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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 145 records · Page 8

Analysis of ocular torsion data from Space Labs D-1 and SL-1

A series of preflight, inflight, and postflight vestibular experiments were conducted on Spacelab missions SL-1 and D-1. Two portions of the investigation, the 'sled' and 'dome' functional objectives, involved recording the torsional motion of human subject's eyes. In the SL-1 sled and dome experiments, preflight and postflight ocular torsion was recorded on 35 mm film using a Nikon motor driven camera (2.6 frames/sec). The film was to be analyzed by measuring the motion of contact lens landmarks using a Hermes senior film scanner. However, an inflight failure of the dome experiment camera flash unit led the crew to utilize the Spacelab video camera as an alternative contingency method for imaging the eye in this FO. A suitable method for analysis of the video data was developed. Results of the analysis are presented.

Oman, C. M.↗

Overview of European and other non-US/USSR/Japan launch vehicle and propulsion technology programs

The following subject areas are covered: majority of propulsion technology development work is directly related to the ESA's Ariane 5 program and heavily involves SEP (Societe Europeenne de Propulsion) in all areas; Hermes; advanced work on magnetic bearings for turbomachinery; electric propulsion using Cs and Xe propellants done by SEP in France, MBB ERNO in West Germany, and by Culham Lab in UK; successfully tested fired H/O composite nozzle exit cone on 3rd stage of Ariane; turbine blades made of composites to allow increase in gas temperature and improvement in efficiency; combined cycle (turboramjet-rocket) engine analysis work done by Hyperspace; and ESA advanced program studies.

Rice, Eric E.↗

CCSDS Advanced Orbiting Systems - International data communications standards for the Space Station Freedom

Established in 1982, the Consultative Committee for Space Data Systems (CCSDS) is an international organization that is staffed by data-handling experts from nearly all of the world's major space agencies. Its goal is to develop standard data-communications techniques so that several agencies may cross-support each other's data flow and thus allow complex, international missions to be flown. Under the general umbrella of Advanced Orbiting Systems (AOS), an international CCSDS task force was formed in 1985 to develop standard data-communications concepts for manned missions, such as the Space Station Freedom and the Hermes space plane, and large unmanned vehicles, such as polar orbiting platforms. The history of the CCSDS and the development of the AOS recommendation are reviewed, and the user services and protocols embodied in its systems architecture are introduced.

Hooke, Adrian J.↗

Columbus Programme (current status)

A description is presented for the Columbus Program. The Columbus program comprises a space segment, a ground segment, and operations preparation program, and a utilization preparation program. The space segment consist of three elements: an Attached Pressurized Module (APM); a Man Tended Free Flyer (MTFF); and a Polar platform (PPF). The ground segment is a program shared with other European programs such as Hermes, for communications, services, training and tracking facilities. The Operations preparation program focuses on preparing the ground segment for readiness for the launch of the space segment elements. And the Utilization preparation program includes definition of candidate payload facilities, initial payload selection and precursor flights (Eureca, Spacelab).

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Space mission support by NASA Space Network

Normal NASA operational considerations and Phase 1 of Space Network (SN) interoperability foresees S band cross support between user spacecraft and space networks or partnering agencies. A typical interoperable scenario for an S band user spacecraft of a partner space agency with the NASA SN is presented. ESA's Hermes Manned Spaceplane exemplifies a typical interoperable user. In order to demonstrate the support potential of the NASA SN, the internal and external interfaces of the TDRSS (Tracking and Data Relay Satellite System), ATDRSS (Advanced TDRSS), and supporting elements are examined. Communications and operational requirements for a typical mission supported by the NASA SN are discussed.

Godfrey, Robert↗

Rise time and response measurements on a LiSOCl2 cell

Dynamic impedance tests were performed on a 180 Ah LiSOCl2 cell in the frame of a short term work contract awarded by Aerospatiale as part of the Hermes Space Plane development work. These tests consisted of rise time and response measurements. The rise time test was performed to show the ability to deliver 4 KW, in the nominal voltage range (75-115 V), within less than 100 microseconds, and after a period at rest of 13 days. The response measurements test consisted of step response and frequency response tests. The frequency response test was performed to characterize the response of the LiSOCl2 cell to a positive or negative load step of 10 A starting from various currents. The test was performed for various depths of discharge and various temperatures. The test results were used to build a mathematical, electrical model of the LiSOCl2 cell which are also presented. The test description, test results, electrical modelization description, and conclusions are presented.

