solar system there are many fascinating objects, remnants of the formation of a rather ordinary star in a rather obscure portion of the galaxy. Historical accident has caused us to be much more curious (and knowledgeable) about "The Inner Planets of the Solar System" than about any of these other objects. In Chapter 3, Marov describes the planets Mercury, Venus, Earth, and Mars, their history and origin, and their environmental conditions, and in Chapter 4 Owen provides similar information about Jupiter, Saturn, Uranus, Neptune, and Pluto, "The Outer Planets of the Solar System." Morrison provides a thorough discussion of "Asteroids, Comets, and Other Small Bodies" in Chapter 5. The understanding of these relics of the formation of the solar system may form the center of our ability to understand the origin of solar systems in general, and of the critical role that the beginning of the solar system had on the prospects for the origin of life and its continued survival and evolution in the face of their recurrent impacts on Earth. In Chapter 6, the first chapter of the third part, Rummel describes the area of "Exobiology," the study of the origin, evolution, and distribution of life in the context of the origin and evolution of the universe. The same processes that have given rise to life on Earth may have given rise to life elsewhere. In Chapter 7, the "Earth and the Biosphere," the nature and function of the Earth are discussed as a specific instance of planetary and biological evolution. The effects of biological processes on the Earth under the influence of human activities are also addressed by Moore and Bartlett in Chapter 7. The final chapter in this section concerns the prospects that life in the universe may be widespread; "SETI," the Search for Extraterrestrial Intelligence, by Billingham and Tarter, presents the arguments for conducting a search for evidence of life elsewhere in the galaxy, and describes the various methods proposed for conducting such a search. While SETI has a distinctly exploration al character, more direct means are available for exploring the solar system around us. The fourth part of the volume addresses this subject of space exploration. Considering the prospects for research on space biology and medicine, the means of providing "Access to Space" are described by Feoktistov and Briggs in Chapter 9. This chapter addresses carriers and launch systems, the unmanned and manned spacecraft that they loft into space, and the task of mission operations by which these precious vessels are monitored, navigated, and controlled. Despite the successes of the past and the capabilities of the present, it is clear that the study of space biology and medicine will be even more rewarding in the future than it has been to date. The work of the next few years that will be undertaken by the U.S. and Russia, both independently and jointly, will focus first on enabling greater capabilities in the exploration of space, and then on using the unique characteristics of the space environment to provide insight and greater understanding into biological systems, their behavior, development, and origin. The chapters of the first volume were written by leaders in their fields from the U.S. and Russia. The material presented summarizes our current understanding of space and its exploration. We understand that the first volume will be of interest not only to medical personnel and biologists, but also to general readers who want information about space beyond their own particular fields of expertise.

Nicogossian, Arnauld E.↗
NASA NTRS2007

Coronas-F Orbit Monitoring and Re-Entry Prediction

Russian scientific satellite CORONAS-F was launched on July, 31, 2001. The object was inserted in near-circular orbit with the inclination 82.5deg and a mean altitude approx. 520 km. Due to the upper atmosphere drag CORONAS-F was permanently descended and as a result on December, 6, 2005 it has finished the earth-orbital flight, having lifetime in space approx. 4.5 years. The satellite structural features and its flight attitude control led to the significant variations of its ballistic coefficient during the flight. It was a cause of some specific difficulties in the fulfillment of the ballistic and navigation support of this space vehicle flight. Besides the main mission objective CORONAS-F also has been selected by the Inter-Agency Space Debris Coordination Committee (IADC) as a target object for the next regular international re-entry test campaign on a program of surveillance and re-entry prediction for the hazard space objects within their de-orbiting phases. Spacecraft (S/C) CORONAS-F kept its working state right up to the end of the flight - down to the atmosphere entry. This fact enabled to realization of the additional research experiments, concerning with an estimation of the atmospheric density within the low earth orbits (LEO) of the artificial satellites, and made possible to continue track the S/C during final phase of its flight by means of Russian regular command & tracking system, used for it control. Thus there appeared a unique possibility of using for tracking S/C at its de-orbiting phase not only passive radar facilities, belonging to the space surveillance systems and traditionally used for support of the IADC re-entry test campaigns, but also more precise active trajectory radio-tracking facilities from the ground control complex (GCC) applied for this object. Under the corresponding decision of the Russian side such capability of additional high-precise tracking control of the CORONAS-F flight in this period of time has been implemented. The organizing of the CORONAS-F ballistic and navigational support (BNS) and solving its main tasks (such as S/C orbit determination (OD) and its motion prediction and connected with them) both for regular mission stage and for additional flight program were realized by the group of specialists from the Mission Control Center (MCC). MCC was also assigned as a principal organization from the Russian side for participation in the 7th IADC re-entry test campaign on CORONAS-F. The CORONAS-F flight features and space environments circumstances during its flight as well as a methodology and technology of spacecraft ballistic and navigational support are given below. The BNS results for different phases of S/C flight, including the results of its re-entry predictions, obtained during the realization of the 7th IADC test campaign are submitted. The accuracy of space vehicle re-entry prediction and its dependence on various factors are analyzed in more details.

