One of NASA’s most ambitious space missions is coming to an end this year. The US space agency launched the Cassini mission in 1997. After a seven-year-long journey from Earth, the probe has been orbiting Saturn and its moons since 2004. Cassini has made some incredible discoveries in the last 13 years. NASA announced Tuesday that it was planning to crash the probe into Saturn on September 15th.

NASA Cassini Saturn
Image Source: NASA / Jet Propulsion Laboratory / YouTube video (screenshot)

Cassini to go on 22 dives between Saturn and its rings

The probe will be doing something it has never done before for a scientific grand finale before taking a suicidal plunge into the distant planet. Scientists at the Jet Propulsion Laboratory would direct the spacecraft to Titan for the last time, which would act as a catapult to put Cassini into the 1200-mile gap between Saturn’s atmosphere and the inner-most rings.

Once the probe is into the gap, it would embark on a series of 22 weekly dives between the planet and its rings between April and September this year. It will study and send back data on the age and composition of the rings. But the mission could meet a premature end if a ring particle hits Cassini. The probe will be traveling at 70,000 miles per hour. At such a high speed, even a tiny particle can destroy the spacecraft, said Cassini flight engineer Joan Stupik.

NASA says the grand finale could be the best part of the mission

Astronomers hope the grand finale would reveal whether the rings were formed at the same time as Saturn about 4.6 billion years ago, or they formed at a later stage when the planet’s gravity shredded a passing moon or asteroid. During the 22 dives, Cassini will also study the planet’s atmosphere and determine the size of the rocky core located at the center of the gas giant.

Project scientist Linda Spilker said no matter how long Cassini lasts, “the grand finale will be spectacular.” It would be venturing into a region never explored before. Scientists wouldn’t be surprised if the grand finale turns out to be the best part of the mission. The spacecraft will send final images hours before the final plunge. But even as it crashes into Saturn, Cassini will be sending data in real-time until it loses contact with the Earth.

Cassini was running out of rocket fuel

Since 2004, the probe has discovered several new moons. It revealed that two of Saturn’s moons – Titan and Enceladus – could have potentially habitable environments. Enceladus has been throwing ice particles out into space. As it crashes into Saturn in September, Cassini will be gathering data that was too risky to collect earlier in the mission.

The probe is running out of rocket fuel needed to adjust its course. Without the fuel, NASA scientists wouldn’t be able to control its course. Astronomers do not want Cassini to someday crash into one of the Saturn’s moons that could have conditions for alien life. Microorganisms still alive on Cassini could contaminate the potential life forms on Titan or Enceladus.