Moho on a budget

[MarcRan17]

I'm sure most of us have been there: your mission plan didn't quite estimate delta-v right and now your probes are drifting in interplanetary space, out of gas and lonely. I've been working on a ksp career save for about a year now, slowly working away shooting off probes in every which direction, and while I've had many successful missions and many on the go, my biggest failure to date on this career has been Operation Infernus. The goal was to place three probes at Moho. One a lander, one an orbital cartography satellite, and one an orbital science satellite. All were for not however, as none were capable of slowing down enough for capture and now they're drifting in low solar orbits, entirely useless to me. 

So I gotta get to Moho eventually (for science!) but I'm working on a very tight (hard mode) budget. I wanna plan the second attempt a little better,  so that I can get to Moho and do all the intended science for as cheap as humanly possible. Now, efficient engines are swell and all, but efficiency in hardware comes at a price. I wanna know what kind of clever planning and design can get me to Moho for the lowest possible funds cost. And that's my challenge to you! Construct a rocket that can get a minimum 1.5 ton payload to Moho, for as little funds as possible. I wanna know your design tricks, I wanna know your wacky but efficient manoeuvring techniques. I want to see the cleverest, cheapest way to send a 1.5t payload to a low Moho orbit. 

 

GROUND RULES:

>payload must have a mass of at least 1.5 tons. 

>final Moho orbit should have an apoapsis no greater than 500km and a perhaps is no greater than 100km

>bonus points will be awarded if you perform the mission after year 2 day 250

>further bonus points will be awarded if you come up with a manouver that's particularly clever. (as judged by me ) 

>a specific set of mods are allowed as follows:

-RLA stockalike 

-Kerbal Engineer Redux

-Dmagic (though it won't really help) 

-Ask about any others, but those should be it for part mods 

 

SCORING:

Score will be directly determined by launch cost. Since payload is only being judged by mass, not content, the cost of the launch should be recorded without a payload. Without a payload, the vehicle should cost no more than about 80000 funds. So, from this I'll determine score. The cost of your vessel at launch, minus the payload, is to be subtracted from 80000. The difference will be your score. Highest score wins. If you performed the mission after y2d250, you'll be awarded an additional 5,000 points. If I found your manoeuvring particularly clever, you'll earn an additional 10,000 points. Thus the theoretical maximum score is 95000, but of course I expect the best submission won't crack 50000. 

 

To submit an attempt, simply reply to this post with a photo of your payload, with either KER or the engineer's report demonstrating that the payload's mass is at least 1.5ton, as well as photos of the vehicle at launch, and in the designated Moho orbit, including  a detailed explanation of your flight plan. Video submissions are of course also welcome. 

 

Best of luck, and happy flying! 

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CURRENT LEADERBOARD:

Maccollo                                     75079 points 

Jetski                                          36334 points

Edited May 29, 2016 by MarcRan17
leaderboard update

[Jetski]

Just getting the ball rolling here.

My attempt leaves lots of room for optimization.  I used about 6K dV to get into Moho orbit, could have saved a little by changing inclination and doing another Pe bump.  Also an Eve flyby would have saved some.  Kept it pretty simple this time, one Pe bump to inside Muns orbit, second bump is an 8 minute NERVA burn to get Moho intercept.  Then an inclination correction just outside of Kerbin's SOI left me with only about 2K braking burn at Moho, very doable with another 8 minute NERVA burn.  I had 11,800 dV to start, so not counting payload I have 5500dV left over. More than enough to get back home if needed.

I made a little Moho lander as my payload, exactly 1.5T, and landed it safely.  A little short of getting back to orbit, but doable if you land on a mountain or are better at suicide burns than I am.

Total cost was 51854 - 3188 for the payload = 48666, giving me a score of 31334.

Window was y3d90 so add 5000 (I'm not sure I understand the point of this, all I had to do was timewarp a while)

Total score 36334.

 

 

 

[virchau]

Would multiple gravity assists count as clever maneuvers?

[maccollo]

On 5/22/2016 at 0:24 PM, MarcRan17 said:

The difference will be your score. Highest score wins. If you performed the mission after y2d250, you'll be awarded an additional 5,000 points. If I found your manoeuvring particularly clever, you'll earn an additional 10,000 points. Thus the theoretical maximum score is 95000, but of course I expect the best submission won't crack 50000. 

