Starship at Venus: How far could it survive?

[Minmus Taster]

Not sure if this fit's into the SpaceX thread or not so I made one for this topic; if a Starship descended into the Venusian atmosphere how far would it make it down? Could it survive reentry into the thicker atmosphere at Interplanetary speeds? How far would it bellyflop into the atmosphere before being crushed? Is there any way it could still deliver surface payloads?

[darthgently]

1 minute ago, Minmus Taster said:

Not sure if this fit's into the SpaceX thread or not so I made one for this topic; if a Starship descended into the Venusian atmosphere how far would it make it down? Could it survive reentry into the thicker atmosphere at Interplanetary speeds? How far would it bellyflop into the atmosphere before being crushed? Is there any way it could still deliver surface payloads?

Interesting questions.  The atmosphere is so thick I wonder if aerobraking a starship from interplanetary without a special heat shield for that job would be feasible.

 If internal pressures were dynamically matched with external pressures I wonder how far down into the atmosphere a starship could make it also

[Mr. Kerbin]

Do a KSP and have multiple aerobreaks at high altitude to slow down easier, high enough this it would be like doing it at Earth, less special tech.

it could probably get like 25 atm?

10?

I, personally don’t think it would make it all the way WITH a surviving payload.

 

[darthgently]

22 minutes ago, Mr. Kerbin said:

Do a KSP and have multiple aerobreaks at high altitude to slow down easier, high enough this it would be like doing it at Earth, less special tech.

it could probably get like 25 atm?

10?

I, personally don’t think it would make it all the way WITH a surviving payload.

 

Yes, KSP atmosphere tapers to zero pressure at the top so one could choose a less stressful brake if that is what you mean, and one could do multi pass also, but you’d need to capture in the first pass and if that amount of aero braking would be too risky then combining aero braking with an initial capture burn would be required (whatever attitude gymnastics that would require).

As for a payload surviving to the surface I’m imagining a Venera level hardened probe as the payload with the entire starship basically being a consumable heatshield for that payload.  Keeping internal pressures the same as the external would keep it from crushing around the probe but the probe deployment mechanisms and any payload doors and controls would need to be Venera grade also I suppose.

A purpose built Venera+ grade entire Starship is an enticing idea…

Edited December 7 by darthgently

[AckSed]

I think someone calculated that an empty rocket stage could just about float at pressures and temperatures within tolerances for that stage: https://selenianboondocks.com/2013/11/venusian-rocket-floaties/

Starship, being bottom-heavy, designed to skydive and mainly made of stainless steel, might just be able to float and survive. If it doesn't burst from the pressure.

[Minmus Taster]

20 minutes ago, AckSed said:

I think someone calculated that an empty rocket stage could just about float at pressures and temperatures within tolerances for that stage: https://selenianboondocks.com/2013/11/venusian-rocket-floaties/

Starship, being bottom-heavy, designed to skydive and mainly made of stainless steel, might just be able to float and survive. If it doesn't burst from the pressure.

That most certainly still breaks the laws of physics given the ships pressure tolerance likely being passed and still weighing hundreds of tons but it's a fun idea, one can dream

[Mr. Kerbin]

1 hour ago, darthgently said:

multi pass also

Yeah- maybe also a little bit of engine use.

It doesn’t have to be a pretty orbit, like within 0.9 eccentricity.

Here’s a REALLY fun idea.

What if we use paragliders or balloons to make some sort of high altitude science-starship-base-thing!

Maybe use helicopter rotors?

It’s a nice dream.

Maybe drop the payload from there?

The closest in stock KSP is Jool when it comes to real life conditions 

193412062024

Edited December 7 by Mr. Kerbin

[AckSed]

9 hours ago, Mr. Kerbin said:

What if we use paragliders or balloons to make some sort of high altitude science-starship-base-thing!

Actually the plan of the 'backyard space program' J. P. Aerospace. They call it the Dark Sky Station, and it's meant as a waystation for the balloon to upper-atmosphere to transfer payloads to the hypersonic balloon. Yes, I know, but it looks cool:

Spoiler

 

[magnemoe]

11 hours ago, Minmus Taster said:

That most certainly still breaks the laws of physics given the ships pressure tolerance likely being passed and still weighing hundreds of tons but it's a fun idea, one can dream

You would need to pressurize the tanks more than 6 bar, say one more than outside,  but pretty sure it would end up too deep to survive for long. 
Now it could be relevant as in delivering an large payload deep into the atmosphere there. 

[kerbiloid]

It will reach the surface.

In pieces.

Because at it will be aerobrake into much denser atmosphere that on the Earth.

