Tatonf

Ok I played KSP for two years and I know how to capture a rocket with retroburn or aerocapture. I also know what a gravity assist is. But I was wondering : in real life, planets can "capture" asteroids. How does it works ? I mean, the asteroid can't do a retroburn, and if they manage to get "aerocaptured" it means that their periapsis is inside the planet's atmosphere and they will eventually fall on the planet. So, how does it work ? How Eve have been able to capture Gilly for exemple ? Can we do something similar with spacecraft ?

I've been thinking to it and I don't think I'm going to do that. Mainly because you can just spam decouplers brainlessly because there's no TWR restrictions, and that's just boring.

I don't know... Reaching an orbit gives you a goal, and I designed all the challenge around it. What kind of goal would you want to set ?

Can you be more specific ? Basically this challenge is already about ships doing maneuvers in space with only decouplers.

Thanks PixelStory. This is my competitor which orbited Ike. Each plate have 6*2*3 TT-38K decouplers under it. When they are gone the craft is pointed retrograde et 2*7 TT-38K are decoupled. You can download the .craft here. - - - Updated - - - It might be when the game will use Unity 5, but even there I have doubts too. Maybe be a giant pyramid can do it ? But I only putted here for fun, I don't think anyone could do it. Moho/Vall are already a big big challenge.

Introduction As you might know (or not), the Orion project was the first study about a spacecraft moved by nuclear bombs. While the project never saw the light due to the nuclear test ban treaty, some prototypes were built with conventional explosives. You can see one of them in .While KSP doesn't feature nuclear bombs (which is a shame), it features explosives in what we call decouplers ! Your mission, should you decide to accept it Is to build a spacecraft capable of reaching an orbit using only decouplers. The spacecraft is landed at the begining of the challenge. Should your vessel explode during the process, your insurance will disavow any knowledge of your actions. Rules - Stock parts only. - Only aesthetics and informational mods. HyperEdit is highly recommanded. - No physic abuse / file editing. - No mad cliping with the offset tool - You are free to pick the celestial body of your choice, but it musn't have an atmosphere. - Your rank is determined by which body you choose. - The craft consists of at least a pod of your choice. - The challenge begins with a landed craft. You are free to use any mod until there. - The landing location is up to you. Feel free to go to the highest mountain. - The only propulsion type allowed is decouplers. You craft must NOT change it's velocity by any other means. - "Orbit" is defined by getting your periapsis above the highest mountain of the celestial body you picked. Reaching escape velocity is also accepted. - Post pictures/video of your exploit or it didn't happen. Preferably with KER or Mechjeb window open. - Posting the .craft file is preferable. Decouplers You are free to use all the decouplers of the stock game ; they are listed below along with their Isp that I determined with experiments. And no, there's no error, they're really that bad. Because Mechjeb/KER aren't designed for calculating delta-V provided by those things, you'll have to do it yourself with the following formula : [TABLE=class: grid, width: 500] [TR] [TD=align: center]Image[/TD] [TD=align: center]Name[/TD] [TD=align: center]Isp (s)[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]TT-38K Radial Decoupler[/TD] [TD=align: center]11.4[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Hydraulic Detachment Manifold[/TD] [TD=align: center]2.9[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]TT-70 Radial Decoupler[/TD] [TD=align: center]6.5[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Structural Pylon[/TD] [TD=align: center]2.3[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]TR-2V Stack Decoupler[/TD] [TD=align: center]1.1[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]TR-2C Stack Separator[/TD] [TD=align: center]0.8[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]TR-18A Stack Decoupler[/TD] [TD=align: center]6.3[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]TR-18D Stack Separator[/TD] [TD=align: center]4.6[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Rockomax Brand Decoupler[/TD] [TD=align: center]1.6[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]TR-XL Stack Separator[/TD] [TD=align: center]3.6[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]TR-38-D Stack Separator[/TD] [TD=align: center]0.5[/TD] [/TR] [/TABLE] Celestial Bodies In this section is listed the different celestial bodies where the challenge can take place, along with the rank you'll get for orbiting it. The highest point serve as reference for orbit's periapsis and the coordinates is where this point is (for Hyperedit, should you use it). They are provided by kerbalmaps and there's no warranty. [TABLE=class: grid, width: 1000] [TR] [TD=align: center]Picture[/TD] [TD=align: center]Name[/TD] [TD=align: center]Highest Point (m)[/TD] [TD=align: center]Coordinates (Lat/Long)[/TD] [TD=align: center]Rank[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Gilly[/TD] [TD=align: center]6400.7[/TD] [TD=align: center]-29.2566 / -123.8708[/TD] [TD=align: center]Do you even try ?[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Pol[/TD] [TD=align: center]5590.3[/TD] [TD=align: center]-62.8308 / 164.5862[/TD] [TD=align: center]Aspiring decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Minmus[/TD] [TD=align: center]5724.7[/TD] [TD=align: center]-62.9297 / 74.7290[/TD] [TD=align: center]Confirmed decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Bop[/TD] [TD=align: center]21755.0[/TD] [TD=align: center]23.8733 / -64.5667[/TD] [TD=align: center]Confirmed decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Ike[/TD] [TD=align: center]12735.2[/TD] [TD=align: center]25.7295 / 178.2971[/TD] [TD=align: center]Explosive decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Dres[/TD] [TD=align: center]5669.8[/TD] [TD=align: center]-85.0012 / 42.6379[/TD] [TD=align: center]Explosive decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Eeloo[/TD] [TD=align: center]3873.5[/TD] [TD=align: center]24.3347 / 27.9602[/TD] [TD=align: center]Staged decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Mun[/TD] [TD=align: center]7061.2[/TD] [TD=align: center]-82.5183 / -152.3254[/TD] [TD=align: center]Staged decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Moho[/TD] [TD=align: center]6817.4[/TD] [TD=align: center]54.6790 / 153.4900[/TD] [TD=align: center]Mad decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Vall[/TD] [TD=align: center]7989.2[/TD] [TD=align: center]-57.4915 / -144.4592[/TD] [TD=align: center]Mad decoupler[/TD] [/TR] [TR] [TD=align: center][/TD] [TD=align: center]Tylo[/TD] [TD=align: center]11282.6[/TD] [TD=align: center]-54.7786 / 20.5774[/TD] [TD=align: center]Scott Manley[/TD] [/TR] [/TABLE] Reward Each time you'll hit the space bar you're likely to hear your decouplers exploding when hiting the ground ! KABOOOM ! (And anyone willing to draw a badge to put in the signature is welcome because I don't even know how to draw a circle on paint) Hall of fame - Tatonf - Explosive decoupler - Orbited Ike Have fun !

