Bring our boys far [winged SSTO "advanced" challenge]

[tseitsei89]

Ok here goes:

My craft named FruitsAreHealthy is using 2x rapier and 1x skipper.

Pictures of the ascent and reentry: http://imgur.com/a/zr4DG

And a video of the landing since I didn't have enough hands/concentration to keep pressing F1 while simultaneously landing  https://www.youtube.com/watch?v=cZT7U80Jcpg&feature=youtu.be

Not my cleanest and nicest landing but didn't break anything so it should be fine

So the score: TWR(surface) is 3.00 with rapiers in rocket mode and skipper activated and I have 1880m/s dv left as can be seen in this picture 

So that means ln(1+3.00)*1880 = 2606.23 points in Rasberry category if I didn't miscalculate

Edited December 27, 2016 by tseitsei89

[Signo]

@tseitsei89: thank you for your entry. That is indeed correct and a wonderful effort. 2606.23 points for you in the berry table. Lovely "aero".

[foamyesque]

Okay, so. Two approaches, then:

 

1. Airbreathing engines are for the weak:

7.39 TWR, 348m/s dV, 20 Kerbals, six-axis RCS control & docking port. Score: 740. I imagine swapping out the passenger module for a short rocket fuselage filled to equal mass would significantly boost that (somewhere around 2.5x, I believe).

2. SSTO:

Orbit stage:

TWR 5.93, dV 238m/s. Score: 460

2nd stage:

TWR 1.06, dV 3769m/s. Score: 2724

3rd stage:

TWR 1.55, dV 2388m/s. Score: 2235

Aggregate score: 5419. One pilot, five-axis RCS (no pitch controls, but the pod can handle that) for the 3rd stage, but no docking ports.

 

 

 

Neither one is, of course, anywhere close to optimized. :v

 

Edited December 27, 2016 by foamyesque

[tseitsei89]

Here is BA-NA-NA-NA-NAAAAA!! 2 nukes + 1 rapier design.

https://www.youtube.com/watch?v=dcmayBEyU4A

There is a little cut/jump at around 7:28 in the video because my first landing attempt was unsuccessful so I had to quickload. The reentry in the video is not pretty but it works  It will flip but if you have pumped all the remaining fuel to the front tanks it will also straighten up once the speed drops. Once it is under control again it is actually quite pleasant to fly.

The craft is LF only and it has TWR(surface) of 0.70 and 3282m/s dv remaining once in 152km x 150km orbit. As can be seen at around 6:20 in the video.

That means the score of ln(1+0.70)*3282 = 1741.52 points in the Banana team

Edited December 27, 2016 by tseitsei89

[Signo]

@foamyesque: thank you very much for your entries - they are both really appreciated and both really "passionfruit", the Mk3 charter makes it for the "largest crew" honorable mention and 740.21 points.

Speaking about your second entry, English is not my mother tongue and I am having pretty hard times to keep you all at bay while "engineering" the rules. This is indeed "correct" but it is not the kind of craft I intended to pit during this challenge. I hope that you agree that this is an attempt to "oversmart" the rules; I need a few extra time to evaluate its admission - the best possible outcome I see for this craft is to resurrect the "Gatecrashers" table. This is a "winged rocket".

I will amend the OP to better clarify that "anything that goes up needs to get back down".

 

[Signo]

@tseitsei89: thank you very much for your entry - your score is indeed 1741.52 and you go on top of the banana table too. If I may, you could mess up with fuel priorities to avoid flipping. Excellent job, closing to the banana limit. 

 

 

[tseitsei89]

21 minutes ago, Signo said:

@tseitsei89: thank you very much for your entry - your score is indeed 1741.52 and you go on top of the banana table too. If I may, you could mess up with fuel priorities to avoid flipping. Excellent job, closing to the banana limit. 

 

 

I dont think messing with fuel priorities would help much since I already pumped all the remaining fuel to the front tanks but it wasnt enough since nukes on the back are very heavy. Maybe moving nukes a lot forward might help though

[Signo]

Just now, tseitsei89 said:

I dont think messing with fuel priorities would help much since I already pumped all the remaining fuel to the front tanks but it wasnt enough since nukes on the back are very heavy. Maybe moving nukes a lot forward might help though

Oh, I did not read carefully - are you going to submit a passionfuit too?

