NASA rover attempting most difficult Martian touchdown yet

This image made available by NASA depicts a possible area through which the Mars 2020 Perseverance rover could traverse across Jezero Crater. This mosaic is composed of aligned images from the Context Camera on the Mars Reconnaissance Orbiter. (NASA/JPL-Caltech/USGS via AP)

This illustration provided by NASA depicts the Mars 2020 spacecraft carrying the Perseverance rover as it approaches Mars. Perseverance's $3 billion mission is the first leg in a U.S.-European effort to bring Mars samples to Earth in the next decade. (NASA/JPL-Caltech via AP)

This illustration provided by NASA shows the Perseverance rover, bottom, landing on Mars. Hundreds of critical events must execute perfectly and exactly on time for the rover to land safely on Feb. 18, 2021. Entry, Descent, and Landing, or "EDL," begins when the spacecraft reaches the top of the Martian atmosphere, traveling nearly 12,500 mph (20,000 kph). EDL ends about seven minutes after atmospheric entry, with Perseverance stationary on the Martian surface. (NASA/JPL-Caltech via AP)

In this illustration provided by NASA, the Perseverance rover fires up its descent stage engines as it nears the Martian surface.. This phase of its entry, descent and landing sequence, or EDL, is known as "powered descent." (NASA/JPL-Caltech via AP)

FILE - This July 23, 2019 photo made available by NASA shows the head of the Mars rover Perseverance's remote sensing mast which contains the SuperCam instrument in the large circular opening, two Mastcam-Z imagers in gray boxes, and next to those, the rover's two navigation cameras, at the Jet Propulsion Laboratory in Pasadena, Calif. The robotic vehicle will hunt for rocks containing biological signatures, if they exist. (NASA/JPL-Caltech via AP)

FILE - In this Dec. 17, 2019 photo made available by NASA, engineers watch the first driving test for the Mars 2020 rover, later named "Perseverance," in a clean room at the Jet Propulsion Laboratory in Pasadena, Calif. (J. Krohn/NASA via AP)

This illustration made available by NASA depicts the Ingenuity helicopter on Mars after launching from the Perseverance rover, background left. It will be the first aircraft to attempt controlled flight on another planet. (NASA/JPL-Caltech via AP)