1. ASTRA: Interdisciplinary study on enhancement of the end-to-end accuracy for spacecraft tracking techniques
- Author
-
Iess, L., Budnik, F., Colamarino, C., Corbelli, A., Di Benedetto, M., Fabbri, V., Graziani, A., Hunt, R., James, N., Lanucara, M., Maddè, R., Marabucci, M., GILLES MARIOTTI, Mercolino, M., Racioppa, P., Simone, L., Tortora, P., Westcott, M., Zannoni, M., Iess Luciano, Budnik Frank, Colamarino Claudio, Corbelli Alberto, Di Benedetto Mauro, Fabbri Valentino, Graziani Alberto, Hunt Rob, James Nick, Lanucara Marco, Maddè Roberto, Marabucci Manuela, Mariotti Gille, Mercolino Mattia, Racioppa Paolo, Simone Lorenzo, Tortora Paolo, Westcott Mark, and Zannoni Marco
- Subjects
tracking systems ,DEEP SPACE NAVIGATION SYSTEMS ,DEEP SPACE TRACKING ,space navigation ,vlbi ,DEEP SPACE ORBIT DETERMINATION - Abstract
Navigation of deep-space probes is accomplished through a variety of different radio observables, namely Doppler, ranging and Delta-Differential One-Way Ranging (Delta-DOR). The particular mix of observations used for navigation mainly depends on the available on-board radio system, the mission phase and orbit determination requirements. The accuracy of current ESA and NASA tracking systems is at level of 0.1 mais at 60 s integration time for Doppler, 1 to 5 m for ranging and 6 to 15 nrad for Delta-DOR measurements in a wide range of operational conditions. The ASTRA study, funded under ESA's General Studies Programme (GSP), addresses the ways to improve the end-to-end accuracy of Doppler, ranging and Delta-DOR systems by roughly a factor of 10. The target accuracies were set to 0.01 mm/s at 60 s integration time for Doppler, 20 cm for ranging and 1 nrad for Delta-DOR. The companies and universities that took part in the study were the University of Rome Sapienza, ALMASpace, BAE Systems and Thales Alenia Space Italy. The analysis of an extensive data set of radio-metric observables and dedicated tests of the ground station allowed consolidating the error budget for each measurement technique. The radio-metric data set comprises X/X, X/Ka and Ka/Ka range and Doppler observables from the Cassini and Rosetta missions. It includes also measurements from the Advanced Media Calibration System (AMCS) developed by JPL for the radio science experiments of the Cassini mission. The error budget for the three radio-metric observables was consolidated by comparing the statistical properties of the data set with the expected error models. The analysis confirmed the contribution from some error sources, but revealed also some discrepancies and ultimately led to improved error models. The error budget reassessment provides adequate information for building guidelines and strategies to effectively improve the navigation accuracies of future deep space missions. We report both on updated error budget for radio-metric observables and the system configurations proposed for the upgrade of ESA's tracking and orbit determination systems.
- Published
- 2012