Fool-proof rocket to Mun AND Minmus - minimalist.

[SunJumper]

This challenge is to get a manned rocket to land on the Mun and then land on Minmus, as small (mass) as possible. As it must be fool-proof, the following parts are not allowed:

• Jet engines
  
• Jet fuel tanks
  
• Wing segments (winglets are OK)
  
• Aerospikes
  
• Ion engines
  
• Xenon tanks
  
• Docking ports
  

The design must have all the kerbal(s) in pod(s). You need only one kerbal.

Also, when the pod lands on Kerbin, it must use parachutes, and not use engines at all.

Here is my entry:

On launchpad

On Mun

On Minmus

Splashdown!

Leaderboard:

tavert - 19.2 tons

Sunjumper - 45 tons

Edited April 27, 2013 by SunJumper

[tavert]

It takes less fuel if you land on Minmus first, then the Mun... you want to bring less mass down into the bigger gravity well. Aerospikes are banned but not LV-N's? Otherwise stock+MechJeb?

[SunJumper]

It takes less fuel if you land on Minmus first, then the Mun... you want to bring less mass down into the bigger gravity well. Aerospikes are banned but not LV-N's? Otherwise stock+MechJeb?

It does not matter which you visit first. Aerospikes are banned because they cannot be controlled easily by Mechjeb. The point is that even a new-comer can use the rocket, so it should be completely flyable by Mechjeb.

[tavert]

K, thanks for the clarification. Also guessing you're requiring a manned capsule, Kerbals on ladders would be far from fool-proof. I'll build something shortly.

[shand]

i'll bite. small i imply mass not part count yes?

the deltaV of the various mission profiles will be pretty similar - but visiting minus first will allow you do to it all on a smaller engine and thus have a smaller engine do the whole above orbit mmission without any additional rocket mass.

are we allowed to use mechjeb 2?

[SunJumper]

i'll bite. small i imply mass not part count yes?

the deltaV of the various mission profiles will be pretty similar - but visiting minus first will allow you do to it all on a smaller engine and thus have a smaller engine do the whole above orbit mmission without any additional rocket mass.

are we allowed to use mechjeb 2?

Yes, you may use mechjeb. It is even recommended.

[RFK128]

Just curious as to why the other parts are not allowed. You already explained the Aerospike, but not the others.

[SunJumper]

Just curious as to why the other parts are not allowed. You already explained the Aerospike, but not the others.

Jet engines are disallowed because flame-out screws with MJs navigation

Jet tanks are useless w/o jet engines

Wing segments are only useful in horizontal flight, which is difficult to sustain depending on the craft (a craft with a rocket payload will be difficult to fly)

Ion engines are ridiculously time consuming

And docking ports require docking, which is difficult (less so for MJ, but this is still the case).

A first timer should be able to fly your craft after learning the controls (this in itself is impossible to test, which is why the other rules are in place)

[tavert]

Have you played with MJ2 yet SunJumper? It has a wonderfully useful "prevent jet flameout" feature. But I think jets are overpowered, the lightest way to get anything to orbit at the moment is: add enough jets to get the payload off the ground, then add tons of intakes so you can reach orbital speed at around 40 km altitude. Ruling them out for any mass-based challenge seems reasonable to me. It's likely the jets will get nerfed at some point (will probably have more to do with nerfing the intakes, so they don't just stack, than the jets themselves), whereas rocket designs hopefully won't need too much changing when the drag model gets redone.

[SunJumper]

Have you played with MJ2 yet SunJumper? It has a wonderfully useful "prevent jet flameout" feature. But I think jets are overpowered, the lightest way to get anything to orbit at the moment is: add enough jets to get the payload off the ground, then add tons of intakes so you can reach orbital speed at around 40 km altitude. Ruling them out for any mass-based challenge seems reasonable to me. It's likely the jets will get nerfed at some point (will probably have more to do with nerfing the intakes, so they don't just stack, than the jets themselves), whereas rocket designs hopefully won't need too much changing when the drag model gets redone.

Yes, however I find jets to be too overpowered anyway.

[tavert]

Wasn't sure if it would be enough, but turns out just adding 2 more tons of fuel to an existing design of mine did the trick: http://imgur.com/a/SJlfb#0

19.22 tons on the pad. Went to Minmus first, then Mun, then just barely had enough fuel left to return (went around for a couple extra aerobraking passes).

[shand]

this is why i was asking if we could use mechjeb 2, as opposed to 1. its generally different. with different tolerances and efficencies.

im working on mine but my laptop cant cope atm. looks like 19 tonnes is the thing to beat! got my:

minmus land>minmus ascent>mun land>Mun ascent>Return>Safe landing, stage done for under 10 tones and a lot of spare fuel. may even be able to do LKO to minmus.

[tavert]

The MJ2 maneuver planner is pretty awesome for getting transfer windows right (only 85 m/s from 10 km Minmus orbit to transfer to Mun!). And it has a real Lambert solver for course corrections. Even with Minmus at nearly 90 degrees from its AN/DN, it got me there with only 40 m/s correction burn. And I might be imagining this, but it feels like the "Land anywhere" autopilot is much more aggressive in its suicide burn than it used to be.

[SunJumper]

The MJ2 maneuver planner is pretty awesome for getting transfer windows right (only 85 m/s from 10 km Minmus orbit to transfer to Mun!). And it has a real Lambert solver for course corrections. Even with Minmus at nearly 90 degrees from its AN/DN, it got me there with only 40 m/s correction burn. And I might be imagining this, but it feels like the "Land anywhere" autopilot is much more aggressive in its suicide burn than it used to be.

