It only takes about 1000 feet to reach terminal velocity from a standing start.
I think it’s doable with existing technology:
Here’s a clip and story about a stuntman doing a high fall onto an airbag - 342 feet onto an airbag 4.5m high, impact speed about 90mph.
To make the math simpler let’s call that 135 feet per second and assume uniform deceleration over the entire height of the airbag which is just about 13.5 feet. If my math is right that works out to 20G for 0.2 seconds. On your back that would be uncomfortable but survivable (people have taken much high G loads for short durations and in worse body positions).
Terminal velocity, as has been noted, is about 120mph in a spread position. So that guy is pretty close to what you’re asking for. Make the airbag a bit taller and this should be quite doable from a physics & survivability standpoint.
For example suppose you want to limit yourself to 10Gs and you’re hitting at 120mph which is right about 60 m/s. It’ll take 0.6 seconds to come to a halt and you’ll travel 18m in that time, so a properly built airbag about 55 feet tall should do the job.
Note that actually being able to pull this off would be tough - you have to hit the airbag in the correct position and most importantly you have to actually be able to hit the thing from 15,000 feet. If you have ever looked out the door of a plane from that altitude you know how tiny things are. I’ve seen film of Dar Robinson doing about a 300 foot jump from a helicopter onto an airbag, camera in the copter, and that airbag, which was the size of a freaking house, looked like a postage stamp.
True. It really doesn’t matter if you’re 5,000 feet or 15,000 feet.
Snow seems to be a good choice, as it has worked for more than one person in a terminal velocity landing. Remember, not only do you have to use the pit o’ stuff to break your fall, you have to later get out of it without drowning or suffocating in the stuff you fell into
The problem with snow is that it has to be on a steep incline. With regard to aerated water, my experience of jacuzzis makes me think that the aeration would push you to the surface.
I wonder if you could survive a fall on Venus (I mean, if the atmosphere wasn’t poisonous and searing hot). The air’s very thick so terminal velocity there might be survivable.
Try the calculation yourself using this tool. Using my SIBMWAG values (Slightly Informed But Mostly Wild-Ass Guess), I get that you’d hit the ground at somewhere between 15 and 25 mph, depending on what you were wearing and your attitude (your orientation in the air, not your mood). So yeah, you might barely live, but you’d be pretty effed up.
However, if you were holding an open umbrella with an area of just 1 square meter (about four feet across), it would slow your descent to an easily-survivable 11mph.
So, if you had Mary Poppins in your spacecraft over Venus, you could kick her chirpy ass out of the airlock and she’d make it to the surface in one piece-- at least until the corrosive atmosphere and intense heat began to sizzle the flesh from her perky bones. See if a spoonful of sugar helps that go down, Mary.