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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 1,063 records · Page 59
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NASA NTRS2009

The Skylab Medical Operations Project: Recommendations to Improve Crew Health and Performance for Future Exploration Missions

From May 1973 to February 1974, NASA conducted a series of three human missions to the Skylab space station, which was a voluminous vehicle largely descendant of Apollo hardware and the first U.S. space station. Crew members of these missions spent record-breaking durations of time in microgravity (28, 59, and 84 days, respectively) and gave the U.S. space program its first experiences with long-duration space flight. The program overcame a number of obstacles to conduct a lauded scientific program that encompassed life sciences, astronomy, solar physics, materials sciences, and Earth observation. Yet Skylab has more to offer than the results of these scientific efforts. The operations that were conducted by the crews and ground personnel represent a rich legacy of operational experience. As we plan a return to the moon and subsequent human exploration of Mars, it is essential to use the experiences and insights of those who were involved in previous programs. Skylab and Skylab Medical Experiments Altitude Test personnel possess unique insight into operations that are being planned for the Constellation Program, such as umbilical extravehicular activity and water landing/recovery of long-duration crew members. The Skylab Program was also well known for its habitability and extensive medical suite.

Scheuring, Richard A.↗
NASA NTRS2015

Dynamic Modeling of Ascent Abort Scenarios for Crewed Launches

For the last 30 years, the United States' human space program has been focused on low Earth orbit exploration and operations with the Space Shuttle and International Space Station programs. After over 40 years, the U.S. is again working to return humans beyond Earth orbit. To do so, NASA is developing a new launch vehicle and spacecraft to provide this capability. The launch vehicle is referred to as the Space Launch System (SLS) and the spacecraft is called Orion. The new launch system is being developed with an abort system that will enable the crew to escape launch failures that would otherwise be catastrophic as well as probabilistic design requirements set for probability of loss of crew (LOC) and loss of mission (LOM). In order to optimize the risk associated with designing this new launch system, as well as verifying the associated requirements, NASA has developed a comprehensive Probabilistic Risk Assessment (PRA) of the integrated ascent phase of the mission that includes the launch vehicle, spacecraft and ground launch facilities. Given the dynamic nature of rocket launches and the potential for things to go wrong, developing a PRA to assess the risk can be a very challenging effort. Prior to launch and after the crew has boarded the spacecraft, the risk exposure time can be on the order of three hours. During this time, events may initiate from either the spacecraft, the launch vehicle, or the ground systems, thus requiring an emergency egress from the spacecraft to a safe ground location or a pad abort via the spacecraft's launch abort system. Following launch, again either the spacecraft or the launch vehicle can initiate the need for the crew to abort the mission and return home. Obviously, there are thousands of scenarios whose outcome depends on when the abort is initiated during ascent and how the abort is performed. This includes modeling the risk associated with explosions and benign system failures that require aborting a spacecraft under very dynamic conditions, particularly in the lower atmosphere, and returning the crew home safely. This paper will provide an overview of the PRA model that has been developed of this new launch system, including some of the challenges that are associated with this effort.

Bigler, Mark↗
NASA NTRS1989

Development and application of nonflammable, high-temperature beta fibers

Recent advances in fiber technology have contributed to the success of the U.S. space program. The inorganic fiber Beta, developed as a result of efforts begun in the early 1960's and heightened following the January 27, 1967 Apollo fire is unique among inorganic and organic fibers. It has been developed into woven, nonwoven, knitted, braided, coated and printed structures. All of these were used extensively for the Apollo, Skylab, Apollo-Soyuz test project, space shuttle, Spacelab, and satellite programs. In addition to being used successfully in the space program, Beta fibers are being used commercially as firesafe fabrics in homes, hospitals, institutions, public buildings, aircraft, and public transportation, wherever total nonflammability is required. One of the most unique applications of the Beta composite structure is the roofing material for the 80,000-seat Detroit Lion's Silverdome and 5 square miles of the Jeddah International Airport in Saudi Arabia. This fiber has been successfully incorporated into 165 major public construction projects around the globe. The United States alone has used more than 12 million square yards of the material. Beta fiber has been used successfully to date and has a promising future with unlimited potential for both space and commercial application. Efforts are currently underway to improve Beta fiber to meet the requirements of extended service life for the Space Station Freedom, lunar outpost, and Mars exploration missions.

