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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

SSTO rockets. A practical possibility

Most experts agree that single-stage-to-orbit (SSTO) rockets would become feasible if more advanced technologies were available to reduce the vehicle dry weight, increase propulsion system performance, or both. However, these technologies are usually judged to be very ambitious and very far off. This notion persists despite major advances in technology and vehicle design in the past decade. There appears to be four major misperceptions about SSTOs, regarding their mass fraction, their presumed inadequate performance margin, their supposedly small payloads, and their extreme sensitivity to unanticipated vehicle weight growth. These misperceptions can be dispelled for SSTO rockets using advanced technologies that could be matured and demonstrated in the near term. These include a graphite-composite primary structure, graphite-composite and Al-Li propellant tanks with integral reusable thermal protection, long-life tripropellant or LOX-hydrogen engines, and several technologies related to operational effectiveness, including vehicle health monitoring, autonomous avionics/flight control, and operable launch and ground handling systems.

PROPELLANT MASS FRACTION↗
NASA NTRS1994

The application of spaceborne GPS to atmospheric limb sounding and global change monitoring

This monograph is intended for readers with minimal background in radio science who seek a relatively comprehensive treatment of the mission and technical aspects of an Earth-orbiting radio occultation satellite. Part 1 (chapters 1-6) describes mission concepts and programmatic information; Part 2 (chapters 7-12) deals with the theoretical aspects of analyzing and interpreting radio occultation measurements. In this mission concept the navigation signals from a Global Positioning System (GPS) satellite that is being occulted by the Earth's limb are observed by a GPS flight receiver on board a low Earth orbiter (LEO) satellite. This technique can be used to recover profiles of the Earth's atmospheric refractivity, pressure, and temperature using small, dedicated, and relatively low-cost space systems. Chapter 2 summarizes the basic space system concepts of the limb-sounding technique and describes a low-cost strawman demonstration mission. Chapter 3 discusses some of the scientific benefits of using radio occultation on a suite of small satellites. Chapter 4 provides a more detailed discussion of several system elements in a radio occultation mission, including the launch system for small payloads, the LEO microsat, the GPS constellation, the GPS flight receiver payload, the mission operations ground control and data receiving system, the ground-based GPS global tracking network for precision orbit determination, and the central data processing and archive system. Chapter 5 addresses the various technology readiness questions that invariably arise. Chapter 6 discusses the overall costs of a demonstration mission such as GPS/MET (meteorological) proposed by the University Navstar Consortium (UNAVCO). Chapter 7 describes a geometrical optics approach to coplanar atmospheric occultation. Chapter 8 addresses major questions regarding accuracy of the occultation techniques. Chapter 9 describes some simulations that have been performed to evaluate the sensitivity of the recovered profiles of atmospheric parameters to different error sources, such as departure from spherical symmetry, water vapor, etc. Chapter 10 discusses horizontal and vertical resolution associated with limb sounders in general. Chapter 11 treats selected Fresnel diffraction techniques that can be used in radio occultation measurements to sharpen resolution. Chapter 12 provides brief discussions on selected special topics, such as strategies for handling interference and multipath processes that may arise for rays traveling in the lower troposphere.

Melbourne, W. G.↗
NASA NTRS1996

Options for flight testing rocket-based combined-cycle (RBCC) engines

While NASA's current next-generation launch vehicle research has largely focused on advanced all-rocket single-stage-to-orbit vehicles (i.e. the X-33 and it's RLV operational follow-on), some attention is being given to advanced propulsion concepts suitable for 'next-generation-and-a-half' vehicles. Rocket-based combined-cycle (RBCC) engines combining rocket and airbreathing elements are one candidate concept. Preliminary RBCC engine development was undertaken by the United States in the 1960's. However, additional ground and flight research is required to bring the engine to technological maturity. This paper presents two options for flight testing early versions of the RBCC ejector scramjet engine. The first option mounts a single RBCC engine module to the X-34 air-launched technology testbed for test flights up to about Mach 6.4. The second option links RBCC engine testing to the simultaneous development of a small-payload (220 lb.) two-stage-to-orbit operational vehicle in the Bantam payload class. This launcher/testbed concept has been dubbed the W vehicle. The W vehicle can also serve as an early ejector ramjet RBCC launcher (albeit at a lower payload). To complement current RBCC ground testing efforts, both flight test engines will use earth-storable propellants for their RBCC rocket primaries and hydrocarbon fuel for their airbreathing modes. Performance and vehicle sizing results are presented for both options.

