Speaker
Mr
Amedeo Rocchi
(GMV/ESOC)
Description
Software able to study and simulate the guidance and navigation process is essential when dealing with complex interplanetary missions. The outputs required from such software are multiple, ranging from the evaluation of stochastic ∆V required to keep the dispersion errors with respect to the nominal trajectory small, to the identification of critical phases of the missions for the guidance and navigation process, to the assessment of the optimal ground station network selection and many others.
In the ESOC Mission Analysis section the two most complete tools available in this context are IntNav (Interplanetary Navigation software tool), developed by GMV and LoTNav (Low Thrust Navigation software tool), developed by DEIMOS Space.
Both tools are composed of several modules and they share a common structure; the core modules of both software are: measurements generation module, parameters estimation module and guidance module. The first module computes the measurements selected for the orbit determination, given the trajectory of the spacecraft and the measurement schedule (availability of observations and ground stations are always taken into account). The parameters estimation module is used to compute partial derivatives of the estimated states with respect to the selected parameters and also to conduct the covariance analysis for knowledge and dispersion. The guidance module finally is used to determine the stochastic manoeuvres to be executed in the guidance process.
Additional modules are also present in both tools (or were added to the core software afterwards), to deal with other functions or analyses to be performed in the navigation context: for example modules for the trajectory computation and sectioning are available in both tools, a reconstruction module is available in IntNav to simulate the trajectory reconstruction of particularly interesting phases in the trajectory (e.g. flybys), and many others are available.
A general overview of this structure will be presented, followed by examples obtained with both tools. JUICE moons tour navigation results obtained with IntNav and Bepi-Colombo interplanetary navigation results obtained with LoTNav will be presented.
The major assumptions will be explained and the encountered issues will be highlighted: flybys with high uncertainties and large navigation manoeuvres, parameters selection choices taken after the results evaluation, the non-trivial optimization process for the manoeuvres targeting and other aspects. Final results for both cases will be then detailed.
| Applicant type | First author |
|---|
Primary author
Mr
Amedeo Rocchi
(GMV/ESOC)
Co-author
Mr
Rüdiger Jehn
(ESA/ESOC)
