1. Cassini Retrospective
Larry W. Esposito & Frank C. Crary
E126
Fall Graduate Seminar
29 September 2017

2. Mission
Launch vehicle: Titan IVB/ Centaur
Weight: 2.2 million pounds (1 million kg)
Launch: Oct. 15, 1997, from Cape Canaveral Air Force Station, Fla.
Earth-Saturn distance at arrival: 934 million miles (1.5 billion km) (10 times Earth to Sun distance)
Distance traveled to reach Saturn: 2.2 billion miles (3.5 billion km)
Saturn's average distance from Earth: 890 million miles (1.43 billion km)
One-way Speed-of-Light Time from Saturn to Earth at Cassini Arrival:84 minutes
One-way Speed-of-Light Time from Saturn to Earth During Orbital Tour: 67 to 85 minutes
Venus Fybys: April 26, 1998 at 176 miles (234 km); June 24, 1999 at 370 miles (600 km)
Earth Flyby: Aug. 18, 1999 at 727 miles (1,171 km)
Jupiter flyby: Dec. 30, 2000 at 6 million miles (10 million km) (closest approach 5:12 a.m. EST)
Saturn Arrival Date: July 1, 2004, UTC (June 30, 2004 PDT)
Primary Mission: 4 years
Two Extended Missions: Equinox ( ) and Solstice ( )
Program
Partners: NASA, European Space Agency (ESA), Italian space agency Agenzia Spaziale Italiana (ASI); total of 17 countries involved
U.S. states in which Cassini work was carried out: 33
Number of people who worked on some portion of Cassini-Huygens: More than 5,000
Cost of mission: $1.422 billion pre-launch development; $710 million mission operations; $54 million tracking; $422 million launch vehicle; $500 million ESA; $160 million ASI; total about $3.27 billion, of which U.S. contribution is $2.6 billion and European partners' contribution $660 million

5. Cassini Orbiter
Dimensions: 22 feet (6.7 meters) high; 13.1 feet (4 meters) wide
Weight: 12,593 pounds (5,712 kg) with fuel, Huygens probe, adapter, etc; 4,685 pounds (2,125 kg) unfueled orbiter alone
Orbiter science instruments: composite infrared spectrometer, imaging system, ultraviolet imaging spectrograph, visual and infrared mapping spectrometer, imaging radar, radio science, plasma spectrometer, cosmic dust analyzer, ion and neutral mass spectrometer, magnetometer, magnetospheric imaging instrument, radio and plasma wave science
Power: 885 watts (603 watts at end of mission) from radioisotope thermoelectric generators
Huygens Probe
Dimensions: 8.9 feet (2.7 meters) in diameter
Weight: 705 pounds (320 kg)
Probe science instruments: aerosol collector pyrolyser, descent imager and spectral radiometer, Doppler wind experiment, gas chromatograph and mass spectrometer, atmospheric structure instrument, surface science package
Huygens Probe Titan Release: Dec. 24, 2004
Huygens Probe Titan Descent: Jan. 14, 2005
Huygens' Entry Speed into Titan's Atmosphere: about 12,400 mph (20,000 kph)

7. Mission Events
December 30, 2000: Cassini-Huygens takes a six-month swing by Jupiter to pick up speed for its journey to Saturn and collaborates with NASA's Galileo spacecraft to study the Jovian system.  June 30, 2004: Cassini arrives at Saturn.  December 13, 2004: Cassini-Huygens makes its first flyby of a Saturnian moon, two in fact: Titan and Dione. For a full list of Cassini's flybys since 2004, visit:  December 24, 2004: The Cassini spacecraft releases the European Space Agency-built Huygens probe at Saturn's moon Titan.  January 14, 2005: The Huygens probe makes its descent through Titan's atmosphere to sample the chemical composition and surface properties of the Saturnian moon.  June 2008: Cassini completes its primary mission to explore the Saturn system and begins its mission extension (Cassini Equinox Mission).  September 2010: Cassini completes its extended mission (Cassini Equinox Mission) and begins its second mission extension (Cassini Solstice Mission), which goes through 2017 and will make the first observations of a complete seasonal period for Saturn and its moons. Learn more at 

8. December 2011:Cassini uses its synthetic aperture radar to obtain the highest resolution images yet of Saturn's moon Enceladus.  December 2012: Cassini uses its visual and infrared mapping spectrometer, or VIMS, instrument to track the transit of Venus -- a first for a spacecraft beyond Earth orbit. The exercise is to test the feasibility of using Cassini's VIMS to observe planets outside our solar system.  March 2013: Cassini makes its last flyby of Saturn's moon Rhea, probing the internal structure of the moon by measuring the gravitational pull of Rhea against the spacecraft's steady radio link to NASA's Deep Space Network here on Earth.  July 2013: Cassini images a backlit Saturn to examine the planet's rings in fine detail and captures a pixel-size Earth in the process. In a campaign to raise awareness about the photo shoot, NASA encourages Earthlings to go outside and wave at Saturn.  April 22, 2017: Closest flyby of Titan moon.  April 23, 2017: First Grand Finale orbit begins.  April 26, 2017: First ringplane crossing. NASA's Cassini spacecraft is back in contact with Earth after its successful first-ever dive through the narrow gap between the planet Saturn and its rings.  September 15, 2017: End of Mission as Cassini begins Final Entry into Saturn's Atmosphere.