Bastien, Caroline↗

Computational methods for shock waves in three-dimensional supersonic flow

A central artificial-viscosity and an upwind-biased difference method are contrived to solve the Euler equations for flowfields over typical spacecrafts. The spatial discretization is based on either nodal or cell-vertex formulation in the domain extending from free stream to the end of the vehicle. The outer boundary is treated as a bow shock in the first method but is placed in the free stream in the second, which captures both bow and internal shocks using an approximate Riemann solver based on high-order extrapolation to the cell face. These methods were tested for the Shuttle and Hermes orbiters at wind-tunnel conditions and angles of attack ranging from 0 to 60 deg. The artificial-viscosity method incorporated with a shock-fitting procedure shows smeared crossflow and wing-shock positions and required 15 percent more CPU per node than the upwind method. Greater flexibility and robustness is demonstrated by the latter on a fixed grid for all cases considered.

Li, Chien-Peng↗

On-orbit demonstrations of automated closure and capture using ESA-developed proximity operations technologies and an existing serviceable NASA Explorer platform spacecraft

Since 1984 the European Space Agency (ESA) has been working to develop an autonomous rendezvous and docking capability to enable Hermes to dock automatically with Columbus. As a result, ESA (with Matra, MBB, and other space companies) have developed technologies that are directly supportive of the current NASA initiative for Automated Rendezvous and Capture. Fairchild and Matra would like to discuss the results of the applicable ESA/Matra rendezvous and capture developments and suggest how these capabilities could be used together with an existing NASA Explorer Platform satellite to minimize new development and accomplish a cost-effective automatic closure and capture demonstration program.

Hohweisner, Bill↗

ASUR

The Ecole Polytechnique Feminine (EPF) is a French engineering school for women. The students who presented the project at the Summer Conference are in the fourth year of a five year program. For the second time, the EPF worked on an aeronautical project with the Ohio State University. This year, the theme was to design a hypersonic carrier aimed to launch an orbiter at Mach 6, a range of 375 miles and an altitude of 95,000 ft. The plane was called ASUR which in French means the blue sky, the same sky that links our countries across the ocean. Moreover, ASUR is an anagram of USRA. This work benefits from work on reusable hypersonic aircraft in Europe, and especially on two of them: STAR-H and Sanger. STAR-H is a French project. This hypersonic aircraft would replace Ariane 5 in launching a shuttle smaller than Hermes. Sanger is a German project. Its objective is to launch a manned shuttle called HORUS, but Ariane 5 would be kept for heavy cargo launches. These two projects are in competition in Europe to be a launcher of the European Space Agency.

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Local measurement of temperatures and concentrations: A review for hypersonic flows

The quality of reentry simulation for Shuttle, HERMES, Sanger, and NASP systematically suffers from the strong non-equilibrium of rotational and vibrational temperature due to the rapid acceleration of the test gas in the nozzle. Therefore the determination of temperatures is necessary and, if possible, preferable by a non-intrusive technique. The specific interests of this review are optical techniques such as electron beam fluorescence, laser-induced fluorescence, and coherent anti-Stokes Raman scattering. The capabilities available for local measurements with temporal resolution and quantitative accuracy are discussed for velocity, temperature, density, species concentrations, and fluctuations due to turbulence. The applicability of these methods of measurement is presented and discussed for the coming topic in aerothermodynamics: experimental techniques of hot gases in high enthalpy flows.

Dankert, C.↗

Operational characterisation of requirements and early validation environment for high demanding space systems

The definition of some modern high demanding space systems requires a different approach to system definition and design from that adopted for traditional missions. System functionality is strongly coupled to the operational analysis, aimed at characterizing the dynamic interactions of the flight element with its surrounding environment and its ground control segment. Unambiguous functional, operational and performance requirements are to be defined for the system, thus improving also the successive development stages. This paper proposes a Petri Nets based methodology and two related prototype applications (to ARISTOTELES orbit control and to Hermes telemetry generation) for the operational analysis of space systems through the dynamic modeling of their functions and a related computer aided environment (ISIDE) able to make the dynamic model work, thus enabling an early validation of the system functional representation, and to provide a structured system requirements data base, which is the shared knowledge base interconnecting static and dynamic applications, fully traceable with the models and interfaceable with the external world.

Barro, E.↗

Planning: Management of predictability and uncertainty and keeping abreast of developments

The purpose of this study is to propose method to set up and control of a space mission plan such as that of the HERMES spaceplane. The interest of this subject, other than its complexity, is due to the need to manage imprecision and uncertainty during a mission, as well as changes in between missions. Under these conditions, the set up and control of a flight plan require certain special attention and this has led us to define a certain number of qualities: mastery of complexity in order to resolve conflicts between activities: configuration, resource and time management; consideration of various criteria such as risk minimization or the attainment of mission objectives; robustness and flexibility to allow for hazards and deviations from the norm during operation without having to draw up new plans; aptness for replanning by making changes to the plan without having to set up the whole plan again; and memorization and explanation facility in order to manage developments between missions.

