[UNOFFICIAL/FANMADE] 0.17 Discussion Thread 2

[FishyFishy13]

Well eves atmosphere is going to get 5x more dense but they didn't say it was going to be tall. The denseness could just be the atmosphere being close to the ground so you might still be able to get outside the atmosphere pack lots of parachutes on your huge lander though because the bottom layer of the atmosphere is going to be extremely thick and your going to need lots of boosters to get it up.

[Winter Man]

It does indeed, it's what causes it in the first place. The shape of the aerofoil causes an uneven increase in speed of the air above and below itself, which causes a difference in pressure (the Bernoulli principle stating that an increase in velocity comes from an decrease in pressure and vice versa). This difference in pressure results in a force perpendicular to the wing, manifesting as the lift and drag forces.

[ramipro]

But if the angle or attack is 0, that principle should only create lift, shouldn't it?

[Rickenbacker]

It does indeed, it's what causes it in the first place. The shape of the aerofoil causes an uneven increase in speed of the air above and below itself, which causes a difference in pressure (the Bernoulli principle stating that an increase in velocity comes from an decrease in pressure and vice versa). This difference in pressure results in a force perpendicular to the wing, manifesting as the lift and drag forces.

This old chestnut again! The Bernoulli principle adds some lift, yes, but the main component of lift comes from angle of attack, or in other words, the wing pushing enough air downwards to lift itself and the plane it's attached to upwards. If the Bernoulli principle was all there was to it, aerobatics planes and fighter jets wouldn't fly at all, as they have most or entirely symmetrical airfoils, so no pressure differential at 0 degree AoA.

KSP obviously doesn't model this, but instead seems to assign a certain amount of 'magical' lift to each wing surface, no matter how it's oriented.

[Rickenbacker]

But wouldn't the thrust from the engines be dampened tremendously by the thick atmosphere? It could still be possible to escape, but it might require an incredible effort.

No, but the denser air would cause more air resistance. Good when landing (aerobraking works better), not so good when taking off (you need a lot more thrust to get through the atmosphere).

[Winter Man]

But if the angle or attack is 0, that principle should only create lift, shouldn't it?

It does, the drag mentioned is 'induced drag', not total drag. There's parasitic drag too, which is the skin of the aeroplane slowing the air down.

This old chestnut again! The Bernoulli principle adds some lift, yes, but the main component of lift comes from angle of attack, or in other words, the wing pushing enough air downwards to lift itself and the plane it's attached to upwards. If the Bernoulli principle was all there was to it, aerobatics planes and fighter jets wouldn't fly at all, as they have most or entirely symmetrical airfoils, so no pressure differential at 0 degree AoA.

KSP obviously doesn't model this, but instead seems to assign a certain amount of 'magical' lift to each wing surface, no matter how it's oriented.

This is true, but it depends on the aerofoil. The high speed jets and aerobatic planes rely more on the angle pushing the air out of the way, but slower planes rely on it quite a bit due to the lower thrust-to-weight ratio and their much lower stall angle.

[Bluekommeh]

Soooo...yeah. On topic, did Nova ever say how he was going to make the gas giant? He said it would just be rocky but does that mean that the atmo will be un-textured?

[neistridlar]

Soooo...yeah. On topic, did Nova ever say how he was going to make the gas giant? He said it would just be rocky but does that mean that the atmo will be un-textured?

From what I've read the gas giant will have no actual surface, just a green atmosphere. If you manage to get down to 0 altitude your craft will magically explode. Apparently its just a placeholder for now though, until the game gets proper support for gas giants.

[Richy teh space man]

Since Eves atmosphere is so thick I guess parachutes will work just fine for a landing then..

Getting off looks like it'll be tricky though, unless you parachute a space plane down perhaps?

[toastar]

Since Eves atmosphere is so thick I guess parachutes will work just fine for a landing then..

Getting off looks like it'll be tricky though, unless you parachute a space plane down perhaps?

Or you know just land the space plane?

[Serratus]

Since Eves atmosphere is so thick I guess parachutes will work just fine for a landing then..

Getting off looks like it'll be tricky though, unless you parachute a space plane down perhaps?

Maybe, but I'm wondering. If Eves atmosphere is 1.7g then it will be 70%(I'm terrible at match; don't judge me...) more 'compacted'. It would give us atmosphere height of ~21Km. That means that You will start aero-breaking where normally parachute would open up on Kerbin altitude-wide. Then it will deploy fully at VERY low. Here's my concern - will the pod have the time to slow down before parachute enters another stage, so that the sudden jolt doesn't rip the thing off of the ship...

EDIT: Keep in mind that I'm assuming Eve and Kerbin are of similar size!

[Richy teh space man]

Or you know just land the space plane?

Thats not Kerbal enough for my liking.. besides which I'll be using that fuel to get back off the planet and rendevous in space..

[Richy teh space man]

Maybe, but I'm wondering. If Eves atmosphere is 1.7g then it will be 70%(I'm terrible at match; don't judge me...) more 'compacted'. It would give us atmosphere height of ~21Km. That means that You will start aero-breaking where normally parachute would open up on Kerbin altitude-wide. Then it will deploy fully at VERY low. Here's my concern - will the pod have the time to slow down before parachute enters another stage, so that the sudden jolt doesn't rip the thing off of the ship...

EDIT: Keep in mind that I'm assuming Eve and Kerbin are of similar size!

I think with the atmosphere being denser it'll start slightly higher then Kerbin, but thats just me guessing..

