Venusian lander

[kerbiloid]

Why do they ignore a crewed Venus landing?
Yes, 90 atm, 450°C, but so what?

***

One day at 450°C means probably nothing for aluminium tanks and hypergolic fuel.

90 atm mean something only for a low pressure thin envelope like a cabin.
If make a fuel tank like a syringe, with a piston pressing the fuel, then afai-can-see the thin aluminium tank will just withstand a 9 MPa compression, equal from both sides (having strength limit ~200 MPa), while the liquid propellant probably doesn't pay much attention for the 90 atm pressure at all (it survives 200-500 atm in a turbopump).

So, probably if use syringe tanks with pistons, and pressure-fed engines for the booster ascent stages, they even should not require a cooling for this day or so.

The cabin and the orbital service module should not be thick and heavy, yes.
So, let's put them into a 4 m wide and high titanium capsule, pressurized with 1 atm hydrogen (for its heat capacity).
Let's make this titanium nosecone jettisonnable to not pushing it into orbit.

Let's put a 4 m wide apogee hypergolic stage under it.

All this thing should be heat-protected for a day or so.
So, let's put this apogee stage + titanium shell with the lightweight orbital part into a thin aluminium shell, cylindric with round ends, 6 m wide.
Let's fill this aluminium case with 90 atm hydrogen and equalize its pressure with an atmospheric piston.

To lower the heat flow throw the aluminium case, let's cover it with carbon fiber soaked in phenolformaldehyde resin (for ablation and low heat conductivity).
Let's jettison this aluminium/ablator shell at 60 km, after getting out of the atmosphere and acid clouds.

Let's put a 6 m wide hypergolic booster stage under it.
No heat protection, it's 450°C hot and with 90 atm in the pistonned tanks.

As the atmosphere is thick, the ascent rocket will anyway raise slowly, so the diameter probably doesn't mean as much as on the Earth.
let's surround all this with radial first stage hypergolic boosters and cover with a smooth conical envelope, made of aluminium, covered with carbon fiber+ablator..

***

So, the ascent stage will start like a ~12 m wide and high darkgray cone with a ring of flames below, get to 10-20-or-how-much km.
Then it drops the conical hull and turns into a 6 m thick cigar with a dark-gray (aluminium covered with carbon+ablator) pointed cylinder on top.

It gets to ~50 km and jettisons the dark-gray shell sections.
Now we can see on top of it a 4 m thick cylindric stage with a shining titanium spheroconical shell.

At ~60 km the 6 m stage separates. The 4 m stage ignites. The titanium nosecone gets jettisonned.

Now a 4 m stage with a titanium lower hemisphere and an orbital ship staying in it is getting to the orbit.

The orbital part (a lightweight, say, 3 t) cabin with a small service module separates and heads to the interplanetary ship.
Then it either docks itself, or gets docked by an Orion-like ship which takes away the descent crew with rocks and delivers to the interplanetary ship.

***

The lower part of the excursion module is trivial: a ring planform, legs, airbrakes, landing engines, chute boxes, jettisonnable 16 m wide heatshield. As usually.

***

On surface they should gather stones around the excursion module.
The spacesuit gets ~100 kg heavy, so doesn't make a sense. The need a rover with a cooled cabin.

They don't spend much time, so a cabin for two can be small.
Let's make it of aluminium, a 2 m sphere.
Let's put it into a titanium shell, 2+ m wide.
Let's pump cold hydrogen between the shells, at 1 atm pressure, to cool the cabin.

Let's surround the titanium shell with pressurized aluminium shell, covered with same carbon+ablator.
And pump hydrogen at 90 atm between them.

So, we get a 3 m wide darkgray sphere with a cabin inside, producing a lot of hot hydrogen, mostly at 90 atm, ~200°C.

Let's pump the hydrogen into a two stage turbine, and cool it down by 20^x expansion to the boiling point, to recycle the liquid hydrogen.

Let's cool the turbine with 450°C hot carbon dioxide from outside, compressing it twice and heating up to 1000°C.

