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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Co-axial Joint Technology Applied to Antenna Backup Structures

The increasing demand to improve focusing accuracy and to accommodate higher frequencies in space communications and radio astronomy has created significant challenges for improving the capability of the constituent systems in radio antennas and telescopes. One important system is the radio antenna/telescope backup structure connections. The backup structure is a key element in providing a stable, precise and rigid support for the reflective surface. The ideal connection for these types of structures is rigid and concentric resulting in minimal deformation with stress/strain curves that are linear, repeatable and exhibiting no hysteresis over the entire service load range. Conceivably such a connection could be designed so that the stress/strain curve mimics the stress/strain characteristics of the connecting member in both tension and compression. When this is achieved then such joints can be said to be 'invisible' in the global behavior of the backup structure. At that point, overall reflector deflection becomes more linear and highly predictable. In conjunction with this advantage, optimized backup structure geometries, adaptive reflectors and compensating algorithms can best be applied in producing an instrument of unparalleled performance. This paper introduces Co-Axial Joint (CAJ) technology as the practical and economical means to produce an invisible connection.

trusses↗
NASA NTRS2001

Mini AERCam: A Free-Flying Robot for Space Inspection

The NASA Johnson Space Center Engineering Directorate is developing the Autonomous Extravehicular Robotic Camera (AERCam), a free-flying camera system for remote viewing and inspection of human spacecraft. The AERCam project team is currently developing a miniaturized version of AERCam known as Mini AERCam, a spherical nanosatellite 7.5 inches in diameter. Mini AERCam development builds on the success of AERCam Sprint, a 1997 Space Shuttle flight experiment, by integrating new on-board sensing and processing capabilities while simultaneously reducing volume by 80%. Achieving these productivity-enhancing capabilities in a smaller package depends on aggressive component miniaturization. Technology innovations being incorporated include micro electromechanical system (MEMS) gyros, "camera-on-a-chip" CMOS imagers, rechargeable xenon gas propulsion, rechargeable lithium ion battery, custom avionics based on the PowerPC 740 microprocessor, GPS relative navigation, digital radio frequency communications and tracking, micropatch antennas, digital instrumentation, and dense mechanical packaging. The Mini AERCam free-flyer will initially be integrated into an approximate flight-like configuration for laboratory demonstration on an airbearing table. A pilot-in-the-loop and hardware-in-the-loop simulation to simulate on-orbit navigation and dynamics will complement the airbearing table demonstration. The Mini AERCam lab demonstration is intended to form the basis for future development of an AERCam flight system that provides on-orbit views of the Space Shuttle and International Space Station unobtainable from fixed cameras, cameras on robotic manipulators, or cameras carried by space-walking crewmembers.

Fredrickson, Steven↗
NASA NTRS2001

Miniaturized Autonomous Extravehicular Robotic Camera (Mini AERCam)

The NASA Johnson Space Center (JSC) Engineering Directorate is developing the Autonomous Extravehicular Robotic Camera (AERCam), a low-volume, low-mass free-flying camera system . AERCam project team personnel recently initiated development of a miniaturized version of AERCam known as Mini AERCam. The Mini AERCam target design is a spherical "nanosatellite" free-flyer 7.5 inches in diameter and weighing 1 0 pounds. Mini AERCam is building on the success of the AERCam Sprint STS-87 flight experiment by adding new on-board sensing and processing capabilities while simultaneously reducing volume by 80%. Achieving enhanced capability in a smaller package depends on applying miniaturization technology across virtually all subsystems. Technology innovations being incorporated include micro electromechanical system (MEMS) gyros, "camera-on-a-chip" CMOS imagers, rechargeable xenon gas propulsion system , rechargeable lithium ion battery, custom avionics based on the PowerPC 740 microprocessor, GPS relative navigation, digital radio frequency communications and tracking, micropatch antennas, digital instrumentation, and dense mechanical packaging. The Mini AERCam free-flyer will initially be integrated into an approximate flight-like configuration for demonstration on an airbearing table. A pilot-in-the-loop and hardware-in-the-loop simulation to simulate on-orbit navigation and dynamics will complement the airbearing table demonstration. The Mini AERCam lab demonstration is intended to form the basis for future development of an AERCam flight system that provides beneficial on-orbit views unobtainable from fixed cameras, cameras on robotic manipulators, or cameras carried by EVA crewmembers.

