NASA successfully delivered a $2.5 billion robotic vehicle to Mars, one that will explore for signs that the planet might once have hosted life.The first stage is “an amazing achievement,” observes Charles Bolden runs the National Aeronautics and Space Administration, or NASA, which built and delivered the vehicle to Mars.NASA named the robotic cruiser Curiosity.The six-wheeled all-terrain vehicle weighs 900 kilograms. Roughly 2.8 meters long, it carries 10 research instruments. A towering peak — Mount Sharp — rises from the center of this basin 150 kilometers (93 miles) wide. Curiosity will spend two years motoring around and exploring the crater floor. The rover will be powered by energy given off by the decay of plutonium, a radioactive element. Curiosity was the first Mars rover that would parachute down through the atmosphere, landing only on its wheels. The spacecraft initially zoomed toward the Red Planet at about 12,875 kilometers per hour. The outside of the spacecraft heated intensely as it zoomed through this atmosphere. Another onboard device can drill into rock, pulverizing it into a fine powder for the rover’s chemical samplers to taste.