Relevance of ASPEN-Mars to Mission Development and Planning
The ASPEN-Mars model will contribute several important components to any Mars aeronomy mission.
3.1 ASPEN-Mars and Instrument Design
The completeness of the ASPEN-Mars parameter space means that instrument concepts can be tested using the ASPEN-Mars model output. For example, ASPEN-Mars can provide reasonable estimates of temperatures, winds, and composition and their distribution with latitude, longitude, and local time, together with their variation as a function of season and solar cycle. Such studies are vital for remote sensing instruments, which must be designed for both benign and extreme conditions. In particular, gradients in the parameter to be measured can degrade the performance of the remote sensing instrument. ASPEN-Mars provides 3-D distributions, with vertical and horizontal gradients that can be fed into remote sensing algorithms and used to guide instrument design, and to define performance expectations with error bars before the instrument leaves the drawing board. This is applicable to all wavelengths from IR to UV, and to both occultation and emission measurements.
3.2 ASPEN-Mars and Mission Design
An important part of mission design is to anticipate the different phases of the mission, and to define a minimum set of success criteria. The ASPEN-Mars model provides global distributions of density and other parameters for any conditions, which can be used to define aerobraking and later phases of the mission. It can also provide guidance on where certain measurements can be expected to be successful, versus where signals may be too weak, either from lack of sunlight, or small concentrations of emitting species. Using the model, different mission scenarios can be explored well in advance, thus reducing risk to the mission success.