Huygens landing on the moon Titan happened in 2005, it is only now that NASA had released the footage of the landing. It is 12 years ago that the probe had landed on Titan. It was the farthest point from Earth that any spacecraft had landed on. The spacecraft that brought the probe, Cassini had orbited around the planet Saturn and is set to end its mission by plunging into Saturn's atmosphere on September 15, 2017.
The way the rig was set up was that Huygens after piggybacking on Cassini, would be dropped into Titan. The probe would then transmit data however it does not have a large enough disk or power to transmit all the data from Titan to Earth. So, the probe would have to send its transmission to Cassini which will in turn store the data and send them to Earth.
However during tests, Cassini was having difficulty picking up data from the probe. All it received were garbled transmission. It was Boris Smeds an ESA engineer who had insisted on testing the transmission and later made sure that all worked fine. It was later found out that variation in the speed of the two crafts had not been properly compensated for and was causing the communication problem, like the two spacecraft were communicating on different frequencies.
Even though the problem was found out later when the spacecraft were millions of miles away in space, the teams at ESA were able to figure out how to correct the problem by using what is called as the Doppler Effect.
So by changing the way the Cassini flew, even though they could not do anything about the Huygen's signal, they moved Cassini farther away make it appear as if Huygens was moving slower and receiving the radio waves from Huygens at a lower frequency thus solving the problem as reported in an article by the Universe Today.
Huygens landing into Titan's atmosphere marked the farthest point a spacecraft from Earth landed on the outer part of our solar system. The probe began taking in pictures and began transmitting to Cassini four minutes into its descent. Although the probe was not able to gather as much data as originally planned because of the communication problem, Cassini was able to capture all the data that was sent to it by Huygens.
The Huygens' images were everything that the images from orbit were not. Instead of hazy and murky images, the probe was able to send clear high resolution images of features on Titan. According to scientists, Huygens images had proven that Titan is an amazing world with a landscape that mimics Earth according to a report from Astrobiology Magazine.