Olds, John↗
NASA NTRS1998

Bantam System Technology Project

This report focuses on determining a best value, low risk, low cost and highly reliable Data and Command System for support of the launch of low cost vehicles which are to carry small payloads into low earth orbit. The ground-based DCS is considered as a component of the overall ground and flight support system which includes the DCS, flight computer, mission planning system and simulator. Interfaces between the DCS and these other component systems are considered. Consideration is also given to the operational aspects of the mission and of the DCS selected. This project involved: defining requirements, defining an efficient operations concept, defining a DCS architecture which satisfies the requirements and concept, conducting a market survey of commercial and government off-the-shelf DCS candidate systems and rating the candidate systems against the requirements/concept. The primary conclusions are that several low cost, off-the-shelf DCS solutions exist and these can be employed to provide for very low cost operations and low recurring maintenance cost. The primary recommendation is that the DCS design/specification should be integrated within the ground and flight support system design as early as possible to ensure ease of interoperability and efficient allocation of automation functions among the component systems.

Moon, J. M.↗
NASA NTRS1998

Spaceflight Effects on Mammalian Development Summary of Research

Pregnant rats were flown as small payloads on the Space Shuttle and studied during the flight and for approximately a week after returning to Earth, when they were due to deliver their offspring. Studies of vestibular function in the rat pups were examined as part of the research program. Daily videorecordings were made of the rats' behavior in the Animal Enclosure Modules (AEMS) and in identical compartments maintained in the Orbiter Environment Simulator at the Kennedy Space Center (referred to below as Synchronous Control groups). There was continuous postflight surveillance of the rat dams, including timelapse recordings of labor and delivery. The videorecords provided by crewmembers constitute the best systematic views of spaceflown rats to date, despite the dramatic deterioration of visibility sustained after about the 4th day of flight. We were able to make both qualitative and quantitative observations. Rats were observed to engage in a varied repertoire of species-typical activities within the confines of the AEM. We devised a kinematic coding scheme by which we classified and quantified the movements made by dams in space and in the 1-g control condition. We found that movements involving pitch and yaw were about equivalent in Flight and Synchronous animals. In contrast, Flight dams displayed about seven times more rolling movements than did Control. NASA enabled early access to the AEMs after the Shuttle landed. Rats were intact and healthy. Body weight gain during the 9-11 day flights was equivalent to Controls. Post-flight observations, derived from 24hr/day videorecordings, showed that Flight rats ambulated less, reared fewer times and spent less time bipedal than did controls. Overall, their anti-gravitational responses appeared compromised.

Alberts, Jeffrey↗
NASA NTRS1999

Hitchhiker On Space Station

The NASA/GSFC Shuttle Small Payloads Projects Office (SSPPO) has been studying the feasibility of migrating Hitchhiker customers past present and future to the International Space Station via a "Hitchhiker like" carrier system. SSPPO has been tasked to make the most use of existing hardware and software systems and infrastructure in its study of an ISS based carrier system. This paper summarizes the results of the SSPPO Hitchhiker on International Space Station (ISS) study. Included are a number of "Hitchhiker like" carrier system concepts that take advantage of the various ISS attached payload accommodation sites. Emphasis will be given to a HH concept that attaches to the Japanese Experiment Module - Exposed Facility (JEM-EF).

