Could entry of Mars with balloons work by inflating to equalize with the atmopheric air pressure while establishing buoyancy before meeting the ground?

Would a balloon pop if dropped from space?

enter image description here https://www.newscientist.com/article/dn10288-inflatable-cushions-to-act-as-spacecraft-heat-shields/

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Blimp on Earth, but a glider on Mars?

When the blimp achieves terminal velocity the heat shield is dropped to increase buoyancy.

  • $\begingroup$ You would need helium gas for inflation. But high pressure tanks with helium would be too heavy for a balloon. $\endgroup$ – Uwe Jan 8 at 20:47
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    $\begingroup$ @Uwe After the balloon is active, the tanks can be dropped. I think parachute would be still needed in the subsonic part of the arrival, to decelerate the probe to a feasible speed to activate the balloon. Also the parachute can be dropped after the baloon is active, it might be non-trivial to do safely. The major problem I see, that the Martian athmospheric pressure is around 2% of the Earth, and so decreases also the lift the baloon can provide. $\endgroup$ – peterh Jan 9 at 4:30
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    $\begingroup$ @Uwe what about hydrogen? It could be liberated chemically so wouldn't require extreme pressurization. It only needs to stay inside the balloon for a short time so diffusion may not be a problem, and there's no oxygen for combustion. $\endgroup$ – uhoh Jan 9 at 4:56
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    $\begingroup$ Generating it chemically doesn't need a pressure vessel. Re-compressing it takes a huge amount of work and requires big, heavy tanks perhaps. $\endgroup$ – uhoh Jan 9 at 5:38
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    $\begingroup$ Tangentally related XKCD what-if.xkcd.com/62 . His summation at the bottom does have bearing on effectiveness of balloons as high drag devices though $\endgroup$ – GremlinWranger Jan 9 at 10:02

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