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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 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Multifunctional Logic Gate Controlled by Temperature

A complementary metal oxide/semiconductor (CMOS) electronic circuit has been designed to function as a NAND gate at a temperature between 0 and 80 deg C and as a NOR gate at temperatures from 120 to 200 C. In the intermediate temperature range of 80 to 120 C, this circuit is expected to perform a function intermediate between NAND and NOR with degraded noise margin. The process of designing the circuit and the planned fabrication and testing of the circuit are parts of demonstration of polymorphic electronics a technological discipline that emphasizes designing the same circuit to perform different analog and/or digital functions under different conditions. In this case, the different conditions are different temperatures.

Stoica, Adrian↗
NASA NTRS2005

Multifunctional Logic Gate Controlled by Supply Voltage

A complementary metal oxide/semiconductor (CMOS) electronic circuit functions as a NAND gate at a power-supply potential (V(sub dd)) of 3.3 V and as NOR gate for V(sub dd) = 1.8 V. In the intermediate V(sub dd) range of 1.8 to 3.3 V, this circuit performs a function intermediate between NAND and NOR with degraded noise margin. Like the circuit of the immediately preceding article, this circuit serves as a demonstration of the evolutionary approach to design of polymorphic electronics -- a technological discipline that emphasizes evolution of the design of a circuit to perform different analog and/or digital functions under different conditions. In this instance, the different conditions are different values of V(sub dd).

Stoica, Adrian↗
NASA NTRS2011

Optimal Terminal Descent Guidance Logic to Achieve a Soft Lunar Touchdown

Altair Lunar Lander is the linchpin in the Constellation Program for human return to the Moon. In the 2010design reference mission, Altair is to be delivered to low Earth orbit by the Ares V heavy lift launch vehicle, and after subsequent docking with Orion in LEO, the Altair/Orion stack is delivered through trans-lunar injection (TLI). The Altair/Orion stack separates from the Ares V Earth departure stage shortly after TLI and continues the flight to the Moon as a single stack. Fig. 1 depicts one version of the Altair lunar lander.

Landing↗
NASA NTRS2012

System and method for embedding emotion in logic systems

A system, method, and computer readable-media for creating a stable synthetic neural system. The method includes training an intellectual choice-driven synthetic neural system (SNS), training an emotional rule-driven SNS by generating emotions from rules, incorporating the rule-driven SNS into the choice-driven SNS through an evolvable interface, and balancing the emotional SNS and the intellectual SNS to achieve stability in a nontrivial autonomous environment with a Stability Algorithm for Neural Entities (SANE). Generating emotions from rules can include coding the rules into the rule-driven SNS in a self-consistent way. Training the emotional rule-driven SNS can occur during a training stage in parallel with training the choice-driven SNS. The training stage can include a self assessment loop which measures performance characteristics of the rule-driven SNS against core genetic code. The method uses a stability threshold to measure stability of the incorporated rule-driven SNS and choice-driven SNS using SANE.

Curtis, Steven A.↗
NASA NTRS2013

N Channel JFET Based Digital Logic Gate Structure

An apparatus is provided that includes a first field effect transistor with a source tied to zero volts and a drain tied to voltage drain drain (Vdd) through a first resistor. The apparatus also includes a first node configured to tie a second resistor to a third resistor and connect to an input of a gate of the first field effect transistor in order for the first field effect transistor to receive a signal. The apparatus also includes a second field effect transistor configured as a unity gain buffer having a drain tied to Vdd and an uncommitted source.

