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Web sources for some current and recent planetary space missions.

AKATSUKI: This Japanese Venus orbiter was launched in 2010, failed to orbit the planet as planned later that year, but managed to get into orbit in late 2015. It is now studying Venus.

Akatsuki (Planet-C) homepage:

CASSINI: After nearly seven years of interplanetary travel, the Cassini spacecraft went into orbit around Saturn for a multi-year mission on July 1 of 2004. Seven months later it dropped the Huygens probe built by the European Space Agency, which made the first-ever landing on the big mystery moon Titan.  Cassini has been studying the planet, its rings and its moons, and recently detected ongoing volcanic activity on the small moon Enceladus.  The large moon Titan, which appears to have an active methane hydrology, will be a continuing focus of the orbiter which is now in an extended mission with a planned end in 2017.

Cassini homepage:

Raw images:

CURIOSITY: The largest rover yet to land on Mars began exploration August 2012 in the huge Gale Crater armed with a battery of innovative scientific equipment.  This NASA mission didn't take long to make the discovery that conglomerate is present on the crater floor, which requires sustained and active water-mediated erosion and deposition.  The rover is currently working its way up the base of the huge central peak of the crater, climbing the layered rocks exposed there.

Curiosity (Mars Science Lander) homepage:

DAWN: This mission to the asteroid belt uses an efficient ion propulsion system to send an orbiter around Vesta in 2011 for about 11 months and around Ceres in 2015.. The new ion propulsion system allows the possibility of multiple orbit targets.  Vesta and Ceres are the third largest and largest asteroids respectively but are very different: Ceres is icy and has a relatively dark surface; Vesta is dry, has basaltic and other igneous rocks on the surface, and is relatively bright.

Dawn homepage:

DEEP IMPACT:  It sounds like a movie, but actually the hollywood folks stole this name from a real NASA mission.  On July 4, 2005, part of the DI probe rammed at high velocity into comet Tempel 1, while the other part flew by to observe and analyze the pyrotechnics.   This mission provided a good experiment to try to understand what comets are made of.  In case you are wondering, the July 4 impact date had everything to do with the holiday of the nation that funded this mission.

Deep Impact home page:

The DI flyby spacecraft was repurposed for a flyby of comet Hartley 2 (which occurred in November, 2010) and for observations of some transiting extrasolar planets.  The mission was renamed EPOXI.

EPOXI home page:

ExoMars2016: This joint European-Russian (ESA-RSO) mission consists of an orbiter-lander combination that arrived at Mars in 2016. The Trace Gas Orbiter went into orbit as planned to study the martian atmosphere, but contact was lost with the experimental Schiaparrelli lander as it descended to the Red Planet.

ESA robotic exploration of Mars home page:

GRAIL: Two spacecraft- named Ebb and Flow-- flew in formation around the Moon in 2012 and precisely measured small changes in velocity between them.  This provided information about the gravity field of, and mass distribution within, the Moon.

GRAIL homepage:

Additional images are available at:

KEPLER: This mission to find explanets uses a photometer to search for variations in light emissions of stars that are experiencing planetary transits (planets moving in front of the disk of the star and dimming the light).  It was launched March. 6, 2009 for an anticipated 4 year mission, but is continuiing studies as part of the "K2" mission.  Kepler has found many exoplanets, which is leading to a reassessment of how planetary systems form and evolve.

Kepler homepage:

JUNO: This orbiter of Jupiter arrived in 2016 to study the gravitational and magnetic fields and atmosphere of the solar system's largest planet, including its composition. On it's highly elliptical polar orbit, the solar-powered spacecraft skims only 5000 km from the cloud tops, avoiding the worst of Jupiter's strong radiation belt.  36 orbits are planned before a deorbit manuever. 

Juno homepage:

LUNAR RECONNAISANCE ORBITER: This orbiter launched in June 2009 to obtain high-resolution images and to map the topography, temperature, and H content of the lunar surface.  A companion spacecraft, LCROSS, crashed into a shadowed area near the south pole of the moon in October 2009, kicking up a plume that confirmed the presence of water ice there.

LRO homepage:

LRO image gallery:

MARS EXPLORATION ROVERS: In January of 2004, twin rovers touched down at separate equatorial locations on Mars to search for signs of liquid water activity in Mars' distant past.  Opportunity is still operational, but Spirit became stuck in sand and lost contact with Earth during the martian winter after power levels dropped below a threshold value.

