When is the earliest possible manned spaceflight?

I bolded the parts that taken together, make it impossible. A shell that can hold the atmosphere at the surface out will not be too light, and it will be on the edge of catastrophic failure (ie, crumpling).

Yeah, I know. It'd have to have a PoD after 2900 for the material technology to even catch up.
 
I had hoped that it was obvious what I thought of the concept by what I wrote; apparently not.
Oh I'd spotted it alright, but Archytas is still around isn't he?

A manned one, that's what kind. 1930s electronics wasn't reliable enough to send up an automated thing and expect it to keep working for years. Also it was power-hungry, and fragile too.
Well it doesn't need to work for years, only months or even weeks, and it doesn't have to work usefully, provided it's transmitting radio pulses it will be enough to convince people (and governments) that such things are possible. Also, a manned satellite will have even more valves, due to having to deal with life-support, and controls and the like.
 
Absolutely no way could they do it with 1940s tech, and if they could they'd be much better advised to take it straight to orbit and forget all this skipping on the atmosphere stuff. They'll need to carry enough fuel to attain full orbit anyway, best to use it once instead of rationing it out in penny packets!

It in no way represents a simplification or a quick dirty approach to space travel. If our stunt pilot record hunters want to just say they went up 200 kilometers, best they hitch a ride on a V-2 and carry a parachute, just like the BIS proposal upthread.

Indeed. American hypersonics proponents looked at the idea (the skip-reentry one) in the '50s, I believe it was, and threw it away because it just didn't work compared to a strictly ballistic or all-lift trajectory (forgive me for being unspecific, I don't have my reference books on me now).

MattII said:
Well it doesn't need to work for years, only months or even weeks, and it doesn't have to work usefully, provided it's transmitting radio pulses it will be enough to convince people (and governments) that such things are possible. Also, a manned satellite will have even more valves, due to having to deal with life-support, and controls and the like.

Two things here:

1: Why would you launch a communication satellite that worked off a battery? For anything more complex than Spunik's beeping, it's going to die in days, and if you want something that lasts longer, you're going to need a constant source of power. Ain't no RTGs or solar cells around back then. Any power source is going to be *big*; so big that putting some people up on it just isn't that big a deal.

2: Crewed satellites can replace valves. Big advantage here! It's the reason early thinkers figured on big stations way back when rather than little satellites. There is also, as I mentioned above, the fact that the smallest practical power system prior to the development of RTGs and solar cells was the mercury boiler, or similar solar thermodynamic units, which are naturally quite large and heavy.

It is also astonishing that you simply keep ignoring the entire idea behind the thread and appear to think it means what's the earliest *post-Sputnik* time someone can launch someone into "space". It is far easier to put someone on a ballistic trajectory than to launch any orbital object (indeed, the Soviets were doing very nearly that, only with dogs and dummies instead of people, several years before they were even capable of launching a satellite), so if someone was simply interested in one-off prestige stunts it would make far more sense to do a simple ballistic flight than try to launch a satellite. The reason this wasn't done IOTL is that none of the early flights *actually were* one-off prestige stunts; the spysat program, the IGY, showing off what your missiles could do (which is similar but not identical to a prestige stunt), all those interacted to make satellite launches get the funding. Doesn't have to be that way ITTL.
 
1: Why would you launch a communication satellite that worked off a battery? For anything more complex than Spunik's beeping, it's going to die in days, and if you want something that lasts longer, you're going to need a constant source of power. Ain't no RTGs or solar cells around back then. Any power source is going to be *big*; so big that putting some people up on it just isn't that big a deal.
The first satellites aren't going to be for communications, they're going to be for working out stable orbits (starting at say 100 km and working up).

2: Crewed satellites can replace valves. Big advantage here! It's the reason early thinkers figured on big stations way back when rather than little satellites. There is also, as I mentioned above, the fact that the smallest practical power system prior to the development of RTGs and solar cells was the mercury boiler, or similar solar thermodynamic units, which are naturally quite large and heavy.
Yes, that's once you figure out all the little kinks that

It is also astonishing that you simply keep ignoring the entire idea behind the thread and appear to think it means what's the earliest *post-Sputnik* time someone can launch someone into "space". It is far easier to put someone on a ballistic trajectory than to launch any orbital object (indeed, the Soviets were doing very nearly that, only with dogs and dummies instead of people, several years before they were even capable of launching a satellite), so if someone was simply interested in one-off prestige stunts it would make far more sense to do a simple ballistic flight than try to launch a satellite.
A ballistic trajectory is all very well and good, but to get to space, you first have to figure out precisely where space starts, I mean it'd do you a fat lot of good launching a rocket to an altitude of say 90 km, and then finding later that any satellite at that height breaks up within a few days or weeks.
 
Now, if you're talking sheer technical possibility, money is no object and what not (like, say, Vorlons showed up and ordered humans to launch someone into space ASAP, even suborbit being fine)...well, it's hard to tell.

Not exactly Vorlons but this might do it:

See this link: http://en.wikipedia.org/wiki/Tunguska_event

OTL: At 7.17 am on 30 June 1908 a small comet impacted at 60°55′N 101°57′E, near the Podkamennaya (Stony) Tunguska River in what is now Evenkia, Siberia, and obliterated a big area of pine forest and killed some reindeer.

AOL: At about 22.30 pm on 29 June 1908 a small comet impacted at 50°55′N 0°E, in England, and obliterated London.

from:
http://en.alternatehistory.com/discussion/showthread.php?t=32020
 
Top