NASA’s Kepler spacecraft was launched in March 2009 aboard a Delta II rocket from Cape Canaveral Air Force Station. Kepler’s mission is to monitor the brightness of more than 100,000 stars in a single region of the sky for at least three years.
While ground-based telescopes and orbiting spacecraft can provide many kinds of new information, different insights are possible when physically present on other bodies in the Solar System. A number of spacecraft have touched down and explored the surface of other worlds, from the human Apollo landings more than 40 years ago to the robotic Mars rovers, Spirit and Opportunity.
Space surface systems are designed to operate on planets and other extraterrestrial bodies including the Moon, asteroids, and comets. Two well-known examples of these surface systems are the NASA Mars Exploration Rovers, Spirit and Opportunity. The rovers landed on Mars in January 2004 for a planned 90-day mission.
There are ## scientific satellites in orbit around Earth, as designated by the AGI satellite database. This number may vary slightly by source, as some satellites may be alternatively classified as either “scientific” or “remote sensing.”
Surface systems include all systems that operate on the surface of an asteroid, comet, or planet other than Earth, for instance, NASA’s Mars Rovers, Spirit and Opportunity. The planned 90-day mission for these vehicles has lasted for 45 months, greatly increasing scientific knowledge of Mars.
Currently, ## scientific satellites are in orbit around the Earth. These satellites address a wide array of scientific issues. For example, NASA characterizes scientific satellites by the following types: astronomy, earth science, planetary science, solar physics, space physics, life science, and microgravity.
Surface systems are those systems that operate on the surface of a planet. Current operational surface systems include the NASA Jet Propulsion Laboratory (JPL) Mars Rovers, Spirit and Opportunity. These robots were launched in June and July 2003, with the purpose of understanding the history of water on Mars.