Main page:

Raw image postings (there are some gems here, but you have to sift through tens of thousands of images to find them):

MARS EXPRESS: The European Space Agency in December of 2003 inserted a spacecraft in orbit around Mars.  Just before reaching Mars, it dropped a small British lander called the Beagle 2, which was never heard from again.  Meanwhile, the orbiter is completely functional and returning much useful data.

Mars Express home page:

MARS ODYSSEY: This NASA orbiter reached Mars in October, 2001.  It has finished its primary mission, but is continuing to chemically map the surface and finding lots of subsurface water ice.  The MO orbiter has also served as the main communication relay to the MER rovers.

Mars Odyssey homepage:

Images can be viewed at:

MARS RECONNAISSANCE ORBITER:  This latest of a series of NASA missions to Mars arrived at the Red Planet in 2006.   It has the highest-resolution imager ever sent into Mars' orbit, sufficient to discern boulders or landers on the surface and to directly characterize the roughness of potential landing sites.

MRO homepage:

On-line image viewer for high-resolution images:

MESSENGER:  This NASA spacecraft went into orbit around Mercury in March 2011. But to slow down sufficiently, MESSENGER had to first flyby Earth once, Venus twice, and Mercury three times.  MESSENGER is only our second spacecraft visit to Mercury, after Mariner 10 in the 1970s. After completing its mission in April 2015, MESSENGER was crashed into the planet.

MESSENGER home page:

NEW HORIZONS:  This mission to Pluto and one or more Kuiper belt objects was launched in January of 2006. It flew by Jupiter in March 2007 to gain speed, getting some bonus science results. It flew through the Pluto system in July 2015, gathering much data quickly.  It is now en route to fly by Kuiper belt object KBO-2014 MU69 in 2019.

New Horizons homepage:

OSIRIS-REx:  This mission to near Earth asteroid Bennu launched September 2016 on a seven-year mission to study the asteroid and return a sample to Earth. The mission's goals are to better understand asteroids in general, including whether they contain organic compounds that could have been used as a precursor to life, to refine models about impact hazards on Earth and how to protect Earth from them, and whether they contain useful resources. 

OSIRIS-REx homepage:

PHOENIX: This mission to the martian arctic (latitude 68 N) followed in the footsteps of the Mars Polar Lander, which crashed on Mars in 1999, and the Mars 2001 Surveyor, which was cancelled. This time the mission proceeded to a successful landing in 2008.  Phoenix dug into the subsurface and analyzed the chemical, physical, and thermal properties of the confirmed icy soil. Included among the instrument suite were optical and atomic force microscopes that  imaged collected soil at unprecedented small scales.

Phoenix NASA missions homepage:

Phoenix University of Arizona homepage:

ROSETTA: This European Space Agency mission provided the first extended investigation of a comet.  Launched in 2004, Rosetta flew by Earth 3 times and Mars 1 time to gain speed, and to obtain bonus science it flew by asteroid Steins in September 2008 and Lutetia in July 2010. Rosetta arrived at target comet 67P/Churyumov-Gerasimenko in 2014, dropped a lander to the surface (Philae), and after much reconnoitering of 67P/C-K, itself was sent to the surface of the nucleus in 2016, deactivating just before touchdown.  

ROSETTA homepage:

STARDUST: On Jan. 2 of 2004 the Stardust spacecraft flew through the cloud of dust and gas surrounding comet Wild 2, collecting particles which were returned to Earth in January, 2006.  As planned, only tiny bits of material were returned, but that's all we need to learn a lot about what comets are made of.  Stardust was the first space mission to retieve extraterrestrial material from a planetary body since 1976, when a Russian lander brought back soil from the moon.  Research continues on the material that has been returned.

Stardust home page:

STARDUST-NEXT: The carrier spacecraft for Stardust is now enroute for a flyby of comet Tempel 1, the same comet investigated by Deep Impact (above).  The flyby is scheduled for February, 2011.

Stardust-next homepage:

VENUS EXPRESS:  Following in the footsteps of Mars Express, this European Space Agency (ESA) spacecraft went into orbit around Venus in 2006.   It has instruments for measuring the magnetic field and plasma environment around Venus, spectrometers for measuring the temperature and composition of the atmosphere, and a multispectral camera for studying cloud structures.

Venus Express homepage:

Venus Express images:

Page last updated October 20, 2016