Edited December 7 by kerbiloid

[darthgently]

46 minutes ago, kerbiloid said:

It will reach the surface.

In pieces.

Because at it will be aerobrake into much denser atmosphere that on the Earth.

Are the outer edges of the atmosphere thin enough for a multipass first pass?  Aerobrake to immediate landing doesn’t have to be the plan

[magnemoe]

8 minutes ago, darthgently said:

Are the outer edges of the atmosphere thin enough for a multipass first pass?  Aerobrake to immediate landing doesn’t have to be the plan

Upper atmosphere is not an problem, multi pass would work as on earth I think. Its the hell diving part. So you will release payload before your electronic cooks. 
Now why would you need an SS size payload, sample return is my only thought. 
Manned SS in orbit for control,  perhaps with an tanker. And the helldiver ship with an blimp with an orbital class rocket you land some rovers picking samples and releasing balloons. UAV from blimp catches the balloon payload. 
Return an load into rocket, blimp drops all except rocket an then launch it at max elevation. Maned SS pick it up and return. 
SS v10++

[kerbiloid]

1 hour ago, darthgently said:

Are the outer edges of the atmosphere thin enough for a multipass first pass?  Aerobrake to immediate landing doesn’t have to be the plan

https://en.wikipedia.org/wiki/Scale_height

Quote

Approximate atmospheric scale heights for selected Solar System bodies:

• Venus: 15.9 km^[6]
• Earth: 8.5 km^[7]
• Mars: 11.1 km^[8]
• Jupiter: 27 km^[9]
• Saturn: 59.5 km^[10]
  • Titan: 21 km^[11]
• Uranus: 27.7 km^[12]
• Neptune: 19.1–20.3 km^[13]
• Pluto: ~50 km^[14]

 

So, the Venus atmosphere uniform height is twice thick as the Earth's one.

As SS can barely pass the Earth air, it will be disintegrated a little bit later.

(More or less, as the gas composition differs.)

[magnemoe]

8 hours ago, kerbiloid said:

https://en.wikipedia.org/wiki/Scale_height

 

So, the Venus atmosphere uniform height is twice thick as the Earth's one.

As SS can barely pass the Earth air, it will be disintegrated a little bit later.

(More or less, as the gas composition differs.)

This makes little sense, why is mars thicker than earth? Yes gravity is lower so it extend farther and it makes aerobraking easier. 
Aerobraking into orbit only affect outer atmosphere. 
Landing on Venus and your probe live an hour if well made. 
Go other places 

[Nuke]

i presume because mars is mostly co2. molecular mass is part of the equation.

[kerbiloid]

9 hours ago, magnemoe said:

This makes little sense, why is mars thicker than earth?

The ratio of the air above and air below the 1 atm level makes.

On Venus it's at 50..60 km.

The gravity on Venus is same.

So, if your heatshield is able to pass throw the amount of gas, corresponding the Earth atmosphere, you have another one below you to aerobrake again.

[PakledHostage]

Counterintuitively, Venus has the most habitable environment in the solar system, other than Earth. It's just not on the surface.  The habitable zone is about 60 km up in Venus' atmosphere, where gravity, pressure and temperature resemble those of Earth. Earth air is also a lifting gas for a balloon in that atmosphere at that level. Maybe one day, we'll build an outpost there with rockets arriving by propulsive landings on the floating station. 

[Minmus Taster]

44 minutes ago, PakledHostage said:

Counterintuitively, Venus has the most habitable environment in the solar system, other than Earth. It's just not on the surface.  The habitable zone is about 60 km up in Venus' atmosphere, where gravity, pressure and temperature resemble those of Earth. Earth air is also a lifting gas for a balloon in that atmosphere at that level. Maybe one day, we'll build an outpost there with rockets arriving by propulsive landings on the floating station. 

Perhaps some research station but never a colony. Too inefficient and risky to build such a large floating structure over a hostile area with known technology. Besides, the acid would melt most building materials over time.

[Nuke]

i dont really see a point in having a floating venus base. you have to do the equivalent of an earth launch and re entry to get there and back (to orbit), and there is no way to do any kind of resource extraction except from the atmosphere. probibly cant carry much mass, so even if you could make product from atmosphere, you could never launch it. at least on the moon or mars you can strip mine like mad and have materials for both colony expansion and export (presumably to elsewhere in the solar system).