Dawn, Frederic S.↗
NASA NTRS1986

Space solar cell research - Problems and potential

The value of a passive, maintenance-free, renewable energy source was immediately recognized in the early days of the space program, and the silicon solar cell, despite its infancy, was quickly pressed into service. Efficiencies of those early space solar arrays were low, and lifetimes shorter than hoped for, but within a decade significant advances had been made in both areas. Better performance was achieved because of a variety of factors, ranging from improvements in silicon single crystal material, to better device designs, to a better understanding of the factors that affect the performance of a solar cell in space. Chief among the latter, particularly for the mid-to-high altitude (HEO) and geosynchronous (GEO) orbits, are the effects of the naturally occurring particulate radiation environment. Although not as broadly important to the photovoltaic community at large as increased efficiency, the topic of radiation damage is critically important to use of solar cells in space, and is a major component of the NASA research program in space photovoltaics. This paper will give a brief overview of some of the opportunities and challenges for space photovoltaic applications, and will discuss some of the current reseach directed at achieving high efficiency and controlling the effects of radiation damage in space solar cells.

Flood, Dennis J.↗
NASA NTRS1992

Space Storable Rocket Technology (SSRT) basic program

The Space Storable Rocket Technology Program (SSRT) was conducted to establish a technology for a new class of high performance and long life bipropellant engines using space storable propellants. The results are described. Task 1 evaluated several characteristics for a number of fuels to determine the best space storable fuel for use with LO2. The results indicated that LO2-N2H4 is the best propellant combination and provides the maximum mission/system capability maximum payload into GEO of satellites. Task 2 developed two models, performance and thermal. The performance model indicated the performance goal of specific impulse greater than or = 340 seconds (sigma = 204) could be achieved. The thermal model was developed and anchored to hot fire test data. Task 3 consisted of design, fabrication, and testing of a 200 lbf thrust test engine operating at a chamber pressure of 200 psia using LO2-N2H4. A total of 76 hot fire tests were conducted demonstrating performance greater than 340 (sigma = 204) which is a 25 second specific impulse improvement over the existing highest performance flight apogee type engines.

Chazen, M. L.↗
NASA NTRS1990

Space Transportation Engine Program (STEP), phase B

The Space Transportation Engine Program (STEP) Phase 2 effort includes preliminary design and activities plan preparation that will allow smooth and time transition into a Prototype Phase and then into Phases 3, 4, and 5. A Concurrent Engineering approach using Total Quality Management (TQM) techniques, is being applied to define an oxygen-hydrogen engine. The baseline from Phase 1/1' studies was used as a point of departure for trade studies and analyses. Existing STME system models are being enhanced as more detailed module/component characteristics are determined. Preliminary designs for the open expander, closed expander, and gas generator cycles were prepared, and recommendations for cycle selection made at the Design Concept Review (DCR). As a result of July '90 DCR, and information subsequently supplied to the Technical Review Team, a gas generator cycle was selected. Results of the various Advanced Development Programs (ADP's) for the Advanced Launch Systems (ALS) were contributive to this effort. An active vehicle integration effort is supplying the NASA, Air Force, and vehicle contractors with engine parameters and data, and flowing down appropriate vehicle requirements. Engine design and analysis trade studies are being documented in a data base that was developed and is being used to organize information. To date, seventy four trade studies were input to the data base.

Source record↗
NASA NTRS1967

Space plans and possibilities.

Space program in 1970s, discussing solar system exploration, investigation of universe, practical applications of space and development of technology

SPACE EXPLORATION↗
NASA NTRS1988

Life sciences - On the critical path for missions of exploration

Life sciences are important and critical to the safety and success of manned and long-duration space missions. The life science issues covered include gravitational physiology, space radiation, medical care delivery, environmental maintenance, bioregenerative systems, crew and human factors within and outside the spacecraft. The history of the role of life sciences in the space program is traced from the Apollo era, through the Skylab era to the Space Shuttle era. The life science issues of the space station program and manned missions to the moon and Mars are covered.

