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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 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Improvements to On-Orbit Sleeping Accommodations

United States On-Orbit Segment (USOS) crew members aboard the International Space Station (ISS) are each furnished with a Crew Quarters that serves as their personal private space for the duration of their expedition. Within these quarters, crew members use sleeping bags to provide a comfortable environment that is conducive to sleeping in microgravity. Microgravity presents unique challenges to obtaining good sleep. Sleep position preferences which are influenced by gravity are disturbed when the feeling is absent while other environmental factors prevent the familiar feeling of lying in bed. NASA developed a new US Sleeping Bag for USOS crew members launching aboard United States Crewed Vehicles (USCVs), using this opportunity to improve upon the current sleeping bag design based on lessons learned from years of living and working in space. The US Sleeping Bag design was based on the current sleeping bag's design with enhancements to key features based on feedback from crew members and sleep study experts at the Johnson Space Center and the Ames Research Center. Key areas of improvement include facilitating thermal comfort in the warm Crew Quarters environment, ease of maintenance when replacing the inner lining, allowing for maximum versatility for adjustment to crew preference, and adding features for additional functionality such as accommodations for a pillow. Two US Sleeping Bags have flown aboard the ISS to date, utilized by veteran crew members who have experience with the existing sleeping bags and have provided feedback and comparisons for assessment. Enabling good sleep is essential for crew member health and productivity, especially in longer duration expeditions. This paper will detail the challenges with sleeping in microgravity and the enhancements made in development of the US Sleeping Bag to provide a better on-orbit sleep environment.

US Sleeping Bag↗
NASA NTRS1992

Review of two-phase flow liquid metal MHD and turbine energy conversion concepts for space applications

Two-phase energy conversion systems could be liquid metal magnetohydrodynamic (LMMHD) with no moving parts or two-phase turbines. Both of them are inherently simple and reliable devices which can operate in a wide range of temperatures. Their thermal efficiency is significantly higher than for conventional cycles due to reheat of vapor by liquid phase during the energy converting expansion. Often they can be more easily coupled to heat sources. These features make two-phase systems particularly promising for space application. Insufficient research has been done in the past. So far achieved LMMHD generator and two-phase turbine efficiencies are in the 40 to 45 percent range. However if certain fluid dynamic and design problems are resolved these efficiencies could be brought into the range of 70 percent. This would make two-phase systems extremely competitive as compared to present or other proposed conversion system for space. Accordingly, well directed research effort on potential space applications of two-phase conversion systems would be a wise investment.

Fabris, Gracio↗
NASA NTRS1975

Technical description of space ultra reliable modular computer (SUMC), model 2 B

The design features of the SUMC-2B computer, also called the IBM-HTC are described. It is general purpose digital computer implemented with flexible hardware elements and microprograming to enable low cost customizing to a wide range of applications. It executes the S/360 standard instruction set to maintain problem state compability. Memory technology, extended instruction sets, and I/O channel variations are among the available options.

Source record↗
NASA NTRS1980

Observable solar features which provide clues to the state of the solar dynamo

Space experiments are suggested to better monitor the solar dynamo and solar luminosity variations. Polar and other magnetic fields, sunspots, coronal holes, filaments and other observable solar and solar wind phenomena can provide us with important links to test and discover physical mechanisms which relate solar activity to terrestrial weather, climate, and possibly population variations.

Schatten, K. H.↗
NASA NTRS1981

Space Shuttle main engine performance assessment - Columbia's first flight

Design features and performance of the Shuttle main engines first flight are presented. Each of the three engines produces 470,000 lb of thrust, operates at 3,012 psia, and has a 77.5 to 1 nozzle expansion ratio. The engines are designed for a 7.5 hr operational life, and will be tested at 109% capacity in future Shuttle flights. The developmental program is outlined, and includes 127,000 sec of operational testing on 19 engines. Engine operations and components are described, noting 100% burning of the hydrogen and oxidizer, high pressure fuel turbopumps, the controller assembly, etc.; details of solutions to fatigue failures and subsequent certification are provided. The nine minute first flight firing revealed a radiant heating of a control sensor transducer, which was shielded for succeeding flights. Alternatives are given for thrust augmentation, for which each 1% yields an additional 800 lb payload increase capability, and can be implemented by 1987.