Fredrickson, Steven E.↗
NASA NTRS2010

DARPA DTN Phase 3 Core Engineering Support

This report covers the initial DARPA DTN Phase 3 activities as JPL provided Core Engineering Support to the DARPA DTN Program, and then further details the culmination of the Phase 3 Program with a systematic development, integration and test of a disruption-tolerant C2 Situation Awareness (SA) system that may be transitioned to the USMC and deployed in the near future. The system developed and tested was a SPAWAR/JPL-Developed Common Operating Picture Fusion Tool called the Software Interoperability Environment (SIE), running over Disruption Tolerant Networking (DTN) protocols provided by BBN and MITRE, which effectively extends the operational range of SIE from normal fully-connected internet environments to the mobile tactical edges of the battlefield network.

Disruption Tolerant Networking (DTN) protocols↗
NASA NTRS2003

120-GHz HEMT Oscillator With Surface-Wave-Assisted Antenna

Two monolithic microwave integrated circuits (MMICs) have been designed and built to function together as a source of electromagnetic radiation at a frequency of 120 GHz. One of the MMICs is an oscillator and is the highest-power 120-GHz oscillator reported thus far in the literature. The other MMIC is an end-fire antenna that radiates the oscillator signal. Although these MMICs were constructed as separate units and electrically connected with wire bonds, future oscillator/ antenna combinations could readily be fabricated as monolithic integrated units. Such units could be used as relatively high-power solid-state microwave sources in diverse applications that include automotive radar, imaging, scientific instrumentation, communications, and radio astronomy. As such, these units would be attractive alternatives to vacuum-tube oscillators, which are still used to obtain acceptably high power in the frequency range of interest. The oscillator (see figure) includes a high-electron-mobility transistor (HEMT), with gate-periphery dimensions of 4 by 37 m, in a common-source configuration. The series feedback element of the oscillator is a grounded coplanar waveguide (CPW) at the source. The HEMT is biased for class-A operation (meaning that current is conducted throughout the oscillation cycle) to maximize the output power of the oscillator. Input and output impedance-matching circuit elements are designed to maximize output power and to establish the conditions needed for oscillation. The design of the antenna takes advantage of surface waves, which, heretofore, have been regarded as highly disadvantageous because they can leak power and degrade the performances of antennas that have not been designed to exploit them. Measures taken to suppress surface waves have included complex machining of circuit substrates and addition of separate substrates. These measures are difficult to implement in standard MMIC fabrication processes. In contrast, because the design of the present antenna eliminates the need to suppress surface waves, the fabrication of the antenna is fully compatible with standard MMIC fabrication processes.

Samoska, Lorene↗
NASA NTRS2015

An Investigation of Interval Management Displays

NASA's first Air Traffic Management (ATM) Technology Demonstration (ATD-1) was created to transition the most mature ATM technologies from the laboratory to the National Airspace System. One selected technology is Interval Management (IM), which uses onboard aircraft automation to compute speeds that help the flight crew achieve and maintain precise spacing behind a preceding aircraft. Since ATD-1 focuses on a near-term environment, the ATD-1 flight demonstration prototype requires radio voice communication to issue an IM clearance. Retrofit IM displays will enable pilots to both enter information into the IM avionics and monitor IM operation. These displays could consist of an interface to enter data from an IM clearance and also an auxiliary display that presents critical information in the primary field-of-view. A human-in-the-loop experiment was conducted to examine usability and acceptability of retrofit IM displays, which flight crews found acceptable. Results also indicate the need for salient alerting when new speeds are generated and the desire to have a primary field of view display available that can display text and graphic trend indicators.

Swieringa, Kurt A.↗
NASA NTRS2017

Solar Flare Termination Shock and the Synthetic Fe XXI 1354.08 Å Line

Solar flares are one of the most energetic phenomena occurred in the solar system. In the standard solar flare model, a fast mode shock, which is often referred to as the flare termination shock (TS), can exist above the loop-top source of hard X-ray emissions. The existence of the termination shock has been recently related to spectral hardening of flare hard X-ray spectrum at energies > 300 keV. Observations of the Fe XXI 1354.08 Å line during solar flares by the IRIS spacecraft have found significant redshift with >100 km/s, which is consistent with a reconnection downflow. The ability to identify such a redshift by IRIS is made possible by IRIS's high time resolution, high spatial resolution, high sensitivity and cadence spectral observations. The ability to identify such a redshift by IRIS suggests that one may be able to use IRIS observations to identify flare termination shocks. Using a MHD simulation to model magnetic reconnection of a solar flare and assuming the existence of a TS in the downflow of the reconnection plasma, we model the synthetic emission of the Fe XXI 1354.08 Å line in this work. We show that the existence of the TS in the solar flare may manifest itself from the Fe XXI 1354.08 Å line.Plain Language SummaryA solar flare is a brief eruption of intense high-energy radiation from the sun's surface, associated with sunspots and causing electromagnetic disturbances on the earth, as with radio frequency communications and power line transmissions. The standard solar flare model proposes that magnetic reconnection drives solar flares and fast mode shock, which is often referred to as the flare termination shock (TS), can exist at the reconnection outflows. The existence of the termination shock has been recently related to spectral hardening of flare hard X-ray spectrum.