I agree that it should be more usefull on Eve but... Would it be a good idea to modify the engine so it would only be usefull in only one situation (ascending from Eve) ?

Thanks for the advice, but ajbuges reminded me that you can make EVA report from the external seat, which is much more convenient.

Well I've been avoiding everything related to planes since I started to play this game 2 years ago, so it's gonna be hard, but I'll give it a try. Thanks !

Yes you're right, I was only thinking of the blocks.

Hmmm may be. But I must be able to right click on the kerbal. May be if I zoom in correctly...

Monopropellant is good only for docking and turning big spacecraft if you don't like reaction wheels. But as you said LF+O have better ISP, and therefore is always a better alternative for everything else. Actually if you could get RCS powered by LF+O instead of monopropellant, it would make the monoprop completly useless.

Ok here's the challenge : getting an EVA repport while flying at Jool AND returning the kerbal back into Jool's orbit. But that's quite hard, because it means going under 120 000m. I tried aerobreaking but that's too hard, even from low Jool orbit your speed is still 5668 m/s, which leads to burning from 198 000m. Because you need fuel and engines to make your ascent, your ship is heavy and therefore have more energy to lose, and the heatshield doesn't seem to handle it. I tried to stack several of them with decouplers, but as soon as I stage everything explodes (because of overheathing says the report). What I could do instead is a power descent, but that would require around 3000 m/s of delta-V if I want to bring my speed to 2668 m/s, not acounting for the gain of speed because of gravity. But that's still doable. My main concern is how to get the Kerbal out to make the EVA report. If he have to support a too strong G-force he just fly off the ship. So it means I have to slow down my ship enough so the atmosphere doesn't slow my vessel, which basically means briging my speed near to 0m/s... And which means I need around 6000 m/s to go back into orbit ! If I could save some speed from my orbit that wouldn't be that hard, but I don't know how to do that. The last problem is the ascent. You can't go above 2500/3000 m/s at best while inside Jool's atmosphere no matter what your altitude is, but you need to achieve 5668 m/s for orbiting Jool. So yes, you can just go straight up and make a radial burn while is space, but that's ineficient compared to a good gravity turn, meaning you need more delta-V... The only good new is that Jool's atmosphere isn't that dense at 120 000m, atomic motors are still working with an ISP of 555s at this altitude (though it decrease quickly at this point, only 400s at 110 000m). But using atomic motor is adding heat to an already existant heat problem...

