I saw the space jump where some one skydiver jumped from a weather balloon. He reached over the speed of sound before the air became dense enough to slow him down to a safe speed to use a parachute.

Could a human hamsterball-like balloon be built with enough surface area and streamer to serve as a parachute?

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We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.

closed as off-topic by Ralph J, J Walters, fooot, Daniel Kiracofe, Gerry Sep 19 '18 at 13:23

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question does not appear to be about aviation, within the scope defined in the help center." – Ralph J, J Walters, fooot, Daniel Kiracofe, Gerry
If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ This new question is still WILDLY off topic for Av.SE and needs to be deleted rather than re-opened. Maybe Space.SE or Worldbuilding.SE will take this sort of question. It does not belong here. $\endgroup$ – Ralph J May 20 '18 at 0:02
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    $\begingroup$ I have a problem with your edit. It renders the old answer invalid. This is quite a no-no on SE. You should edit your question without making the given answers invalid. $\endgroup$ – Federico Sep 11 '18 at 7:33

Contrary to some of the comments, the problem with this would not be in containing the helium. That part is easy, and there are plenty of high-tech fabrics that can easily withstand the sort of differential pressures that would be encountered. Doing that while also changing volume could be an interesting project, but should be entirely manageable.

The big problem will be the heating. In the case of the parachutist who jumped from a balloon, he started at altitude with essentially zero velocity (horizontal nor vertical), and gained speed as he fell through the atmosphere, reaching Mach 1 briefly. There would certainly be some significant aerodynamic heating encountered at those speeds, but nothing approaching the Mach 25 speeds that the shuttle reaches on re-entry that get the tiles glowing orange.

The difference in the two cases is the fact that the shuttle was orbiting, which has some very serious horizontal velocity (between 7 and 8 km/second, roughly 28,000 kph), while the parachutist didn't. So unless your spacecraft can essentially kill all its horizontal velocity while still in space (good luck -- that would need a huge amount of fuel burned pretty rapidly in order to null out your velocity before falling into the atmosphere & beginning re-entry), you're going to be dealing with the horizontal velocity causing you more heating than your balloon is going to be able to cope with.

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    $\begingroup$ While it clarifies a lot the matter and where the problems are, it departs from the OP's assumption: Making contact with first molecules at the "speed of sound". I don't know how to understand this speed that is likely to be about null, but anyway it's in theory possible, e.g. by carefully determining an orbit around another body, with its apogee on Earth side, and using gravity assist to cancel apogee velocity exactly at the desired altitude. $\endgroup$ – mins Nov 18 '16 at 7:29
  • $\begingroup$ No, this question should not be edited into re-open-able. $\endgroup$ – Ralph J Sep 10 '18 at 1:41
  • $\begingroup$ i edited it. I am trying to bring the question in scope without invalidating any answers so I can one day ask again. $\endgroup$ – Muze Sep 17 '18 at 22:24
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    $\begingroup$ This question is now on version # 15 and is still off-topic. I spent the time to give an answer to the question as it was back on version 1 or 2 or whatever it was on two years ago, and this answer doesn't look very responsive to the question in its current form. That's less a function of an answer that was written only tangentially addressing the question as asked, and much more a function of the moving target this question has become. $\endgroup$ – Ralph J Sep 18 '18 at 0:30

The OPs question is stated in the context of a human carried to very high altitude by a balloon, not a human in orbit. SpaceShip One and Two are other examples of vehicles which rise through the atmosphere and then descend, without adding horizontal velocity needed for orbit. The human, the SpaceShips and the proposed blimp start at zero speed relative to the air mass they rise through, meaning they have the rotational speed of the airmass above the earth.

Presumably the blimp would be lifted by a truly enormous balloon, but would not necessarily be a Goodyear vehicle. The proposal is for a lighter-than-air craft with the lifting part shaped by differential pressure and containing both helium bag(s) and plain air bag(s) within its envelope.

Pressure could be bled down from the air supported part and the helium lifting bag(s) as the vehicle rises, maintaining whatever differential is needed to provide shape. Helium for reinflation during descent could be carried in external tanks which are dropped (with parachutes) after being emptied during descent.

Could the vehicle described exceed the speed of sound as it fell through the upper atmosphere, as a human jumper did? Remember that the falling SpaceShips exceeded Mach 1 while never getting past 350 knots indicated airspeed. That's a heck of a blimp, but need not be inflated to full size during that phase of the descent. A 'reefed' blimp might succeed in exceeding the speed of sound during descent, but an inflated one is unlikely to get going that fast. Remember that a blimp is only lighter than air at and below a ceiling, so it must free-fall if above that ceiling...

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    $\begingroup$ This isn't so much an answer as it is a response to the answer by Ralph J. I know it's a bit long to be a comment...but it would be better served as one if you could shorten this up and put it there. $\endgroup$ – Jay Carr Nov 18 '16 at 18:57

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