Radio Science and Planetary Exploration Laboratory

Radio Science Laboratory

Research

The laboratory collaborates with various space agencies such as NASA/JPL, ESA and ASI on various interplanetary missions:

Cassini-Huygens mission (NASA/ESA/ASI): Since 2001, the laboratory's research team has been involved in analysing Doppler data from the Cassini probe to conduct experiments on general relativity and gravimetric studies of the Saturn system (Saturn and its main rocky satellites, including Titan). The team conducted an important analysis on the influence of numerical errors in orbital determination software on the estimates derived from the data.

Pioneer mission (NASA): The group is studying the “Pioneer Anomaly”, an anomalous acceleration of the spacecraft that causes it to move away from the Sun faster than predicted by current physics. The team's results suggest that the anomaly is generated by anisotropy in the thermal output of the probe itself and not by as yet unknown physical phenomena.

BebiColombo mission (ESA) - MORE (Mercury Orbiter Radioscience Experiment): Europe's ambitious BepiColombo mission will orbit Mercury, and the MORE radio science experiment will provide range data with accuracies of less than 20 cm. The Forlì group, in partnership with ASI and other universities, is developing software to calibrate radiometric data to remove noise generated by solar plasma and the Earth's atmosphere. Furthermore, the laboratory is involved in the experiment to determine the rotational state of Mercury based on photographic surveys of the surface, for which a method is being studied to optimise the choice of sites to be photographed (using genetic algorithms) in order to maximise the information contained in the images. Finally, the group is responsible for the definition of the data exchange standard between different agencies and the development of read/write file routines.

Juno mission (NASA): The NASA/ASI Juno probe is currently cruising towards Jupiter. The Forlì team will provide support to the gravimetry experiment through the data calibration routine for removing plasma and atmospheric noise and by carrying out spacecraft orbital determination processing.

JUICE mission (ESA): The new mission (formerly known as LAPLACE and EJSM, now JUICE: JUpiter Icy moon Explorer) selected by ESA to study the Jupiter system will be launched in 2022. The Forlì team has been part of the requirements definition team for onboard radio science experiments (Joint Science Definition Team) since 2008.

Navigation of Interplanetary Probes - SW Correlator ESA ΔDOR: As a subcontractor of the DIAA department of the La Sapienza University of Rome, the radio science group was involved in the writing of SW for the European Space Agency (ESA) to correlate radio signals from probes and natural radiosources acquired simultaneously from two separate ground stations, to determine the angular position of a probe in flight in the solar system. The above SW was subsequently validated and successfully used by ESA-ESOC's Flight Dynamics team for the Venus Express spacecraft's orbit insertion manoeuvre in 2005.

Navigation of interplanetary probes - Estimation of tropospheric phase delay using GNSS measurements and microwave radiometers: the team is developing software that, by processing data from a worldwide network of geodetic GNSS receivers (IGS) and a rover receiver located at a particular site, is able to estimate the phase delay generated by water vapour in the troposphere affecting interplanetary signals. This way the effect of phase delay can be removed from the radiometric data, thereby increasing the accuracy of probe positioning in space. The same physical quantity is also measured by special instruments called microwave radiometers: the Forlì group took part in a study to define a new-generation radiometer capable of measuring phase delay with high accuracy and time stability.

Educational Activities

The laboratory provides educational support for the courses FOUNDATIONS OF ORBITAL MECHANICS of the Aerospace Engineering degree and the courses SPACECRAFT ORBITAL DYNAMICS AND CONTROL and SPACECRAFT ATTITUDE DYNAMICS AND CONTROL of the International Master's Degree in Aerospace Engineering.
Internships and theses projects (both Bachelor and Master) are also available for Aerospace Engineering students.

Resources

A range of calculation equipment is available in the laboratory:

• DELL PowerEdge R710 Workstation
Dual Intel Xeon X5680 (3.33GHz, 6 cores, 12 threads, 12MB cache)
Ram 64GB DDR3 1333MHz ECC (8x8Gb DIMM)
HDD 2x2Tb 3.5” 10k rpm SAS, hot-swappable, RAID-1
HDD 600Gb 3.5” 15k rpm, SAS, hot-swappable, RAID-1
Slim DVD-drive
4x Gigabit Ethernet NIC
Matrox G200 video card

• Hewlett Packard XW6200 Workstation
Dual Intel Xeon 3.06GHz Xeon Processors
1.5 GB DDR266 PC2100 ECC
500GB (7,200 rpm) SATA II Hard Drive
16X/48X DVD ROM Drive
nVIDIA Quadro NVS 200 AGP
19" LCD Monitor Samsung

And the following equipment:

-GPS Receiver
Ashtech uZ- CGRS 1
12 parallel dual frequency channels with Z-Tracking
Two bidirectional RS-232 serial ports expandable to 4
128 Mbyte internal memory
L1/L2 Choke Ring antenna with Dorne&Margolin C146-10 receiving element.
LNA 38dB gain, pre-filtered +/- 15MHz on L1/L2 centre frequencies.
Hemispherical protection dome for ChokeRing antenna.