Let's power this with a hydrolox-fueled jet engine and combine both 1000°C exhausts (water steam and carbon dioxide) in one high vertical pipe.
Let's put a "golden" umbrella on top of the hull, below the exhaust pipe.

So, the rover will be looking like a steam locomotive covered with an umbrella, with a high exhaust pipe throwing to the skies a roaring torch of 1000°C hot gases.
Also this can rotate a wheel of the drill.

The wheels and the arm (maybe even some kind of drill) will be usual.

***

So, after landing on the surface, sliding down from the ship cabin into the rover cabin through a tunnel, they will make a circle around the ship, collect a tonne of stones, return back to the cabin and start.

The hydrolox should be produced by the interplanetary ship electrolizer right before the descent.

The expedition total crew is 6: pilot/commander, doctor, 2 x (engineer + geologist).
The pilot and the doctor stay in the interplanetary ship.

2 landers. 2 Orion-like orbital ships.
One field team lands, returns, another one catches them with Orion.
Then they change and spend another landere. So, they collect stones from two places on the surface.
The pilot can remotely pilot them all if needed.

On return they distribute the humans and stones between the 2 Orions and return.
If one Orion is damaged, all six return in the functional one. So, they have a return capsule backup.
To make the second capsule useful in any case, they should gather 2-3 tonnes of stones, so 1-2 tonnes per lander.

Edited July 9, 2019 by kerbiloid

[Rus-Evo]

Is it scientifically possible to cool a lander on Venus to our temps?  

If it is, is it then possible to make it light enough?

And this is on top of the DV penalties for the very heavy crew capsule.

And then there is the DV required to reach orbit.

I feel that one might land on the Moon, Mars, Ceres and Titan before this due to order of difficulty.

[Guest]

1 hour ago, Rus-Evo said:

Is it scientifically possible to cool a lander on Venus to our temps?  

Sure, as long as your radiators don’t melt you’d just need a lot of energy! :3 (I wonder if Tungsten would work...)

@kerbiloid

It seems like a high difficulty, high cost, high risk place to visit, maybe that’s why. We are still just noobies dipping a toe into the low gravity, low atmosphere places. Venus is like hardmode. We would probably get pwnd. XD

Edited July 9, 2019 by Guest

[kerbiloid]

1 hour ago, Rus-Evo said:

very heavy crew capsule.

And this is exactly about a lightweight crew capsule instead of heavy one.

1 hour ago, Rus-Evo said:

Is it scientifically possible to cool a lander on Venus to our temps?  

Depends on the lander heat capacity (and here it is ~200..300 t of room temperature fuel) and duration (several hours is enough).
Together with the Al-Ti thermos described above it should give a day for play.

Even tiny Venera probes stayed working for an hour.

1 hour ago, Rus-Evo said:

And then there is the DV required to reach orbit.

And if the capsule is ~4 t, then the ascent stage is ~200..300 t, nothing special.

1 hour ago, Rus-Evo said:

I feel that one might land on the Moon, Mars, Ceres and Titan before this due to order of difficulty.

Moon and Mars are first steps, but Ceres and Titan - that's what is another order of difficulty.
Because on the Mars you can stay for 1.5 years at 0.4 g.
The Venusian expedition takes a little longer than a halfyear.

But Ceres and Titan have no acceptable natural gravity to keep your health, but require long years of flight if use chemical engines.
So, the Belt and beyond ultimately require a gas-core or a fusion nuke and an artificial gravity. The Mercury as well.

While Mars and Venus can be visited using just chemical drives.

28 minutes ago, Dale Christopher said:

Venus is like hardmode.

Not as hardmode as asteroids and giants' moons (see above).

Also we can see that every flight between the Jupiter big moons requires almost as much fuel as the Martian or Venusian expedition. The well works well.

Edited July 9, 2019 by kerbiloid

[NSEP]

Rocket engines are pretty much useless on the surface of Venus, if we were to use rockets to take of from the surface of Venus we would need a behemoth of a rocket (you would need 27km/s of Delta V in order to get from the surface to orbit). and all that has to somehow be built and get down to the surface too. If we really wanted to go to the surface of Venus, why not take advantage of that thick atmosphere? What if we had some sort of helicopter/balloon that would carry the spaceraft up to an altitude where the pressure would be simulair to Earth, so they can launch the capsule back to earth using a earth-sized rocket, rather than a humongous monstrosity.

