Cassini's T-119 flyby was a unique 'double midnight' flyby. Titan was on the night side of Saturn as was Cassini's closest approach. This also was the last Titan occultation for Cassini's Radio Science team.
Cassini’s radio science engineering operations team.
Cassini team members watch for a signal from the spacecraft. It was expected to be unusually challenging for the spacecraft to both lock onto a signal sent from Earth and then immediately transmit it back in the two minutes that the signal was passing through Titan’s atmosphere en route to Earth.
Before and during the experiment, Aseel Anabtawi talked to controllers at the Deep Space Communications Complex in Canberra, Australia, where a giant radio antenna collected and refined the radio signal from Cassini.
The Cassini team celebrate data showing that the spacecraft locked onto the signal from Earth and rebroadcast back to Earth. Cassini was about 600 million miles (a billion kilometers) from Earth throughout the experiment.
Essam Marouf and Earl Maize bump fists on a job well done. Much could have gone wrong but, through collaboration, communication, and a bit of luck, the experiment worked.
After sending a radio signal through Titan’s atmosphere, the spacecraft re-oriented and bounced a signal off of Titan’s hard surface at just the right angle so that the signal would be received by Earth. Here the team views a visualization of the data as it arrives.