Sulzman, Frank M.↗
NASA NTRS2003

Orbital Space Plane (OSP) Program

Lockheed Martin has been an active participant in NASA's Space Launch Initiative (SLI) programs over the past several years. SLI, part of NASA's Integrated Space Transportation Plan (ISTP), was restructured in November of 2002 to focus the overall theme of safer, more afford-able space transportation along two paths - the Orbital Space Plane Program and the Next Generation Launch Technology programs. The Orbital Space Plane Program has the goal of providing rescue capability from the International Space Station by 2008 and transfer capability for crew (and limited cargo) by 2012. The Next Generation Launch Technology program is combining research and development efforts from the 2nd Generation Reusable Launch Vehicle (2GRLV) program with cutting-edge, advanced space transportation programs (previously designated 3rd Generation) into one program aimed at enabling safe, reliable, cost-effective reusable launch systems by the middle of the next decade. Lockheed Martin is one of three prime contractors working to bring Orbital Space Plane system concepts to a system definition level of maturity by December of 2003. This paper and presentation will update the international community on the progress of the' OSP program, from an industry perspective, and provide insights into Lockheed Martin's role in enabling the vision of a safer, more affordable means of taking people to and from space.

McKenzie, Patrick M.↗
NASA NTRS1971

To the moon and beyond

Manned flight from Montgolfier Balloon to Apollo 13, discussing future space programs including lunar base and space shuttle

Gilruth, R. R.↗
NASA NTRS1976

Evaluation of HAL/S language compilability using SAMSO's Compiler Writing System (CWS)

NASA/Langley is engaged in a program to develop an adaptable guidance and control software concept for spacecraft such as shuttle-launched payloads. It is envisioned that this flight software be written in a higher-order language, such as HAL/S, to facilitate changes or additions. To make this adaptable software transferable to various onboard computers, a compiler writing system capability is necessary. A joint program with the Air Force Space and Missile Systems Organization was initiated to determine if the Compiler Writing System (CWS) owned by the Air Force could be utilized for this purpose. The present study explores the feasibility of including the HAL/S language constructs in CWS and the effort required to implement these constructs. This will determine the compilability of HAL/S using CWS and permit NASA/Langley to identify the HAL/S constructs desired for their applications. The study consisted of comparing the implementation of the Space Programming Language using CWS with the requirements for the implementation of HAL/S. It is the conclusion of the study that CWS already contains many of the language features of HAL/S and that it can be expanded for compiling part or all of HAL/S. It is assumed that persons reading and evaluating this report have a basic familiarity with (1) the principles of compiler construction and operation, and (2) the logical structure and applications characteristics of HAL/S and SPL.

Feliciano, M.↗
NASA NTRS1982

Total-dose radiation effects data for semiconductor devices, volume 3

Volume 3 of this three-volume set provides a detailed analysis of the data in Volumes 1 and 2, most of which was generated for the Galileo Orbiter Program in support of NASA space programs. Volume 1 includes total ionizing dose radiation test data on diodes, bipolar transistors, field effect transistors, and miscellaneous discrete solid-state devices. Volume 2 includes similar data on integrated circuits and a few large-scale integrated circuits. The data of Volumes 1 and 2 are combined in graphic format in Volume 3 to provide a comparison of radiation sensitivities of devices of a given type and different manufacturer, a comparison of multiple tests for a single data code, a comparison of multiple tests for a single lot, and a comparison of radiation sensitivities vs time (date codes). All data were generated using a steady-state 2.5-MeV electron source (Dynamitron) or a Cobalt-60 gamma ray source. The data that compose Volume 3 represent 26 different device types, 224 tests, and a total of 1040 devices. A comparison of the effects of steady-state electrons and Cobat-60 gamma rays is also presented.