Bastien-Thiry, Christophe↗

Remote geochemical experiment package for Discovery class missions

Remote sensing x-ray and gamma-ray spectrometers can be used to infer elemental composition on atmosphereless bodies, such as asteroids, the moon, and Mercury. The composition of the planetary body and variations in its surface chemistry are of fundamental importance in understanding the formation and dynamics of that body. Thus, for Discovery class missions, x-ray fluorescence (XRF), gamma-ray spectrometer (GRS), or a combined Geochemical Experiment Package (GEP) have been proposed. These instruments can meet the mission science objectives, while still meeting the weight, power, and cost constraints. These missions include the Near Earth Asteroid Rendezvous, the Main-belt Asteroid Rendezvous, and others such as HERMES (Mercury Orbiter). This paper presents the results of calculations done to assess the sensitivity of a combined instrument to obtain elemental compositions of planetary bodies with an uncertainty small enough to be scientifically useful.

Clark, Pamela E.↗

Numerical simulation of entry flow over blunt swept-wing planes

Viscous, heat-conducting flow with chemical and vibrational relaxation processes of the constituent gases surrounding winged spacecraft is considered in the continuum regime. The Navier-Stokes equations are appended by additional vibrational energy and species rate equations and supplemented by the equations of state and the phenomenological laws based on mixture rules or collisional cross sections. Numerical convective flux can be obtained from several forms of one-dimensional Riemann solver, with or without entropy correction. High-order accuracy is obtained from two types of reconstructive interpolation. A number of explicit and implicit numerical schemes have been implemented as a means to yield converged solutions. Both shock-fitting, finite-difference and shock-capturing, finite-volume techniques have been tested for configurations such as a sphere, double ellipsoid, blunt-edge delta wing, a European Hermes vehicle, and the U.S. Shuttle Orbiter. The shock-fitting code provides excellent results only for simple configurations, whereas the shock-capturing code leads to overall satisfying solutions for complex geometries.

Li, C. P.↗

Lunar and Planetary Science XXXV: Origin of Planetary Systems

The session "Origin of Planetary Systems" included the following reports: (12753) Povenmire - Standard Comparison Small Main Belt Asteroid?; Gravitational Frequencies of Extra-Solar Planets; 'Jumping Jupiters' in Binary Star Systems; Hermes, Asteroid 2002 SY50 and the Northern Cetids - No Link Found!; What Kind of Accretion Model is Required for the Solar System; and Use of an Orbital Phase Curve of Extrasolar Planet for Specification of its Mass.

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ELaNa - Educational Launch of Nanosatellite Enhance Education Through Space Flight

One of NASA's missions is to attract and retain students in the science, technology, engineering and mathematics (STEM) disciplines. Creating missions or programs to achieve this important goal helps strengthen NASA and the nation's future work force as well as engage and inspire Americans and the rest of the world. During the last three years, in an attempt to revitalize educational space flight, NASA generated a new and exciting initiative. This initiative, NASA's Educational Launch of Nanosatellite (ELaNa), is now fully operational and producing exciting results. Nanosatellites are small secondary satellite payloads called CubeSats. One of the challenges that the CubeSat community faced over the past few years was the lack of rides into space. Students were building CubeSats but they just sat on the shelf until an opportunity arose. In some cases, these opportunities never developed and so the CubeSat never made it to orbit. The ELaNa initiative is changing this by providing sustainable launch opportunities for educational CubeSats. Across America, these CubeSats are currently being built by students in high school all the way through graduate school. Now students know that if they build their CubeSat, submit their proposal and are selected for an ELaNa mission, they will have the opportunity to fly their satellite. ELaNa missions are the first educational cargo to be carried on expendable launch vehicles (ELY) for NASA's Launch Services Program (LSP). The first ELaNa CubeSats were slated to begin their journey to orbit in February 2011 with NASA's Glory mission. Due to an anomaly with the launch vehicle, ELaNa II and Glory failed to reach orbit. This first ELaNa mission was comprised of three IU CubeSats built by students at Montana State University (Explorer Prime Flight 1), the University of Colorado (HERMES), and Kentucky Space, a consortium of state universities (KySat). The interface between the launch vehicle and the CubeSat, the Poly-Picosatellite Orbital Deployer (P-POD), was developed and built by students at California Polytechnic State University (Cal Poly). Integrating a P-POD on a NASA ELV was not an easy task. The creation of new processes and requirements as well as numerous reviews and approvals were necessary within NASA before the first ELaNa mission could be attached to a NASA launch vehicle (LV). One of the key objectives placed on an ELaNa mission is that the CubeSat and PPOD does not increase the baseline risk to the primary mission and launch vehicle. The ELaNa missions achieve this objective by placing a rigorous management and engineering process on both the LV and CubeSat teams. So, what is the future of ELaNa? Currently there are 16 P-POD missions manifested across four launch vehicles to support educational CubeSats selected under the NASA CubeSat Initiative. From this initiative, a rigorous selection process produced 22-student CubeSat missions that are scheduled to fly before the end of 2012. For the initiative to continue, organizations need to submit proposals to the annual CubeSat initiative call so they have the opportunity to be manifested and launched.

