A Revised Thermosphere for the Mars Global Reference Atmospheric Model (Mars-Gram Version 3.4)

A Revised Thermosphere for the Mars Global Reference Atmospheric Model (Mars-Gram Version 3.4)
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 68
Release: 2018-07-02
Genre:
ISBN: 9781722144982

This report describes the newly-revised model thermosphere for the Mars Global Reference Atmospheric Model (Mars-GRAM, Version 3.4). It also provides descriptions of other changes made to the program since publication of the programmer's guide for Mars-GRAM Version 3.34. The original Mars-GRAM model thermosphere was based on the global-mean model of Stewart. The revised thermosphere is based largely on parameterizations derived from output data from the three-dimensional Mars Thermospheric Global Circulation Model (MTGCM). The new thermospheric model includes revised dependence on the 10.7 cm solar flux for the global means of exospheric temperature, temperature of the base of the thermosphere, and scale height for the thermospheric temperature variations, as well as revised dependence on orbital position for global mean height of the base of the thermosphere. Other features of the new thermospheric model are: (1) realistic variations of temperature and density with latitude and time of day, (2) more realistic wind magnitudes, based on improved estimates of horizontal pressure gradients, and (3) allowance for user-input adjustments to the model values for mean exospheric temperature and for height and temperature at the base of the thermosphere. Other new features of Mars-GRAM 3.4 include: (1) allowance for user-input values of climatic adjustment factors for temperature profiles from the surface to 75 km, and (2) a revised method for computing the sub-solar longitude position in the 'ORBIT' subroutine. Justus, C. G. and Johnson, D. L. and James, B. F. Marshall Space Flight Center...

Mars Global Reference Atmospheric Model (Mars-Gram) Version 3.8

Mars Global Reference Atmospheric Model (Mars-Gram) Version 3.8
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 34
Release: 2018-06-03
Genre:
ISBN: 9781720619970

Mars Global Reference Atmospheric Model (Mars-GRAM) Version 3.8 is presented and its new features are discussed. Mars-GRAM uses new values of planetary reference ellipsoid radii, gravity term, and rotation rate (consistent with current JPL values) and includes centrifugal effects on gravity. The model now uses NASA Ames Global Circulation Model low resolution topography. Curvature corrections are applied to winds and limits based on speed of sound are applied. Altitude of the F1 ionization peak and density scale height, including effects of change of molecular weight with altitude are computed. A check is performed to disallow temperatures below CO2 sublimination. This memorandum includes instructions on obtaining Mars-GRAM source code and data files and running the program. Sample input and output are provided. An example of incorporating Mars-GRAM as an atmospheric subroutine in a trajectory code is also given.Justus, C. G. and James, B. F.Marshall Space Flight CenterMARS (PLANET); MARS ATMOSPHERE; ATMOSPHERIC TEMPERATURE; ATMOSPHERIC MODELS; ATMOSPHERIC DENSITY; SUBROUTINES; USER MANUALS (COMPUTER PROGRAMS); COMPUTER AIDED TOMOGRAPHY; TOPOGRAPHY

Astrodynamics

Astrodynamics
Author:
Publisher:
Total Pages: 878
Release: 2000
Genre: Astrodynamics
ISBN:

Vols. 1-2, 4 contain the Proceedings of the Society's 3rd (1956)-5th (1958) annual meeting; v. 3 contains the Proceedings of the Western Regional Meeting of the AAS, Aug. 1958.

Space Life Sciences

Space Life Sciences
Author: Eleanor A. Blakely
Publisher:
Total Pages: 208
Release: 2004
Genre: Astronauts
ISBN:

"This symposium was organized to bring together the multidisciplinary expertise required to assess risk of exposure to space radiation.... Topics addressed ranged from what is known or predicted about radiation environments for human exploration, and what shielding would be required based on ALARA radiation protection guidelines. The development of new physics cross section models, and improved ion beam transport codes was reported, as well as biological demonstrations of the consequences of specific shielding materials and applications to manned missions to Mars and beyond. Advancements in the biological measurements of radiation-induced protein expression profiles, membrane damage, bystander effect, and adaptive response were presented, and countermeasures evaluated. Finally several presentations addressed specific approaches to integrate the physical and biological parameters in order to assess key elements of the risk and the associated uncertainties."--Page 1277.

The Atmosphere and Climate of Mars

The Atmosphere and Climate of Mars
Author: Robert M. Haberle
Publisher: Cambridge University Press
Total Pages: 613
Release: 2017-06-29
Genre: Science
ISBN: 1107016185

This volume reviews all aspects of Mars atmospheric science from the surface to space, and from now and into the past.

Mars Global Reference Atmospheric Model 2000 Version (Mars-Gram 2000)

Mars Global Reference Atmospheric Model 2000 Version (Mars-Gram 2000)
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 54
Release: 2018-06-03
Genre:
ISBN: 9781720620037

This report presents Mars Global Reference Atmospheric Model 2000 Version (Mars-GRAM 2000) and its new features. All parameterizations for temperature, pressure, density, and winds versus height, latitude, longitude, time of day, and L(sub s) have been replaced by input data tables from NASA Ames Mars General Circulation Model (MGCM) for the surface through 80-km altitude and the University of Arizona Mars Thermospheric General Circulation Model (MTGCM) for 80 to 170 km. A modified Stewart thermospheric model is still used for higher altitudes and for dependence on solar activity. "Climate factors" to tune for agreement with GCM data are no longer needed. Adjustment of exospheric temperature is still an option. Consistent with observations from Mars Global Surveyor, a new longitude-dependent wave model is included with user input to specify waves having 1 to 3 wavelengths around the planet. A simplified perturbation model has been substituted for the earlier one. An input switch allows users to select either East or West longitude positive. This memorandum includes instructions on obtaining Mars-GRAM source code and data files and for running the program. It also provides sample input and output and an example for incorporating Mars-GRAM as an atmospheric subroutine in a trajectory code.Justus, C. G. and James, B. F.Marshall Space Flight CenterATMOSPHERIC GENERAL CIRCULATION MODELS; MARS ATMOSPHERE; MATHEMATICAL MODELS; TEMPERATURE; PRESSURE; DENSITY (MASS/VOLUME); WIND (METEOROLOGY); PARAMETERIZATION; LONGITUDE; TRAJECTORIES; THERMOSPHERE; TABLES (DATA); SUBROUTINES; SOLAR ACTIVITY; PERTURBATION; EXOSPHERE; ATMOSPHERIC MODELS; ATMOSPHERIC CIRCULATION