Design
| Enviro |
Astro | Propulsion
| Power | Thermal
| Structures | AD&C
| CDHS |
Test
Atmospheric
drag is a significant
environmental
factor to consider when designing a Low Earth Orbit
(LEO), aerocapture, aerobraking or re-entry mission.
Mathematical models developed for the Earth's atmosphere
resemble those used for other planetary bodies.
Atmospheric
Drag
Atmospheric
density models help to predict the amount of frictional
heating that is expected on a spacecraft's surface
from drag. The design of a spacecraft's thermal
protection shield (TPS) is based on these predictions.
The
exponential density model
is
a simple expression for atmospheric density used
in preliminary design estimates. Essentially, it
characterizes atmospheric density as decreasing
exponentially with altitude.
The
Jacchia Density Model
is used primarily for
the upper atmosphere. It is an accurate statistical
model but does not account for winds.
