The Micro Mechjeb Mission

[Foxster]

Here's a little challenge for all you Mechjeb experts and those that want to learn to be.

Your mission, should you choose to accept it, is to get a tiny craft into a stable Kerbin orbit using a fixed set of items, with the flight controlled only by Mechjeb.

Here is what you may use. You must use only these parts and you must use them all:

2 x O-10 engines

2 x RV-105 thruster blocks

1 x QBE probe

1 x Z100 battery

2 x FL-R10 RCS tanks (one must be full and the other contain 56 units)

1 x AR202 Mechjeb case (or add Mechjeb to the QBE with Mechjecb Engineer for All)

The rules:

1. You may arrange the parts in any order and change their angles but you must use them all and no others.

2. The craft must stay in one piece and you may not use a Launch Stability Enhancer

3. The entire trip must be controlled by Mechjeb's Ascent guidance and once its on you can't turn it off

4. Once the craft is on the launchpad you may only press these keys as follows:

Mouse click the "Engage autopilot" button in Mechjeb (i.e. no turning autopilot on once in the air)

The R key once (optional)

The T key once (optional)

The Z key once

The space bar once

5. You may press no other keys i.e. no manual steering or changing throttle

6. No use of other Mechjeb guidances such as Landing, Docking, Maneuver Planner, etc.

7. No other mods. No shrinking parts or altering their physics or properties.

8. No refueling with cheats, mods or otherwise.

The challenge will be to use Mechjeb's dozens of options and adjustable values to achieve an optimal controlled flight to orbit using parts barely capable of doing so.

The winner will have the highest Pe in a stable orbit around Kerbin and this must be above 69,077.553m (top of atmosphere).

Your entry will require a single screenshot of your craft in orbit showing all the relevant Mechjeb windows where you have set values and chosen options, plus the Orbit Info window.

I need to be able to reproduce your craft and flight so either tell me of any tweaks I need to make or post a craft file. Note that there are sometimes slight variations that creep in even on such a short journey, so if you manage to get a great Periapsis once but then I can't reproduce it then I'm afraid it won't count.

Good luck!

--------

Those who managed to hit the spacebar and then sit on their hands as intended:

OP - 69.674km

Those who couldn't resist fiddling:

EdFred - 80.024km

Edited January 17, 2015 by Foxster

[Cmdr. Arn1e]

Challenges like this usually require the OP's attempt!

this seems like a very restricted challenge, which might turn a lot of people off, but seems to be totally valid under the rules and regulations, bar your attempt to kick things off to show what is possible

[Foxster]

Ah, I know what you mean. I have done this though. I wouldn't set a challenge if I couldn't. Its just that if I do show my solution then it will give away both one of the few (the only?) possible designs and how to have MJ fly it. Which would make doing the challenge a bit pointless.

I will say that the craft is straightforward - albeit with one small logical tweak required to optimize dv. The 'skill' will be in getting MJ to fly it, which is also quite possible once you figure out the best way to get it to do so. In other words, there is no trick to this, its just a matter of arranging the parts and choosing the right MJ options and values.

I certainly learnt something about MJ from doing this. I always previously wondered why I could launch minimum dv craft better than MJ, so I decided to figure out why. Others just might learn something about the plethora of often undocumented MJ features while trying this challenge.

If it doesn't grab anyone at all in a day or so I'll post my solution and folks can then improve on it if they want to.

Edited January 14, 2015 by Foxster

[Wavechaser]

Erm, it may be possible, but it's extremely hard to achieve a stable orbit around Kerbin only using the smallest monoprop tanks and some monoprop engines. Seriously, 2 may be too hard.

[foamyesque]

Without Mechjeb at all, but otherwise hewing to the challenge requirements, I can consistently hit 120x-40 orbits. It's probably possible, but I'd like to see OP's solution.

