"NASA is in the final stages of preparing the Perseverance rover for its trip to
the red planet, which could begin anytime between July 17th and August 5th if
everything goes as planned. Over the past week, the team assembled the machine,
tested what needed to be tested and filled its tanks with fuel. They also attached
the Mars Helicopter and its delivery system onto the rover’s belly, making sure
it’s ready to fly in Martian skies and pave the way for future space unmanned
aerial vehicles.

Last year, the agency proved that its space chopper can fly in Martian conditions
when it tested the 4-pound vehicle in JPL's Space Simulator. The team replicated
the Martian atmosphere and gravity inside the vacuum cylinder, where the
helicopter was able to hover around 2 inches above the ground. Next time the
helicopter flies, it’ll be on Mars."

See:

https://www.engadget.com/nasa-mars-h...192754688.html