Maybe it would also be a good idea to have an airship outpost in the atmosphere of Venus, where they would have one of these landing crafts. So instead of landing there for a day and leaving immediately, you could explore the surface for a day, get back up to cool down and analyze the samples, and get back down for another expedition. They could do many more expeditions this way.

I don't think visiting Venus is a good idea, but is sure is a fun idea, (to think about at least).

[magnemoe]

1 hour ago, Dale Christopher said:

Sure, as long as your radiators don’t melt you’d just need a lot of energy! :3 (I wonder if Tungsten would work...)

@kerbiloid

It seems like a high difficulty, high cost, high risk place to visit, maybe that’s why. We are still just noobies dipping a toe into the low gravity, low atmosphere places. Venus is like hardmode. We would probably get pwnd. XD

Extreme high cost and high risk, you could probably pull of an manned Saturn grand tour much easier. 
And that would be an very high return mission bringing stuff like drilling rigs. 
Permanent Mars bases and similar is obviously trivial. 

Endgame of national pride before the interstellar probes start calling home. 
They beat us to Pluto so let us do Venus. 
 

[NSEP]

9 minutes ago, magnemoe said:

Extreme high cost and high risk, you could probably pull of an manned Saturn grand tour much easier. 
And that would be an very high return mission bringing stuff like drilling rigs. 
Permanent Mars bases and similar is obviously trivial. 

Endgame of national pride before the interstellar probes start calling home. 
They beat us to Pluto so let us do Venus. 
 

Manned atmospheric Venus missions could act as a stepping stone towards manned mission to the atmospheres of gas giants. There will still be an epic sequel after that Endgame of national pride before interstellar probes.

[Scotius]

The question we should start with is not "How?" but "Why?". What do you want to find in that nightmarish environment, that would justify paying enormous cost of such mission AND putting the crew at high risk?

[NSEP]

1 hour ago, Scotius said:

The question we should start with is not "How?" but "Why?". What do you want to find in that nightmarish environment, that would justify paying enormous cost of such mission AND putting the crew at high risk?

This is the problem i have with a manned mission to the surface of Venus, why? There is no point in going to the surface of Venus manned. There is nothing you can do on the surface of Venus manned that you can't do unmanned. The idea i posted here earlier with the helicopter/balloon craft can be without humans in order to do a sample return, or maybe its shouldn't be done at all. Maybe we should just leave the surface of Venus alone and don't bother with Venus for a while.

[Ultimate Steve]

If we go to Venus, I would imagine that the ascent would not be rocket only. I would imagine a partial balloon/Zeppelin or propellor ascent until the atmospheric pressure gets down to something more reasonable. Maybe you could have a large floating base station at 1 or so atm and base the rockets from there with lighter capsules and have heavier balloon like Landers to transfer crew and equipment to and from the surface.

[Guest]

29 minutes ago, Ultimate Steve said:

If we go to Venus, I would imagine that the ascent would not be rocket only. I would imagine a partial balloon/Zeppelin or propellor ascent until the atmospheric pressure gets down to something more reasonable. Maybe you could have a large floating base station at 1 or so atm and base the rockets from there with lighter capsules and have heavier balloon like Landers to transfer crew and equipment to and from the surface.

I like that idea but, when coming back up to the floating base would rendezvous be practice? I'd image you (and the base) would be at the mercy of the wind. Having said that tho i duno anything about the weather patterns on Venus. >_< 

Edited July 10, 2019 by Guest

[kerbiloid]

10 hours ago, NSEP said:

Rocket engines are pretty much useless on the surface of Venus

Well, that's a problem, thanks.
Probably the first stage should anyway be equipped with a nuke and thermal nozzles using carbon dioxide as propellant.
So, either they could be solid-core, or the Venus lander is the task of the same phase of space as transmartian objects.

