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

[Pds314]

Hmm... might it be possible to do this by some very precise calculations and several stages of Ion-engines? You could get retrograde velocity of something like 60,000 m/s in the first stage.

Then you could always add hundreds of aerodynamic nosecones onto the ship to reduce its drag/mass ratio.

[MarcRan17]

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

If you wannnnnnt.... but seriously, Eve is tricky enough as it is. I chose Eve because I've seen Duna Pretty much maxed out once before, Kerbin isn't a challenge to get to, Laythe and Jool are just a long ways out and that entails all sorts of other added difficulties. Slow Solar orbital velocity, long flight time to get there, etc. Eve was in my opinion, the most suitable alternate target. Easy enough to get to, thick atmosphere, but not quite impossibly thick, and it has a high Solar Orbital Velocity.

[pigletx2]

This challenge is flawed, I can create a craft that goes 2 m to sea level, then fly out into L.E.O. with just infiniglide. The hard part is getting to eve.

[BlazingAngel665]

;867139']I do not think it is possible' date=' 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?[/quote']

This means that when you enter Eve's SOI you will be moving at 22km/s Then factor in all of your acceleration into Eve's fairly deep gravity well. You would easily be clocking in at 35km/s add in a gilly gravity assist to get to 38km/s and the burn your NERVA the whole way down to make it 41km/s

Better yet, get into an orbit that is Eeloo sized or bigger, then turn retro-grade. Drop you Perihelion to Eve's altitude, but leave your Aphelion high. This will easily give you intercept speeds of over 60km/s. I suspect this is how the guy in the OP did his. Sundiving is a very efficient method of gaining velocity.

[Ryu Gemini]

This challenge is flawed, I can create a craft that goes 2 m to sea level, then fly out into L.E.O. with just infiniglide. The hard part is getting to eve.

Disallow infiniglide then.

.

[MarcRan17]

This challenge is flawed, I can create a craft that goes 2 m to sea level, then fly out into L.E.O. with just infiniglide. The hard part is getting to eve.

Thank you for pointing that out. Considering that the challenge is based on the ultimate aerobrake, I will disallow the use of wings and winglets. They shouldn't be needed anyways.

[Jasonbail]

does a kerbal have to take part in the aerobrake or can it just be a part?

Edited December 27, 2013 by Jasonbail

[entaran]

Actually, that Duna entry should've been disallowed anyway.

In your challenge description you state that the purpose is to aerobrake then circularise after exit. If you don't aerobrake enough to HAVE an apoapsis inside the SOI it shouldn't be allowed.

Otherwise it's pointless, you're just firing mk1 cockpits into the atmosphere as fast as possible.

(It's actually possible to hit Eve at 83,772 m/s)... my best so far. Ofc if you even consider re-entry heating or the G force deceleration you're both dead and atomised.

[totalitor]

I tried today getting very far...7 years beyond Eeloo. And there I noticed that I don't have power to do anything, solar panels didn't work so far away.

Maybe I went too far. When I was getting back my ship awakened and I hit Eve's atmosphere faster than ever, but I got only couple of kilometres better result.

So next time I will try reversing orbit on apoapsis.

[Horn Brain]

This means that when you enter Eve's SOI you will be moving at 22km/s Then factor in all of your acceleration into Eve's fairly deep gravity well. You would easily be clocking in at 35km/s add in a gilly gravity assist to get to 38km/s and the burn your NERVA the whole way down to make it 41km/s

Better yet, get into an orbit that is Eeloo sized or bigger, then turn retro-grade. Drop you Perihelion to Eve's altitude, but leave your Aphelion high. This will easily give you intercept speeds of over 60km/s. I suspect this is how the guy in the OP did his. Sundiving is a very efficient method of gaining velocity.

You are completely wrong on every number except for the NERVA boost and the starting figure. Eve's gravity well is nothing when you're travelling 22 km/s. It wouldn't even add 1 km/s. Gilly giving you a 3 km/s boost at 35 km/s is also ridiculous. Gilly has no effect on objects with that speed unless they hit the surface.

