Engineering topics

Howard, James W.

Publications and source records attributed to Howard, James W..

5 records

NASA NTRS2008

Environment Challenges for Exploration of the Moon

NASA's Constellation Program is designing a new generation of human rated launch and space transportation vehicles to first replace the Space Shuttle fleet, then support develop of a permanent human habitat on the Moon, and ultimately prepare for human exploration of Mars. The ambitious first step beyond low Earth orbit is to develop the infrastructure required for conducting missions to a variety of locations on the lunar surface for periods of a week and establishment of a permanent settlement at one of the lunar poles where crews will serve for periods on the order of approx.200 days. We present an overview of the most challenging aspects of the lunar environment that will need to be addressed when developing transport and habitat infrastructure for long term human presence on the Moon including low temperatures and dusty regolith surfaces, radiation environments due to galactic cosmic rays and solar energetic particles, charging of lunar infrastructure when exposed to lunar plasma environments, and secondary meteor environments generated by primary impacts on the lunar surface.

Minow, Joseph I.↗

NASA NTRS2008

Using Space Weather Variability in Evaluation the Radiation Environment Specifications for NASA's Constellation Program

Hardware design environments for NASA's Constellation Program-the Vision for Space Exploration program to design and build new vehicles for servicing low Earth orbit and the Moon and beyond-have been developed that are necessarily conservative in nature to assure robust hardware design and development required to build space systems which will meet operational goals in a wide range of space environments, This presentation will describe the rationale used to establish the space radiation and plasma design environments specified for a variety of applications including total ionizing radiation dose, dose rate effects, and spacecraft charging and will compare the design environments with "space weather" variability to evaluate the applicability of the design environments and potential vulnerabilities of the system to extreme space weather events.

Coffey, Victoria N.↗

NASA NTRS2008

Using Space Weather Variability in Evaluating the Environment Design Specifications for NASA'S Constellation Program

Spectral models of solar particle events and trapped radiation belts are necessary for the design requirements of total ionizing radiation dose, single event effects, and spacecraft charging. Space radiation and plasma environment specifications for hardware design are necessarily conservative to assure system robustness for a wide range of space environments.

Coffey, Victoria N.↗

NASA NTRS2007

Using Space Weather Variability in Evaluating the Radiation Environment Design Specifications for NASA's Constellation Program

NASA's Constellation program, initiated to fulfill the Vision for Space Exploration, will create a new generation of vehicles for servicing low Earth orbit, the Moon, and beyond. Space radiation specifications for space system hardware are necessarily conservative to assure system robustness for a wide range of space environments. Spectral models of solar particle events and trapped radiation belt environments are used to develop the design requirements for estimating total ionizing radiation dose, displacement damage, and single event effects for Constellation hardware. We first describe the rationale using the spectra chosen to establish the total dose and single event design environmental specifications for Constellation systems. We then compare variability of the space environment to the spectral design models to evaluate their applicability as conservative design environments and potential vulnerabilities to extreme space weather events

Coffey, Victoria N.↗

NASA NTRS2003

A NASA Perspective and Validation and Testing of Design Hardening for the Natural Space Radiation Environment (GOMAC Tech 03)

With the dearth of dedicated radiation hardened foundries, new and novel techniques are being developed for hardening designs using non-dedicated foundry services. In this paper, we will discuss the implications of validating these methods for the natural space radiation environment issues: total ionizing dose (TID) and single event effects (SEE). Topics of discussion include: Types of tests that are required, Design coverage (i.e., design libraries: do they need validating for each application?) A new task within NASA to compare existing design. This latter task is a new effort in FY03 utilizing a 8051 microcontroller core from multiple design hardening developers as a test vehicle to evaluate each mitigative technique.

Day, John H.↗