One of NASA’s most successful spacecraft to date, Cassini, is slated to make its fateful plunge into Saturn’s atmosphere today, ending its 13 year tour of the Saturn system and countless historic scientific discoveries.

Cassini began making weekly dives toward Saturn’s atmosphere in April, collecting never before seen data on Saturn’s ring system and atmosphere as it traveled between the planet and its rings on 22 approaches – something no man-made craft has ever done before.  This week, however, Cassini will execute its final plunge toward Saturn, this time, with no intention of surfacing again.

According to NASA’s calculations, contact will be permanently severed with the spacecraft at approximately 7:55 a.m. EST, approximately one minute after it enters Saturn’s atmosphere, which begins at an altitude of 1,190 miles about the planet’s estimated cloud tops.  Saturn, as a gas giant, does not have a surface to speak of.  As Cassini plunges into Saturn’s cloudy exterior, it will reach speeds approaching 70,000 miles per hour, and ultimately be destroyed by the combination of heat and pressure applied to it by the giant planet as it plummets.

The spacecraft will use its thrusters as it falls, to try to angle itself to keep its radio antennae dialed in on Earth-based receivers, so scientists and researchers can glean as much as possible from the craft’s final moments before its systems suffer too much damage to continue transmitting.  If the antennae shifts any more than a few degrees away from Earth as it falls, communications will cease immediately, so NASA’s team intends to ramp the craft’s thrusters from 10% to 100% capacity within less than a minute, in order to try to maintain pitch control as it truly heads where no man, or man-made object, has gone before.