Thompson, J. R., Jr.↗
NASA NTRS1993

Designing the Space Transfer Vehicle (STV)

An evolutionary approach to develop STV system features that provide modularity, design margines, and simple interfaces is presented. A modular design minimizes modifications and requalification for block changes. Since several subsystems do not have to be modified in response to a change in another subsystem, design margins provide options for growth. It is concluded that the approach will lower program schedule and cost risk, while enhancing safety and reliability.

Austin, Robert E.↗
NASA NTRS1971

Modular space station phase B extension: Shuttle interface requirements

The interface requirements cover both the ground and orbital phases of operation from the launch of the first MSS module until the initial modular station has been manned and in routine operation. As a point of reference, the two-stage, fully reusable space shuttle was selected. The space shuttle is briefly described from the standpoint of its features most important to the interface requirements with the MSS. The environment induced upon the MSS elements when transported to and from orbit by the shuttle orbiter also is included. The mission operation includes the space shuttle launch facilities, the ground flow of the MSS modules, and the orbital operations of rendezvous, MSS buildup, resupply of the manned station, and orbiter descent and landing. The shuttle's once-around abort case is described as it affects the MSS interface requirements. The interfaces between the orbiter and the MSS resulting from the ground and orbital operations, are also described.

Source record↗
NASA NTRS1991

Using Gaussian windows to explore a multivariate data set

In an earlier paper, I recounted an exploratory analysis, using Gaussian windows, of a data set derived from the Infrared Astronomical Satellite. Here, my goals are to develop strategies for finding structural features in a data set in a many-dimensional space, and to find ways to describe the shape of such a data set. After a brief review of Gaussian windows, I describe the current implementation of the method. I give some ways of describing features that we might find in the data, such as clusters and saddle points, and also extended structures such as a 'bar', which is an essentially one-dimensional concentration of data points. I then define a distance function, which I use to determine which data points are 'associated' with a feature. Data points not associated with any feature are called 'outliers'. I then explore the data set, giving the strategies that I used and quantitative descriptions of the features that I found, including clusters, bars, and a saddle point. I tried to use strategies and procedures that could, in principle, be used in any number of dimensions.

Jaeckel, Louis A.↗
NASA NTRS2010

A Dual Launch Robotic and Human Lunar Mission Architecture

This paper describes a comprehensive lunar exploration architecture developed by Marshall Space Flight Center's Advanced Concepts Office that features a science-based surface exploration strategy and a transportation architecture that uses two launches of a heavy lift launch vehicle to deliver human and robotic mission systems to the moon. The principal advantage of the dual launch lunar mission strategy is the reduced cost and risk resulting from the development of just one launch vehicle system. The dual launch lunar mission architecture may also enhance opportunities for commercial and international partnerships by using expendable launch vehicle services for robotic missions or development of surface exploration elements. Furthermore, this architecture is particularly suited to the integration of robotic and human exploration to maximize science return. For surface operations, an innovative dual-mode rover is presented that is capable of performing robotic science exploration as well as transporting human crew conducting surface exploration. The dual-mode rover can be deployed to the lunar surface to perform precursor science activities, collect samples, scout potential crew landing sites, and meet the crew at a designated landing site. With this approach, the crew is able to evaluate the robotically collected samples to select the best samples for return to Earth to maximize the scientific value. The rovers can continue robotic exploration after the crew leaves the lunar surface. The transportation system for the dual launch mission architecture uses a lunar-orbit-rendezvous strategy. Two heavy lift launch vehicles depart from Earth within a six hour period to transport the lunar lander and crew elements separately to lunar orbit. In lunar orbit, the crew transfer vehicle docks with the lander and the crew boards the lander for descent to the surface. After the surface mission, the crew returns to the orbiting transfer vehicle for the return to the Earth. This paper describes a complete transportation architecture including the analysis of transportation element options and sensitivities including: transportation element mass to surface landed mass; lander propellant options; and mission crew size. Based on this analysis, initial design concepts for the launch vehicle, crew module and lunar lander are presented. The paper also describes how the dual launch lunar mission architecture would fit into a more general overarching human space exploration philosophy that would allow expanded application of mission transportation elements for missions beyond the Earth-moon realm.