Krasowski, Michael J↗
NASA NTRS2014

Lunar Station: The Next Logical Step in Space Development

The International Space Station (ISS) is the product of the efforts of sixteen nations over the course of several decades. It is now complete, operational, and has been continuously occupied since November of 20001. Since then the ISS has been carrying out a wide variety of research and technology development experiments, and starting to produce some pleasantly startling results. The ISS has a mass of 420 metric tons, supports a crew of six with a yearly resupply requirement of around 30 metric tons, within a pressurized volume of 916 cubic meters, and a habitable volume of 388 cubic meters. Its solar arrays produce up to 84 kilowatts of power. In the course of developing the ISS, many lessons were learned and much valuable expertise was gained. Where do we go from here? The ISS offers an existence proof of the feasibility of sustained human occupation and operations in space over decades. It also demonstrates the ability of many countries to work collaboratively on a very complex and expensive project in space over an extended period of time to achieve a common goal. By harvesting best practices and lessons learned, the ISS can also serve as a useful model for exploring architectures for beyond low-­‐ earth-­‐orbit (LEO) space development. This paper will explore the concept and feasibility for a Lunar Station. The Station concept can be implemented by either putting the equivalent capability of the ISS down on the surface of the Moon, or by developing the required capabilities through a combination of delivered materials and equipment and in situ resource utilization (ISRU). Scenarios that leverage existing technologies and capabilities as well as capabilities that are under development and are expected to be available within the next 3-­5 years, will be examined. This paper will explore how best practices and expertise gained from developing and operating the ISS and other relevant programs can be applied to effectively developing Lunar Station.

Lunar↗
NASA NTRS2016

Predictive Lateral Logic for Numerical Entry Guidance Algorithms

Recent entry guidance algorithm development123 has tended to focus on numerical integration of trajectories onboard in order to evaluate candidate bank profiles. Such methods enjoy benefits such as flexibility to varying mission profiles and improved robustness to large dispersions. A common element across many of these modern entry guidance algorithms is a reliance upon the concept of Apollo heritage lateral error (or azimuth error) deadbands in which the number of bank reversals to be performed is non-deterministic. This paper presents a closed-loop bank reversal method that operates with a fixed number of bank reversals defined prior to flight. However, this number of bank reversals can be modified at any point, including in flight, based on contingencies such as fuel leaks where propellant usage must be minimized.

Smith, Kelly M.↗
NASA NTRS2015

SMART: A Propositional Logic-Based Trade Analysis and Risk Assessment Tool for a Complex Mission

This paper introduces a new trade analysis software called the Space Mission Architecture and Risk Analysis Tool (SMART). This tool supports a high-level system trade study on a complex mission, such as a potential Mars Sample Return (MSR) mission, in an intuitive and quantitative manner. In a complex mission, a common approach to increase the probability of success is to have redundancy and prepare backups. Quantitatively evaluating the utility of adding redundancy to a system is important but not straightforward, particularly when the failure of parallel subsystems are correlated.

Ono, Masahiro↗
NASA NTRS2017

Programmable Logic Device (PLD) Design Description for the Integrated Power, Avionics, and Software (iPAS) Space Telecommunications Radio System (STRS) Radio

The Space Telecommunications Radio System (STRS) provides a common, consistent framework for software defined radios (SDRs) to abstract the application software from the radio platform hardware. The STRS standard aims to reduce the cost and risk of using complex, configurable and reprogrammable radio systems across NASA missions. To promote the use of the STRS architecture for future NASA advanced exploration missions, NASA Glenn Research Center (GRC) developed an STRS compliant SDR on a radio platform used by the Advance Exploration System program at the Johnson Space Center (JSC) in their Integrated Power, Avionics, and Software (iPAS) laboratory. At the conclusion of the development, the software and hardware description language (HDL) code was delivered to JSC for their use in their iPAS test bed to get hands-on experience with the STRS standard, and for development of their own STRS Waveforms on the now STRS compliant platform.The iPAS STRS Radio was implemented on the Reconfigurable, Intelligently-Adaptive Communication System (RIACS) platform, currently being used for radio development at JSC. The platform consists of a Xilinx ML605 Virtex-6 FPGA board, an Analog Devices FMCOMMS1-EBZ RF transceiver board, and an Embedded PC (Axiomtek eBox 620-110-FL) running the Ubuntu 12.4 operating system. Figure 1 shows the RIACS platform hardware. The result of this development is a very low cost STRS compliant platform that can be used for waveform developments for multiple applications.The purpose of this document is to describe the design of the HDL code for the FPGA portion of the iPAS STRS Radio particularly the design of the FPGA wrapper and the test waveform.

