Sounds like an improbable mix of Hindenburg Zeppelin and Bigelow modules. Wait... It just dawned on me. If a BA330 or BA2100 was filled with breathable air and dropped inside Venus atmosphere, would it FLOAT, the damn thing ???!!!

In short - yes. They would float, and even float at the altitude, when the pressure and temperature are close enough to Earth. Albeit I would prefer something like Cloud Nine tensegrity sphere.
 
On lifting from any aerostat platform back into orbit, launching/releasing conventional rocket powered transports would seem fraught. Thinking about those mining proposals and potential engineering challenges using tethered scoops to the surface. Has any thought been given, to have tethers to higher orbiting platforms? There has always been those earth to space cable ride proposals. How much would such a lesser distance tethered ride pose from any Venus atmosphere buoyant platform to the some higher orbital station?
 
Well from the moment a floating city or venus balloon can lift 20 mt to 200 mt, then it can lift an orbital launch vehicle.
Black Arrow for the smallest satellite launch vehicle, but manned craft needs at least 3 mt (think Gemini) which translates as a 100 - 300 mt booster.
Then again, since Landis is telling us a 1-km wide balloon could lift 700 000 mt... plenty enough for chemical rockets. Heck, plenty enough for a nuclear pulse Orion.
 
Black Arrow for the smallest satellite launch vehicle, but manned craft needs at least 3 mt (think Gemini) which translates as a 100 - 300 mt booster.

Nah. You are making a mistake here: manned surface-to-orbit craft that did not need to LAND, would be much lighter than Gemini. Simply because it does not need to have heat shield, or survive the re-entry forces. It could ride out of atmosphere under the rocket's fairing, which would then just be detached. It could be made very-very lightweight and compact, maybe even without proper life support system (if it would meet with orbiting spaceship fast enough, we could just put crew into spacesuits, and use their own life support).

Essentially what you need to took off from Venus to orbit - is small, solid-fueled booster, like, for example, original Minotaur-I rocket (which weighted about 36 tons and was able to boost 0,5 ton to orbit). Such small booster could be delivered from Earth in launch container, equipped with heat shield & use parachutes and propulsive landing to dock with the floating base. When the crew would need to return to orbit, they would board the launch capsule on top of the booster & use it to boost themselves to the orbit - where they would meet the orbiting return spacecraft.
 
Black Arrow for the smallest satellite launch vehicle, but manned craft needs at least 3 mt (think Gemini) which translates as a 100 - 300 mt booster.

Nah. You are making a mistake here: manned surface-to-orbit craft that did not need to LAND, would be much lighter than Gemini. Simply because it does not need to have heat shield, or survive the re-entry forces. It could ride out of atmosphere under the rocket's fairing, which would then just be detached. It could be made very-very lightweight and compact, maybe even without proper life support system (if it would meet with orbiting spaceship fast enough, we could just put crew into spacesuits, and use their own life support).

Essentially what you need to took off from Venus to orbit - is small, solid-fueled booster, like, for example, original Minotaur-I rocket
No point in anything needed to land. I would want a suicide pill if the rocket didn’t light—- to spare the feeling of being crushed and roasted. At least I could feel high.
 
A balloon containing a cubic meter of breathable air would be capable of hoisting about half a kilogram
So, if we take the late Bigelow BA330 for a start
330 cubic meters divided by two: it could thus lift 165 kg of payload across Venus atmosphere ?

And then was the BA2100 project, so 2100 cubic meters; half of that is 1050 kg, soooo - it could float across Venus atmosphere with a bit more than 1 mt of payload ?

My mind is blown (appropriate word, really LMAO).

In passing, it may be possible to mix helium & air modules, all of them BA2100s.
For example: three BA2100, two of them filled with helium and one with air, could lift 2250 + 2250 + 1125 = 5625 kg across Venus atmosphere.
Some record durations according to weight
- Gemini: 14 days, 3800 kg, two men
- Apollo: 11 days, 30 000 kg, three men
- Soyuz: 18 days, 7000 kg, three men (they ended in very poor shape, however)

Or maybe we could hang a 19 800 kg Salyut there, and get a 237 days mission duration.

Endless possibilities...
 
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No point in anything needed to land. I would want a suicide pill if the rocket didn’t light—- to spare the feeling of being crushed and roasted. At least I could feel high.
Essentially yes, if the rocket failed, there would be no capability of crash-landing safely. Maybe on Mars, but definitely not on Venus. So, we could keep the takeoff capsule very-very light, and therefore use a pretty compact rocket to haul it on the Venus orbit.

