The Eve Dive Challenge (Duna Dive's big Brother)

[MarcRan17]

THE CHALLENGE

Get as close as you can to the sea level of Eve without deorbiting your space craft in a traditional aerobrake maneuver with really high speeds.

BACKGROUND

So over a year ago I posted a challenge here with a name I can't remember, that was wiped out by the forum massacre in April. The challenge was to perform the closest aerobrake you could to Duna without hitting the surface or deorbiting. There were some great entries, coming sometimes only 7km above the surface. Then IstasPumaNevada submitted their entry which made a closest approach of 1861m ASL and a radar altitude of a mere 143.6m and Escaped again! Needless to say, he won. Upon giving some more thought to it, I figured, that if he could make an escape after a 143m shave, there just wasn't enough atmosphere for the challenge. Where better to go for a thicker atmosphere than Eve?

SPECIFICS/RULES

-Because you are attempting to prevent a deorbit, your apoapsis MUST end up above the atmosphere and you must exit the atmosphere thereafter (this would be the first step in an aerobrake, the foundation of the challenge, which would then be followed by a cirularization burn at apoapsis)

-There are no restrictions on entry speed, that's where your creativity comes in. (I won't specify the way IstasPumaNevada succeeded as I'm hoping someone else will figure it out, and I'm hoping that someone else will do better)

-You MAY use engine thrust to assist you in escaping the atmosphere after entry, HOWEVER, your score will be doubled if you don't use ANY thrust while in the atmosphere.

-As proof of your achievement, you have two possible ways of submitting your attempt.

1. As a video. This is by far the easiest way to submit an entry as I can see exactly what's going on for every second of the attempt. The video must begin shortly before entering the atmosphere, and end shortly after exiting again

and upon exiting, you must show a quick view of the orbital map to prove that you have indeed escaped the atmosphere again. Be sure to have your UI visible so I can see your altitude as this is what your score will be judged by.

2. As an album of screencaps. This is harder to do, but better for people who don't have the software or the performance ability to do a video. All images must include the UI, particularly the resources dialogue, the Altimeter and the

Mission Elapsed Time (MET). The first picture must show your craft before entry. The last must show your craft after escaping the atmosphere again. Any pictures included in between will be used to judge your score. the picture that

has the lowest reading on the altimeter is what your score will be based off of, so take a handfull of pics as you approach periapsis. If you're attempting an un-powered aerobrake you must have the resources dialogue open at all times or

else make it clear that there are no engines on your craft.

-Landing isn't allowed. The goal is to aerobrake as low as possible. Dropping into the atmosphere with a 10,000m/s craft from above and then popping out again doesn't count either. Must work as an effective aerobrake

- Wings and Winglets, or any aerodynamic Lifting Surface (including control Surfaces) are disallowed as one can abuse the infiniglide glitch to escape again.

- One Kerbal must go along for the ride. Just imagine his face, it'll be worth it.

- The Developer console, (alt-F12) is strictly forbidden. No infinite fuel, no gravity hacking.

MODS

- All informational mods, are allowed, such as Kerbal Engineer.

- Mechjeb is allowed as it doesn't really provide any sort of performance enhancement

- FAR is allowed, however, this will put you in a separate category.

- Parts mods are only allowed so long as they do NOT include engines, particularily future tech engines like antimatter, black hole, or entropy engines, whatever they're called, NO ENGINE MODS.

- No Savefile editing. I WILL KNOW... O_O You MUST get to Eve in a flight all the way from Kerbin.

SCORING

Scores will be counted as follows:

According to the KSP wiki, Eve's atmosphere tops off at 96,708.574 m so We'll say that your score is that altitude minus your closest approach altitude and multiplied by two if you did it without thrust

This means that the maximum physically possible score is 193,417 points. I HIGHLY DOUBT ANYONE WILL ACHIEVE ANYWHERE NEAR THAT as Eve's atmosphere is Five times as thick as Kerbin's ASL and roughly 25 times as thick as Duna's

If you feel I missed anything or have any suggestions for alterations in the Rules, let me know below, other than that, good luck and happy flying.

I attempted this Challenge using Devhacks as proof of concept, and While I'm certain that the speeds I achieved are possible, because of the way the stock atmosphere is scaled, I highly doubt that anyone will make it below 35km, but by all means, prove me wrong!

