Washington, September 15:  On its last journey after its launch 20 years ago, NASA’s Cassini mission began transmitting data before its final plunge into Saturn on Friday.

NASA’s Cassini spacecraft will complete its remarkable story of exploration with an intentional plunge into Saturn’s atmosphere on Friday, ending its mission after nearly 20 years in space.

Launched in 1997, Cassini arrived in orbit around Saturn in 2004 on a mission to study the giant planet, its rings, moons and magnetosphere. In April of this year, Cassini began the final phase of its mission, called its Grand Finale — a daring series of 22 weekly dives between the planet and its rings.

On Sept. 15, Cassini will plunge into Saturn, sending new and unique science about the planet’s upper atmosphere to the very end. After losing contact with Earth, the spacecraft will burn up like a meteor. This is the first time a spacecraft has explored this unique region of Saturn — a dramatic conclusion to a mission that has revealed so much about the ringed planet, said NASA

The spacecraft’s fateful dive is the final beat in the mission’s Grand Finale, 22 weekly dives, which began in late April, through the gap between Saturn and its rings.

No spacecraft has ever ventured so close to the planet before.

The mission’s final calculations predict loss of contact with the Cassini spacecraft will take place on Friday at 7.55 a.m. EDT (5.25 pm Friday India time).

Due to the travel time for radio signals from Saturn, which changes as both Earth and the ringed planet travel around the Sun, events currently take place there 83 minutes before they are observed on Earth.

This means that, although the spacecraft will begin to tumble and go out of communication at 6.31 a.m. EDT (4.01 pm India time) at Saturn, the signal from that event will not be received at Earth until 83 minutes later.

“The spacecraft’s final signal will be like an echo. It will radiate across the solar system for nearly an hour and a half after Cassini itself has gone,” said Earl Maize, Cassini project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

(With inputs from IANS)