NASA's Mars helicopter almost ready for take off

The functional test (50 RPM spin) was executed on the stand in the airlock. This marked the last time the rotor blades will be operated until the rover reaches the Martian surface.

The NASA Mars Helicopter will be the first aircraft to fly on another planet. The twin-rotor, solar-powered helicopter will remain encapsulated after landing, deploying once mission managers determine an acceptable area to conduct test flights.

And from NASA:

The Mars Helicopter is considered a high-risk, high-reward technology demonstration. If the small craft encounters difficulties, the science-gathering of the Mars 2020 mission won't be impacted. If the helicopter does take flight as designed, future Mars missions could enlist second-generation helicopters to add an aerial dimension to their explorations.

"Our job is to prove that autonomous, controlled flight can be executed in the extremely thin Martian atmosphere," said JPL's MiMi Aung, the Mars Helicopter project manager. "Since our helicopter is designed as a flight test of experimental technology, it carries no science instruments. But if we prove powered flight on Mars can work, we look forward to the day when Mars helicopters can play an important role in future explorations of the Red Planet."

Along with investigating difficult-to-reach destinations such as cliffs, caves and deep craters, they could carry small science instruments or act as scouts for human and robotic explorers.