[mattjaynes]

For aviation noobs (like me) wondering how low the balloon would have to be in order for a helicopter to be an option for retrieval:

"The maximum altitude which can be reached during forward flight typically depends on the ability of the engine to breathe the thinner air rather than the rotor's ability to provide lift. Turbine-engine helicopters can reach around 25,000 feet (7,620 meters). But the maximum height at which a helicopter can hover is much lower - a high performance helicopter can hover at 10,400 feet (3,170 meters)."

Source: https://www.virginexperiencedays.co.uk/experience-blog/how-h...

[benhurmarcel]

A helicopter was successfully hovered to land on the Everest though, at 8,848 m (29,029 ft).

https://en.wikipedia.org/wiki/Didier_Delsalle#Mount_Everest_...

[ceejayoz]

(For context, the atmosphere at 65k feet is about 1/5 of Everest.)

[cduzz]

Is the one on mars able to operate with really thin air because mars has less gravity?

A "balloon retrieval bot" using battery powered propulsion, launched by another platform such as a rocket (or another balloon!) might be a fun thing for someone at raytheon to pitch.

[ceejayoz]

Large, much faster blades, and very light construction.

https://en.wikipedia.org/wiki/Ingenuity_(helicopter)

> The planet's atmospheric density is about 1⁄100 that of Earth's at sea level, or about the same as 87,000 ft (27,000 m), an altitude never reached by existing helicopters. This density reduces even more in Martian winters. To keep Ingenuity aloft, its specially shaped blades of enlarged size must rotate between 2400 and 2900 rpm, or about 10 times faster than what is needed on Earth.

[HarHarVeryFunny]

Of course that helps, but the whole design was made for it. It's dual rotors were designed for the environment, and rotate at 2500 rpm+ vs 500rpm for a normal helicopter.

[Tepix]

A remote controlled helicopter/multicopter could perhaps be used to shred the balloon if it can fly high enough.

[BurningFrog]

This is why no one brings down the bodies from Everest.