Jones, David L.↗
NASA NTRS1994

Satellite emission features in two Seyfert galaxies: New evidence that radio-quiet AGN possess subrelativistic winds

Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) spectra are presented for three bright Seyfert galaxies including one (PG 1351+64) which possesses blue-displaced absorption features in C IV, Si IV, N V, and Ly-alpha (but not in Mg II) similar to those seen at high redshift in the broad-absorption-line (BAL) quasi-stellar objects (QSOs). Several features of the absorptions in PG 1351+64, including variability seen in archival International Ultraviolet Explorer (IUE) data, confirm their similarity to the BAL clouds rather than to the 'associated absorber' phenomenon which they superficially resemble. In PG 1351+64 'satellite' emission lines (called herein E1 and E2) have been detected nearly symmetrically placed at +/- 4000 km/s around the Mg II emission line; this velocity is just larger than the most blue-displaced of the BALs, suggesting that these two phenomena are related. The satellite line luminosity, L(E1) approximately = (3 x 10(exp 41) erg/s)/sq. h(sub 75), requires a cloud emission measure n(sub e)(exp 2)V(sub c) approximately = (1 x 10(exp 64)/cc)/sq. h(sub 75) at T approximately = 30,000 K. We believe the Mg II lines are produced by 50-90 km/s shocks driven into dense (approximately 10(exp 6)/cc, pre-shock) clouds by the ram pressure of a 0.1 solar mass/yr wind leaving the nucleus at velocity 4000 km/s. The detection of satellite lines in Mg II, the detection of the blue-shifted cloud in H-alpha and H-beta and the nondetection of this cloud in C IV restricts the cloud shocks to velocities v(sub c) less than or = 90 km/s and requires a cloud/wind density contrast greater than or = 10(exp 3). In this model, the emitting clouds are located at distances of R(sub eff) approximately = 10(exp 18-19) cm from the nucleus and are entrained and shock-accelerated to approximately 4000 km/s. The possible detection of similar 'satellite' emission features in the non-BAL Seyfert, Ton 951, suggests that the subrelativistic wind that accelerates BAL clouds is a physical feature of many radio-quiet active galactic nuclei (AGN).

Stocke, John T.↗
NASA NTRS1975

Manned systems utilization analysis (study 2.1). Volume 1: Executive summary

Man's contribution to the achievement of scientific mission objectives in the space environment is investigated in terms of potential improvement in future applications of scientific instruments relative to the need for interactive manned support operations. Emphasis is placed on experience gained from space programs and the development of empirical techniques to associate the benefit of repair and management actions. Design features are addressed in terms of weight, volume, and reliability associated with designing for space maintenance. The results of the following programs are examined: the OVI series of automated spacecraft; the OSO-7 automated spacecraft; and the Skylab S-056 X-ray telescope experiment in the ATM. It is shown that orbital maintenance is the most realistic means of achieving high system availabilities for scientific instruments.

Wolfe, R. R.↗
NASA NTRS1978

Space Shuttle - Bringing cryohydrogen technology down to earth

The External Tank must provide a safe storage container for both LH2 and LO2, a means of maintaining propellant quality in order to meet the engine pump net positive suction pressure requirements, and a structural strong-back for the Space Shuttle system, all at the minimum recurring cost and weight, while maintaining quality and reliability. The present paper summarizes External Tank design features and discusses the advantages of using LH2 and LO2 for the Space Shuttle system.

Odom, J. B.↗
NASA NTRS1993

Articulating Fold Mirror for the Wide-Field/Planetary Camera II

The Articulating Fold Mirror (AFM) is a space qualified, ultraviolet compatible device that incorporates many advanced features including a highly lightweighted mirror and electrostrictive solid state actuators that provide precise and repeatable open loop performance. The design, fabrication and testing of the AFM are described.

Articulating↗
NASA NTRS2018

Effects of Space Weathering on Reflectance Spectra of Ureilites: First Studies

Ureilites are differentiated meteorites (ultramafic rocks interpreted to be mantle residues) that contain as much carbon as the most carbon-rich carbonaceous chondrites (CCs). Reflectance spectra of ureilites are similar to those of some CCs. Hence, ureilitic asteroids may accidentally be categorized as primitive because their spectra could resemble those of C-complex asteroids, which are thought to be CC-like. We began spectral studies of progressively laser-weathered ureilites with the goals of predicting UV-VIS-IR spectra of ureilitic asteroids, and identifying features that could distinguish differentiated from primitive dark asteroids. Space weathering has not previously been studied for ureilites, and, based on space weathering studies of CCs and other C-rich materials, it could significantly alter their reflectance spectra.

