The generation of either electrical power or propulsive thrust with an electrodynamic tether system necessarily depends on driving a return current through the system's ambient space plasma environment. An electrical connection is, therefore, required between the plasma and each end of the tether. The voltage required to drive current through the system is derived either from the orbital motion of the conducting tether through the magnetic field of the Earth, or from a high-voltage power supply...

Topics: NASA Technical Reports Server (NTRS), ELECTRODES, TETHERLINES, SPACECRAFT PROPULSION, INFLATABLE...

A noise model is formulated to describe the impulse noise in many digital systems. A simplified model, which assumes that each noise burst contains a randomly weighted version of the same basic waveform, is used to derive the performance equations for a correlation receiver. The expected number of bit errors per noise burst is expressed as a function of the average signal energy, signal-set correlation coefficient, bit time, noise-weighting-factor variance and probability density function, and...

Topics: NASA Technical Reports Server (NTRS), DIGITAL SYSTEMS, ELECTROMAGNETIC NOISE, WAVEFORMS, RADIO...

We discuss the design, current status, and ongoing development of a cryogenic delay line for long-baseline direct-detection interferometry in the far-infrared.

Topics: NASA Technical Reports Server (NTRS), CRYOGENICS, DELAY LINES, INTERFEROMETRY, FAR INFRARED...

The theory, algorithms, and test data correlation analysis of a math model developed to predict performance of the Space Station Freedom Vacuum Exhaust System are presented. The theory used to predict the flow characteristics of viscous, transition, and molecular flow is presented in detail. Development of user subroutines which predict the flow characteristics in conjunction with the SINDA'85/FLUINT analysis software are discussed. The resistance-capacitance network approach with application...

Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, EXHAUST SYSTEMS, FLOW...

High-energy cryogenic propellant is an essential element in future space exploration programs. Therefore, NASA and its industrial partners are committed to an advanced development/technology program that will broaden the experience base for the entire cryogenic fluid management community. Furthermore, the high cost of microgravity experiments has motivated NASA to establish government/aerospace industry teams to aggressively explore combinations of ground testing and analytical modeling to the...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, LIQUID HYDROGEN, CRYOGENIC...