It should be finished this summer, in time for next year’s launch
NASA’s Mars Helicopter — which is exactly what you think it would be — has recently finished another round of important tests and is expected to be integrated with the rover for the Mars 2020 launch this summer. Getting a heavier-than-air craft to fly on Mars is tough because Martian air is much thinner than Earth’s.
Earlier this year, JPL conducted tests of the helicopter in “a simulated Martian environment” that put the helicopter through temperatures as low as minus 130 degrees Fahrenheit and flew it in a vacuum chamber that simulated Martian air — it was also attached to a “motorized lanyard” to help simulate Martian gravity. Some of the testing was to ensure that the Mars Helicopter could survive the conditions it would experience during an actual rocket launch.
The Mars Helicopter is now back at JPL, where it will has already had a new solar panel installed. NASA says that it isn’t putting any science instruments on the helicopter beyond a camera, but that instead it’s a “technology demonstrator” to prove that it’s possible to remotely fly a Martian drone from Earth.
The Mars 2020 mission is still scheduled to launch in July 2020 and arrive on Mars on February 18th, 2021. You cannot go, but you can submit your name to be etched on a silicon chip that will be placed onboard. The main destination for the mission is the Jezero crater, where NASA hopes its rover might find signs of ancient life.