LEADERBOARD (STOCK AERODYNAMIC MODEL):

Name: Score(Atmo cap - alt(x2 sans engines): Altitude(Atmo cap - score): Powered?:

1. metaphor 150,025pts 21,696m No

2. obi-juan 121,515pts 35,951m No

3. totalitor 118,757pts 37,330m No

4.

5.

LEADERBOARD (FAR AERODYNAMICS):

1.

2.

3.

4.

5.

BONUS: IstasPumaNevada's Duna Dive submission:

Edited December 31, 2013 by MarcRan17
updated leaderboard

[Fengist]

Have you actually tried this on Eve? Duna is one thing, low grav, very little atmosphere. Yea, it's doable. Eve? Umm no. It's like flying through soup with a rock tied to your ass.

[GusTurbo]

To be fair, any craft that is able to dip into the atmosphere and escape will qualify, so this is very doable. Not to the same degree as the Duna one, but still very doable.

[MarcRan17]

Ok valid point, Eve is kinda ridiculous, but the alternative is Kerbin. Unless you wanna go for Laythe, which, let's be honest is WAYYYY out of the way.

[Fengist]

Ok valid point, Eve is kinda ridiculous, but the alternative is Kerbin. Unless you wanna go for Laythe, which, let's be honest is WAYYYY out of the way.

All I can tell you is I've hit the Eve atmosphere at well... WELL over 3,500 m/s and it was like slamming into a brick wall. Try it yourself. If you manage to get even 30km and come back out I'll be amazed. Hell, I'd be stunned if you made it to 40.

[numerobis]

Have you actually tried this on Eve? Duna is one thing, low grav, very little atmosphere. Yea, it's doable. Eve? Umm no. It's like flying through soup with a rock tied to your ass.

Am I missing something that would make this challenge hard to successfully complete? All you have to do is aerobrake and get back out of the atmosphere; that's a routine activity. Winning the challenge will, I'm sure, involve some interesting designs.

[totalitor]

Have I understood correctly: If I dive let's say 1 m from sea level and I climb back to orbit using engines - that's ok?

Or if I land and then climb back to orbit?

[MarcRan17]

Have I understood correctly: If I dive let's say 1 m from sea level and I climb back to orbit using engines - that's ok?

Or if I land and then climb back to orbit?

Landing is not a flyby, so no. The Idea is to do an aerobrake as low as you can. Yes, though, you CAN use engines, as long as they're stock. but you'll double your score if you don't. You just need to escape the atmosphere again doing a traditional aerobrake

[Traches]

-FAR is DEFINITELY NOT ALLOWED as it changes the atmosphere's characteristics

Would make the challenge a lot more fun. With the stock model, it basically comes down to who can hurl a mk2 cockpit the fastest.

[MarcRan17]

All I can tell you is I've hit the Eve atmosphere at well... WELL over 3,500 m/s and it was like slamming into a brick wall. Try it yourself. If you manage to get even 30km and come back out I'll be amazed. Hell, I'd be stunned if you made it to 40.

If 3500 is what you think of as A LOT for this challenge, see the attached video above. he hit Duna's atmosphere at 39,500m/s. And he didn't cheat either, he explained his methods and they were very clever. I'm hoping I'll see something more clever this time around. The reason I chose Eve this time is because IstasPumaNevada just about hit the surface and still escaped Duna again. I figure that if I want to see better I need more atmosphere to work with. I don't expect anyone to get much within 10km above the ground heck It'd be freaking impressive if anyone made it past 45000m, but the point is that I want to be surprised by ingenuity, and dumbfounded by speed. For The record, I tried this using Dev Hacks and managed to get below 42,000m and still exit the atmosphere, and while I'm sure you're saying "that's cheating though, of course you did it" I know for a fact that this IS legitimately obtainable speed.

[-ELF-]

I do not think it is possible, but what if someone launches from kerbin, stops clockwise rotation, gains counter-clockwise speed enough to orbit sun on the orbit of Eve but in counter-direction?

wiki says Eve is moving along its orbit at 11000 m/s. And so, spaceship will be moving at the same speed when they meet, so, 22000 m/s is minimal relative speed... I do really think it will allow you to dive for around 20 km into violet soup, won't it?

