LOS ANGELES Mark Giordano Youth Jersey , Sept. 14 (Xinhua) -- On Friday morning, the U.S. National Aeronautics and Space Administration (NASA)'s Cassini spacecraft will dive into Saturn's atmosphere and disintegrate.
"Look up tonight & see Saturn in the sky. Tomorrow, our spacecraft will be part of the planet it studied for so long," Cassini's team said on Twitter Thursday night.
The probe was running low on fuel, and the 13-year tour of the Saturn system mission must end. The spacecraft will make a deliberate plunge into Saturn's atmosphere to avoid the small possibility of it crashing into a potentially habitable moon, in particular Enceladus.
The long-lived spacecraft's fateful dive was the final beat in the mission's Grand Finale, which began in late April Jaromir Jagr Youth Jersey , through the gap between Saturn and its rings. No spacecraft has ever ventured so close to the planet before.
On its final orbit, Cassini will plunge into Saturn's atmosphere at tens of thousands of miles per hour, sending back new and unique science to the very end. After losing contact with Earth, the spacecraft will burn up like a meteor, becoming part of the planet itself.
"The spacecraft is transmitting the last data from its recorders," Cassini team tweeted on Thursday afternoon.
The spacecraft is in the process of emptying its onboard solid-state recorder of all science data, including the final images taken by its imaging cameras Johnny Gaudreau Youth Jersey , prior to reconfiguring for a near-real-time data relay during the final plunge. The communications link with the spacecraft is continuous from now through the end of mission.
Because of Earth's rotation, this 11-hour downlink begins with the NASA Deep Space Network (or DSN) antenna station in California, which then hands off receiving to a station in Canberra, Australia. From this point the spacecraft holds this orientation, its antenna pointed toward Earth, for the remaining several hours of the mission.
According to the mission's final calculations, after beginning its descent into Saturn's upper atmosphere Michael Frolik Womens Jersey , the spacecraft is expected to lose radio contact with Earth at 4:55 a.m. PDT (1155 GMT) on Friday.
Cassini will enter Saturn's atmosphere at an altitude of about 1,915 km above the planet's estimated cloud tops, where the air pressure is 1-bar, equivalent to sea level on Earth. During its dive into the atmosphere, the spacecraft's speed will be approximately 113,000 km per hour.
According to NASA, when the probe first begins to encounter Saturn's atmosphere Mike Smith Womens Jersey , Cassini's attitude control thrusters will begin firing in short bursts to work against the thin gas and keep Cassini's saucer-shaped high-gain antenna pointed at Earth to relay the mission's precious final data.
As the atmosphere thickens, the thrusters will be forced to ramp up their activity, going from 10 percent of their capacity to 100 percent in the span of about a minute. Once they are firing at full capacity, the thrusters can do no more to keep Cassini stably pointed, and the spacecraft will begin to tumble.
Cassini is set to make groundbreaking scientific observations of Saturn. Before contact is lost, eight of Cassini's 12 scientific instruments will be operating. All of the mission's magnetosphere and plasma science instruments, plus the spacecraft's radio science system Troy Brouwer Womens Jersey , and its infrared and ultraviolet spectrometers will collect data during the final plunge.
In particular, the spacecraft's Ion and Neutral Mass Spectrometer (INMS) will be directly sampling the atmosphere's composition, which cannot be done from orbit. It will potentially offer insights into the giant planet's formation and evolution.
When the antenna points just a few fractions of a degree away from Earth, communications will be severed permanently. The predicted altitude for loss of signal is about 1,500 kilometers above Saturn's cloud tops. From that point, the spacecraft will begin to burn up like a meteor.