Highest point on Eve, nearest the Equator?

[bigdad84]

Hi, i am currently planning a rescue mission to Eve to get Jeb, and have the craft designed and in LKO, with 8800 Delta-V. (is that enough?)... besides that, whats the highest point on Eve, closest to the Equator? Or what altitude should I be at, so 8800 is enough to get back into orbit?

[austin4050]

not sure if 8800 is enough, Eve has very very high gravity, try it all I can say is quicksave!!

[M5000]

Hi, i am currently planning a rescue mission to Eve to get Jeb, and have the craft designed and in LKO, with 8800 Delta-V. (is that enough?)... besides that, whats the highest point on Eve, closest to the Equator? Or what altitude should I be at, so 8800 is enough to get back into orbit?

I /think/ 8800 DV should be enough to get you to LEO from pretty much any point on Eve.. I think the actual DV from sea level is like 7800 or 8000 or something.. Hang on, let me check the Wiki..

Oh.. The Wiki says it takes about 11,500 DV to get into orbit..Jeez..

Well, here's this, though: "The land masses look like purple sand dunes. Its tallest point is 6450 m above sea level and is just south of the equator, at 1.90° W, 11.86° S."

[tavert]

That highest point from the wiki is pre-0.21. Now the highest point is more like 7540 meters, it's a bit further from the equator at around 25 south, 158.5 west. Eve's equatorial surface rotation speed is only 55 m/s compared to Kerbin's 175, so the altitude is more important than the latitude, and I haven't found anywhere else higher than 7000 m in 0.21 besides that mountain range.

8800 m/s delta-V can be enough from a high-altitude start, but you'll also need a good TWR. Eve's gravity is 1.7 times stronger than Kerbin's. And until you're at 11 km altitude, your engines will perform as if they're at sea level on Kerbin.

[Sof]

All delta-V measurements you make on your rocket always assume max thrust at all times. Obviously this isn't the best way to do things on planets with thick atmospheres. Assuming your delta-V was measured with respect to Eve gravity and atmosphere, I think 8800 will just about make it from the highest altitude launch and smart flying.

[tavert]

All delta-V measurements you make on your rocket always assume max thrust at all times.

The delta-V capacity of a rocket is entirely independent of thrust, it only depends on specific impulse and mass ratio. Eve's thick atmosphere amplifies the difference between atmospheric and vacuum specific impulse for many of the engines in KSP (luckily performance saturates above 1 atmosphere and never gets worse than at Kerbin sea level), and it also amplifies the importance of ascending at terminal velocity until you start your gravity turn (which you shouldn't do until 25-30 km on Eve). But these have to do with how much delta-V you use during ascent, not how much capacity your design has.

Edited July 31, 2013 by tavert

[Sof]

The delta-V capacity of a rocket is entirely independent of thrust, it only depends on specific impulse and mass ratio. Eve's thick atmosphere amplifies the difference between atmospheric and vacuum specific impulse for many of the engines in KSP (luckily performance saturates above 1 atmosphere and never gets worse than at Kerbin sea level), and it also amplifies the importance of ascending at terminal velocity until you start your gravity turn (which you shouldn't do until 25-30 km on Eve). But these have to do with how much delta-V you use during ascent, not how much capacity your design has.

Thats what I meant.

[bigdad84]

Eve is just a bad place to go... What lands on Eve stays on Eve... Except JEB!

[Brotoro]

It's not the highest point on the planet, and I didn't look everywhere, but the highest spot I found near the equator is this one (6,498 meters):

Here is a view of the area. It's not just a single mountain peak, so it's a a fairly good-sized landing area:

And here's the little ISA MapSat scan I did for my quick search, with the landing site indicated:

Edited August 1, 2013 by Brotoro

[saik0]

Hi, i am currently planning a rescue mission to Eve to get Jeb, and have the craft designed and in LKO, with 8800 Delta-V. (is that enough?)... besides that, whats the highest point on Eve, closest to the Equator? Or what altitude should I be at, so 8800 is enough to get back into orbit?

It's enough assuming an elevation of > 6000m, given ideal TWR and ascent profile. The best I managed pre 0.21 at a starting elevation of 6450 m was 8118 dv. (Using MechJeb ascent)

[bigdad84]

It's enough assuming an elevation of > 6000m, given ideal TWR and ascent profile. The best I managed pre 0.21 at a starting elevation of 6450 m was 8118 dv. (Using MechJeb ascent)

Is MechJeb the most efficient though?

[tavert]

Is MechJeb the most efficient though?

Not necessarily. MechJeb's pretty good at tracking terminal velocity, better than most pilots working without instrumentation. MechJeb's efficiency depends how carefully you set the parameters for the start, end, and shape of the gravity turn. A good pilot can outfly MechJeb in most cases.

