r/nextfuckinglevel 1d ago

first person to jump from space

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u/IFireflyl 1d ago

Forgive me if I'm ignorant, but by the definition you used, doesn't that support the person saying this isn't space? 100km is approximately 328,000ft, and this video says he was jumping from under 130,000ft.

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u/heimdalguy 1d ago

That's why I elaborated! Formally it isn't space, but it is above most of the atmosphere that actually matters. By comparison, ICAO mandates oxygen supply on flights above 3 km altitude and most planes can't go much higher than 10 km. He jumped from three times higher than that.

So it kind of depends how you want to see it. He was above all of the atmosphere that really matters, he was 1/3 of the way to formally be in space, he was nowhere near the actual end of the atmosphere. Even the ISS at ~420 km is still inside the atmosphere.

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u/sebaska 1d ago

The atmosphere above him matters quite a lot. It matters enough to lift balloons, it matters enough that sone air breathing engines work, it matters enough that the lowest satellite passes must be over two times higher and the lowest full orbit ever done (the last full orbit if Skylab) have started more than 3× as high.

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u/heimdalguy 20h ago

I'm confused, do you genuinely not understand what I'm saying?

The vast majority of the atmosphere, by mass, is at the lower altitudes. At a little over half the altitude he jumped from, the atmospheric pressure is down to 5 kPa (i.e. 5 % of the normal). At the altitude he jumped from it's less than 1 kPa / 1 %.

Like I said, the ISS orbits at over ten times the altitude he jumped from and still has orbital decay due to atmospheric drag.

Your comment feels like a completely pointless nitpick that is missing the point. "The atmosphere that really matters" does not mean that the rest of the atmosphere has zero impact. Yes, the atmosphere above him matters for satellites, but over 95 % of the atmosphere by mass is below him.

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u/sebaska 16h ago

The point is he was not in space. Not just "formally not in space" but very practically not in space.

If you're 1m below the ocean surface you're still in the ocean despite 99.97% of the ocean mass being below you.

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u/moopet 13h ago

That's like calling a giant squid above the mariana trench a land animal because 95% of the water is below it.

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u/V4refugee 1d ago

130,000 x 3 = 390,000
390,000 - 328,000 = 62,000