Finally, 60 km/s is not possible for an object on an elliptic orbit around the sun with a periapsis at Eve's orbit. If you add solar escape velocity at Eve's orbit (~19 km/s) and Eve's orbital velocity (~11 km/s) you get 30 km/s. To get 60 km/s you need to do a sun dive all the way to near the surface of the sun and burn a ton of fuel at periapsis, then hit Eve on the way out.

Don't make up numbers.

[Kasuha]

I guess this challenge is mostly about patience. Build a big craft, send it way behind Eeloo, turn the orbit retrograde, and speed down to hit Eve at as much speed as possible. You need to hit it retrograde on its orbit around Sun (+22,000 m/s), but you need to hit atmosphere along Eve's rotation (+109 m/s). After crossing the SOI, adjust your passing height and watch what happens.

I don't see infinite fuel and debug menu prohibited anywhere in the rules but I assume it is expected you won't use it.

To prevent dive/launch-without-landing I would suggest specifying that all used thrust must be applied prograde.

[Jasonbail]

You can take a mk1 cockpit and strap a ton of thruster blocks on and the drag co-efficient can be brought down to .01 which makes even eves density seem low. How they calculate drag really needs some looking at because this is completely unintuitive.

Also isn't infiniglide not possible with the control surfaces being super slow?

Edited December 27, 2013 by Jasonbail

[Highlad]

May I ask if infinite fuel is allowed? Probably not, but if not, it would be wise to put it in the rules.

Edit: Kashua, you sir, have ninja'd me.

Edited December 27, 2013 by Highlad

[obi_juan]

My computer is just enough to run the game, but if you want I could try to make a video of this Dive.

To obtain this velocity I was thinking in use Jool gravity help... But I also wanted to have an orbit in the opposite direction to the orbit of EVE... So any help of Jool will reduce a little my velocity so at last I made a high orbit of 7 years around Kerbol, in the highest point I change the direction of my orbit with only 800m/s.

The ship had 7 LV-N Atomic Rocket Motor and 16km/s of delta-V, all the velocity that I did not use for change the orbit direction was used to accelerate the ship in direction to EVE...

Javascript is disabled. View full album

The minimum altitude by Mechjeb says that was 35.951Km but the lower screenshot was taken at 35.960Km.

And here a few screenshot of the travel

Javascript is disabled. View full album

I have other powered ship with higher drag but 8500m/s delta-V with Aerospikes... So I could make a dive in EVE and come back... But the points will be lower than for this ship.

If anybody wanted to obtain a lower dive than me is very easy:

1) Use the same command pod, is the one with lower drag. Any other part will increase your drag and the deceleration will be higher.

2) Obtain a higher relative velocity to go to EVE. I was playing to this game in the last 3 moths and I don't have good control on the interplanetary trajectories, I'm sure that could be optimized. The other option is build a new ship with double of the fuel and accelerate more.

Edited December 28, 2013 by obi_juan
Added screenshot of the ship and the travel.

[MarcRan17]

does a kerbal have to take part in the aerobrake or can it just be a part?

Good Question. I'm going to say yes, one kerbal, as otherwise you could just send the part with the lowest drag and call it a day.

Actually, that Duna entry should've been disallowed anyway.

In your challenge description you state that the purpose is to aerobrake then circularise after exit. If you don't aerobrake enough to HAVE an apoapsis inside the SOI it shouldn't be allowed.

Otherwise it's pointless, you're just firing mk1 cockpits into the atmosphere as fast as possible.

(It's actually possible to hit Eve at 83,772 m/s)... my best so far. Ofc if you even consider re-entry heating or the G force deceleration you're both dead and atomised.

Perhaps I worded it wrong, you do NOT have to circularize, the idea is to perform an aerobrake that would make it possible, but I have no qualms about it if you just ditch the planet again afterwards. Yes, the point of the competition is more or less to see how fast you can slap the atmosphere with a command pod. And yes, in reality you'd just vaporize, but this is KSP. That's the point.