Daelemans, Gerard↗
NASA NTRS1999

The Hitchhiker's Guide to I&T

With over two dozen missions since the first in 1986, the Hitchhiker project has a reputation for providing quick-reaction, low-cost flight services for Shuttle Small Payloads Project (SSPP) customers. Despite the successes, several potential improvements in customer payload integration and test (I&T) deserve consideration. This paper presents suggestions to Hitchhiker customers on how to help make the I&T process run smoother. Included are: customer requirements and interface definition, pre-integration test and evaluation, configuration management, I&T overview and planning, problem mitigation, and organizational communication. In this era of limited flight opportunities and new ISO-based requirements, issues such as these have become more important than ever.

Wright, Michael R.↗
NASA NTRS1999

Shuttle Hitchhiker Experiment Launcher System (SHELS)

NASA's Goddard Space Flight Center Shuttle Small Payloads Project (SSPP), in partnership with the United States Air Force and NASA's Explorer Program, is developing a Shuttle based launch system called SHELS (Shuttle Hitchhiker Experiment Launcher System), which shall be capable of launching up to a 400 pound spacecraft from the Shuttle cargo bay. SHELS consists of a Marman band clamp push-plate ejection system mounted to a launch structure; the launch structure is mounted to one Orbiter sidewall adapter beam. Avionics mounted to the adapter beam will interface with Orbiter electrical services and provide optional umbilical services and ejection circuitry. SHELS provides an array of manifesting possibilities to a wide range of satellites.

Daelemans, Gerry↗
NASA NTRS1998

Demonstrating the Performance Benefits of the Strutjet RBCC for Space Launch Architectures

The Rocket Based Combined Cycle (RBCC) engine synergistically combines the best elements of airbreathing and rocket propulsion to benefit a wide range of future reusable launch vehicles. Aerojet's Strutjet RBCC offers high I(sub sp) during mid-phase acceleration, and high thrust for boost and final ascent phases. The result is a relatively low gross weight vehicle with lower thrust requirements than comparable all-rocket solutions. Relative to combination propulsion systems, the integrated propulsive elements of the Strutjet reduce engine weight and complexity. In the recent NASA Highly Reusable Space Transportation (HRST) study, vehicles with RBCC-class engines were projected to have lower per flight operations costs than comparable rockets. The more benign operating environment of the RBCC engine primary rockets (2000 psi chamber pressure, lower internal temperatures, gas generator cycle) lead to longer service life, fewer maintenance actions, and increased reliability. Operations costs are typically the most significant contributor to life cycle costs. RBCC-powered vehicles lend themselves naturally to horizontal takeoff, which typically requires less thrust for a given gross vehicle weight when compared to an all-rocket-powered vehicle. The lower thrust requirements reduce engine size and/or quantity, reducing the n of ground personnel and facilities required to maintain the vehicle. The reduced sensitivity to mass fraction also allows the vehicle to be designed with higher margins for improved life and reliability. Because of its multi-mode ascent operation and ability to perform long cruise segments, the strutjet RBCC offers RLV designers a chance to create vehicles with an unprecedented level of mission flexibility. Features such as supersonic cruise, flyback, off-set launch, self-ferry, horizontal takeoff and landing, multi-base operation, and flexible aborts open up a broad range of potential revenue producing missions. The Strutjet can lead to low-cost vehicle designs in traditional areas such as LEO cargo delivery and ISS resupply, and also lead to economically attractive vehicles for small payload missions difficult to achieve with all-rocket solutions. The performance capability of the Strutjet RBCC has been demonstrated in all operating mod underfunding from NASA MSFC and Aerojet as a result of over 1000testsand over 13 years of continuous development-a significant resource investment in the Strutjet engine design.

