Cassini first flew between Saturn and its rings
At about 12:00 Moscow time the space probe “Cassini” performed the first of 22 “dives” the final part of the mission, first flying between Saturn and its ring system.
It’s a risky maneuver, since any sufficiently large particle of dust can damage the devices of the apparatus and to change its trajectory. Cassini will be up to three thousand kilometers above the dense atmosphere of the planet and almost five thousand kilometers from the inner D-ring. The connection with the device will be interrupted almost for a day — about 11:30 the engineers turned the main antenna from the Ground, turning it into a kind of shield. The first images and the link with Cassini is expected on April 27 around 10:30 Moscow time. Details published on a special page mission dedicated to the final stage.
360-degree video showing the first dive Cassini in the representation of artists
Such a scenario of the final phase was chosen to command the mission to solve several problems at once — to measure gravitational and magnetic fields of the planet, the chemical composition of the rings, and also to protect the moons of Saturn from the random “intrusion” of earthly life. It is believed that certain microorganisms could survive a 20-year journey of the apparatus in space. Since the amount of fuel required to maneuver the probe is almost over, soon Cassini can become unmanageable. Therefore, the team decided to shut down the apparatus in a controlled fall into the dense layers of the atmosphere of Saturn. It will happen on 15 September 2017.
The final phase of the mission began April 22, when the device was last moved closer to a Titan. Gravity of the largest moon of Saturn has adjusted the orbit of a celestial body and now the machine will do 22 turns, each of which will pass through the region between the rings and the atmosphere of the planet. The researchers carefully analyzed data about the area, it is expected that there is practically no large fragments of the material of the rings. To protect the equipment engineers use the main antenna as a shield.
Shields Up! As we pass over #Saturn, we’re turning our high-gain antenna into a shield RIGHT NOW to deflect an oncoming ring particles. pic.twitter.com/kAxzY53uwT
— CassiniSaturn (@CassiniSaturn) April 26, 2017
The distance to the pressure level of one atmosphere of the gas envelope of Saturn during the first “dive” will be 2950 miles to inner edge of D-ring — 4760 kilometres. According to the plan, the camera will take a picture in front of “duck” of the Northern pole of the planet. Then Cassini will estimate the amount of dust particles in the rings using the UV-spectrometer at scattering light of the Sun on them. In addition, the probe will take a series of shots of the upper atmosphere of the planet, the resolution will be about ten times better than all the previous images of Saturn.
Interestingly, in honor of this event Google has posted on the front page of its search engine Doodle with “Cassini”, flying between the rings and atmosphere of Saturn.
Vladimir Korolev