And hopefully they'll do something about those stupids impossible aerobreakings with less useless heatshield and ships not exploding at 198 000m.

As everyone know, no one has ever been to Dres. I don't know why we should change that by adding interesting features to it.

Indeed. That is because the Sun have an atmosphere starting à600 000m.

Try to disable the gimbal of your engines (right click on them). Sometimes they are causing the wiggling.

The small inline reaction wheel consumes 15/min and the pod 1.8/min for a total of 16.8/min ; while a single OX-STAT provides 21/min, so you shouldn't have any problem with electric charge. Duna is not far enough to have problems with photovoltaic panels. I don't use any limiter, just engage the SAS and it should be ok. It's true that this reaction wheel is overpowered for this kind of craft but it's totally doable. Howerver here's a tip : if you press Caps Lock you can enable smooth controls.

I did that on purpose because if I have low TWR I would burn further away from the Mun and lose some Oberth effect. To make direct ascent equivalent to orbit you have to burn everything before reaching the altitude of the orbit. Isn't the delta-V gain with the orbit that you all talk about just come from the Oberth effect ?

Well in a challenge way that's ok I think, since it makes your spacecraft smaller. For a more practical solution you could do the same thing that I've done : decouple your parachute. EDIT : I know remember why I choose the spider : their gimbal were supposed to maintain the stability of the craft without a reaction wheel.

I have troubles landing without a drogue chute, but I guess it's possible at low altitudes. I considered the ant engine but though the TWR would to be to week.

I can't think of anything smaller : This 565 kg craft features : - The probodobodyne OKTO2 for control - A Z-200 battery plus 2 photovoltaic pannels for electricity. You could get rid of the battery and one of the panel, but it lets you with only 5 electricity units. While possible it's too annoying. - An Oscar tank and two spiders for thrust - A Small reaction wheel. Even if the spiders are supposed to have great thrust vectoring (8° !) the spacecraft was totally uncontrolable without it. I don't know why. - A normal chute and a drogue chute for landing. The drogue chute is decoupled during landing, which allow a 300 m/s boost in delta-V. Here are some pictures I made : Note that the chute isn't enough for slowing the spacecraft, you have to use some retrorockets. I picked a random landing site (only condition was on the day side), but I think it could go ASL. While il would consume a bit more fuel to go back in orbit, the parachute would be more effective, so it doesn't change anything I think.

I tried the two different methods from the Mun and found out that the two technics are equivalent in terms on delta-V (which makes sense). However on Kerbin a vertical ascent requires much more delta-V. I deduced that atmospheric frictions were responsible of that. As said above you can do a "direct ascent" with a gravity turn but that just mean you're making an orbit without stopping the engines for your escape. For me it's orbit.

This is a bit sad because you just need a bit more to get the full ship home (550 m/s with a burn at periapsis). I tried some Ike slingshoot but the fact that your orbit is retrograde AND inclined by 15° doesn't help at all. Most of the time you end up with orbits that makes your ship crash on Duna or put you into an even more inclined orbit. I got some eliptical orbits that would have a periapsis at 60 km for better Oberth effect and a pretty high apoapsis. Problem is, you would need to wait an unknow numbers of windows before the apoapsis get ligned up correctly so a burn at periapasis would get you home with a Hohmann transfer. Or you could go for some Duna gravity assist. But I got bored with that so good luck.

I don't know if there's a mod which support that, but having parts capable of creating water/food/oxygen would be the best way to go I think. This is what they plan to do for Mars One I think.