As far I know I am legally permitted to say we went as deep as 800 feet, but the deepest depth does not exceed that by much.
Legally, okay, fine. My understanding is that the current world record for a technical (scuba) dive is over 300 meters deep. I'm pretty sure that a WWII-era submarine has a deeper crush depth than that, not to get into the sort of pressures that a modern submarine could withstand.
Q: Though I have read of deep submergence research vehicles going as deep as 7 miles, how does that compare with (a genuinely unbelieveable) 200,000 miles?
Once you get out into space, moving through space is easy. There's isn't much gravity around to pull you places you don't want to go. There isn't any air to slow you down. Mostly you just get to the speed you want, in the direction you want, and turn of the engines and coast until you need to start worrying about orbital insertions (math for this is pretty simple) and landing.
Just in terms of withstanding the environment: what's so difficult about being in space? Once you've solved the problem of getting there, staying warm and protecting yourself from radiation seem to be the only issues.
If your only evidence is that 200,000 miles is "genuinely unbelievable", then you don't really have any particular reasons for why it
couldn't have been done.
A: There are not any submarines in the sky, but there sure are plenty of aircraft in the sea.
Yes, I have noticed this "falling" that things tend to do once they're not actively keeping themselves from doing so anymore. Fortunately if you do a good enough job of keeping yourself from falling, it eventually becomes no effort at all -- the Earth stops pulling. All you need is enough energy to get into orbit, and having watched Saturn V footage and seen a space shuttle launch, I have little difficulty believing that they provide enough energy. (I read not too long ago that the temperatures inside the solid rocket boosters are high enough to
boil steel..... how badass is that?)
So there are a lot of aircraft in the sea. There's lots of aircraft in the air, too -- just because there have been some failures, doesn't make the task impossible.
You need to address the specific technical difficulties in putting a rocket into space.
Why don't we have the technology? What's required that we lack?