On an optimistic note, if the lander has such powerful fans that they can lift it in air, they should work as a cooling system as well.
Heating the carbon dioxide from 450 to 1000, and using hydrogen as heat carrier.

Everything about aluminium-titanium pressurized thermos and pistonned tanks, though, stays same.

10 hours ago, NSEP said:

What if we had some sort of helicopter/balloon that would carry the spaceraft up to an altitude where the pressure would be simulair to Earth, so they can launch the capsule back to earth using a earth-sized rocket, rather than a humongous monstrosity.

A helicopter is unlikely an option, as this its mechanics should be enormously heavy, and the rotation speed is limited by the viscous atmosphere.
A launch balloon should withstand the pressure and the temperature, so unlikely a flexible material is applicable on the surface, while a metal envelope is too heavy.
A thermal nozzle looks more perspective. At least because a jet fan is also a fan. Use a fan to fly and an umbrella to land.

9 hours ago, magnemoe said:

Endgame of national pride before the interstellar probes start calling home. 
They beat us to Pluto so let us do Venus. 

A rather strange and wrong assumption at all.
Even didn't have this in mind, considering all these flights as a far-future/alternative-reality thing.
The trigger of this Venusian lander idea was the article about Picard's submersibles in wikipedia.

"Beat us to Pluto"? First land a human on that Pluto. Otherwise the Soviet tortoises were the first persons on the Moon, lol. Why not? They passed by and made a selfie.

8 hours ago, Scotius said:

The question we should start with is not "How?" but "Why?". What do you want to find in that nightmarish environment, that would justify paying enormous cost of such mission AND putting the crew at high risk?

Main purpose of any human mission on another landmass is to collect samples.
A biorobot makes this faster and better, as it has an expert system just in one meter from the hands.
It can quickly sort and collect most interesting samples, and it can quickly grab and drop them without long rituals and complicated algorithms.
We should not underestimate the biobots' usefullness from pure technical point of view.

Another point is that a crewed lander is the most extreme case of any lander at all.
So, if get a crewed lander, an uncrewed one is just its simplified case. So, a crewed lander is the best starting idea. It can be later downshifted to an uncrewed one.

Edited July 10, 2019 by kerbiloid

[Ultimate Steve]

5 hours ago, Dale Christopher said:

I like that idea but, when coming back up to the floating base would rendezvous be practice? I'd image you (and the base) would be at the mercy of the wind. Having said that tho i duno anything about the weather patterns on Venus. >_< 

Good question. I guess I am just too uses to KSP, which doesn't simulate weather.

In real life, there has been a few experiments with deploying fighters from airships and reconnecting them. This is a step up from that, as it would be docking two airships instead of a plane to an airship... Maybe large nets could be used if wind was an issue? Then reeling the craft in?

Remember, there was a semi serious NASA proposal to send a crewed airship to Venus, although not all the way to the surface, so the winds probably aren't too crazy.

Granted, that's without atmospheric docking, but many of the elements are there.

[mikegarrison]

We could just keep pumping more and more CO₂ into the atmosphere and recreate Venus right here. Then we wouldn't have to worry about travelling.

[DDE]

1 hour ago, Ultimate Steve said:

Good question. I guess I am just too uses to KSP, which doesn't simulate weather.

In real life, there has been a few experiments with deploying fighters from airships and reconnecting them. This is a step up from that, as it would be docking two airships instead of a plane to an airship... Maybe large nets could be used if wind was an issue? Then reeling the craft in?

Remember, there was a semi serious NASA proposal to send a crewed airship to Venus, although not all the way to the surface, so the winds probably aren't too crazy.

Granted, that's without atmospheric docking, but many of the elements are there.

Actually, given diminished absolute speeds and a bouncy exterior, airship docking should be easier than airplane docking.

[Dafni]

We'd also have to take care about the corrosion and electric wind.

All bare metal will be attacked, and the electric wind on Venus might mess with accurate telemetry big time.

 

Just something to keep in mind.

 

[jost]

20 hours ago, kerbiloid said:

Why do they ignore a crewed Venus landing?
Yes, 90 atm, 450°C, but so what?