Yes, the suicide burn previously was just a braking burn.

[Syre]

Eh. The whole point of this challenge being for mechjeb just kinda ruins it for me.

[Sputnik-1]

The whole "Mechjeb is okay for everything but everything is not okay for mechjeb" sort of irks me. Why should aerospikes and jet engines be banned just because an AUTOPILOT can't handle it, barring it from us other pilots that fly manually?

ADding on:

A beginner should be flying manually, how are you supposed to learn when you aren't piloting your ship at all?

I'm going to whip something up for this challenge anyways.

Edited April 22, 2013 by Sputnik-1

[SkyRender]

The whole "Mechjeb is okay for everything but everything is not okay for mechjeb" sort of irks me. Why should aerospikes and jet engines be banned just because an AUTOPILOT can't handle it, barring it from us other pilots that fly manually?

Well, that's kind of why it's a "fool-proof" rocket. Jet engine and aerospike rockets are much more finnicky even without an autopilot. The idea is to engineer a rocket that is reliable and useful even for new players, as well as being able to go places besides just to orbit.

I might adapt one of my classic rockets to this challenge when I get home later.

[Sputnik-1]

Well, that's kind of why it's a "fool-proof" rocket. Jet engine and aerospike rockets are much more finnicky even without an autopilot. The idea is to engineer a rocket that is reliable and useful even for new players, as well as being able to go places besides just to orbit.

I might adapt one of my classic rockets to this challenge when I get home later.

I understand the "fool-proof" thing. But jet engines aren't hard to manage, and IIRC mechjeb 2 has anti flameout.

[Istas]

SunJumper: I'm going to ask you to specifically state that you need one of the manned pods, cockpits, or cans, because as stated the rules allow having a Kerbal cling to a ladder. I know that violates the -spirit- of the challenge, but if it's not clearly stated I'll be tempted to do it, or disappointed if someone else does.

[MoShY]

My question is about MechJeb, if new players are supposed to fly these rockets. Would it be better if they flew it themselves and got experience not just sit there and watch a program do all the work?

[Wait- Was That Important?]

It does not matter which you visit first. Aerospikes are banned because they cannot be controlled easily by Mechjeb. The point is that even a new-comer can use the rocket, so it should be completely flyable by Mechjeb.

I would argue your point. If the newcomer isn't using MechJeb, then Aerospikes are just the same as any other engine for them- they have gimbals and work the same. A newcomer could use them if they flew manually which, presumably, most newcomers will at first

[SunJumper]

My question is about MechJeb, if new players are supposed to fly these rockets. Would it be better if they flew it themselves and got experience not just sit there and watch a program do all the work?

Because Mechjeb would find some of these parts tough to handle, a new player would too flying manually.

[Istas]

My question is about MechJeb, if new players are supposed to fly these rockets. Would it be better if they flew it themselves and got experience not just sit there and watch a program do all the work?

Please let's not get into another mechjeb yes/no discussion, that has happened far too many times and has been talked to death.

[Guest]

Ok, here we go!

Jeb drank a little to much and now has to take a leak.

Ok, under way now.

Jeb was asleep the first time by, but after a few extra times around he finally gets it dialed in.

It was a long ride. Time to stretch.

Jeb's gettin warmed up now.

Next stop : The Mun!

Coming in a little hot!

Jeb, have you been drinking again?

Okay! Home sweet home!

I hope the chute doesn't catch on fire.

Would somebody please come pick me up?

I really had big fun putting this together. KSP is a beautiful game.

(i turned on infinite fuel. Does that count?)

Edited April 23, 2013 by Otis

[tavert]

I understand the "fool-proof" thing. But jet engines aren't hard to manage, and IIRC mechjeb 2 has anti flameout.

Not hard to manage especially with MechJeb 2, but they are way overpowered. Anything judged on mass will be forced to use jets if they're allowed, so the designs are more varied without them.

SunJumper: I'm going to ask you to specifically state that you need one of the manned pods, cockpits, or cans, because as stated the rules allow having a Kerbal cling to a ladder. I know that violates the -spirit- of the challenge, but if it's not clearly stated I'll be tempted to do it, or disappointed if someone else does.

I've been trying for several days now to get a 2.22-ton jet-powered contraption to and from the Mun with 2 Kerbals hanging on to ladders, it's really tedious since you can only use 4x physical warp. Also be very careful at the SOI transition, it's best to let go of the ladders while you change SOI otherwise Krakensbane can tear your ship apart and/or send your Kerbals flying. I probably would have gotten it done by now if I weren't trying to do it using only 60 units of fuel for the entire trip. If you have the patience to go to Minmus too, I applaud you. Though I'm guessing SunJumper won't approve for this challenge.

I would argue your point. If the newcomer isn't using MechJeb, then Aerospikes are just the same as any other engine for them- they have gimbals and work the same. A newcomer could use them if they flew manually which, presumably, most newcomers will at first

Aerospikes don't have gimbals. And the drag issue tends to make rockets with aerospikes unstable if they're placed behind the CoM (as engines usually are), although with enough winglets that can be fixed. If you're scoring on mass like this challenge, I think aerospikes are legitimate and there's no harm in allowing them, they have their uses but I don't think they are the best choice for this particular task anyway.

Edited April 23, 2013 by tavert