Airborne forest fire research

The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included

Man-machine shuttle support program

Human factors support requirements for space shuttle progra

Study of the astronaut's capabilities to maintain life support systems and cabin habitability in weightless conditions. Mod 3. A new technique for investigating cargo transfer in simulated weightless environments

Simulation of cargo transfer in weightlessness environmen

Hybrid water immersion simulation of manual IVA performance in weightlessness

A description is given of the development, tests, and analysis of a manual simulator. The simulator was developed to test mass handling and translation under weightlessness conditions by a test subject. The system is composed of a hybrid simulator with a combination of water immersion and mechanical, Peter Pan, simulation. The concept operates on the equivalence principle, with the subject and the cargo remaining quasi-stationary. Movement is effected through a moving device controlled through force by the subject. Motion response is determined through computations of the inertial movement under such conditions

Threshold effects and Planck scale Lorentz violation: combined constraints from high energy astrophysics

Recent work has shown that dispersion relations with Planck scale Lorentz violation can produce observable effects at energies many orders of magnitude below the Planck energy M. This opens a window on physics that may reveal quantum gravity phenomena. It has already constrained the possibility of Planck scale Lorentz violation, which is suggested by some approaches to quantum gravity. In this work we carry out a systematic analysis of reaction thresholds, allowing unequal deformation parameters for different particle dispersion relations. The thresholds are found to have some unusual properties compared with standard ones, such as asymmetric momenta for pair creation and upper thresholds. The results are used together with high energy observational data to determine combined constraints. We focus on the case of photons and electrons, using vacuum Cerenkov, photon decay, and photon annihilation processes to determine order unity constraints on the parameters controlling O(E/M) Lorentz violation. Interesting constraints for protons (with photons or pions) are obtained even at O((E/M)^2), using the absence of vacuum Cerenkov and the observed GZK cutoff for ultra high energy cosmic rays. A strong Cerenkov limit using atmospheric PeV neutrinos is possible for O(E/M) deformations provided the rate is high enough. If detected, ultra high energy cosmological neutrinos might yield limits at or even beyond O((E/M)^2).Comment: 35 pages, 13 Figures, RevTex4. Version published in PRD. Expanded introduction, updated discussion of possible constraint if GZK cutoff is confirmed. Corrected typos. Added and updated reference

Preliminary design polymeric materials experiment

A typical Advanced Technology Laboratory mission flight plan was developed and used as a guideline for the identification of a number of experiment considerations. The experiment logistics beginning with sample preparation and ending with sample analysis are then overlaid on the mission in order to have a complete picture of the design requirements. The results of this preliminary design study fall into two categories. First specific preliminary designs of experiment hardware which is adaptable to a variety of mission requirements. Second, identification of those mission considerations which affect hardware design and will require further definition prior to final design. Finally, a program plan is presented which will provide the necessary experiment hardware in a realistic time period to match the planned shuttle flights. A bibliography of all material reviewed and consulted but not specifically referenced is provided

High energy constraints on Lorentz symmetry violations

Lorentz violation at high energies might lead to non linear dispersion relations for the fundamental particles. We analyze observational constraints on these without assuming any a priori equality between the coefficients determining the amount of Lorentz violation for different particle species. We focus on constraints from three high energy processes involving photons and electrons: photon decay, photo-production of electron-positron pairs, and vacuum Cerenkov radiation. We find that cubic momentum terms in the dispersion relations are strongly constrained.Comment: 7 pages, 1 figure, Talk presented at CPT01; the Second Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, 15-18 Aug. 2001. Minor numerical error corrected, gamma-decay constraint update