Because at the moment any technology to survive on Venus surfase and return back to orbit is science fiction. And since robotic landers didn't survive longer than an hour on venus surface there isn't much point except to proove it's possible. Which would be cool indeed but ain't enough to spenzöd the needed ressources. The reasons were discussed in length some years ago:

Tldnr: Won't gonna happen anytime soon.

Xkcd did a comparision of several bodys of the solar system, quote: " Venus is a terrible place"

https://what-if.xkcd.com/30/

[kerbiloid]

27 minutes ago, jost said:

Because at the moment any technology to survive on Venus surfase and return back to orbit is science fiction.

As well as Martian ones.

27 minutes ago, jost said:

And since robotic landers didn't survive longer than an hour

Even without active cooling. Just several fans inside and a radiator surface.

28 minutes ago, jost said:

Xkcd did a comparision of several bodys of the solar system, quote: " Venus is a terrible place"

Can't argue with this ultimate argument...

[jost]

2 minutes ago, kerbiloid said:

As well as Martian ones.

Nope. There exist several mission plans how to do a manned Mars expedition:

https://en.m.wikipedia.org/wiki/List_of_crewed_Mars_mission_plans

The technology is there. Mars delta v requirements and it's environment are much friendlier than venus. 

It's mainly a funding problem. Constellations long term goal was to go Mars. It was stopped because of lack of funding. Not because of the technical issues.

 

Venus is a different story 

[Guest]

@Ultimate Steve @DDE

I wasn’t really thinking of could you attach them practically, more that a airship staging point would have to hold station within the same area as the decent mission and would this be practical with winds. (I did a search and found this) 

Quote

At the very top of the cloud layers on Venus, wind speeds reach 355 km/hour (or 100 meters/second). This is the same the jet stream here on Earth. As you descend through the cloud layers, though, the wind speeds pick up. In the middle layer, the winds can reach speeds of more than 700 km/hour. That’s faster than the fastest tornado speed ever recorded on Earth.

https://www.universetoday.com/36816/winds-on-venus/

The prospect of keeping two balloons at different altitudes together seems very iffy. Not to mention landing and possibly having to deal with 700 km/hour winds. @_@. 

(The more you look into Venus the more hellish it becomes! Who the hell thought up this planet!)

Edited July 10, 2019 by Guest

[Ultimate Steve]

26 minutes ago, Dale Christopher said:

The prospect of keeping two balloons at different altitudes together seems very iffy. Not to mention landing and possibly having to deal with 700 km/hour winds. @_@. 

(The more you look into Venus the more hellish it becomes! Who the hell thought up this planet!)

Wow, I didn't realize it was that bad. Now, if the wind was moving uniformly in the same direction, it would be easier, but if it was turbulent, well...

Would wind be any less extreme on the night side due to lack of differential solar heating? Night there is pretty long.

[DDE]

2 hours ago, Ultimate Steve said:

Wow, I didn't realize it was that bad. Now, if the wind was moving uniformly in the same direction, it would be easier, but if it was turbulent, well...

Would wind be any less extreme on the night side due to lack of differential solar heating? Night there is pretty long.

Apparently it's pretty crazy.

Quote

Shortly after passing into daylight, the Vega-2 aerostat plunged several kilometers, to a level of 0.9 atmospheres, dangerously close to the lower limit of its stable float zone.

 

[Rus-Evo]

On 7/9/2019 at 6:41 PM, kerbiloid said:

And this is exactly about a lightweight crew capsule instead of heavy one.

 

Yes but my point was I dont think you could make a lightweight crew capsule.

[SRB]

AFAIK, a blimp filled with breathing gas would float in the Venus atmosphere.

 

[lajoswinkler]

On 7/9/2019 at 6:21 PM, Rus-Evo said:

Is it scientifically possible to cool a lander on Venus to our temps?  

If it is, is it then possible to make it light enough?

And this is on top of the DV penalties for the very heavy crew capsule.

And then there is the DV required to reach orbit.

I feel that one might land on the Moon, Mars, Ceres and Titan before this due to order of difficulty.

Yes, a nuclear reactor powered refrigerator could do it. But just landing. Returning back to orbit is a nope.