Johnson, D.↗
NASA NTRS1998

A Status of the Advanced Space Transportation Program from Planning to Action

A Technology Plan for Enabling Commercial Space Business was presented at the 48th International Astronautical Congress in Turin, Italy. This paper presents a status of the program's accomplishments. Technology demonstrations have progressed in each of the four elements of the program; (1) Low Cost Technology, (2) Advanced Reusable Technology, (3) Space Transfer Technology and (4) Space Transportation Research. The Low Cost Technology program element is primarily focused at reducing development and acquisition costs of aerospace hardware using a "design to cost" philosophy with robust margins, adapting commercial manufacturing processes and commercial off-the-shelf hardware. The attributes of this philosophy for small payload launch are being demonstrated at the component, sub-system, and system level. The X-34 "Fastrac" engine has progressed through major component and subsystem demonstrations. A propulsion system test bed has been implemented for system-level demonstration of component and subsystem technologies; including propellant tankage and feedlines, controls, pressurization, and engine systems. Low cost turbopump designs, commercial valves and a controller are demonstrating the potential for a ten-fold reduction in engine and propulsion system costs. The Advanced Reusable Technology program element is focused on increasing life through high strength-to-weight structures and propulsion components, highly integrated propellant tanks, automated checkout and health management and increased propulsion system performance. The validation of rocket based combined cycle (RBCC) propulsion is pro,-,ressing through component and subsystem testing. RBCC propulsion has the potential to provide performance margin over an all rocket system that could result in lower gross liftoff weight, a lower propellant mass fraction or a higher payload mass fraction. The Space Transfer Technology element of the program is pursuing technology that can improve performance and dramatically reduce the propellant and structural mass of orbit transfer and deep space systems. Flight demonstration of ion propulsion is progressing towards launch. Ion propulsion is the primary propulsion for Deep Space 1; a flyby of comet West-kohoutek-lkemura and asteroid 3352 McAuliffe. Testing of critical solar-thermal propulsion subsystems have been accomplished and planning is continuing for the flight demonstration of an electrodynamic tether orbit transfer system. The forth and final element of the program, Space Transportation Research, has progressed in several areas of propulsion research. This element of the program is focused at long-term (25 years) breakthrough concepts that could bring launch costs to a factor of one hundred below today's cost or dramatically expand planetary travel and enable interstellar travel.

Lyles, Garry↗
NASA NTRS2000

Analysis of the Laser Propelled Lightcraft Vehicle

Advanced propulsion research and technology require launch and space flight technologies, which can drastically reduce mission costs. Laser propulsion is a concept in which energy of a thrust producing reaction mass is supplied via beamed energy from an off-board power source. A variety of laser/beamed energy concepts were theoretically and experimentally investigated since the early 1970's. During the 1980's the Strategic Defense Initiative (SDI) research lead to the invention of the Laser Lightcraft concept. Based upon the Laser Lightcraft concept, the U.S. Air Force and NASA have jointly set out to develop technologies required for launching small payloads into Low Earth Orbit (LEO) for a cost of $1.0M or $1000/lb to $ 100/lb. The near term objectives are to demonstrate technologies and capabilities essential for a future earth to orbit launch capability. Laser propulsion offers the advantages of both high thrust and good specific impulse, I(sub sp), in excess of 1000 s. Other advantages are the simplicity and reliability of the engine because of few moving parts, simpler propellant feed system, and high specific impulse. Major limitations of this approach are the laser power available, absorption and distortion of the pulsed laser beam through the atmosphere, and coupling laser power into thrust throughout the flight envelope, The objective of this paper is to assist efforts towards optimizing the performance of the laser engine. In order to accomplish this goal (1) defocusing of the primary optic was investigated using optical ray tracing and (2), time dependent calculations were conducted of the optically induced blast wave to predict pressure and temperature in the vicinity of the cowl. Defocusing of the primary parabolic reflector causes blurring and reduction in the intensity of the laser ignition site on the cowl. However, because of the caustic effect of ray-tracing optics the laser radiation still forms a well-defined ignition line on the cowl. The blast wave calculations show reasonable agreement with previously published calculations and recent detailed CFD computations.