Price, W. E.↗
NASA NTRS1986

Support for global science: Remote sensing's challenge

Remote sensing uses a wide variety of techniques and methods. Resulting data are analyzed by man and machine, using both analog and digital technology. The newest and most important initiatives in the U. S. civilian space program currently revolve around the space station complex, which includes the core station as well as co-orbiting and polar satellite platforms. This proposed suite of platforms and support systems offers a unique potential for facilitating long term, multidisciplinary scientific investigations on a truly global scale. Unlike previous generations of satellites, designed for relatively limited constituencies, the space station offers the potential to provide an integrated source of information which recognizes the scientific interest in investigating the dynamic coupling between the oceans, land surface, and atmosphere. Earth scientist already face problems that are truly global in extent. Problems such as the global carbon balance, regional deforestation, and desertification require new approaches, which combine multidisciplinary, multinational research teams, employing advanced technologies to produce a type, quantity, and quality of data not previously available. The challenge before the international scientific community is to continue to develop both the infrastructure and expertise to, on the one hand, develop the science and technology of remote sensing, while on the other hand, develop an integrated understanding of global life support systems, and work toward a quantiative science of the biosphere.

Estes, J. E.↗
NASA NTRS1987

Advanced long term cryogenic storage systems

Long term, cryogenic fluid storage facilities will be required to support future space programs such as the space-based Orbital Transfer Vehicle (OTV), Telescopes, and Laser Systems. An orbital liquid oxygen/liquid hydrogen storage system with an initial capacity of approximately 200,000 lb will be required. The storage facility tank design must have the capability of fluid acquisition in microgravity and limit cryogen boiloff due to environmental heating. Cryogenic boiloff management features, minimizing Earth-to-orbit transportation costs, will include advanced thick multilayer insulation/integrated vapor cooled shield concepts, low conductance support structures, and refrigeration/reliquefaction systems. Contracted study efforts are under way to develop storage system designs, technology plans, test article hardware designs, and develop plans for ground/flight testing.

Brown, Norman S.↗
NASA NTRS2004

A 2-to-48-MHz Phase-Locked Loop

A 2-to-48-MHz phase-locked loop (PLL), developed for the U.S. space program, meets or exceeds all space shuttle clock electrical interface requirements by taking as its reference a 2-to-48-MHz clock signal and outputting a phaselocked clock signal set at the same frequency as the reference clock with transistor- transistor logic (TTL) voltage levels. Because it is more adaptable than other PLLs, the new PLL can be used in industries that employ signaling devices and as a tool in future space missions. A conventional PLL consists of a phase/frequency detector, loop filter, and voltage-controlled oscillator in which each component exists individually and is integrated into a single device. PLL components phase-lock to a single frequency or to a narrow bandwidth of frequencies. It is this design, however, that prohibits them from maintaining phase lock to a dynamically changing reference clock when a large bandwidth is required a deficiency the new PLL overcomes. Since most PLL components require their voltage-controlled oscillators to operate at greater than 2-MHz frequencies, conventional PLLs often cannot achieve the low-frequency phase lock allowed by the new PLL. The 2-to-48-MHz PLL is built on a wire-wrap board with pins wired to three position jumpers; this makes changing configurations easy. It responds to variations in voltage-controlled oscillator (VCO) ranges, duty cycle, signal-to-noise ratio (SNR), amplitude, and jitter, exceeding design specifications. A consensus state machine, implemented in a VCO range detector which assures the PLL continues to operate in the correct range, is the primary control state machine for the 2-to-48-MHz PLL circuit. By using seven overlapping frequency ranges with hysteresis, the PLL output sets the resulting phase-locked clock signal at a frequency that agrees with the reference clock with TTL voltage levels. As a space-shuttle tool, the new PLL circuit takes the noisy, degraded reference clock signals as input and outputs phase-locked clock signals of the same frequency but with a corrected wave shape. Since its configuration circuit can be easily changed, the new PLL can do the following: readily respond to variations in VCO ranges, duty cycle, SNR, amplitude, and jitter; continuously operate in the correct VCO range because of its consensus state machine; and use its range detector implements to overlap seven frequency ranges with hysteresis, thus giving the current design a flexibility that exceeds anything available at the time of this development. These features will benefit any industry in which safe and timely clock signals are vital to operation.

Koudelka, Robert D.↗
NASA NTRS1963

ADDRESS BY

United states space program - launch vehicles, satellites and spacecraft

SPACE PROGRAM↗