We have always looked out to the universe in wonder, imagining if there could be, or could have ever been, life on other planets. NASA has been taking significant strides toward answering that question in the last 60 years, but the most recent answers come from a car-sized rover on the surface of Mars aptly named Curiosity.
Curiosity's name was selected by a NASA panel following a nationwide student contest. 12-year-old Clara Ma, a sixth-grade student from Kansas, submitted the winning entry. Ma chose the name because she considers curiosity to be an everlasting flame that lives in everyone. She believes it makes people get out of bed and consider what surprises life holds each day, and curiosity is the passion that drives people in their everyday lives.
Curiosity was designed to explore the Gale crater on Mars. Launching from Cape Canaveral on November 26, 2011, officials received a signal on the ground shortly after spacecraft separation. The spacecraft was flying free and headed for Mars after separation from the United Launch Alliance Atlas V rocket that started its journey to the Red Planet. Intensive preparations were done during the 45 days before Curiosity entered the Martian atmosphere, leading up to Curiosity landing on Aeolis Palus inside Gale Crater on August 6, 2012. After an impressive 560 million km (350 million mi) journey, Curiosity landed less than 2.4 km (1.5 mi) from the touchdown target.
The first drive occurred on August 22, 2012. The first drive is a testing phase after landing in which engineers first conduct tests to check that the rover is in a "safe state" and then move it for the first time beyond its original landing zone. Curiosity was moved forward about 15 feet, rotated 120 degrees, and then reversed about 8 feet. Before making the first drive, mission controllers needed to make sure there were no immediate hazards directly beneath Curiosity's wheels. They also needed to deploy the High Gain Antenna, the mast, test communications links, the sampling system, and make a few other checks before sending Curiosity off on its expedition. One of the biggest concerns after landing is stability. Even though Curiosity can handle steep cliffs of up to 50 degrees and has a ground clearance of 60 centimeters, it's impossible to predict down to the last inch where the spacecraft will land. If Curiosity had ended up, say, with one wheel on top of a rock and the others on a slope, engineers would want to know about it and make sure the rover could maneuver successfully to a safer position. This first drive was successful, and Curiosity was then deemed operational.
Curiosity's goals include investigating the Martian climate and geology, assessing whether Gale's selected field site has ever had conditions that were environmentally favorable for microbial life and planetary habitability, all in preparation for human exploration. On June 24, 2014, after Curiosity completed one Martian year — 687 Earth days — it was found that Mars once had favorable environmental conditions for microbial life. The mission objectives evolved to developing predictive models for the preservation process of organic compounds and biomolecules. The region Curiosity is set to explore has been compared to the Four Corners region of the North American west.
On August 6, 2013, Curiosity played "Happy Birthday to You" audibly in honor of the one Earth year mark of its landing on Mars. This was the first time a song was played out loud on the surface of another planet. This birthday celebration was also the first time music was transmitted between two planets. Curiosity's two-year mission was extended indefinitely in December 2012, and NASA celebrated the fifth anniversary of the Curiosity rover landing on August 5, 2017. Curiosity is still operational, and as of November 19, 2020, Curiosity has been on Mars for 2946 sols (3027 Earth days) since landing on August 6, 2012.
