NASA has had many successful space missions and programs, including over 150 manned missions. Many of the notable manned missions were from the Apollo program, a sequence of missions to the Moon which included the achievement of the first man to walk on the Moon, during Apollo 11. The Space Shuttle program has also been a success,[citation needed] despite the loss of two of the Space Shuttles, Challenger and Columbia which resulted in the deaths of their entire crews. The Space Shuttles were able to dock with the space station Mir while it was operational, and are now able to dock with the International Space Station – a joint project of many space agencies. NASA's future plans for space exploration are with the Project Constellation.
There have been many unmanned NASA space missions as well, including at least one that visited each of the other seven planets in our Solar System, and four missions (Pioneer 10, Pioneer 11, Voyager 1, and Voyager 2) that have left our solar system. There has been much recent success with the missions to Mars, including the Mars Exploration Rovers, the Mars Reconnaissance Orbiter, and the Phoenix Mars Lander. NASA remains the only space agency to have launched space missions to the outer solar system beyond the asteroid belt.
Built entirely by the Jet Propulsion Laboratory (JPL) in Pasadena, California, NASA probes have been continually performing science at Mars since 1997, with at least two orbiters since 2001 and several Mars rovers. The orbiting Mars Odyssey and Mars Reconnaissance Orbiter will continue monitoring the geology and climate of the Red Planet, as well as searching for evidence of past or present water and life, as they have since 2001 and 2006, respectively. If the Mars Global Surveyor spacecraft's nine-year lifetime is typical, these probes will continue to advance our knowledge for years to come. The Mars Exploration Rovers Spirit and Opportunity have been traversing the surface of Mars at Gusev crater and Meridiani Planum since early 2004, and will continue to image and investigate those environments. They have both already operated over seventeen times longer than expected, and remain a promising part of NASA's future. Adding to this flotilla is the Phoenix Mars Lander, which executed a perfect powered touchdown in the northern latitudes of Mars on May 25, 2008 after a 10-month journey of more than 420 million miles.
