Tim,

If the bubble is 1.5m (5') diameter it could accommodate an adult human in a near lotus position.

Surface area is 4 x pi x (0.75)^2   or about 7 square metres.

Assuming space blanket like thickness (mylar emergency blankets) the collapsed package is going to be phablet sized.

I'd regard this as the lower bound of size given material requirements. This also ignores a pressurisation system and gas supply.

Computing/recording/locator beacon capacity is strongly tech level dependent.

Rob O'Connor
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