Edited December 8 by Nuke

[AckSed]

Besides, floating balloons are out, floating carbon-composite hexagonal tiles making a floating surface are in: https://www.researchgate.net/publication/359228323_Cloud_Continents_Terraforming_Venus_Efficiently_by_Means_of_a_Floating_Artificial_Surface

[magnemoe]

1 hour ago, Nuke said:

i dont really see a point in having a floating venus base. you have to do the equivalent of an earth launch and re entry to get there and back (to orbit), and there is no way to do any kind of resource extraction except from the atmosphere. probibly cant carry much mass, so even if you could make product from atmosphere, you could never launch it. at least on the moon or mars you can strip mine like mad and have materials for both colony expansion and export (presumably to elsewhere in the solar system).

Agree, an orbital station makes some sense as you can remote control rovers and drones with minimal lightspeed lag. 
But probably just as well use an Starship or other craft arriving with the probes and return at next window. 

[PakledHostage]

9 hours ago, Minmus Taster said:

Perhaps some research station but never a colony. Too inefficient and risky to build such a large floating structure over a hostile area with known technology. Besides, the acid would melt most building materials over time.

Venus at 60 km is no more immediately dangerous than the surface of Mars. It's arguably less so. You could go outside on a balcony or to work on the exterior of the habitat in what amounts to scuba gear (e.g. a neoprene suit and respirator). And many common materials like plastics (e.g. HDPE, PVC), Teflon, glass, some stainless steels, etc are unaffected by sulfuric acid. Structures can be protected from it. You would also build redundancy into the station, just as you would have to on Mars. Gravity wells and ISRU are a different matter, but given a choice between moisture farming on Tatooine Mars, or living in a cloud city on Bespin Venus, I would choose Venus.

Edited December 9 by PakledHostage

[darthgently]

12 hours ago, PakledHostage said:

Venus at 60 km is no more immediately dangerous than the surface of Mars. It's arguably less so. You could go outside on a balcony or to work on the exterior of the habitat in what amounts to scuba gear (e.g. a neoprene suit and respirator). And many common materials like plastics (e.g. HDPE, PVC), Teflon, glass, some stainless steels, etc are unaffected by sulfuric acid. Structures can be protected from it. You would also build redundancy into the station, just as you would have to on Mars. Gravity wells and ISRU are a different matter, but given a choice between moisture farming on Tatooine Mars, or living in a cloud city on Bespin Venus, I would choose Venus.

The tech to live in Venusian clouds or on the surface of the Moon or Mars is no less complex (and possibly more) than that to live in rotating orbital habs.  The gravity well of a body could be useful for manufacturing or physiological reasons but other than access to resources I see no pressing reason to occupy clouds or surfaces over occupying wherever is convenient

[magnemoe]

12 hours ago, PakledHostage said:

Venus at 60 km is no more immediately dangerous than the surface of Mars. It's arguably less so. You could go outside on a balcony or to work on the exterior of the habitat in what amounts to scuba gear (e.g. a neoprene suit and respirator). And many common materials like plastics (e.g. HDPE, PVC), Teflon, glass, some stainless steels, etc are unaffected by sulfuric acid. Structures can be protected from it. You would also build redundancy into the station, just as you would have to on Mars. Gravity wells and ISRU are a different matter, but given a choice between moisture farming on Tatooine Mars, or living in a cloud city on Bespin Venus, I would choose Venus.

Question is why? On Mars you can do stuff robots can not practically do like repairs and operate heavier requirements like drill rigs for core samples. And you have resources you can use for the return trip. 
No I don't think an self sufficient colony on Mars would work but an permanent research base makes sense if transport is cheap enough.  

On Venus, why not just stay in orbit. Its not like you can even extract fuel to get back into orbit after floating in the atmosphere. 
The outer solar system makes much more sense. 

[Nuke]

51 minutes ago, darthgently said:

The tech to live in Venusian clouds or on the surface of the Moon or Mars is no less complex (and possibly more) than that to live in rotating orbital habs.  The gravity well of a body could be useful for manufacturing or physiological reasons but other than access to resources I see no pressing reason to occupy clouds or surfaces over occupying wherever is convenient

launching a rocket still requires a lot of ground infrastructure. you might get the cost down a lot but launching from and landing at a floating installation requires that installation have a lot of industrial capacity, or a lot of storage, neither of which is easy to float. a rotating hab does not require the trip up and down the well. especially if were just talking a science installation to operate clockwork rovers on the surface. for an industrial hub, there are better locales for that (moon, mars and belt being a lot more accessible).

for an agrarian colony it kind of works out well. if you can convince people to want to live on the rim of hell anyway. but at some point in the greater colonization of the solar system it makes sense to have a few bread baskets, and earth is finite. that is a lot further down the tech tree though. perhaps if airship to orbit ever works out, it will be well suited to a venusian application (you dont ever really want to land those things anyway).