Feikema, Douglas↗
NASA NTRS2001

JEM-EF Space Station Carrier System

The NASA/GSFC Shuttle Small Payloads Projects Office (SSPPO) is developing a carrier system for accommodating scientific and applications payloads on the Japanese Experiment Module - Exposed Facility (JEM-EF). The carrier structure provides for flexible mounting of payload instrumentation in nadir, zenith, or limb-viewing positions. Avionics capability will be provided to accommodate up to four payloads with independent power and signal connections. The JEM-EF carrier builds on over 15 years of experience in developing and operating the "Hitchhiker" carriers used on the Space Shuttle. This paper describes the carrier system, potential payload configurational and related GSFC activities.

Daelemans, Gerard J.↗
NASA NTRS1999

Analysis of the Laser Lightcraft Vehicle

Advanced propulsion research and technology concepts require launch and space flight technologies, which can drastically reduce mission costs. Laser propulsion is a concept in which energy of a thrust producing reaction mass is supplied via beamed energy from an off-board power source. A variety of laser beamed energy concepts were theoretically and experimentally investigated since the early 1970's. During the 1980's the Strategic Defense Initiative (SDIO) research lead to the invention of the Laser Lightcraft concept. Based upon the Laser Lightcraft concept, the propulsion research center, TD 40, within the Space Transportation Directorate of NASA MSFC has set out to develop technologies required for launching small payloads into Earth Orbit for a cost of $1.0M or $1000/lb to $100/lb. The near term objectives are to demonstrate technologies and capabilities essential for a future earth to orbit launch capability. Laser propulsion offers the advantages of both high thrust and good specific impulse, I(sp) in excess of 1000 s(exp -1). Other advantages are the simplicity and reliability of the engine because of few moving parts; simplistic propellant feed system, and low specific fuel consumption as a result of high specific impulse. Major limitations of this approach are the laser power available, absorption and distortion of the pulsed laser beam through the atmosphere, and coupling laser power into thrust throughout the flight envelope. This summer's effort focused on performance of the laser engine, which included 1) optical ray tracing and 2), a time dependent calculation of the optically induced blast wave.

Feikema, Douglas A.↗
NASA NTRS2003

Places Only Sails Can Go

Solar sails are a near term, low thrust, propellantless propulsion technology suitable for orbital maneuvering, station keeping, and attitude control applications for small payloads. Furthermore, these functions can be highly integrated, reducing mass, cost and complexity. The solar sail concept is based on momentum exchange with solar flux reflected from a large, deployed thin membrane. Thrust performance increases as the square of the distance to the sun. In comparison to conventional chemical systems, there are missions where solar sails are vastly more and less economical. The less attractive applications involve large payloads, outer solar system transfers, and short trip times. However, for inclination changes and station keeping at locations requiring constant thrust, the solar sail is the only economical option for missions of more than a few weeks duration. We compare the location and energies required for these applications between solar sails, advanced electric propulsion, and conventional rockets. We address the effect on mass fraction to understand solar sail mission cost and capability. Finally, the benefit of potential applications to near term science missions is reported.

Montgomery, Edward E., IV↗
NASA NTRS2003

Launch Condition Deviations of Reusable Launch Vehicle Simulations in Exo-Atmospheric Zoom Climbs

The Defense Advanced Research Projects Agency has proposed a two-stage system to deliver a small payload to orbit. The proposal calls for an airplane to perform an exo-atmospheric zoom climb maneuver, from which a second-stage rocket is launched carrying the payload into orbit. The NASA Dryden Flight Research Center has conducted an in-house generic simulation study to determine how accurately a human-piloted airplane can deliver a second-stage rocket to a desired exo-atmospheric launch condition. A high-performance, fighter-type, fixed-base, real-time, pilot-in-the-loop airplane simulation has been modified to perform exo-atmospheric zoom climb maneuvers. Four research pilots tracked a reference trajectory in the presence of winds, initial offsets, and degraded engine thrust to a second-stage launch condition. These launch conditions have been compared to the reference launch condition to characterize the expected deviation. At each launch condition, a speed change was applied to the second-stage rocket to insert the payload onto a transfer orbit to the desired operational orbit. The most sensitive of the test cases was the degraded thrust case, yielding second-stage launch energies that were too low to achieve the radius of the desired operational orbit. The handling qualities of the airplane, as a first-stage vehicle, have also been investigated.

