Galileo Missions to JuptierGalileo Missions to Juptier

Craig LieneckCraig Lieneck

Galileo SpacecraftGalileo Spacecraft

One of the most complex One of the most complex robotic spacecraft ever robotic spacecraft ever flown.flown.Consists of two Consists of two spacecrafts:spacecrafts:– Orbiter:Orbiter:

On-orbit mass:On-orbit mass: 2380 Kg 2380 KgPower System:Power System: Radioisotope Radioisotope Thermal Generators (RTGs)Thermal Generators (RTGs)

– Atmospheric Probe:Atmospheric Probe:On-orbit mass:On-orbit mass: 335 Kg 335 KgPower System:Power System: Storage Storage batteries of 580 Wbatteries of 580 W

Mission Goals - ProbeMission Goals - Probe

Determine the chemical composition of the Determine the chemical composition of the Jovian atmosphere. Jovian atmosphere. Characterize the structure of the atmosphere to Characterize the structure of the atmosphere to a depth of at least 10 bars. a depth of at least 10 bars. Investigate the nature of cloud particles and the Investigate the nature of cloud particles and the location and structure of cloud layers. location and structure of cloud layers. Examine the Jovian radiative heat balance. Examine the Jovian radiative heat balance. Study the nature of Jovian lightning activity. Study the nature of Jovian lightning activity. Measure the flux of energetic charged particles Measure the flux of energetic charged particles down to the top of the atmosphere. down to the top of the atmosphere.

Mission Goals - OrbiterMission Goals - Orbiter

Investigate the circulation and dynamics of the Jovian Investigate the circulation and dynamics of the Jovian atmosphere. atmosphere. Study the interaction of the Jovian magnetosphere with Study the interaction of the Jovian magnetosphere with the Galilean satellites.the Galilean satellites.Characterize the morphology, geology, and physical Characterize the morphology, geology, and physical state of the Galilean satellites. state of the Galilean satellites. Investigate the composition and distribution of surface Investigate the composition and distribution of surface minerals on the Galilean satellites.minerals on the Galilean satellites.Determine the gravitational and magnetic fields and Determine the gravitational and magnetic fields and dynamic properties of the Galilean satellites. dynamic properties of the Galilean satellites. Study the atmospheres, ionospheres, and extended Study the atmospheres, ionospheres, and extended gas clouds of the Galilean satellites. gas clouds of the Galilean satellites.

Initial SetbacksInitial Setbacks

Initial Launch Plan:Initial Launch Plan:– May 1986.May 1986.– Carried on Space Shuttle to low-orbit.Carried on Space Shuttle to low-orbit.– Centaur Rockets to Jupiter.Centaur Rockets to Jupiter.

Problems:Problems:– Challenger Disaster occurred in January, 1986.Challenger Disaster occurred in January, 1986.– Centaur Rockets forbidden on Space Shuttle.Centaur Rockets forbidden on Space Shuttle.

The SolutionThe Solution

VEEGA – “Venus-Earth-Earth-Gravity-Assist”VEEGA – “Venus-Earth-Earth-Gravity-Assist”– Galileo to use the gravity of Venus and Earth to boost Galileo to use the gravity of Venus and Earth to boost

to Jupiter.to Jupiter.– Brought spacecraft closer than expected to sun.Brought spacecraft closer than expected to sun.– Kept spacecraft in space longer than expected.Kept spacecraft in space longer than expected.

LiftoffLiftoff

Launched aboard Atlantis Space Shuttle on Launched aboard Atlantis Space Shuttle on October 18, 1989.October 18, 1989.

Tracking GalileoTracking Galileo

Used Deep Space NetworkUsed Deep Space Network

Series of large antennas equally around Earth. Series of large antennas equally around Earth.

VenusVenus

February 19, 1990 February 19, 1990

Galileo flies within Galileo flies within 12,000km of Venus.12,000km of Venus.

Images gave new Images gave new information about information about structure and structure and dynamics of dynamics of atmosphere.atmosphere.

Earth Flyby 1Earth Flyby 1

December 8, 1990December 8, 1990

Flew 960km over Flew 960km over Western Atlantic Western Atlantic Ocean.Ocean.

1000 pictures for an 1000 pictures for an Earth-Rotation movie.Earth-Rotation movie.

Asteroid Belt - 1Asteroid Belt - 1stst Time Time

October 29, 1991October 29, 1991

Encountered Asteroid 951 GaspraEncountered Asteroid 951 Gaspra

Photographed 60% of surface from 5000km.Photographed 60% of surface from 5000km.

