New procedure for determining minimum time orbit transfers

Computer program includes time minimizing function required for propellant constrained minimum time impulsive transfer between coplanar circular orbits or unrestricted orbits. Basic formulation is extended to include inclined circular or inclined elliptic orbits

Computer program for interplanetary conic patching

Computer program enables study of one-way transfers, single and double planet flybys, single and double planet stopovers, or mixed flyby and stopover trajectories. In each operation it first computes the heliocentric conic which connects the centers of the launch and target planets and requires a given trip time

Fatigue failure load indicator

An indicator for recording the load at which a fatigue specimen breaks during the last cycle of a fatigue test is described. A load cell is attached to the specimen which is alternately subjected to tension and compression loads. The output of the load cell which is proportional to the load on the specimen is applied to the input of a peak detector. Each time the specimen is subjected to a compression load, means are provided for applying a positive voltage to the rest of the peak detector to reset it. During the last cycle of the tension load the peak detector measures the maximum load on the specimen. Means are provided for disconnecting the load cell from the peak detector when there is a failure in the specimen

Multibody Interplanetary Swingby Trajectories /MIST-1/

Computer program incorporates new isolation procedure to determine interplanetary trajectories which utilize a maximum of three flybys. Program also computes singe planet flybys and direct transfer trajectories. The three principle systems employed in MIST-1 use as their fundamental plane the mean plane of the earth's orbit around the sun

Configurations of Handles and the Classification of Divergences in the String Partition Function

The divergences that arise in the regularized partition function for closed bosonic string theory in flat space lead to three types of perturbation series expansions, distinguished by their genus dependence. This classification of infinities can be traced to geometrical characteristics of the string worldsheet. Some categories of divergences may be eliminated in string theories formulated on compact manifolds.Comment: 24 pages, DAMTP-R/94/1

Titanium honeycomb structure

A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks

Umbilical disconnect actuator

Contamination of sensitive equipment when squibs are fired is prevented by O-rings which retain the debris of squib discharge within the disconnect device

Cosmic Strings, Zero Modes and SUSY breaking in Nonabelian N=1 Gauge Theories

We investigate the microphysics of cosmic strings in Nonabelian gauge theories with N=1 supersymmetry. We give the vortex solutions in a specific example and demonstrate that fermionic superconductivity arises because of the couplings and interactions dictated by supersymmetry. We then use supersymmetry transformations to obtain the relevant fermionic zero modes and investigate the role of soft supersymmetry breaking on the existence and properties of the superconducting strings.Comment: 12 pages, RevTex, submitted to Phys. Rev.

Experimental economics: Methods, problems and promise

The purpose of this paper is to discuss the growing importance of experimentation in economic analysis. We present a variety of economic issues that have been explored with laboratory techniques. We also address some common objections to experimentation, as well as some of the principal lessons that have been learned.

Calibration of Hewlett-Packard network analyzers: A precision viewpoint

Alternative calibration procedures are examined for Hewlett-Packard vector network analyzers which lead to an improved open-circuit capacitance model, and hence, higher measurement accuracy