Ivanov, N. M.↗
NASA NTRS1989

Robot acting on moving bodies (RAMBO): Preliminary results

A robot system called RAMBO is being developed. It is equipped with a camera, which, given a sequence of simple tasks, can perform these tasks on a moving object. RAMBO is given a complete geometric model of the object. A low level vision module extracts and groups characteristic features in images of the object. The positions of the object are determined in a sequence of images, and a motion estimate of the object is obtained. This motion estimate is used to plan trajectories of the robot tool to relative locations nearby the object sufficient for achieving the tasks. More specifically, low level vision uses parallel algorithms for image enchancement by symmetric nearest neighbor filtering, edge detection by local gradient operators, and corner extraction by sector filtering. The object pose estimation is a Hough transform method accumulating position hypotheses obtained by matching triples of image features (corners) to triples of model features. To maximize computing speed, the estimate of the position in space of a triple of features is obtained by decomposing its perspective view into a product of rotations and a scaled orthographic projection. This allows the use of 2-D lookup tables at each stage of the decomposition. The position hypotheses for each possible match of model feature triples and image feature triples are calculated in parallel. Trajectory planning combines heuristic and dynamic programming techniques. Then trajectories are created using parametric cubic splines between initial and goal trajectories. All the parallel algorithms run on a Connection Machine CM-2 with 16K processors.

Davis, Larry S.↗
NASA NTRS1992

Application of space-marching methods to hypersonic forebody flow fields

The heavy reliance on CFD in the design of hypersonic flight vehicles emphasizes the importance of choosing computationally efficient techniques. As a result, the development and application of space-marching flow solvers for the parabolized Navier-Stokes equations have received considerable attention in the past decade. This paper summarizes a space-marching approach used at NASA Ames Research Center for the analysis of hypersonic vehicle forebodies. Aspects of the simulation process are addressed that contain features unique to space-marching flow solvers, such as grid generation, initial condition specification, and finite-rate chemistry models. For completeness, sections are also included on turbulence modeling and equilibrium air chemistry modeling. The discussion includes an overview of the computational methods utilized as well as a number of relevant results.

Lawrence, Scott L.↗
NASA NTRS2005

Tool Measures Depths of Defects on a Case Tang Joint

A special-purpose tool has been developed for measuring the depths of defects on an O-ring seal surface. The surface lies in a specially shaped ringlike fitting, called a capture feature tang, located on an end of a cylindrical segment of a case that contains a solid-fuel booster rocket motor for launching a space shuttle. The capture feature tang is a part of a tang-and-clevis, O-ring joint between the case segment and a similar, adjacent cylindrical case segment. When the segments are joined, the tang makes an interference fit with the clevis and squeezes the O-ring at the side of the gap.

