691 research outputs found
Technical feasibility demonstration model of orbiting experiment for study of extended weightlessness
Technical feasibility demonstration model of primate orbiting experiment for study of extended weightlessnes
Development of prototype mass measurement system for spaceflight
Construction and evaluation of prototype equipment to monitor mass changes of astronauts during orbital fligh
A preliminary evaluation of an F100 engine parameter estimation process using flight data
The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the compact engine model (CEM). In this step, the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion control law development
Nonlinear phase shift from photon-photon scattering in vacuum
We show that QED nonlinear effects imply a phase correction to the linear
evolution of electromagnetic waves in vacuum. We provide explicit solutions of
the modified Maxwell's equations for the propagation of a superposition of two
plane waves, and calculate analytically and numerically the corresponding phase
shift. This provides a new framework for the search of all-optical signatures
of photon-photon scattering in vacuum. In particular, we propose an experiment
for measuring the phase shift in projected high-power laser facilities.Comment: 4 pages, 1 figure. Some references were added, and the comparison
with AC Kerr effect has been improve
Refurbishment and testing of orbiting primate experiment hardware for the study of extended weightlessness
The hardware for the technical feasibility demonstration models for weightlessness analysis was improved, and a 60-day test was conducted. The results are presented in detail
Eldred B. Wales Correspondence
Entries include brief biographical information with a typographical error and correspondence with Dr. Wales concerning his announcement to present a copy of his book Overweight and Your PBI in person to the Maine State Library, for the Maine Author Collection
James B. Vickery Correspondence
Entries include a typed introductory letter to Vickery from the Maine State Library and a letter typed on receipt of a gift of Vickery\u27s book, the celebrated An Illustrated History of the City of Bangor for the Maine Author Collection
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