Cassini, NASA’s spaceship that has flown and taken incredible pictures around Saturn for 20 years, will end its journey and disappear forever on Friday. NASA experts plan to direct the spacecraft near the giant Saturn’s moon, Titan, close enough to be reached by the ringed planet’s gravity. At this moment, Cassini will take a new orbit to Saturn and begin its way to the death plunge, fulfilling its mission.

The spacecraft is considered one of the most scientific and technical accomplishments in our time. Despite the fact that it is not the first space probe to reach Saturn, it is the first to enter into its orbit. Thanks to it, we have access to many real-photos detailing not only the color, form, and texture of the gaseous planet, but also of magnificent areas in our solar system “where life could potentially gain a foothold,” according to Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate at Headquarters in Washington.

Image credit: NASA
Image credit: NASA

Besides the many pictures that the great spacecraft mission took from Saturn, Cassini also sent data of the moons and geysers spewing from the rare Saturn satellite Enceladus. When Cassini enters the atmosphere, it will break into pieces, burn, and melt until it completely disappears inside the gaseous planet. In that very last second, the billion-dollar spacecraft will still be sending information to Earth about Saturn and its composition.

The Cassini-Huygens – an orbiter and a lander, both named after the astronomers Giovanni Cassini and Christiaan Huygens – started to be designed when Ronald Reagan was president, and blasted off from Cape Canaveral on October 15, 1997, during the tenure of Bill Clinton. However, the National Aeronautics and Space Administration was not the only one involved in this collaboration. It was planned, built, launched, and operated along with the European Space Agency, and the Italian Space Agency.

“That final flyby of Titan will put Cassini on an impacting trajectory and there is absolutely no coming out of it,” said Earl Maize. “We’re going to go so deep into the atmosphere the spacecraft doesn’t have a chance of coming out.”

The ‘final kiss goodbye’ and Grand Finale of Cassini

NASA scientists have been brilliant at planning the Cassini’s journey and last stages. Since the spacecraft arrived at Saturn 13 years ago, it has taken photos from different positions. However, it did not use many times its reserve of fuel to search and place in the best locations. Instead, it used the same gravity of Titan to surround the moon and look for perfect angles to study the planet and its spectacular rings.

Although it only used its fuel reserve to make significant changes in the directions, the spaceship is actually running out of fuel, and NASA doesn’t want Cassini to freely float over Saturn or the entire space, becoming space trash and contaminating the moon or planet.

Image credit; NASA
Image credit; NASA

Scientists estimate that Cassini will surround the moon at the end of this week around an estimated of 120,000km, at 19:04 GMT (20:04 BST; 15:04 EDT; 12:04 PDT). Considering the immensity of the space and how separated objects are, this is not an extremely large distance. It will be an enough amount required to reach useful conclusions about the satellites, the planet, and the entire Cassini’s 20-year journey.

It will take a series of 22 orbits to send Cassini in between the great gas planet and its amazing rings. The space agency is calling the following Titan encounter the “final kiss goodbye.” After that happens, the ship will enter into a Saturn’s zone that nothing made by humans has ever visited or studied. This final stage is called the Grand Finale.

Titan, the first of all Cassini’s reasons

NASA did not estimate to study these space areas the first moment when the agency was planning what Cassini was going to do. It only expected the spaceship to send information about Titan, one of the biggest satellites in the Solar System.

“The Cassini mission has taught us so very much, and to me personally I find great comfort from the fact that Cassini will continue teaching us right up to the very last seconds,” said Curt Niebur, a Cassini scientist at NASA Headquarters in Washington, DC.

Titan, considered the largest moon that surrounds Saturn and the sixth moon ever discovered – by the Dutch astronomer, Christiaan Huygens, in 1655 – is extremely cold, and had possible channels or lakes of liquid methane over its surface.

The sixth ellipsoidal Saturn’s moon is 50 percent larger and 80 percent more massive than ours. It’s the second largest moon in the Solar System after Jupiter’s moon Ganymede, and bigger than Mercury.

It was impossible for us to know that Titan is primarily composed of water ice and rocky material before Cassini spacecraft because of the dark atmosphere that covers the moon. Its surface is smooth and has a few craters, mountains, and possible cryovolcanoes.

Source: BBC