P.S. In pure theory, we could try to combine some kind of inflatable heat shield, parachute and baloon, so even in case of failed launch the crew would be able to stay in Venus upper atmosphere... But what the point, since there would be no one to rescue them in time? Hovewer, such "survival kits" may be practical after a permanent skybases over Venus would be established - and there would be the ability to send rescue drone to catch the baloons and haul unfortunate astronauts to safety.
 
Or maybe we could hang a 19 800 kg Salyut there, and get a 237 days mission duration.

Endless possibilities...
Yep, it seems that it's actually pretty possible to put an aerostatic base over Venus. Must point out -

- Gemini: 14 days, 3800 kg, two men
- Apollo: 11 days, 30 000 kg, three men
- Soyuz: 18 days, 7000 kg, three men (they ended in very poor shape, however)
- that those calculations refer to vaccum spacecraft. On Venus, there would be atmosphere around (non-breathable, but still), making a lot of things much easier. The habitable module could be made of lightweight materials, since its walls did not need to compensate for internal pressure only by themselves.

P.S. You need to add about 30-40 tons for return rockets, though.
 
A bit more information. The "Vega" (Venus-Galileo) balloons were roughly spherical form, 3.4 meters in diameter - about 20-21 cubic meters volume, filled with helium. The total weight of the whole assembly was 21 kg - counting the envelope, gondola and scientific equipment inside. So, circa 1 kg of lifting force per 1 cubic meter of helium on 54-60 km altitude.
 
Yeah, that return rocket is the main issue. Venus being just a little smaller than Earth, I wanted to know its "low orbit, 300 km high orbital delta-v." I managed (at least) to find low Venus orbit numbers and compare them to Earth's. Couple of "Venus sample return" papers provided the numbers (attached).
Well, seems they are only 600 m/s apart.
ISS orbital velocity, 300 km+ around Earth: 7700 m/s
Low Venus orbit, also 300 km: 7100 m/s

As for the ascent losses (drag - gravity - steering) they seems pretty similar, in a 1500 m/s ballpark. Which is hardly surprising, as the gravity pull are almost similar (for gravity losses) while Venus atmosphere 50 km high is almost Earth-like (for drag losses). And steering losses are the smallest of the three.

So Venus being a touch smaller than Earth helps, but only a little... so that "return rocket" will have to be multistage rather than SSTO. Damn you, Venus.

What is pretty interesting is that I can now compare Earth, Venus, Mars and Moon surface-to-orbit ascent delta-v.
Takes 9400 m/s for Earth, 8800-something for Venus, 4200 m/s for Mars and 2400 m/s for the Moon.

As for escape velocities, from the surface
- Earth 11.2 km/s
- Venus 10.4 km/s
- Mars 5 km/s
- Moon: 2.4 km/s

Chemical rockets, single-stage are on their knees (0.80 mass fraction) around 6500 m/s. Bottom line: as far as SSTO is concerned, Musk was right saying we are living on the wrong planet. Earth, NO, Venus, NO better, Mars, YES, Moon - hell, YES.
 

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So Venus being a touch smaller than Earth helps, but only a little... so that "return rocket" will have to be multistage rather than SSTO. Damn you, Venus.
Essentially yes. And considering that such rocket must survive re-entry from orbital, or even interplanetary speed in workable condition - I suppose, the solid-fuel one is the only real solution. Liquid-fuel rocket have too many potential points of failure, while solid-fuel rocket could be made extremely durable.
 
if i remember right HAVOC use Solids to get crew back to Venus Orbit

there were other proposals using chemicals that are hypergolic with carbondioxide
even Nuclear Ramjet lucky that was for a unmanned probe
 
Could HAVOK actuaIly be a LOFTID ballute in its own right? Or be wrapped in one tethered down as a keel-heater? I'd like to pre deploy as much as possible with starkicker just shoving it towards Venus in toto.
 
Makes some sense, since Venus screws SSTO - reusable or not - much like Earth, then might as well go multistage. And from there, two-stage solid is good enough - and less complex and fragile.
 
Mogul balloon chains? I was thinking the sunlight might allow a statite-tether set up...could you get away with two such tether statites with lines that form an X. The two statites tack towards/away from each other to scissor payloads up and down?
 

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