I don't see infinite fuel and debug menu prohibited anywhere in the rules but I assume it is expected you won't use it.

To prevent dive/launch-without-landing I would suggest specifying that all used thrust must be applied prograde.

I was about to correct you and say that I had banned the use of the Dev console, but it appears I forgot that. Thank you. And also a good point on applied thrust, will edit rules to match.

And in Response to Obi_Juan

Well done. You beat my attempt and I used Dev hacks to prove the concept. I would think that your mechjeb reading is likely more accurate as the in game altimeter seems to take just a little bit more time switching values as it has to cycle through them vertically. Your final score is Eve's altitude, 96708.574 - your lowest altitude, 35,951.3, multiplied by two for doing it without engines, = 121,515pts, putting you in first place. Well done!

[totalitor]

I didn't have a kerbal onboard, so my entry is not good. Delete that, I will try another time. I have hit Eve 40000 m/s, but kerbal with command seat didn't survive.

[MarcRan17]

I didn't have a kerbal onboard, so my entry is not good. Delete that, I will try another time. I have hit Eve 40000 m/s, but kerbal with command seat didn't survive.

If you manage a closer pass I'll update your score, But I made that rule change after your entry, so I think it's only fair to allow you to keep your position. Additionally, the purpose of the 1 kerbal rule is more or less to ensure someone doesn't send a single tiny piece of debris through which has minimal drag, though this is still countered by the fact that the Mark 2 cockpit has lower drag than most parts in the game if I recall... all the same it's not really an important rule, you still performed an aerobrake with a craft roughly the same parameters of a manned pod, so I'll still count it if you'd like.

[metaphor]

RCS ports have a drag of 0.001:

21,696 m lowest altitude coming in at 30 km/s. Sorry about the freeze frames, my computer can't handle the aerobraking and video recording at the same time.

[totalitor]

I made a new attempt. I had speed 40000 m/s when entering Eve's atmosphere. Kerbal died when he was on command seat...but then I send him alone aerobraking. Result : 40720 m.

Do you accept this? Rule says: One Kerbal must go along for the ride.

It did! And no rockets used on atmosphere becouse there were none left.

Metaphor: brilliant idea! I still had more speed...

Edited December 29, 2013 by totalitor

[obi_juan]

RCS ports have a drag of 0.001:

exceptional work, every time that I made a ship the drag was added with the parts, for this reason I use the command pod with lower drag... But RCS port reduces drag, very clever to notice it.

Also the drag of the drag of the Mk2 Cockpit is only in the surface of the cylinder. The program don't give to the front of the cylinder or the bottom any drag. the disadvantage or use so many RCS ports is that the ship mass is increased. In a quick mock of your design I found that the drag of your ship will be around 0.009, near of the 10% of the original drag.

Without the linear RCS in the front of the command port the drag was the same, using RV-105 RCS Thruster Block in the front the drag don't change.

I suppose that your clever design was that MarcRan17 was looking for in this challenge.

I wonder if there another person with a better design.

[metaphor]

The total drag of a craft is based only on the sum of each individual mass * drag. So a ship with one command pod with 0.08 drag and 1 ton mass and 100 RCS thrusters with 0.001 drag and 0.02 ton mass will have a total mass of 1+100*0.02=3 tons and a total drag of ((1*0.08)+(100*0.02*0.001)) / 3 = 0.027.

The more RCS ports you put on it, the higher the mass will be but the closer the total drag will come to 0.001. (Don't use the linear RCS ports, they only have a drag of 0.01) Since there's only so many RCS ports you can put on the side of the cockpit, an idea for a ship with even less total drag might be a ship with massless cubic octags on the side filled with RCS ports. That would be a whole lot of parts and lag though, so I'm not going to try it, maybe someone else can.

[totalitor]

New record for me: 37330 m, no engines used on atmosphere. I don't think I can't get any better from this.

[MarcRan17]

New record for me: 37330 m, no engines used on atmosphere. I don't think I can't get any better from this.

Nice Job, I'll update your score