Engineering topics

Gilland, J.

Publications and source records attributed to Gilland, J..

4 records

NASA NTRS2019

Uncertainty in Electric Propulsion Erosion Measurements

Uncertainty in erosion rates as measured by different methods is discussed and quantified. The work focuses on case studies from components on the Hall Effect Rocket with Magnetic Shielding (HERMeS) Hall thruster, but the methods can be extended for many electric propulsion applications. The primary method used for evaluating erosion is non-contact profilometry of masked and exposed components. Accurate quantification of the erosion rates of components is critical to determining lifetime and is therefore critical to mission planning purposes.

Mackey, J.↗

NASA NTRS2018

Preliminary Analysis of the Gradient Field Imploding Liner Fusion Propulsion Concept

The advancement of human deep space exploration requires the continued development of energetic in-space propulsion systems, advancing from current chemical engines to nuclear thermal rockets to future high energy concepts such as nuclear fusion. This paper presents the initial results of a NASA Innovative Advanced Concepts (NIAC) Phase I study funded to investigate the feasibility of a new pulsed fusion propulsion concept based on the rapid implosion of a fuel target injected at high velocity into a strong stationary magnetic field. The proposed concept takes advantage of the significant advances in terrestrial magneto-inertial fusion designs while attempting to mitigate the most common engineering impediments to in-space propulsion applications. A semi-analytic numerical model used to estimate target compression physics and energy release is presented, leading to estimates for engine performance. A preliminary vehicle design concept is outlined, and representative trajectory analyses for rapid Mars and Saturn missions are provided. The paper concludes with an overview of proposed next steps for theoretical and experimental validation of the concept.

Propulsion↗

NASA NTRS1980

The infrared radiometer on the sounder probe of the Pioneer Venus mission

The functional aspects of the Large Probe Infrared Radiometer Instrument are presented taking into account the experiment's objective to measure the net thermal flux as the Venus Probe descended into the planet's atmosphere, as well as to detect water vapor, cloud layers and their infrared opacity. The optical elements, including the detectors are described and a brief review of the instrument's calibration is given.

Boese, R. W.↗

NASA NTRS1977

Pioneer-Venus large probe infrared radiometer /LIR/ optical system

The LIR (large probe infrared radiometer) instrument has been developed for the NASA Ames Research Center for use in the 1978 Venus Atmospheric Probe Mission. The mission objectives are to determine the nature and composition of the clouds, the composition and structure of the atmosphere, and the atmospheric circulation pattern of the planet Venus. The LIR is a six-channel (3-50 micron) internally calibrated radiometer which measures the radiance difference at plus or minus 45 deg to the horizontal as viewed through a single diamond window in the spacecraft. The LIR optical system consists of a unique arrangement of hollow light pipes which optically couple a six element detector/filter array to the spacecraft window while mechanically and thermally isolating the array from the window's harsh thermal environment. A single rotating section with a 45 deg bend and containing a collimator alternately views up and down through director/extender pipes located adjacent to the diamond window. Light is transferred from the rotating section to a fixed section containing a diamond diffuser to scramble the light. This minimizes asymmetries and improves channel field of view overlap.

Brown, F. G.↗