[Dooz]

I would like to know how to accelerate to those insane speeds using stock in specific....

[Ryu Gemini]

Perhaps there could be a stock division and a FAR division.

.

[tavert]

I would like to know how to accelerate to those insane speeds using stock in specific....

The most efficient way of getting to really high speeds with stock parts that I know of is doing a bielliptic transfer, first out to the edge of the solar system (almost but not quite solar escape, as far out as you have the patience for), then down to a very low solar periapsis. Burning the rest of your fuel at a low solar periapsis will give you a big Oberth boost, but since you're more or less guaranteed to be on a solar escape trajectory at this point you'll have to time things carefully so you intersect Eve as you cross its orbit.

[MarcRan17]

Perhaps there could be a stock division and a FAR division.

.

This isn't a bad idea. Though the stock division is what the challenge basically already is. No Modded engines allowed. On this note I'm going to add a FAR category

[numerobis]

tavert: is that the best, or should you set periapsis at Eve, but retrograde?

[Commissioner Tadpole]

I think I'm going to try this. Eve is really close to Kerbin, so at least it's not like Jool-5.

Also, wouldn't the correct term be Duna Dive's big Sister?

[totalitor]

Ok am I first? I got 45600 meters, no rockets used in atmosphere, all stock.

Still had speed to espace from Eve system so result could be better.

I use Fraps demo version, so recording only 30 s and then again. That's why there are tiny gaps on video.

Here is the proof:

Edited December 26, 2013 by totalitor

[Pds314]

Just tried this, everything went wrong. My 300-tonne vehicle didn't take fuel from the correct tanks, lost an engine due to overheat, lost 5 orange tanks of nuke-fuel, was nearly impossible to get to orbit, and finally underwent 82 G of deceleration during reentry and lost its final engine. It also lost a lot of momentum below 20 km.

At 33 km, it was moving 8 km/s. By just a few seconds later at 24, it was limited to a mere 1.7. During the peak of this period, it exceeded 800 m/s^2 according to the fight log. It is truly a wonder that it even survived as much as it did.

So yeah, point is, FAR people, 6-tonne (empty) missiles can get down to about 30 km totally safely if they start at 13 km/s relative to Eve. Go a few km lower and the ship is doomed.

[MarcRan17]

Ok am I first? I got 45600 meters, no rockets used in atmosphere, all stock.

Still had speed to espace from Eve system so result could be better.

I use Fraps demo version, so recording only 30 s and then again. That's why there are tiny gaps on video.

Here is the proof:

http://youtu.be/j0_M3ajVwAw

First submission. lowest altitude, as close as I could tell anyways, was 45,573m. 96,708-45,573=51,135pts*2(because of lack of engines)=102,271pts. Because you're the only one who's submitted an entry so far, you're in first place. Not Bad at all. Bielliptic Transfer I take it, based on the speeds. Well Done.

[totalitor]

Biellictic transfer? No, just had a powerful rocket. Normal transfer from Kerbin to Eve, had over 20000 m/s deltav on Kerbin orbit.

Full speed after entering Eve gravity field.

[numerobis]

I tried to scam this challenge with a silly submission, and was thwarted by some KSP physics I didn't know! The idea: cube struts have no mass and drag, so they should fly through the atmosphere untouched, right? So I flew into orbit, set Pe to 15km, decoupled a cube strut on its own, and switched to follow that piece of debris. The truth: a cube strut on its own has mass and drag! The cube crashed into the sea.

[Cashen]

A good way to approach this would be to do a bi-elliptic transfer, by setting your periapsis near Eve and your apoapsis as far out as realistically possible. Then, if your craft has enough dV, at apoapsis you can burn to reverse the direction of the orbit, so you're orbiting the sun retrograde. Then not only could you get an extremely high velocity at your periapsis, but if you do encounter Eve you will be traveling in opposite directions, so the relative velocity would be... insane.

[Pds314]

Have I understood correctly: If I dive let's say 1 m from sea level and I climb back to orbit using engines - that's ok?

Or if I land and then climb back to orbit?

If you get within a meter of sea-level on Eve, your not getting back to orbit using rockets without a heck of a lot of staging.

[Pds314]

What about its bigger brother? The Jool-dive challenge?