[Thor Wotansen]

Oh noes!  It seems I must defend my title!  @tseitsei89 I hereby throw down the space-glove.

[tseitsei89]

52 minutes ago, Signo said:

Oh, I did not read carefully - are you going to submit a passionfuit too?

Currently working on it. I take it that new rule is that every part you launch must come back to kerbin safely?

[Signo]

2 minutes ago, tseitsei89 said:

Currently working on it. I take it that new rule is that every part you launch must come back to kerbin safely?

Yes: "winged rockets" were pretty much ruled out before the "first amendment"; the original purpose of the challenge I had in mind was to work on aero and TWR balance to maximize the results of a completely reusable utility aircraft. 

Due to my inexperience in managing the rules and due to the endless resources of the community this is now a grand carnival. A very good one, but in my opinion not exactly "spot on". 

We are however already approaching the ceilings for a few categories; I gathered enough data (I hope) to propose a new challenge, with a better set of rules.

 

[tseitsei89]

I present you the Passionate Mammoth. Weighing a whopping 543t on the runway and using not 1 not 2 but 3 mammoth engines!

Able to reach 156km x 155km orbit with a surface TWR of 5.94 and still have 1995m/s dv  left

Again a couple of cuts in the video (before reentry and before landing) because of quickloads.

 

Reentry took some attempts since balancing the fuel load is an accurate job with this craft:

Too much fuel in the front and it cannot keep the nose up --> Overheat and explode

Too much fuel in the back --> It flips and crashes to the ground

But after finding the right balance it was quite easy

 

Landing was hard because I havent flown a plane this big in ages. It still weighs 184t when landing. 

 

Score here will be ln(1+5.94)*1995 = 3864.92 points for team Passionfruit

https://www.youtube.com/watch?v=tkU8C4oEetA

[Signo]

@tseitsei89: thank you for your entry, that is why team Passionfruit does exist. A whopping 3864.92 points. Best score to date. You are currently holding the "Triple Crown". 

 

[tseitsei89]

5 minutes ago, Signo said:

@tseitsei89: thank you for your entry, that is why team Passionfruit does exist. A whopping 3864.92 points. Best score to date. You are currently holding the "Triple Crown". 

 

Thanks! This was a fun challenge I enjoyed it

[Signo]

Ladies and gentlemen, I would like to close this challenge as soon as possible because I think that it needs a pit stop and an overhaul.

TWR has got too much weight in this evaluation process, below I will show you a couple of example pictures to better explain my point of view.

However I do not want to end this abruptly, I think that Sunday the 8th, 23.00 GMT can be a reasonable deadline for anybody still wishing to submit any entry.

I would like to gather, if possible, any feedback you have on this challenge and any suggestion on how to implement a consistent scoring system.

I would like to thank again all the participants. It was quite an impressive airshow.

 

 

Following a comparison of two hypothetical bananas: (these are by no means "entries", hosts should never enter their own contest imo, apart for "never done before" achievements; moreover there is just the "moneyshot" so I am disqualified)

 

	TWR	d/V	Score
Banana2k (sample 1)	0.51	4855	2000.79
Crack O'Maface 3 (sample 2)	0.50	4926	1997.32

 

In such a close TWR contest I was expecting the second craft to top the score of the first due to the range advantage but I was wrong.

As I wrote above, I am open to any suggestion that could help the balance.

 

Sample 1

 

Sample 2

Edited December 28, 2016 by Signo

[Hodari]

My only real feedback on this is that I would suggest putting more thought into the scoring system beforehand and then sticking to it once the challenge has been posted.  Not that the scoring matters THAT much(I think a good challenge should be one where just completing it at all is a significant accomplishment and the scoring is secondary from there), but if you are going to have scores, it's not fair to keep changing the system multiple times after people have already put the effort into completing it.  Try to spend some time thinking about what types of crafts you would expect people to use for it and make sure your scoring system works well for those.  Put at least some thought into what ways people might come up with to try and "beat the system" with something unusual in order to max out their scores and make sure your scoring system accounts for those as well.  And if someone still manages to come up with something that you weren't expecting...unless it's a rather blatant exploit, you might just have to accept it.  After all, these challenges are just for fun anyway, so don't take things TOO seriously, but do try to think them through ahead of time.

