This graphic illustrates the Radio Science Occultation Experiment conducted on Friday May 10, 2013

May 16, 2013

+ Higher Resolution

This graphic illustrates the Radio Science Occultation Experiment conducted on Friday May 10, 2013.

Details and description of terms:

Dots are spaced at 15-minute (15 m) intervals along the central blue line representing Cassini's path behind Saturn, going from right to left, which is southwest to northeast in the sky. Terms and abbreviations:

2 / 3 Way: Signal received on Earth based on uplink from Earth. 2-Way means same DSN station uplinking & receiving; 3-Way means a different station receiving.

1-W: One way downlink communications, spacecraft not receiving an uplink reference frequency

2-W: Two-way (see above)

3-W: Three-way (see above)

71.6° S: Southern Saturn Latitude

Greek letter B (beta): Angle of ring-plane slant as viewed from Earth

Red letter A: Saturn's A ring

Red Letters CD: Cassini Division in Saturn's rings

Red Letter B: Saturn's B ring

Red Letter F: Saturn's F ring

Acquisition: Receiving the signal from Cassini in the DSN antennas and receivers

Blind pointing: A technique for pointing DSN antenna based on predictions

ERT: Earth-Receive Time

Exp: Experiment (Radio Science Occultation Experiment)

D/L: Downlink; signal from spacecraft to Earth

DOY: Day of Year

DSN: Deep Space Network

DSS: Deep Space Station (DSN Station)

DS-63: A 70-meter diameter DSN station at Madrid, Spain

DS-55: A 34-meter diameter DSN station at Madrid, Spain

DSS-45: A 34-meter diameter DSN station at Canberra, Australia

HGA: Cassini's High-Gain Antenna

Monopulse pointing: A closed-loop technique for refinement of DSN antenna pointing based on received signal

Rev 190: Cassini's Saturn orbit #190

RSS: Cassini Radio Science Subsystem

RTLT: Round-Trip LIght-Time of the radio signals

S/C: Spacecraft

TBD: To be determined (was determined) in real time

U/L: Uplink; signal from Earth to spacecraft

UTC: Universal Time Coordinated

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

For more information about the Cassini-Huygens mission visit or .


Image courtesy of Cassini Radio Science Subsystem team.

Credit: Essam A. Marouf (EAM)