SPENVIS is a WWW-based instrument intended to facilitate the use of models of
the spatial environment in a consistent and structured way. The model packages,
that are available for
Mars are briefly described below:
Coordinate generators
Most of the models implemented in SPENVIS require as input a set of point on a
spacecraft trajectory. In the case of Mars, these sets of points are produced by the
orbit generator. In general, the orbit generator tool has to be
used before the models themselves can be accessed.
SPENVIS Is able to detect whether a spacecraft trajectory: if this is not the case, the
system will issue an error message and prompt the user to run the orbit tool, after
which the model in question can be run.
In addition, the model menu on the packages page will adapt automatically
to the selection of trajectories.
Once a trajectory has been generated, it can be used by
different models. This means that, in the context of a given
project, it is not
necessary to generate orbits for each model separately.
Warning! When running the orbit generator, all outputs
previously obtained with models that use the orbit generators's data are
deleted. This is to ensure consistency between results, and to avoid errors in
the plotting routines that produce the graphical output. The input parameters
for the models are not deleted, so that they can be run again in the same way.
MEREM
The interplanetary radiation environment and its effects on systems and crews of long-duration space
missions is becoming an increasing concern as a result of the growing interest in the operation of equipment
on Mars, potentially leading to manned missions to Mars on the thirty-year timescale. Much of the current
experience of manned space-flight results from operation in missions in low-Earth orbit, where there is
significant benefit from geomagnetic shielding against some of the principal radiation sources, and the
possibility of rapid return to Earth in the event of an emergency, such as very intense solar energetic particle
events. The assessment of the interplanetary radiation threat, and the performance of mitigation measures,
therefore requires careful and accurate assessment.
The MarsREM study (ESA Contract 19770/06/NL/JD, 2007) addressed part of
this problem by developing the Mars Energetic Radiation Environment Model (MEREM)
framework, which has been
integrated into SPENVIS.
MEREM allows the user
to input mission-related information such as mission
epoch (defining solar cycle and Martian season), duration, Mars orbit,
coordinates of lander/habitat and local
soil conditions. MEREM produces a variety of
output quantities: particle flux or fluence spectra as a function of
species, absorbed dose, effective dose, etc.
ECSS Space Environment Standard
The SPENVIS system
contains a copy
of the European Cooperation for Space
Standardization (ECSS) standard on space environment.
The
official site
is maintained by ESTEC.
Links are available from the help pages to the relevant ECSS standards, and
from the ECSS pages to the SPENVIS model and help pages.