Urschel, Peter H.↗
NASA NTRS1997

Changes in gravity influence rat postnatal motor system development: from simulation to space flight

Our research examines the role of the environment in postnatal nervous system development. Recently we have been studying the effects of changes in gravity on the motor system of rats from postnatal day (P) 2 to 31 using kinematic analysis of swimming, walking, and righting reflexes. Using the tail suspension model of weightlessness we identified sensitive and critical periods of motor system development corresponding to the time during which a motor skill is first achieved. Motor performance in suspended animals was marked by slow swimming, walking, and air-righting, all of which were characterized by hindlimb extension. (Walton et al, Neurosci. 52,763,1992). The critical periods identified in these studies contributed to determining the age of animals for a small payload, NIH.R3. This 9-day mission (STS-72) included 2 litters at P5, P7, or P15 at launch. The P7-16 and P15-24 groups were studied post-flight. On the landing day (R+0) surface righting, swimming and walking were slower in flight compared to control animals. Differences were more marked in the younger animals and the hindlimbs were more affected than the forelimbs with marked, prolonged extension of, at least, the ankle joint angle. Readaptation to 1G was slower in the P7-16 group with righting reflexes adapting first, walking last. We have shown that gravity is an important factor in postnatal nervous system development and that its affect depends on the age of the animal, duration of the perturbation, and the motor function studied.

Non-NASA Center↗
NASA NTRS2004

Aerodynamic Characteristics and Glide-Back Performance of Langley Glide-Back Booster

NASA-Langley Research Center is conducting system level studies on an-house concept of a small launch vehicle to address NASA's needs for rapid deployment of small payloads to Low Earth Orbit. The vehicle concept is a three-stage system with a reusable first stage and expendable upper stages. The reusable first stage booster, which glides back to launch site after staging around Mach 3 is named the Langley Glide-Back Booster (LGBB). This paper discusses the aerodynamic characteristics of the LGBB from subsonic to supersonic speeds, development of the aerodynamic database and application of this database to evaluate the glide back performance of the LGBB. The aerodynamic database was assembled using a combination of wind tunnel test data and engineering level analysis. The glide back performance of the LGBB was evaluated using a trajectory optimization code and subject to constraints on angle of attack, dynamic pressure and normal acceleration.

Pamadi, Bandu N.↗
NASA NTRS2004

Neptune Orbiters Utilizing Solar and Radioisotope Electric Propulsion

In certain cases, Radioisotope Electric Propulsion (REP), used in conjunction with other propulsion systems, could be used to reduce the trip times for outer planetary orbiter spacecraft. It also has the potential to improve the maneuverability and power capabilities of the spacecraft when the target body is reached as compared with non-electric propulsion spacecraft. Current missions under study baseline aerocapture systems to capture into a science orbit after a Solar Electric Propulsion (SEP) stage is jettisoned. Other options under study would use all REP transfers with small payloads. Compared to the SEP stage/Aerocapture scenario, adding REP to the science spacecraft as well as a chemical capture system can replace the aerocapture system but with a trip time penalty. Eliminating both the SEP stage and the aerocapture system and utilizing a slightly larger launch vehicle, Star 48 upper stage, and a combined REP/Chemical capture system, the trip time can nearly be matched while providing over a kilowatt of science power reused from the REP maneuver. A Neptune Orbiter mission is examined utilizing single propulsion systems and combinations of SEP, REP, and chemical systems to compare concepts.

Fiehler, Douglas I.↗