Galileo came within 1600km.Galileo came within 1600km.

Earth Flyby 2Earth Flyby 2

December 8, 1992December 8, 1992

Came within 305km.Came within 305km.

Scientists calibrated Scientists calibrated instruments one last instruments one last time.time.

Asteroid Belt – 2Asteroid Belt – 2ndnd Time Time

Encountered Asteroid Encountered Asteroid Ida August 28, 2993Ida August 28, 2993

Twice the size of Twice the size of Gaspra.Gaspra.

Surprise - Found Surprise - Found small moon orbiting small moon orbiting Ida (Dactyl).Ida (Dactyl).

Shoemaker/Levy-9Shoemaker/Levy-9

Galileo observes Galileo observes impact of S/L-9 into impact of S/L-9 into Jupiter in 7/94 Jupiter in 7/94

23 fragments splash 23 fragments splash into Juptier.into Juptier.

Galileo was 240 Galileo was 240 million km away.million km away.

Final Mission - JupiterFinal Mission - Jupiter

7/13/95 – 7/13/95 – Atmospheric Probe Atmospheric Probe released released from spacecraft. from spacecraft.

7/27/95 – 7/27/95 – Orbiter Deflection Manuver Orbiter Deflection Manuver (ODM)(ODM)

10/9/95 – 10/9/95 – Initial descent.Initial descent.

10/11/95 – 10/11/95 – Tape recorder troubles. Tape recorder troubles.

12/7/95 – 12/7/95 – Probe reaches Jupiter’s Probe reaches Jupiter’s atmosphere.atmosphere.

Final Mission - ProbeFinal Mission - Probe

Entered atmosphere at Entered atmosphere at 160,000mph.160,000mph.

Deployed parachute and Deployed parachute and released heat sheild.released heat sheild.

58 minute descent through 95 58 minute descent through 95 miles of Jovian atmosphere.miles of Jovian atmosphere.

Atmosphere drier than earlier Atmosphere drier than earlier predictions. Clouds and predictions. Clouds and lightning observed in distance.lightning observed in distance.

Probe vaporized after Probe vaporized after encountering 450mph winds.encountering 450mph winds.

Final Mission - OrbiterFinal Mission - Orbiter

Originally planned 11 orbits.Originally planned 11 orbits.

First 11 orbits designed for First 11 orbits designed for close-up pictures of moons.close-up pictures of moons.

At same time, measurements At same time, measurements made of Jupiter's made of Jupiter's magnetosphere.magnetosphere.

Final Misson - ExtendedFinal Misson - Extended

Mission extended for GEM – Galileo Europa Mission.Mission extended for GEM – Galileo Europa Mission.– Observed fire, ice, and water on the moon Europa.Observed fire, ice, and water on the moon Europa.

– Supported theory of underground ocean on Europa.Supported theory of underground ocean on Europa.

– Made way through Jupiter’s radiation to observe Lava fountain on Io. Made way through Jupiter’s radiation to observe Lava fountain on Io.

Missions would be extended two more times for further research.Missions would be extended two more times for further research.

Io Europa Ganymede Callisto

ConclusionConclusion

9/21/03 - 9/21/03 - Galileo guided into Jupiter’s dense Galileo guided into Jupiter’s dense atmosphere, destroying the spacecraft. atmosphere, destroying the spacecraft.

Done Done to avoid any impact with Galilean Satellites.to avoid any impact with Galilean Satellites.

Last signal: 12:43:14 PDT.Last signal: 12:43:14 PDT.

Total Distance Traveled: Total Distance Traveled: 4,631,778,000km = about 2.8 billion miles4,631,778,000km = about 2.8 billion miles

Major Accomplishments:Major Accomplishments:– First mission for long-term observation of Jovian system.First mission for long-term observation of Jovian system.– Evidence of liquid layers of saltwater on Europa.Evidence of liquid layers of saltwater on Europa.– Ganymede and Castillo volcanic activity.Ganymede and Castillo volcanic activity.– First observation of asteroid with moon.First observation of asteroid with moon.

ReferencesReferences

http://www.jpl.nasa.gov/galileo/tour/tourtoc.htmlhttp://www.jpl.nasa.gov/galileo/tour/tourtoc.html

http://www.jpl.nasa.gov/galileo/index.htmlhttp://www.jpl.nasa.gov/galileo/index.html