PASADENA, Calif. — NASA is staunchly defending the science plans for its flagship Mars rover Curiosity in the wake of a recent senior-level review that at times harshly criticized the mission's science operations.

Mission scientists announced Thursday (Sept. 11) that the car-size Curiosity rover has reached the base of Mount Sharp, a 3-mile-high (5 kilometers) mountain rising from the center of the rover's Gale Crater landing site. Curiosity had been driving toward the mountain since it landed on Mars in 2012.

NASA officials lauded the success so far of Curiosity's $2.5 billion mission. However, they also responded to criticism raised in the recent NASA Planetary Senior Review Panel report, which NASA commissioned to help allocate financial resources for seven planetary missions, including Curiosity's Mars exploration. [Biggest Mars Discoveries by Curiosity So Far]