Guo, Lijia↗
NASA NTRSDate not supplied

ANA Analysis of NORDO’s in ASRS

This presentation provides an overview and summary of results from an intern research project to analyze aviation safety incidents to determine frequency and characteristics relevant to unmanned aircraft.

Radio Communication↗
NASA NTRSDate not supplied

The Lunar Regolith Terrain (LRT) Field: A New Lunar Surface Planetary Analog Facility at NASA Marshall Space Flight Center (MSFC)

Introduction: NASA is moving toward a new age of exploration and resource utilization of the lunar surface. Challenges related to exploration, resource utilization, and construction at the Lunar South Pole will require advanced technology and well-designed mission concepts and operations. NASA Marshall Space Flight Center (MSFC) has added new capabilities to support surface mobility and construction activities to meet industry, academia, and NASA research and development goals for lunar applications. The Lunar Regolith Terrain (LRT) field is a new, large-area, lunar regolith simulant planetary analog testing ground for users interested in surface mobility and lunar construction activities. The LRT complements NASA MSFC’s other lunar environment testing facilities such as the Lunar Surface Simulator (V20 dirty vacuum chamber), the Lunar Environment Testing System (LETS), among many others. Lunar Regolith Terrain (LTR) Description: The Lunar Regolith Terrain field is an outdoor planetary analog environment facility located on base at MSFC. The lunar regolith simulant is JSC-1A feedstock material (volcanic cinder sand sourced from Meriam Crater, Flagstaff, AZ). The field contains more than 500 tons of lunar regolith simulant confined within a 125 ft x 125 ft (38 m x 38 m) area. The field is placed ~ 50% over paved parking lot and ~ 50% over a natural ground. Currently, the depth of regolith ranges between ~ 5 in - ~ 4 ft (~ 13cm – 1.2m) but can be modified to suit user needs. The lunar regolith simulant that makes up the field has representative geotechnical, geochemical, and optical properties of lunar mare basalt. An area within the LRT of lunar highlands terrain simulant is planned. Additional Features of the LRT: The LRT was designed to allow rapid modification of the terrain’s topography obstacles in the field. The terrain can be reshaped to suit specific testing requirements that may require flat expanses, steep hills, or heavily cratered and rocky landscapes. Large rocky obstacles in Fig. 1 are artificial landscape boulders (faux-rocks) that can be easily placed by users or removed entirely. Areas of the field also contain buried fiducials, large sheets, bar stock, and pipes of various composition and dimensions to allow for possible ground penetrating radar and shallow seismic studies. Rapid modification capabilities will also allow for burial of additional user-specific materials to enable in-situ resource utilization detection (e.g., burial of hydrogen sources for neutron detection or other materials). The field is also equipped with on-site office space with an air-conditioned and heated trailer with 120/240V power and lighting. The site has Wi-Fi and Cellular signal coverage. Direct radio frequency communication with the Huntsville Operations Support Center (HOSC) is in development. Additional on-site workspace and secure equipment storage is available in adjacent buildings. Accessibility to the field is straightforward with on-site parking and access for delivery of instruments, payloads, and additional equipment. Community Availability: The LRTF provides an accessible planetary analog surface environment for surface mobility testing, autonomous roving operations, developing advanced navigation techniques and operations development. Interested parties can contact the abstract authors for additional details, tours, and scheduling.

Lunar Regolith↗
NASA NTRSDate not supplied

Marshall Space Flight Center: Lunar Regolith Terrain (LRT)

