Launches: August 20 and September 5, 1977
Voyager 1 and 2 flew by Jupiter and Saturn, and Voyager 2 also visited Uranus and Neptune. Both craft are now heading out of our solar system. Voyager 1 is the most distant human-made object in space.
Launch: October 6, 1990
A joint NASA/European Space Agency mission, Ulysses for the first time sent a spacecraft out of the the plane in which Earth and other planets orbit the Sun in order to study the Sun's poles. Ulysses continues to monitor the Sun.
Launches: April 24, 1990; December 2, 1993
These two instruments served as the main camera capturing pictures on NASA's Hubble Space Telescope.
Launch: October 15, 1997
A joint endeavor of NASA, the European Space Agency and the Italian Space Agency, Cassini is conducting an intensive study of Saturn's rings, its moons and magnetosphere.
Launch: February 7, 1999
Stardust successfully flew through the cloud of dust that surrounds the nucleus of comet Wild-2 and gathered a sample of cometary material.
Launch: June 19, 1999
This ocean-observing satellite carries an instrument called a scatterometer, which sends radar pulses to the ocean surface and measures the "backscattered" or echoed radar pulses bounced back to the satellite.
Launch: December 18, 1999
This imaging instrument aboard NASA's Terra satellite is designed to obtain high-resolution global, regional and local views of Earth in 14 color bands.
Launch: December 18, 1999
Carried onboard NASA's Terra satellite, this imaging system collects images from nine widely spaced angles as it glides above Earth.
Launch: December 22, 1999
This satellite is designed to monitor the total amount of the Sun's energy reaching Earth.
First light: March 2001
The Keck Interferometer links two 10-meter (33-foot) telescopes, forming the world's most powerful optical telescope system.
Launch: April 7, 2001
Odyssey is an orbiting spacecraft designed to determine the makeup of the martian surface, to detect water and shallow buried ice, and to study the radiation environment.
Launch: December 7, 2001
This oceanography mission is a follow-up to Topex/Poseidon and will monitor global ocean circulation and monitor events such as El Niño.
Launch: Mar. 17, 2002
This joint U.S.-German mission consists of two spacecraft flying in tandem to measure Earth's gravitational field very precisely.
Launch: May 4, 2002
This instrument onboard NASA's Aqua satellite makes highly accurate measurements of air temperature, humidity, clouds and surface temperatures.
Launch: Apr. 28, 2003
This mission uses ultraviolet wavelengths to measure the history of star formation.
First rover launch: June 10, 2003. Second rover launch: July 7, 2003
Two rovers, working on opposite sides of Mars, successfully completed their primary mission in April 2004. As of November 2004, both rovers are now in extended missions.
Launch: August 25, 2003, ET (August 24 PT)
Formerly known as the Space Infrared Telescope Facility, Spitzer is using infrared technology to study celestial objects that are hidden from view. The mission is part of NASA's Great Observatories Program.
Launch: March 2, 2004
The European Space Agency's Rosetta spacecraft will rendezvous with a comet in 2014. JPL's microwave instrument onboard Rosetta will study gases given off by the comet.
Launch: July 15, 2004
This instrument, which flies aboard NASA's Aura spacecraft, is designed to improve our understanding of ozone.
Launch: July 15, 2004
This instrument onboard NASA's Aura spacecraft is an infrared sensor designed to study Earth's troposphere and look at ozone.
Launch: January 12, 2005
Deep Impact traveled to comet Tempel 1 and deployed an impactor that was essentially "run over" by the nucleus of Tempel 1 on July 4, 2005. The spacecraft is now on a trajectory to fly past Earth in December 2007.
Launch: August 12, 2005NASA's Mars Reconnaissance Orbiter will take the most powerful telescopic camera ever to another planet, plus five other scientific instruments.
Launch: Apr. 28, 2006
CloudSat is the first spacecraft to study clouds on a global basis.