Challenge accepted.

Rocket cost minus the payload is 13340. Launch happens on year 3, day 84, so the score is 80000+5000-13340=71660
There's still some room for improvement, as I screwed up the capture burn quite badly, and suffered significant gravity losses as a result. Still had enough margins to get the 1.5 ton payload into a 35x35 km orbit.

 

Edited May 27, 2016 by maccollo

[Spartwo]

Seems like fun, expect to see this post updated.

[MarcRan17]

@Jetski Nicely done! Yeah i don't really know why I thought the date bonus made sense. It's specifically relevant to the date in my Career save, but It was late when I drafted this post. Didn't really think it through. Oh well, I suppose most everyone gets a 5000 point bonus then... 

@maccollo Very nice! Consider me happily surprised. I did NOT expect a rocket that cheap to make it that far. I guess it has a lot to do with using conventional engines instead of NERVAs or ion propulsion. Also, that transfer... Your plane change was only 21.2m/s... I'm not sure I quite caught all that happened there in the video, Don't have a lot of time to rewatch though. Was your transfer done while at Moho's AN, or DN?

@virchau Yes, If you can find a way to pull of a bunch of gravity assists that get you to Moho, then by all means!

@Spartwo I hope so!  

[maccollo]

@MarcRan17 The inclination change is done during the escape burn. That's also why I launch towards about 110 degrees instead of 90 degrees. The launch window is pretty easy to remember: Day 84, 6:00 Kerbin time.As for the Nerva, it really doesn't make sense for these small payloads. I think it's possible to redesign my rocket to cost less than even a single Nerva.

[MarcRan17]

Huh. Very interesting. I never even thought to try going interplanetary without nuclear... I mean I always knew it was possible, just always for some reason assumed it was inefficient. 

[virchau]

Can you use KAC (Kerbal Alarm Clock)?

[MarcRan17]

@virchau Sure, absolutely. Doesn't make the actual rocket fly any better. 

[maccollo]

Redesigned the launcher. More kickbacks is always the answer! Rocket cost minus the payload is now 9921, less than a nerva engine. Launch date is the same as last time, year 3, day 84/85, so the score is 75079.

 

[herbal space program]

So would you consider awarding further bonuses for more ambitious missions with lifters under the original cost limit? I'm working on a lifter that I think can land Jebediah and return him home for a little over 50,000. While this wouldn't score so well with the current rules, I think it does address your broader goal of maximizing ROI for a Moho mission. Landing Kerbals and bringing them and their experiments back would greatly increase the amount of science and money your investment will earn in a tight career game. Anyway, it's just a thought. I'll of course post my mission either way.

[MarcRan17]

@maccollo Huh. Moar boosters actually IS the solution then... I dunno why I ever doubted as much. Nice submission! That capture burn is a doozy though huh. 

@herbal space program I mean I suppose I could. Not sure how I would math that out though... Double points for return? Fixed rate? Points based on payload mass? But then how do I factor in mass and cost simultaneously? (suggestions are welcome) 

Edited May 29, 2016 by MarcRan17

[herbal space program]

1 hour ago, MarcRan17 said:

 

@herbal space program I mean I suppose I could. Not sure how I would math that out though... Double points for return? Fixed rate? Points based on payload mass? But then how do I factor in mass and cost simultaneously? (suggestions are welcome) 

How about if we get to multiply our scores at the end by the ratio of our payload mass to the 1.5 ton minimum, keeping the original base score calculation and 80k limit on lifter cost? The more mass you send, the lower your base score will be, but the higher the multiplier. Above some mass, it just won't be possible any more with a lifter significantly under 80k, so cost is still a factor. Landing the payload and/or returning it to Kerbin safely could each also create score multiplier, say 1.5X. With multipliers rather than fixed bonuses, your base score, that is how cheaply you can bring the whole thing home, will always still be a key factor. If the whole challenge is  about getting a 1.5 ton payload into  500km orbit, I feel like we're already pretty close to being done with Maccollo's entry.

Edited May 29, 2016 by herbal space program

[MarcRan17]

@herbal space program hmmmm not a bad plan. I agree with you on the last point for sure. Not much better than a <10k funds rocket. I'll look into it when I'm off of work.