Introduction: NASA is moving toward a new age of exploration and resource utilization of the lunar surface. Challenges related to exploration, resource utilization, and construction at the Lunar South Pole will require advanced technology and well-designed mission concepts and operations. NASA Marshall Space Flight Center (MSFC) has added new capabilities to support surface mobility and construction activities to meet industry, academia, and NASA research and development goals for lunar applications. The Lunar Regolith Terrain (LRT) field is a new, large-area, lunar regolith simulant planetary analog testing ground for users interested in surface mobility and lunar construction activities. The LRT complements NASA MSFC’s other lunar environment testing facilities such as the Lunar Surface Simulator (V20 dirty vacuum chamber), the Lunar Environment Testing System (LETS), among many others. Lunar Regolith Terrain (LTR) Description: The Lunar Regolith Terrain field is an outdoor planetary analog environment facility located on base at MSFC. The lunar regolith simulant is JSC-1A feedstock material (volcanic cinder sand sourced from Meriam Crater, Flagstaff, AZ). The field contains more than 500 tons of lunar regolith simulant confined within a 125 ft x 125 ft (38 m x 38 m) area. The field is placed ~ 50% over paved parking lot and ~ 50% over a natural ground. Currently, the depth of regolith ranges between ~ 5 in - ~ 4 ft (~ 13cm – 1.2m) but can be modified to suit user needs. The lunar regolith simulant that makes up the field has representative geotechnical, geochemical, and optical properties of lunar mare basalt. An area within the LRT of lunar highlands terrain simulant is planned. Additional Features of the LRT: The LRT was designed to allow rapid modification of the terrain’s topography obstacles in the field. The terrain can be reshaped to suit specific testing requirements that may require flat expanses, steep hills, or heavily cratered and rocky landscapes. Large rocky obstacles in Fig. 1 are artificial landscape boulders (faux-rocks) that can be easily placed by users or removed entirely. Areas of the field also contain buried fiducials, large sheets, bar stock, and pipes of various composition and dimensions to allow for possible ground penetrating radar and shallow seismic studies. Rapid modification capabilities will also allow for burial of additional user-specific materials to enable in-situ resource utilization detection (e.g., burial of hydrogen sources for neutron detection or other materials). The field is also equipped with on-site office space with an air-conditioned and heated trailer with 120/240V power and lighting. The site has Wi-Fi and Cellular signal coverage. Direct radio frequency communication with the Huntsville Operations Support Center (HOSC) is in development. Additional on-site workspace and secure equipment storage is available in adjacent buildings. Accessibility to the field is straightforward with on-site parking and access for delivery of instruments, payloads, and additional equipment. Community Availability: The LRTF provides an accessible planetary analog surface environment for surface mobility testing, autonomous roving operations, developing advanced navigation techniques and operations development. Interested parties can contact the abstract authors for additional details, tours, and scheduling.

Lunar Regolith↗
NASA NTRSDate not supplied

Marshall Space Flight Center: Lunar Regolith Terrain (LRT)

Introduction: NASA is moving toward a new age of exploration and resource utilization of the lunar surface. Challenges related to exploration, resource utilization, and construction at the Lunar South Pole will require advanced technology and well-designed mission concepts and operations. NASA Marshall Space Flight Center (MSFC) has added new capabilities to support surface mobility and construction activities to meet industry, academia, and NASA research and development goals for lunar applications. The Lunar Regolith Terrain (LRT) field is a new, large-area, lunar regolith simulant planetary analog testing ground for users interested in surface mobility and lunar construction activities. The LRT complements NASA MSFC’s other lunar environment testing facilities such as the Lunar Surface Simulator (V20 dirty vacuum chamber), the Lunar Environment Testing System (LETS), among many others. Lunar Regolith Terrain (LTR) Description: The Lunar Regolith Terrain field is an outdoor planetary analog environment facility located on base at MSFC. The lunar regolith simulant is JSC-1A feedstock material (volcanic cinder sand sourced from Meriam Crater, Flagstaff, AZ). The field contains more than 500 tons of lunar regolith simulant confined within a 125 ft x 125 ft (38 m x 38 m) area. The field is placed ~ 50% over paved parking lot and ~ 50% over a natural ground. Currently, the depth of regolith ranges between ~ 5 in - ~ 4 ft (~ 13cm – 1.2m) but can be modified to suit user needs. The lunar regolith simulant that makes up the field has representative geotechnical, geochemical, and optical properties of lunar mare basalt. An area within the LRT of lunar highlands terrain simulant is planned. Additional Features of the LRT: The LRT was designed to allow rapid modification of the terrain’s topography obstacles in the field. The terrain can be reshaped to suit specific testing requirements that may require flat expanses, steep hills, or heavily cratered and rocky landscapes. Large rocky obstacles in Fig. 1 are artificial landscape boulders (faux-rocks) that can be easily placed by users or removed entirely. Areas of the field also contain buried fiducials, large sheets, bar stock, and pipes of various composition and dimensions to allow for possible ground penetrating radar and shallow seismic studies. Rapid modification capabilities will also allow for burial of additional user-specific materials to enable in-situ resource utilization detection (e.g., burial of hydrogen sources for neutron detection or other materials). The field is also equipped with on-site office space with an air-conditioned and heated trailer with 120/240V power and lighting. The site has Wi-Fi and Cellular signal coverage. Direct radio frequency communication with the Huntsville Operations Support Center (HOSC) is in development. Additional on-site workspace and secure equipment storage is available in adjacent buildings. Accessibility to the field is straightforward with on-site parking and access for delivery of instruments, payloads, and additional equipment. Community Availability: The LRTF provides an accessible planetary analog surface environment for surface mobility testing, autonomous roving operations, developing advanced navigation techniques and operations development. Interested parties can contact the abstract authors for additional details, tours, and scheduling.

