EARTH UPPER ATMOSPHERE FORECAST TOOL FOR MISSION DESIGN AND OPERATIONS EXPRO+

Objective: To develop a software for VLEO atmospheric environment models that could reduce mission design margins and risks of satellite loss by non-compensated atmospheric drag effects at low altitudes.Description: Atmospheric density increase during geomagnetically active periods is a well know phenomenon. However, the increase of atmospheric density is not well-constrained and predictableand becomes particularly troublesome for the early phases of spacecraft commissioning that rely on a very low altitude (e.g. 200 to300 km) initial orbit. To date, for general spacecraft design purposes, the ESA Space Environment Information System (SPENVIS) includes various Earth atmosphere and wind models, some of which also consider geomagnetic activity. Several upper-atmosphere co-exist butthere are no comprehensive model or database of atmospheric and thermospheric parameters allowing to capture intra- (local time, seasonal, solar and magnetospheric inputs-driven) and inter-model variabilities, in order to derive better informed engineering margins. In such context, the proposed activity aims to fill that gap by developing a software allowing to interrogate models and definevariability envelopes based on major variability drivers (e.g. solar events, seasonal effects etc.) useful for design and exploitationphases. Software outputs shall feed the existing Space Weather modelling network with relevant products. In addition, the activity will establish a method to build model-based, time-dependent, 3D atmospheric parameter snapshots in order to produce a database of relevant parameters (at least species densities, temperatures as a function of altitude), including variabilities over different timescales relevant to mission design and planning (e.g. daily to seasonal) as a function of local time and latitude. This activity encompasses the following tasks: - Review the existing state of the art models of the upper atmosphere, including preferably couplingeffects between the thermosphere / ionosphere system and solar inputs, as well as state of the art (e.g. ML based) methods allowingto capture atmospheric variability and temporal evolution as a function of external forcing (e.g. solar activity). - Define LEO/VLEO user and software requirements definition, including interfacing with relevant Space Weather tools and databases, and the capability toevolve as updated models and data become available. - Concept design, and a preliminary architecture design. - Develop and test critical functions to validate the approach. - Consolidate the design, full implementation and testing of the software. - Validatethe software by using independent data where possible and inter-models comparisons.Procurement Policy: C(1) = Activity restricted to non-prime contractors (incl. SMEs). For additional information please go to:http://www.esa.int/About_Us/Business_with_ESA/Small_and_Medium_Sized_Enterprises/Opportunities_for_SMEs/Procurement_policy_on_fair_access_for_SMEs_-_the_C1-C4_Clauses