[saik0]

Not necessarily. MechJeb's pretty good at tracking terminal velocity, better than most pilots working without instrumentation. MechJeb's efficiency depends how carefully you set the parameters for the start, end, and shape of the gravity turn. A good pilot can outfly MechJeb in most cases.

Assuming ideal gravity turn parameters, how exactly?

Also, to ancually answer OP's question from the title. I did some high res mapping of Eve's new tallest mountain. The peak is 7541 meters above sea level at -158.47446, -24.99460.

[rakutenshi]

If you use FAR you can make a huge dent in the d/v required due to the fact that making it aerodynamic actually counts... completely optional but due to the lack of the aerodynamic overhaul on the official side, I rather like it.

[tavert]

Assuming ideal gravity turn parameters, how exactly?

Even with ideal gravity turn parameters, MechJeb is constrained to fly one type of trajectory in terms of pitch-versus-altitude curve (well, two settings depending whether you have corrective steering on or off), and can only manage throttle via limiting to terminal velocity, limiting to an acceleration, and/or limiting to a throttle percentage. Flying manually, you're less constrained in that you can vary your pitch and throttle almost arbitrarily (only subject to throttle ramp limits and rotational inertia). If MechJeb's type of trajectory happens to coincide exactly with the true optimum, then there will be no way to beat MechJeb. But that would be a complete coincidence and there's no mathematical reason for it to happen for all general designs. For example, if different stages have significantly different TWR, then the optimal trajectories during those stages should likely be a bit different. Though the ideal MechJeb performance (after you've gone through the parameter tuning process) will in all likelihood be quite close to the ideal perfect-piloting performance.

Also, to ancually answer OP's question from the title. I did some high res mapping of Eve's new tallest mountain. The peak is 7541 meters above sea level at -158.47446, -24.99460.

Sweet, that's the same one I found. Thanks for collecting the data, it was getting slow for me to mess around with several-hundred-meg CSV's from ISA MapSat. Hopefully your plugin is more efficient than that (or you're more patient or on a better machine than I am).

Edited August 1, 2013 by tavert

[bigdad84]

For anyone who happens to care, I made it into Eve orbit with a ship containing a little less than 8800Dv from an altitude of 6,4XX. (The catch) had to bail the kerbal out and use his EVA pack for the remaining circularization.

[Hannu]

I have not tried 0.21 yet, but in 0.20 8800 m/s was enough from over 6000 m. My most capable Eve lander had some 9400 m/s and it could ascent from 5400 m. Now I used Mechjeb's ascent, but have made it also by hand. I am not sure if I remember right, but maybe gravity turn start was 35 km and percent value 60 % or 70 %. From 5400 m it took few tries, but eventually I had over 100 m/s left. Ascent parameters are quite sensitive. My ship's TWR was 2.0-2.2 when stages were full (except last stage, which is lower).

Eve is just a bad place to go... What lands on Eve stays on Eve... Except JEB!

I do not see any reason for this statement. Is it some historical from very old versions? It is completely possible to descend to and ascent from Eve with stock parts. If you use just a seat for an astronaut it is relatively easy, but I feel that pod is "right" way and then it is somewhat more complicated. The most difficult part is ascent from Kerbin, but If you launch a landing stage, a transport stage and a return ship with separate launches, you should not need over 600-700 t rockets. I try to make one launch missions. Such a mission needs nearly 2000 t and 1000 part launchers. Probably less, if you use asparagus -style, but in my opinion it is unaesthetic and I do not use it if is not absolutely necessary.

Edited August 20, 2013 by Hannu

[oggylt]

For anyone who happens to care, I made it into Eve orbit with a ship containing a little less than 8800Dv from an altitude of 6,4XX. (The catch) had to bail the kerbal out and use his EVA pack for the remaining circularization.

I was about to offer you to use eva pack to get to LKO and rescue ship could pick jeb up

[aeronerd]

All delta-V measurements you make on your rocket always assume max thrust at all times. Obviously this isn't the best way to do things on planets with thick atmospheres. Assuming your delta-V was measured with respect to Eve gravity and atmosphere, I think 8800 will just about make it from the highest altitude launch and smart flying.

delta V is invariant with throttle in KSP. real rockets vary ISP with throttle, but not in game.

[magnemoe]

I like this location close to the equator, 6.500 meter. It as two benefits, fist its an pretty large and flat area, secondly as its close to equator it required lite plane change burn and it was easy to do manually with mechjeb to show landing point.

As my Eve landing was part of an minimal weight grand tour. fuel used during plane change was just as important as fuel used during accent.

Note that mechjeb sacrifices fuel use for accuracy then landing automatic on planets with atmosphere. Pretty smart of it as any fool with an parachute can land with atmosphere the main issue is to get close to the target.

This lander was not fully able to reach orbit, lacked around 100 m/s.

Edited September 12, 2013 by magnemoe