[Signo]

@Hodari: thank you, I was expecting something like this. Keep in mind that this was my first attempt to host a challenge. I fully understand your point but you must admit that this community is pretty "hostile" in terms of discovering sneaky ways around the system. Next time I hope it will be "set in stone". By the way, the only true rule change was about the formula and it happened just after your submission. I tried to keep it as much "open" as possible, I think that the only true "rejection" was about @foamyesque staging craft. 

I would like once more to apologize about your "score change".

If I may, this is a game, nobody bombed your diamond mine and you can still submit a new entry. It takes less than 15 minutes with warps.

 

[Eidahlil]

3 hours ago, Signo said:

any feedback you have on this challenge and any suggestion on how to implement a consistent scoring system

I'd say define a scenario (not necessarily publicly), why the specific parameters are wanted, and go from there what the scoring/penalties should be.

• Low TWR is bad because it takes a long time to perform an ejection burn (and you don't want to split the node)? Calculate the losses from that and use it as a penalty. I'm not sure what exactly the formula is, but I'd guess something like 1+cos(16.5/Initial TWR) (TWR lower than 0.092 getting a zero, obviously) as the multiplier would be a start (to very roughly estimate losses from burning off prograde). A quick google indicates it's a bit tricky to calculate precisely though.
• Low TWR is bad because landing somewhere is more expensive? Pretty sure that's easier to calculate (in vacuum). Something like 1/(1+0.46/(Initial TWR+Final TWR)) as a very rough multiplier perhaps.
• Low TWR is bad because long burns are boring? Take your dream hourly salary, convert to IMF SDR, raise to the power of 3.1416, and, ehhh, not sure where I'm going with this. Don't forget to factor in the time warp, but I can make up formulas all day.

Generally probably try to avoid having too many categories though. But don't worry, I think it was all good. Even if I did not manage to beat @tseitsei89's heavy spaceplane entry. I'll be waiting for the next challenge.

3 hours ago, Signo said:

these are by no means "entries", hosts should never enter their own contest imo

I would actually disagree. So long as the rules are fairly and transparently applied, there's nothing wrong with hosts entering their own challenges. This is not a lottery, the host has no unfair advantage.

Edited December 29, 2016 by Eidahlil

[tseitsei89]

33 minutes ago, Eidahlil said:

I would actually disagree. So long as the rules are fairly and transparently applied, there's nothing wrong with hosts entering their own challenges. This is not a lottery, the host has no unfair advantage.

This I agree with!

No reason why the host couldn't participate as long as the rules are clear

[Hodari]

1 hour ago, Signo said:

@Hodari@foamyesque

I would like once more to apologize about your "score change".

If I may, this is a game, nobody bombed your diamond mine and you can still submit a new entry. It takes less than 15 minutes with warps.

Yeah, like I said...I'm not that worried about the score anyway, just figured since you were asking for feedback, I'd mention that changing the rules/scoring is something that should be avoided as much as possible.

And yeah, the actual mission itself might only take 15 minutes or so, but especially with SSTO's, there will be a LOT more time going into designing and testing the craft first.  I'm probably not going to do another entry for this challenge, but if you come up with another good one, I'll definitely give it a shot.

[Signo]

@Hodari, @tseitsei89 and @Eidahlil - thank you for your feedbacks. They are all really appreciated.

 

@hodari - you are right, and you forgot to mention the "well, it does not work..." moments you have when you first try a design.  

I know that it takes time and I would like to improve the quality of that time for the people entering the next challenge.

 

I still think that it is not completely fair for a host to enter his own contest - just to avoid any possible "conflict of interest". 

 

Speaking about the scoring system, I think that it would be better to have more strict gates at the "entrance" and a simple scoring system kinda like - Build a single rapier powered craft, best remaining d/V at LKO wins. It would still be "exploitable" as usual but with less room for any real game-breaking craft.

Thank you all again, I love you guys.

 

Edited December 30, 2016 by Signo