Lunar Regolith↗
NASA NTRSDate not supplied

High Altitude Re-entry Plasma Emulation Experiment (HARPEE)

A table-top apparatus has recently been constructed at the NASA Glenn Research Center to investigate potential solutions for the radio-frequency communication blackout problem -- experienced by landing modules during high-speed atmospheric entry. This customized plasma chamber was designed to emulate Earth-based atmospheric entry plasmas with electron densities in the range of 10^16 m^-3 to 10^19 m^-3. The system makes use of a 40-kHz, perforated coaxial electrode pair to generate a disk-shaped, static plasma with an approximate diameter and thickness of 405 mm and 100 mm, respectively. A translatable Langmuir probe was employed to characterize the radial profile of electron temperature and density as a function the 40-kHz power (< 1 kW) and dry-nitrogen flow rate (< 160 SCCM).

plasma↗
NASA NTRS2024

Secondary Electron Suppression with Carbonized Aerogels

The goal addressed by this project is reduced DC power for high data rate RF communications by increasing the efficiency of traveling Wave Tubes (TWT) for RF communication, which are used by most space missions for communication and radio science at microwave frequencies. The capability needed is a robust electron collector surface with a secondary electron emission lower than ordinary graphite, which is the state of the art. While it is known that replacing a smooth surface with a textured one will reduce secondary electron emission, no robust textured surface is known. Carbonized polyimide aerogels promise the necessary robustness along with reduced secondary electron emission, allowing further improvement of TWT efficiency, achieving a very good return on the low investment made. Aerogels are known to be robust materials, and carbon aerogels are expected to have low secondary electron emission because of their open surface structure. The objective of this proposal is to demonstrate the low secondary electron emission of carbon aerogels and their robustness.

Secondary electron sippression↗
NASA NTRS2011

Design, Development and Pre-Flight Testing of the Communications, Navigation, and Networking Reconfigurable Testbed (Connect) to Investigate Software Defined Radio Architecture on the International Space Station

The Communication Navigation and Networking Reconfigurable Testbed (CoNNeCT) is a NASA-sponsored mission, which will investigate the usage of Software Defined Radios (SDRs) as a multi-function communication system for space missions. A softwaredefined radio system is a communication system in which typical components of the system (e.g., modulators) are incorporated into software. The software-defined capability allows flexibility and experimentation in different modulation, coding and other parameters to understand their effects on performance. This flexibility builds inherent redundancy and flexibility into the system for improved operational efficiency, real-time changes to space missions and enhanced reliability/redundancy. The CoNNeCT Project is a collaboration between industrial radio providers and NASA. The industrial radio providers are providing the SDRs and NASA is designing, building and testing the entire flight system. The flight system will be integrated on the Express Logistics Carrier (ELC) on the International Space Station (ISS) after launch on the H-IIB Transfer Vehicle in 2012. This paper provides an overview of the technology research objectives, payload description, design challenges and pre-flight testing results.

Over, Ann P.↗
NASA NTRS1979

Pulsed radio frequency interference effects on data communications via satellite transponder

Power-limited communication links may be susceptible to significant degradation if intentional or unintentional pulsed high level radio frequency interference (RFI) is present. Pulsed RFI is, in fact, of current interest to NASA in studies relating to its Tracking and Data Relay Satellite System (TDRSS). The present paper examines the impact of pulsed RFI on the error probability performance of a power-limited satellite communication link: the assumed modulation scheme is PN coded binary PSK. The composite effects of thermal noise, pulsed CW and pulsed Gaussian noise are analyzed, where RFI arrivals are assumed to follow Poisson statistics. Under the assumption that the satellite repeater is ideal and that integrate and dump filtering is employed at the ground receiver, an exact error probability expression and associated approximations are derived. Computed results are generated using an arbitrarily specified RFI model.

Weinberg, A.↗