The spacecraft trajectory is defined in terms of a mission, i.e. in
addition to defining the spacecraft orbital elements, the time period
the spacecraft is in orbit has to be specified as well. A mission can be
subdivided in segments, with different orbital characteristics.
Once the mission has been defined, orbital parameters
have to be specified for each mission segment. Once this is done, a
page with a summary table of the mission segments is
presented and the trajectory generation can be started.
The segment and mission lengths and epochs defined in this fashion are
used by the environment and effects models that run on a spacecraft
trajectory. Hence, these parameters need not be specified when running
the models in question. In particular, the
radiation sources and effects models
use the segment and mission lengths to scale orbit averaged fluxes to
segment and mission fluences, or to add dose contributions from trapped
particles to those from solar protons (which are defined for the total
mission length only).
Four sets of pre-defined directions can be selected by
(for the other users, the default setting parallel to the velocity
vector is used):
The Solar radiation pressure parameter is defined as
0.451x10-8 K A/M,
It is recommended to produce
of the trajectory before proceeding with the environment models.
Five different orbit types can be selected:
The remaining orbital elements (inclination, right ascension of the ascending note,
argument of perigee and true anomaly) are defined in the same way as in the general
The mission summary page is skipped when an uploaded trajectory is used.
button will start the calculation and
bring up the "Results" page.