At any rate it may change again before 0.17

[Endeavour]

Maybe, but I'm wondering. If Eves atmosphere is 1.7g then it will be 70%(I'm terrible at match; don't judge me...) more 'compacted'. It would give us atmosphere height of ~21Km. That means that You will start aero-breaking where normally parachute would open up on Kerbin altitude-wide. Then it will deploy fully at VERY low. Here's my concern - will the pod have the time to slow down before parachute enters another stage, so that the sudden jolt doesn't rip the thing off of the ship...

EDIT: Keep in mind that I'm assuming Eve and Kerbin are of similar size!

With 1.7x Kerbin gravity, I would assume the planet would be around that much bigger than Kerbin. Also, I think the atmospheric height would increase, but I'm not sure on that.

[Joe4evr]

With 1.7x Kerbin gravity, I would assume the planet would be around that much bigger than Kerbin. Also, I think the atmospheric height would increase, but I'm not sure on that.

Actually, it doesn't necessarily mean anything about the size, just that the mass of the planet is 1.7 times Kerbin's. Black holes, for instance, are really tiny, but have the mass of a whole star just compressed to the densest form possible.

[Banbite]

Ye, assuming that Eve got the same density as kerbin it will have a radius that's 1.7 times larger than Kerbin (if it's surface acceleration is 1.7g), aka 1020 km. The difference would be something like this:

Dunno what it will do with the atmosphere density and pressure but my bet is that the atmosphere will be thinner but a lot denser when you get down in it.

Wonder if it's gonna be completely clouded so you can't see the surface from orbit, like Venus and Titan, or if it's just gonna be like Kerbins. But anyway will surely be an interesting planet to travel to.

[Da_Dumples]

I wonder if since the atmosphere is so thick, that if you were do deploy a parachute while going too fast, you might just tear off your parachute. Maybe we'll have to do a quick retroburn and then deploy a parachute in order to land safely. I just hope that the new planets aren't as laggy as Kerbin is at the moment.

[Kosmo-not]

Eve's radius is 700km (100km more than Kerbin).

[Serratus]

Mars has 0.376 grav force.

This is what Wiki says

The atmosphere of Mars is relatively thin and is composed mostly of carbon dioxide (95.32%). There has been interest in studying its composition since the detection of trace amounts of methane,^[2][3] which may indicate the presence of life on Mars, but may also be produced by a geochemical process,volcanic or hydrothermal activity.^[4]

The atmospheric pressure on the surface of Mars varies from around 30 pascals (0.0044 psi) on Olympus Mons's peak to over 1,155 pascals (0.1675 psi) in the depths of Hellas Planitia, with a mean surface level pressure of 600 pascals (0.087 psi), compared to Earth's sea level average of 101.3 kilopascals (14.69 psi) (i.e. about 0.6% of Earth's), and a total mass of 25 teratonnes, compared to Earth's 5148 teratonnes. However, the scale height of the atmosphere is about 11 kilometres (6.8 mi), somewhat higher than Earth's 7 kilometres (4.3 mi).

It seems logical to me that the harder the gravity pulls on atmosphere - the more it's going to compress it. That's where the high density comes from after all. Same amount of gas in smaller space.

[Shadownailshot]

Mars has 0.376 grav force.

It seems logical to me that the harder the gravity pulls on atmosphere - the more it's going to compress it. That's where the high density comes from after all. Same amount of gas in smaller space.

Does not necessarily mean the same amount of gas in a smaller space. The density is usually caused by more atmosphere pressing down on top of the lower levels because of the higher gravity. My thought would be that the higher gravity would mean a larger, denser atmosphere. A lot more gas pressed into a larger space. My guess is that the atmosphere will top off somewhere around 100km from the surface, as opposed to Kerbin's ~69km.

[Serratus]

Does not necessarily mean the same amount of gas in a smaller space. The density is usually caused by more atmosphere pressing down on top of the lower levels because of the higher gravity. My thought would be that the higher gravity would mean a larger, denser atmosphere. A lot more gas pressed into a larger space. My guess is that the atmosphere will top off somewhere around 100km from the surface, as opposed to Kerbin's ~69km.

Well, yes, but that has more to do with the ratio of atmosphere thickness and planet size. Except planet size doesn't determine it's gravity - the mass does. So counting thickness of atmosphere, based on the fact that we THINK it will be 1.7 times bigger is without purpose. Someone here said that Eva will be only 100Km in diameter bigger. I'd say that with nearly same size, but bigger mass, the atmosphere will be 45-40km tops.

[JeremyG]

I'm starting to wonder how many times it happens that a dev comes in here looking at your speculations, and thinks "Oh, this is a much better idea than I had. Let's change it!"

[AncientAstronaut]

I'm starting to wonder how many times it happens that a dev comes in here looking at your speculations, and thinks "Oh, this is a much better idea than I had. Let's change it!"

Probably very, very, very rarely. They have a lot of ideas for how they want to do stuff.

[Winter Man]

planet size doesn't determine it's gravity - the mass does

Well. Kind of both for surface gravity because it gets weaker at distance. But you're right about the atmosphere assuming it has the same quantity of gas there. Which it might not.

[BurningSky93]

Well. Kind of both for surface gravity because it gets weaker at distance. But you're right about the atmosphere assuming it has the same quantity of gas there. Which it might not.

This^

Surface gravity equation

g = ((4 pi)/3)*G*rho*r

Where g is the surface gravity, G is Newton's gravitational constant, rho is mean density and r is radius