NASA's Cassini begins 'Grand Finale' at Saturn: Google commemorates milestone with a doodle

New Delhi: NASA's Cassini spacecraft is making its first dive through the narrow gap between Saturn and its rings on Wednesday, April 26, 2017, beginning its final set of 22 orbits around the ringed planet.

As Cassini enters its final phase called the 'Grand Finale' on Saturn mission, Google is celebrating the 20-year journey of the spacecraft with a doodle on its homepage.

Google doodle features an animated version of the Cassini spacecraft taking images of the Saturn as it passes through its rings.

Because that gap is a region no spacecraft has ever explored, Cassini will use its dish-shaped high-gain antenna - 13 feet or 4 meters across - as a protective shield while passing through the ring plane, as per NASA.

Although no particles larger than smoke particles are expected, the precautionary measure is being taken on the first dive.

The Cassini team will use data collected by one of the spacecraft’s science instruments (the Radio and Plasma Wave Subsystem, or RPWS) to ascertain the size and density of ring particles in the gap in advance of future dives.

As a result of its antenna-forward orientation, the spacecraft will be out of contact with Earth during the dive, adds NASA.

As Cassini plunges past Saturn, the spacecraft will collect rich and valuable information far beyond the mission’s original plan, including measuring Saturn’s gravitational and magnetic fields, determining ring mass, sampling the atmosphere and ionosphere, and making the last views of Enceladus.

The earliest time Cassini will make radio contact with Earth is scheduled at 12:05 a.m. PDT (3:05 a.m. EDT) on April 27. Images and other data are expected to begin flowing in shortly after communication is established.

Cassini made its 127th and final close approach to Saturn's moon Titan on April 21. The spacecraft passed at an altitude of about 608 miles (979 kilometers) above the surface of Saturn's moon on April 21 at 11:08 p.m. PDT (2:08 a.m. EDT on April 22).

The spacecrfat has transmitted close-up images of Saturn's rings and clouds from its last encounter with Titan to the Earth.

Cassini, which has been circling the Saturn planet for 13 years, is expected to culminate its journey on September 15 this year.