REFLECTANCE SPECTRA UREILITES↗
NASA NTRS1992

Hey! What's Space Station Freedom?

This video, 'Hey! What's Space Station Freedom?', has been produced as a classroom tool geared toward middle school children. There are three segments to this video. Segment One is a message to teachers presented by Dr. Jeannine Duane, New Jersey, 'Teacher in Space'. Segment Two is a brief Social Studies section and features a series of Presidential Announcements by President John F. Kennedy (May 1961), President Ronald Reagan (July 1982), and President George Bush (July 1989). These historical announcements are speeches concerning the present and future objectives of the United States' space programs. In the last segment, Charlie Walker, former Space Shuttle astronaut, teaches a group of middle school children, through models, computer animation, and actual footage, what Space Station Freedom is, who is involved in its construction, how it is to be built, what each of the modules on the station is for, and how long and in what sequence this construction will occur. There is a brief animation segment where, through the use of cartoons, the children fly up to Space Station Freedom as astronauts, perform several experiments and are given a tour of the station, and fly back to Earth. Space Station Freedom will take four years to build and will have three lab modules, one from ESA and another from Japan, and one habitation module for the astronauts to live in.

Vonehrenfried, Dutch↗
NASA NTRS1987

Positive position feedback control for large space structures

A new technique for vibration suppression in large space structures is investigated in laboratory experiments on a thin cantilever beam. This technique, called Positive Position Feedback, makes use of generalized displacement measurements to accomplish vibration suppression. Several features of Positive Position Feedback make it attractive for the large space structure control environment: The realization of the controller is simple and straightforward. Global stability conditions can be derived which are independent of the dynamical characteristics of the structure being controlled, i.e., all spillover is stabilizing. The method cannot be destabilized by finite actuator dynamics, and the technique is amenable to a strain-based sensing approach. The experiments control the first six bending modes of a cantilever beam, and make use of piezoelectric materials for actuators and sensors, simulating a piezoelectric active-member. The modal damping ratios are increased by factors ranging from 2 to 130.

Fanson, J. L.↗
NASA NTRS2003

Surface Material Analysis of the S-type Asteroids: Removing the Space Weathering Effect from Reflectance Spectrum

Recent years, many researchers have been observing a lot of asteroid reflectance spectra in the UV, visible to NIR at wavelength region. Reflectance spectroscopy of asteroid at this range should bring us a lot of information about its surface materials. Pyroxene and olivine have characteristic absorption bands in this wavelength range. Low-Ca pyroxene has two absorption bands around 0.9 microns and 1.9 microns. The more Ca and Fe content, the longer both absorption band centers. On the other hand, reflectance spectrum of olivine has three complicated absorption bands around 1 m, and no absorption feature around 2 microns. In general, reflectance spectra of many asteroids that are considered to be silicate rich (i.e., S- and A type asteroids) show redder slope and more subdued absorption bands than those of terrestrial minerals and meteorites. These features are now believed to be caused by the space weathering effect, which is probably caused by micrometeorite bombardment and/or solar wind. This process causes nanophase reduced iron (npFe(sup 0)) particles near the surface of mineral grains, which leads the optical change. Therefore, the space weathering effect should be removed from asteroid reflectance spectra to compare with those of meteorite and terrestrial minerals. In this report, we will apply the expanded modified Gaussian model (MGM) to the reflectance spectra of S-type asteroids 7 Iris and 532 Herculina and compare them with those of meteorites.

Ueda, Y.↗
NASA NTRS1971

Space shuttle staging simulation

The overall capability is described and delineated of a new digital computer program for simulation of space shuttle vehicle staging maneuvers. The important distinctive feature of the program is that it enables simulation of linkage-type separation devices (as well as all the more usual types) and includes the effects of interference aerodynamics and thrust impingement. A general flow description and a moderately detailed description of the major simulation components are presented. Some typical simulation results are shown, and the flexibility and growth potential of the basic simulation are discussed.

Hall, C. E.↗