[MarvinKitFox]

Translation:

"I built this here contraption, and fiddled with it until it rolls over and begs for lunch. Now YOU do the same, with less motivation"

no thanx

[Foxster]

Translation:

"I built this here contraption, and fiddled with it until it rolls over and begs for lunch. Now YOU do the same, with less motivation"

no thanx

Fair enough. The idea behind the "contraption" was that it is the lightest possible stock craft that can achieve orbit (or at least that came out another challenge to do so) and there is a max dv (that I know of) that can be achieved with it. Once the fairly trivial build is done then the 2nd part is to get MJ to fly it to orbit, with a level playing field on the craft design.

I'll give a clue...The launch dv I had from the craft was 4686m/s and that is through no cheats, mods or abuse. Just from positioning the parts. Hopefully we can all agree that should be enough for a ~70K orbit.

Unless someone is still working on it and doesn't want their efforts spoiled then I'll post the craft picture (but not how to set MJ to fly it) later today.

[EdFred]

KSP computer is at home, but I know you gotta rotate the engines to maximize the thrust vector. After that it's determining when to start the gravity turn and at what turn percentage to do so.

[foamyesque]

Unless someone is still working on it and doesn't want their efforts spoiled then I'll post the craft picture (but not how to set MJ to fly it) later today.

Eh, go ahead. I was working on it, but like I said, I don't have MechJeb, and without it do so some throttle management my best was 120kmx-40km. Control sequence was R, spacebar, and lock in T as the craft became horizontal. A picture wouldn't really impact my efforts either way because I was balancing it to far more precision than a screenshot would display anyway.

[Foxster]

[Foxster]

My attempt...

[EdFred]

I made a 80 x 96 orbit and I followed the above rules. What was NOT listed in the rules was the prohibition of using the mouse button.

How I accomplished was ad follows:

Engaging the limit the acceleration to 22.5m/s

Click engage engage autopilot

Press space bar.

At 6500-6700m press R

Above 20,000m click the mouse button to de-limit acceleration.

[flashcactus]

I'd love to try, but I have exams going on now … the part positioning is fairly obvious, though. I guess no other mods also means no FAR, which makes things a tad less interesting for me but nonetheless worth trying. Also, does this have to be done in 0.90? (it has several memory leaks and I don't have that much RAM).

There's also a possibility I'll go and do a full-on analysis to try and determine the optimal parameters once I get to it

- - - Updated - - -

I made a 80 x 96 orbit and I followed the above rules. What was NOT listed in the rules was the prohibition of using the mouse button.

Gotta love dem loopholes…

[Foxster]

I made a 80 x 96 orbit and I followed the above rules. What was NOT listed in the rules was the prohibition of using the mouse button.

http://webpages.charter.net/edfred/mechjebmicro.jpg

How I accomplished was ad follows:

Engaging the limit the acceleration to 22.5m/s

Click engage engage autopilot

Press space bar.

At 6500-6700m press R

Above 20,000m click the mouse button to de-limit acceleration.

Well, yes, but I think you do know that the idea was to let MJ fly the craft rather you helping out. This would seem to cover that:

3. The entire trip must be controlled by Mechjeb's Ascent guidance and once its on you can't turn it off.

Good effort though.

I'll create one result table for those that can hit the space bar and then sit on their hands and one for those that just have to have one more key or mouse button press.

- - - Updated - - -

I'd love to try, but I have exams going on now … the part positioning is fairly obvious, though. I guess no other mods also means no FAR, which makes things a tad less interesting for me but nonetheless worth trying. Also, does this have to be done in 0.90? (it has several memory leaks and I don't have that much RAM).

There's also a possibility I'll go and do a full-on analysis to try and determine the optimal parameters once I get to it

You'd be surprised about it being obvious. A lot of us would assume, like most of the engines, that it just points down and so is optimal by default.

No other mods. Once you open that can of worms there really can't be a level playing field. For the same reason it needs to be 0.90.

Be good if you did do the analysis. I hope there's some killer setting or values that will mean we can get MJ to fly a craft to orbit even better.

Edited January 17, 2015 by Foxster