Skrobot, Garrett Lee↗

Performance, Facility Pressure Effects, and Stability Characterization Tests of NASA's Hall Effect Rocket with Magnetic Shielding Thruster

NASA's Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5 kW Technology Demonstration Unit-1 (TDU-1) has been the subject of extensive technology maturation in preparation for flight system development. Part of the technology maturation effort included experimental evaluation of the TDU-1 thruster with conducting and dielectric front pole cover materials in two different electrical configurations. A graphite front magnetic pole cover thruster configuration with the thruster body electrically tied to cathode, and an alumina front pole cover thruster configuration with the thruster body floating were evaluated. Both configurations were also evaluated at different facility background pressure conditions to evaluate background pressure effects on thruster operation. Performance characterization tests found that higher thruster performance was attained with the graphite front pole cover configuration with the thruster electrically tied to cathode. A total thrust efficiency of 68% and a total specific impulse of 2,820 s was demonstrated at a discharge voltage of 600 V and a discharge power of 12.5 kW. Thruster stability regimes were characterized with respect to the thruster discharge current oscillations and with maps of the discharge current-voltage-magnetic field (IVB). Analysis of TDU-1 discharge current waveforms found that lower normalized discharge current peak-to-peak and root mean square magnitudes were attained when the thruster was electrically floated with alumina front pole covers. Background pressure effects characterization tests indicated that the thruster performance and stability were mostly invariant to changes in the facility background pressure for vacuum chamber pressure below 1×10-5 Torr-Xe (for thruster flow rates of 20.5 mg/s). Power spectral density analysis of the discharge current waveforms showed that increasing the vacuum chamber background pressure resulted in a higher discharge current dominant breathing mode frequency. Finally, IVB maps of the TDU-1 thruster indicated that the discharge current became more oscillatory with higher discharge current peak-to-peak and RMS values with increased facility background pressure at lower thruster mass flow rates; thruster operation at higher flow rates resulted in less change to the thruster's IVB characteristics with elevated background pressure.

Electric Propulsion↗

Performance, Facility Pressure Effects, and Stability Characterization Tests of NASA's Hall Effect Rocket with Magnetic Shielding Thruster

NASAs Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5 kW Technology Demonstration Unit-1 (TDU-1) Hall thruster has been the subject of extensive technology maturation in preparation for flight system development. Part of the technology maturation effort included experimental evaluation of the TDU-1 thruster with conducting and dielectric front pole cover materials in two different electrical configurations. A graphite front pole cover thruster configuration with the thruster body electrically tied to cathode and an alumina front pole cover thruster configuration with the thruster body floating were evaluated. Both configurations were also evaluated at different facility background pressure conditions to evaluate background pressure effects on thruster operation. Performance characterization tests found that higher thruster performance was attained with the graphite front pole cover configuration with the thruster electrically tied to cathode. A total thrust efficiency of 68 and a total specific impulse of 2,820 s was demonstrated at a discharge voltage of 600 V and a discharge power of 12.5 kW. Thruster stability regimes were characterized with respect to the thruster discharge current oscillations and with maps of the current-voltage-magnetic field (IVB). Analysis of TDU-1 discharge current waveforms found that lower normalized discharge current peak-to-peak and root mean square magnitudes were attained when the thruster was electrically floated with alumina front pole covers. Background pressure effects characterization tests indicated that the thruster performance and stability was mostly invariant to changes in the facility background pressure for vacuum chamber pressure below 110-5 Torr-Xe (for thruster flow rate above 8 mgs). Power spectral density analysis of the discharge current waveform showed that increasing the vacuum chamber background pressure resulted in a higher discharge current dominant frequency. Finally the IVB maps of the TDU-1 thruster taken at elevated magnetic fields indicated that the discharge current became more oscillatory with increased facility background pressure at lower thruster mass flow rates, where thruster operation at higher flow rates resulted in less change to the thrusters IVB characteristics.

Hall Thrusters↗