Venus program

The United States has launched nine spacecraft in the direction of Venus. Three of these were part of the Mariner series (2, 5, and 10) and two were part of the Pioneer Venus program in 1978. Two more were part of the Vega series, in which balloons were dropped into the planet s atmosphere. Another was the Magellan spacecraft of 1989-90, and the last one was part of the Galileo mission of the same period. 

The numerieal methods which were used in our work were discussed in detail previously [2, 3J and only a general outline will be presented here. The equations of motion were integrated by using a modified public domain program Venus [4]. For an intermolecular potential we have used a potential calculated by Bludsky, Spirko, Herouda, and Hobza [5] (BSHH) who reported ab initio calculations of an Ar-benzene cluster and fitted the results to a potential funetion which is based on pair-wise atom-atom interactions. This is called the BSHH potential. 

VENUS, A General Ghetnical Dynamics Gomputer Program. 

Most of NASA s anticorrosion efforts are concentrated on the launch site, where the high temperamres of the launch and the humid coastal atmosphere encourage corrosion. However, corrosion is a concern in other aspects of the space program, as well. Batteries used in the International Space Station (ISS) must be prevented from corroding in the ISS s artificial, earth-like atmosphere NASA s mission of planetary exploration requires that scientists know the corrosivity of a planet s atmosphere before a craft can land safely. Venus, for example, has a highly corrosive atmosphere that makes lander design very difficult. 

Spacecraft simultaneously in the Jovian system. Additionally, the decadal survey recommended that NASA should select its fourth mission in the New Frontiers program from among the following mission concepts Comet Surface Sample Return, Lunar South Pole Aiken Basin Sample Return, Saturn probe, Trojan Tour and Rendezvous, and Venus In Situ Explorer. 

A three-year program has been, conducted in ttie VENUS critical facility at Mol aimed at obtaining reference data for the calibration of computer codes, used for... 

Base WL, Duchovic RJ, Bu X, Komomicki A, Lim KF, Lu DB, Peslherbe GB, Swamy KN, VandeLinde SR, Varandas A, Wang B, Wolf RJ (19%) VENUS% a general chemical dynamics computer program. Quantum Chem Program Exchange 16 671... 

Bu X, Base WL, Pirraglia T (1991) Vectorization of the general Monte Carlo classical trajectray program VENUS. J Comput Chem 12 1014-1024... 

Initial conditions for the classical trajectories are chosen so that the results from an ensemble of trajectories may be compared with experiment and/or theory, and used to make predictions about the chemical system s molecular dynamics. In this article Monte Carlo methods ate described for sampling the appropriate distributions to select initial values of coordinates and momenta for unimolecular and bimolecular reactions. The procedures described are incorporated in the general chemical dynamics computer program VENUS. ... 

The classical trajectory simulations were carried out with VENUS interfaced with the semiempirical electronic structure theory computer program MOPAC. To simulate experimental conditions for (gly-H) -I-diamond collisions, the center of a beam of (gly-H)+ ion projectiles is aimed at the center of the surface, with fixed incident angle 0, and fixed initial translational energy, E,. The radius of the beam was chosen so that the beam overlapped a unit area on the surface. For each trajectory, the projectile was randomly placed in the cross section of this beam and then randomly rotated about its center of mass so that it had an initial random orientation with respect to the surface. The azimuthal angle, %, between the beam and a fixed plane perpendicular to the surface, was sampled randomly between 0 and 2n. Such a random sampling of X simulates collisions with different domains of growth on the diamond surface. 

Swamy, S. R. Vande Linde, A. Varandas, H. Wang, and R. J. Wolf, Quantum Chem. Program Exchange, 16, 671 (1996). Venus. 

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