VHDL↗
NASA NTRS2018

Grasp Assist Device with Automatic Mode Control Logic

A system includes a glove, sensors, actuator assemblies, and controller. The sensors include load sensors which measure an actual grasping force and attitude sensors which determine a glove attitude. The actuator assembly provides a grasp assist force to the glove. Respective locations of work cells in the work environment and permitted work tasks for each work cell are programmed into the controller. The controller detects the glove location and attitude. A work task is selected by the controller for the location. The controller calculates a required grasp assist force using measured actual grasping forces from the load sensors. The required grasp assist force is applied via the glove using the actuator assembly to thereby assist the operator in performing the identified work task.

Davis, Donald R.↗
NASA NTRS2020

History and Logic Model NASA Goddard Space Flight Center Instrument and Payload Systems Engineering Technical Performance Study

Historically, some NASA missions have exceeded schedule and cost commitments. Studies suggest technical performance is a contributor. The 1980 NASA Project Management Study concluded, "one of the most significant contributors to cost and schedule growth is inadequate definition of technical and management aspects of a program..." (as cited in GAO/NSIAD-93-97, p. 11). The 1991 NASA Roles and Missions Report identified a "need for increased emphasis on technological readiness and requirements on the front end of a program" (as cited in GAO/NSIAD-93-97, p. 11). The 1992 NASA Program Costs Report stated that NASA officials identified, among other things, "insufficient definition studies... [and] program redesigns and technical complexities" as reasons for cost and schedule overruns (GAO/NSAID-93-97, p. 11). The 2002 Task Force on Acquisition of National Security Space Programs found "requirements definition and control issues, unhealthy cost bias in proposal evaluation, widespread lack of budget reserves required to implement high risk programs on schedule, and an overall underappreciation of the importance of appropriately staffed and trained system engineering staff to manage the technologically demanding and unique aspects of space programs" (DoD, 2003, p.i.) In 2007, The NASA Office of the Chief Engineer chartered the NASA Instrument Capability Study (NICS) “to determine whether NASA instrument developers are facing challenges that impact the capability to design and build quality instruments or whether there are flaws in the acquisition strategy evidenced by schedule delays, cost overruns, and increased technical risk via design deficiencies. The... team was also chartered to determine if occurrences [are]... isolated cases or if there are generic issues... If the issues [are] found to be generic, the team [is] to offer solutions to recover such capability" (NICS Report, 2008, p. vi). The 2008 NICS Report, led by Goddard Space Flight Center (GSFC), identified challenges to instrument technical performance consistent with findings from previous reports. In 2017, the Instrument Project Division (IPD) Implementation Study was initiated to determine if there was a change in meeting schedule and cost commitments after implementing certain NICS recommendations. In 2018, the Instrument Technical Performance Study was initiated to determine the current state of Instrument Technical Performance in the GSFC Payload & Instrument Systems Engineering Branch. The purpose of the combined studies is to answer the question, "Is there a relationship between meeting NASA scientific instrument technical success and meeting schedule and cost commitments? If yes, what is the relationship?" References Department of Defense Office of the Under Secretary of Defense for Acquisition, Technology, and Logistics. (2003). The report of the defense science board/ air force scientific advisory board joint task force on acquisition of national security space programs. Washington DC. Government Accounting Office. (1992). NASA program costs: Space missions require substantially more funding than initially estimated. GAO/NSIAD-93-97. Washington DC. National Aeronautics and Space Administration, National Oceanic and Atmospheric Agency, Department of Defense. (2008). The NASA instrument capability study final report. NP-2008-11-058-GSFC. Washington DC.

Robbins, Geraldine↗