Electrical/​Electronics

Suitably formulated spatial modulation of a scene imaged by a computed-tomography imaging spectrometer (CTIS) has been found to be useful as a means of improving the imaging performance of the CTIS. As used here, “spatial modulation” signifies the imposition of additional, artificial structure on...

LiCoO2 and LiNiO2 fibers have been investigated as alternatives to LiCoO2 and LiNiO2 powders used as lithium-intercalation compounds in cathodes of rechargeable lithium-ion electrochemical cells. In making such a cathode, LiCoO2 or LiNiO2 powder is mixed with a binder [e.g.,...

Progress has been made in a continuing effort to develop a spaceborne computer system for processing readout data from a Fourier-transform infrared (FTIR) spectrometer to reduce the volume of data transmitted to Earth. The approach followed in this effort, oriented toward reducing design time...

An effort related to that described in the preceding article focuses on developing a spaceborne processing platform for fast and accurate onboard classification of image data, a critical part of modern satellite image processing. The approach again has been to exploit the versatility of...

A technique for simulating extreme-temperature operation of integrated circuits that incorporate silicon carbide (SiC) junction field-effect transistors (JFETs) has been developed. The technique involves modification of NGSPICE, which is an open-source version of the popular Simulation...

Progress has been made in a continuing effort to develop multi-chip power modules (SiC MCPMs). This effort at an earlier stage was reported in “SiC Multi-Chip Power Modules as Power-System Building Blocks” (LEW-18008-1), NASA Tech Briefs, Vol. 31, No. 2 (February 2007), page 28.

A radio communication and ranging system has been proposed for determining the relative position and orientations of two approaching spacecraft to provide guidance for docking maneuvers. On Earth, the system could be used similarly for guiding approaching aircraft and for automated...

A scheme for protection against short circuits has been devised for series strings of lithium electrochemical cells that contain built-in short-circuit protection devices, which go into a high-resistance, current-limiting state when heated by excessive current. If cells are simply...

A theoretical and experimental study was conducted of the limit imposed by photon-detector jitter on the capacity of a pulse-position- modulated optical communication system in which the receiver operates in a photon-counting (weak-signal) regime. Photon-detector jitter is a random delay between...

The term “electromagnetically clean solar array” (“EMCSA”) refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interference to and...

A one-page document describes a Ka-band transponder being developed for use in deep-space radio science. The transponder receives in the Deep Space Network (DSN) uplink frequency band of 34.2 to 34.7 GHz, transmits in the 31.8 to 32.3 GHz DSN downlink band, and performs regenerative ranging on a DSN...

A document discusses the replication of the functionality of the onboard space-shuttle general-purpose computers (GPCs) in field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). The purpose of the replication effort is to enable utilization of proven...

Register today for NASA Tech Briefs' National Nano Engineering Conference (NNEC), the premier event focused on current and future developments in engineering innovations at the nanoscale. The event returns to Boston this year on November 12-13 at the Boston Colonnade Hotel, featuring the fourth annual Nano 50...

A prototype of an advanced robotic vision system both (1) measures its own motion with respect to a stationary background and (2) detects other moving objects and estimates their motions, all by use of visual cues. Like some prior robotic and other optoelectronic vision systems, this...

A wide-band penetrating radar system for measuring the thickness of sea ice is under development. The need for this or a similar system arises as follows: Spatial and temporal variations in the thickness of sea ice are important indicators of heat fluxes between the ocean and atmosphere and, hence,...

A proposed device for combining or switching electromagnetic beams would have three ports, would not contain any moving parts, and would be switchable among three operating states:

This design allows broadband power combining with high isolation between the H port and E port, and achieves a lower insertion loss than any other broadband planar magic-T. Passive micro wave/millimeter-wave signal power is combined both in-phase and out-of-phase at the ports, with the phase error being less than...

The Next Generation Flight Controller Trainer (NGFCT) is a relatively inexpensive system of hardware and software that provides high- fidelity training for space-shuttle flight controllers. NGFCT provides simulations into which are integrated the behaviors of emulated space-shuttle vehicle onboard...

A quasi-optical transmission line (QOTL) has been developed as a low-loss transmission line for a spaceborne cloud-observing radar instrument that operates at a nominal frequency of 94 GHz. This QOTL could also readily be redesigned for use in terrestrial millimeter- wave radar systems and...

Single-event upsets (SEUs) pose great threats to avionic systems' state machine control logic, which are frequently used to control sequence of events and to qualify protocols. The risks of SEUs manifest in two ways: (a) the state machine's state information is changed, causing the...

A document discusses a method by which GMSK (Gaussian minimum shift keying) modulation and a pseudonoise (PN) ranging signal may be combined. By isolating the in-phase and quadrature components after carrier lock, and extracting their low-pass and band-pass filtered components, there is enough information...

A document discusses placing memory modules on the high-speed serial interconnect, which is used by a spacecraft’s computer elements for inter-processor communications, to allow all multiple computer system architectures to access the spacecraft data storage at the same time. Each memory board is...

A report discusses integrating multiple memory modules on the high-speed serial interconnect (IEEE 1393) that is used by a spacecraft’s inter-module communications in order to ease data congestion and provide for a scalable, strong, flexible system that can meet new system-level mass memory requirements.