Barcelona Scooter by Sam Haskins c1980. For those who are interested, it was originally a transparency sandwich - a photograph of a mural montaged onto a photograph of the couple on a scooter. This version was digitally remastered by scanning both transparencies separetely and combining the images in Photoshop.
1:27 am EDT (10:27 pm PDT - Sept. 11) Apoapse, or farthest point from Saturn in the orbit (800,000 miles, 1.3 million kilometers from Saturn)
7:56 pm EDT (4:56 pm PDT) Downlink of final Titan data begins
ERT 9:19 pm EDT (6:19 pm PDT)
3:58 pm EDT (12:58 pm PDT) Scheduled time when the final image will be taken by Cassini’s cameras
4:22 pm EDT (1:22 pm PDT) Spacecraft turns antenna to Earth; communications pass begins for final playback from Cassini’s data recorder, including final images.
Communications link is continuous from now to end of mission (~14.5 hours) 5:45 pm EDT (2:45 pm PDT)
11:15 pm EDT (8:15 pm PDT)
Deep Space Network station in Canberra, Australia, takes over tracking Cassini to end of mission
1:08 am EDT (10:08 pm PDT - Sept. 14) High above Saturn, Cassini crosses the orbital distance of Enceladus for the last time
3:14 am EDT (12:14 am PDT)
Spacecraft begins a 5-minute roll to point instrument (INMS) that will sample Saturn’s atmosphere and reconfigures systems for real-time data transmission at 27 kilobits per second (3.4 kilobytes per second).
Final, real-time relay of data begins
ERT 4:37 am EDT 1:37 am PDT
3:22 am EDT (12:22 am PDT) High above Saturn, Cassini crosses the orbital distance of the F ring (outermost of the main rings) for the last time
6:31 am EDT (3:31 am PDT) Atmospheric entry begins; thrusters firing at 10% of capacity
ERT 7:54 am EDT (4:54 am PDT)
6:32 am EDT (3:32 am PDT) Thrusters at 100% of capacity; high-gain antenna begins to point away from Earth, leading to loss of signal
ERT 7:55 am EDT (4:55 am PDT)
Pinpointing a Moment
As Cassini heads for its Sept. 15 plunge into Saturn, the mission team will continue to update their predicted time for loss of signal. This is the predicted time during Cassini’s dive into Saturn when the spacecraft is expected to begin tumbling due to increasing atmospheric density, permanently severing the spacecraft’s radio link with Earth. At this point the spacecraft’s mission is over.
The predicted time for loss of signal changes because of effects from Saturn’s atmosphere on each of the spacecraft’s final five orbits. On these passes, Cassini dips briefly into Saturn’s upper atmosphere, which causes drag.
This drag alters Cassini’s velocity, which in turn affects when the spacecraft will reach Saturn’s atmosphere on the mission’s final day. More drag makes the spacecraft slow down in its orbit, which can move the end-of-mission time slightly earlier, by seconds or even minutes. The time could move forward slightly if the atmosphere turns out to be less dense than expected based on the previous passes.
Cassini’s flight team reviews the trajectory after each pass to see how the spacecraft’s course was affected by the atmosphere. They use the new information to update their prediction of how the remaining passes will further alter the trajectory, and from these predictions they generate an updated time for loss
Good to know:
• It takes about 83 minutes for radio signals to travel across the 1.4 billion km between Earth and Saturn.
• No images will be taken during the final plunge into Saturn, as the data transmission rate required to send images is too high and would prevent other high-value science data from being returned.
• The final images will be taken on 14 September and are planned to include images of Titan, Enceladus, moonlet ‘Peggy’, a propeller feature in the rings and a colour montage of Saturn and its rings, including the aurora at the north pole (examples of previously released images of these targets are shown here).
• Eight instruments (CDA, CIRS, INMS, MAG, MIMI, RPWS, RSS, UVIS) will collect data during the final plunge, transmitting it back to Earth in near-real time.
• The mission is ending because, after two decades in space, its fuel is running out. To ensure a safe disposal of the spacecraft, and to avoid an unplanned impact onto pristine icy satellites such as ocean-bearing moon Enceladus, Cassini is being directed into the gas planet itself, where it will burn up.
• Since April, Cassini has been making weekly dives through the 2000 km gap between Saturn and its rings. This ‘Grand Finale’ maximises the scientific return of the mission, giving close dives past the inner and outer edges of the rings and the planet’s small inner moons, as well as close encounters with the upper reaches of Saturn’s atmosphere.
• The 22 Grand Finale orbits were supported by ESA ground stations, which received signals from Cassini to gather crucial radio science and gravitational science data.
• A final distant flyby with Titan on 11 September gave the gravitational assist needed to put the spacecraft on an impact course with Saturn.
(french version - english version here) Montage pour un dossier d’orientation dans le cursus de la bijouterie-joaillerie option sertissage. L'ensemble était imprimé pour faire un livret. Aucune des photos ne m’appartient.