Ream, M. Bryan↗
NASA NTRS1990

Advanced Microwave Precipitation Radiometer (AMPR) for remote observation of precipitation

The design, development, and tests of the Advanced Microwave Precipitation Radiometer (AMPR) operating in the 10 to 85 GHz range specifically for precipitation retrieval and mesoscale storm system studies from a high altitude aircraft platform (i.e., ER-2) are described. The primary goals of AMPR are the exploitation of the scattering signal of precipitation at frequencies near 10, 19, 37, and 85 GHz together to unambiguously retrieve precipitation and storm structure and intensity information in support of proposed and planned space sensors in geostationary and low earth orbit, as well as storm-related field experiments. The development of AMPR will have an important impact on the interpretation of microwave radiances for rain retrievals over both land and ocean for the following reasons: (1) A scanning instrument, such as AMPR, will allow the unambiguous detection and analysis of features in two dimensional space, allowing an improved interpretation of signals in terms of cloud features, and microphysical and radiative processes; (2) AMPR will offer more accurate comparisons with ground-based radar data by feature matching since the navigation of the ER-2 platform can be expected to drift 3 to 4 km per hour of flight time; and (3) AMPR will allow underflights of the SSM/I satellite instrument with enough spatial coverage at the same frequencies to make meaningful comparisons of the data for precipitation studies.

Galliano, J. A.↗
NASA NTRS1998

The Spacing of the Interstellar 6.2 Microns and 7.7 Microns Emission Features as an Indicator of PAH Size

A database of astrophysically relevant, infrared spectral measurements on a wide variety of neutral as well as positively and negatively charged polycyclic aromatic hydrocarbons ranging in size from C10H8 through C48H20 is now available to extend the interstellar PAH model. Beyond simply indicating general characteristics of the carriers, this collection of data now makes it possible to conduct a more thorough interpretation of the details of the interstellar spectra and thereby derive deeper insights into the nature of the emitting material and conditions in the emission zones. This paper is the first such implementation of this spectral database. The infrared spectra of PAH cations, the main PAH form in the most energetic emission zones, are usually dominated by a few strong features in the 1650 - 1100 per centimeter (6.1 - 9.1 microns) region which tend to cluster in the vicinity of the interstellar emission bands at 1610 per centimeter and 1320 per centimeter (6.2 and 7.6 microns) but with spacings typically somewhat less than that observed in the canonical interstellar spectrum. However, the spectra in the database show that this spacing increases steadily with molecular size. Extrapolation of this trend indicates that PAHS in the 50 to 80 carbon atom size range are entirely consistent with the observed interstellar spacing. Furthermore, the profile of the 1610 per centimeter (6.2 microns) interstellar band indicates that PAHS containing as few as 20 carbon atoms contribute to this feature.

Hudgins, Douglas M.↗
NASA NTRS1990

Evaluation, development, and characterization of superconducting materials for space applications

The anisotropic electromagnetic features of a grain-aligned YBa2Cu3O(x) bulk sample derived from a process of long-time partial melt growth were investigated by the measurements of direct current magnetization (at 77 K) and alternating current susceptibility as a function of temperature, with the fields applied parallel and perpendicular to the c axis, respectively. The extended Bean model was further studied and applied to explain the experimental results. Upon comparison of the grain-aligned sample with pure single crystal materials, it is concluded that because of the existence of more effective pinning sites in the grain-aligned sample, not only its critical current density perpendicular to the c axis is improved, but the one parallel to the c axis is improved even more significantly. The anisotropy in the critical current densities in the grain-aligned sample at 77 K is at least one to two orders of magnitude smaller than in the pure single crystal. The measurement of anisotropy of alternating current susceptibility as a function of temperature, especially its imaginary part, shows that there are still some residues of interlayer weak links in the grain-aligned samples, but they are quite different from and far less serious than the weak links in the sintered sample.

Thorpe, Arthur N.↗
NASA NTRS1990

Advanced-technology space station study: Summary of systems and pacing technologies

The principal system features defined for the Advanced Technology Space Station are summarized and the 21 pacing technologies identified during the course of the study are described. The descriptions of system configurations were extracted from four previous study reports. The technological areas focus on those systems particular to all large spacecraft which generate artificial gravity by rotation. The summary includes a listing of the functions, crew requirements and electrical power demand that led to the studied configuration. The pacing technologies include the benefits of advanced materials, in-orbit assembly requirements, stationkeeping, evaluations of electrical power generation alternates, and life support systems. The descriptions of systems show the potential for synergies and identifies the beneficial interactions that can result from technological advances.

Butterfield, A. J.↗