End of the Cassini Mission to Saturn

Two days from now, on Friday the 15th of September 2017 the Cassini Spacecraft will make it’s final orbit around Saturn. After exploring Saturn and its moons for the past 13 years Cassini is now nearly out of fuel and NASA has decided to plunge the probe into the atmosphere of the ringed planet. The reason for ending the probe’s mission in this fiery fashion is to make certain that Cassini does not crash onto one of Saturn’s moons and possibly contaminate it with micro-organisms from Earth.

The Cassini-Huygens mission began almost 20 years ago on the 15th of October 1997 when the spacecraft was launched from Kennedy Space Center aboard a Titan IV-Centaur rocket. The probe’s long seven year journey to Saturn required gravity boosting flybys from Venus (twice), Earth and Jupiter in order to gain enough energy to reach the outer Solar System. The image below shows the Cassini-Huygens spacecraft prior to its launch.

Cassini-Huygens Spacecraft (Credit: NASA)

Entering orbit around Saturn on the first of July 2004 Cassini released the Huygens landing module on the 25th of December 2004 and Huygens successfully landed on the Moon Titan on January the 14th, 2005. The lander, which was built by the European Space Agency, operated for 90 minutes sending back images and instrument measurements from the surface of the second largest moon in the Solar System. The first image below is a picture of the Huygens lander and the second is an image from the surface of Titan.

Huygens Lander (Credit: David Monniaux)
The Surface of Titan (Credit: ESA-NASA-JPL)

During it’s short operating life the Huygens lander found that the atmosphere of Titan was denser than Earth’s by about 45% with a composition of 95% nitrogen and 5% methane at a temperature of 98.3 degrees Kelvin (-179.3 Celsius). The rocks in the surface image above are actually water ice at a temperature so cold they are as hard as rocks!

The discoveries on Titan by Huygens were augmented by those of the Cassini orbiter which found both large lakes of liquid methane along with signs of channels other indications of erosion caused by flowing liquid methane. Between them Cassini and Huygens portray Titan as a world very similar to our own except it is so cold that methane has replaced water.

Since then the Cassini orbiter has continued its mission, making several major discoveries. One of the most important has been the eruptions of water ‘volcanoes’ spewing out of the moon Enceladus. The energy causing these eruptions is thought to be generated by the tidal forces of Saturn and its other moons and is similar to the process that heats Jupiter’s moons Io and Europa. After discovering the ‘volcanos’ the Cassini spacecraft was even sent into them in an attempt to analyze their composition. The plumes are indeed water but with a small amount of complex hydro-carbons mixed in. Are these complex molecules a sign of the beginning of life on Enceladus? Only time, and a lander to the moon will tell. The picture below is an artists idea of the hydro-thermal activity on Enceladus.

Hydro-Thermal Activity on Enceladus (Credit: NASA-JPL-Caltech)

As far as I’m concerned however the best part of any mission to Saturn is simply the images of the planet and its system of rings. So without further ado I’ll just add a few below.

Saturn by Cassini (Credit: NASA-JPL)
Saturn’s North Pole (Credit: NASA-JPL)
Saturn’s Rings (Credit: NASA-JPL)

NASA has actually set up live internet coverage of Cassini’s final moments, although we can’t be quite certain exactly when that will happen. The show will start at 7AM Eastern Daylight Time on Friday the 15th and if you’d like to tune in, I will be, click on the link below to be taken to NASA’s Cassini End of Mission Activities website.


More Space News for April

Two days ago NASA held a press conference to announce some of the results that scientists have discovered from the Cassini spacecraft. Cassini is in orbit around the planet Saturn and is in the final few months of it’s twenty year long mission.

Cassini orbiting Saturn

The press conference mainly dealt with some new discoveries about Saturn’s moon Enceladus which we knew from earlier observations was an ice covered world similar to Jupiter’s moon Europa. For several years now NASA astronomers have speculated that, again like Europa, Enceladus might have a liquid ocean beneath the ice covering, an ocean that could support life.

Now the heat energy that keeps the ocean warm would come from the flexing and squeezing of the moon’s interior caused by the interacting gravitational fields of Saturn and it’s other moon’s, the tidal pulls. The same process is known to cause the numerous volcanoes on Jupiter’s moon Io and are suspected to keep the ocean on Europa warm. The heat generated by this process could also provide the energy for life on Enceladus.

Images taken of Enceladus by Cassini have discovered plumes of water spewing out of the Moon like geysers and now Cassini has even succeeded in flying through those plumes and identifying some of the chemicals contained in them. In their announcement NASA scientists stated that Cassini has detected considerable amounts of both Carbon Dioxide and Methane both of which are commonly associated with living processes. The image below details the processes going on at the moon.

Enceladus Geothermal Processes

These results give us another possible home for life in our Solar system. Along with Mars and Europa, Enceladus is another world we need to explore further. A specialized mission to search for life on Enceladus may take years to develop and launch however, but someday we’ll know whether or not we have close neighbors living around the ringed planet.

If you’d like to read more about NASA’s announcement click on the link below.


There has also been another announcement from NASA concerning grant money being funded to a series of new technology programs. These grants are called the NASA Innovative Advanced Concept or NIAC program and are intended to study possible future technologies for spaceflight. The initial Phase I grants are about $125,000 dollars while Phase II grants can be as much as a half a million dollars.

The Phase I grants can be very interesting, even far out concepts while the Phase II grants tend to be a bit more realistic. In the Phase I group are included four completely new type of propulsion technologies, two are intended for interstellar travel, along with  a ‘vacuum balloon’ to drift over the surface of Mars and  Solar Surfing!

The Phase II grants include a probe of the interior of the planet Venus and a fusion enabled Pluto orbiter and lander. If you’d like to read a bit more about these possible future space technologies click on the link below.


There’s always something new happening in space so I hope you’ll be coming back soon.