Ōsumi Challenge: Get to orbit, SRBs only, totally unguided

[Snark]

Your mission:  Launch a ship to Kerbin orbit, completely unguided (i.e. the only interaction you have is to hit the spacebar once to launch off the pad), using nothing but SRBs.

Note:  Challenge allows use of timers from Smart Parts Continued (see rules below).  It's doable in pure stock without the timers, but there's no separate category for pure-stock entries.

 

Background:

This challenge is inspired by Ōsumi-5, the first successful Japanese satellite, launched in 1970.  It was put into orbit aboard the Lambda 4S launch vehicle:  a four-stage rocket entirely powered by solid fuel, that had no guidance or control systems at all.  As described here,

Quote

The weirdest thing about the L-4S rocket is that it doesn't have guidance, navigation and control (GNC) built in! It was because some people in Japan said that the technology like GNC could be put into missiles, which they couldn't accept. (the Japanese constitution prohibits the act of war.)
And the engineers did come up with a way. The 1st and 2nd stages used the aerodynamic effects of the tail assembly. The 2nd(again) and 3rd stages used a motor to spin the rocket like a giant gyroscope, thus holding the rocket steady. The 4th stage stopped the spinning, and before it lit the engine did a little bit of maneuvering to put it steady,(and the boosters weren't firing at that time so it wasn't really GNC.) then made the rocket spin again, then finally, put it to orbit.

Lots of additional discussion (with plenty of numbers) here.

This immediately struck me as one of the most Kerbal things I ever heard, so naturally this challenge was the first thing to spring to mind. 

 

The rules:

1. You must put a craft into orbit around Kerbin.
2. It must be powered solely by solid fuel.
   • No engines that are supplied by liquid fuel or any other propellant.
   • So, basically, just SRBs, plus Sepratrons and/or LES if you like.
3. It must have no control input whatsoever, other than the initial stage action to launch it off the pad.
   • In other words:  you launch it, then completely hands-off.
   • You just sit there and watch it complete its mission.  No interacting with the ship in any way.
   • This includes not just control input like WASD, but also adjusting tweakables, etc.
   • No SAS turned on.
   • No active reaction wheels at all (not that this matters, with SAS turned off and no player input...)
   • No aerodynamic control surfaces (fixed surfaces only).  (again, not that this matters, with SAS turned off and no player input...)
4. With the exception of two specific mod parts (see below), it must be pure stock only.
   • No modded parts at all, other than specified below.
   • No mods that affect game physics at all.
   • No mods that affect ship control at all (such as MechJeb, or the flight computer in RemoteTech).
   • No modification (e.g. via ModuleManager) any of the characteristics of stock parts.  You can use the stock game's built-in editor tweakables, that's it.
   • Mods that have no physical effect on the ship at all are fine (e.g. visual F/X like PlanetShine or Scatterer, or info displays)
5. There are two specific mod parts that you ARE allowed to use.  These are from Smart Parts Continued.  The two specific parts are:
   • The AGT-Timer (full name: AGT-Timer Timed Action Group Trigger).  This is a timer which, when activated by a staging action, will wait a set time limit before activating the next stage.
   • The Drainex-1 (full name: Drainex 1 - Fuel Sensor and Action Group Trigger).  When you stick this to an SRB, it will activate the next stage when the SRB burns out.
   • To be clear, none of the other SmartParts parts are allowed.  Just the above two.
6. No time warp allowed.
   • This one's a bit subtle... it's to avoid a sneaky back-door way for the player to get some control of the ship.  Turning on time warp will instantly stop all ship rotation, which is an unfair magical "stabilization" of the ship.  So, don't.
   • Physics warp is allowed as a timesaver, if you like, as long as you're not exploiting it to cause some sort of kraken effect.

 

Some gotchas and warnings:

• When launching your ship:  after it goes to the pad, wait a few seconds before taking off, so that the initial physics oscillations have a chance to die down.  Very tiny perturbations to the initial angle of the ship can have a big impact on its eventual orbit!
• Don't run RealPlume.  Turns out it's not just a visual F/X mod; it affects engine performance.  (Thanks to @tg626 for tracking this down.)

 

Submission guidelines:

• Just post in this thread, with the following items included.
• Please share your .craft file somewhere public (e.g. dropbox, Google Drive, whatever) so people can download and try it out.  (The fun part here is that the .craft file is all that's needed, since no piloting is involved.  Anyone can just hit spacebar on the launch pad and see how it flies!)
• Include either a screenshot or a brief description of your craft on the launchpad.
• Provide the following information (which, of course, can be checked by anyone who downloads your .craft file):
  • Mass on launchpad
  • Mass after achieving orbit
  • Periapsis altitude
  • Apoapsis altitude
  • Orbital eccentricity.  This is calculated as:  (Ap - Pe) / (Ap + Pe + 2R_Kerbin), where R_Kerbin is Kerbin's planetary radius of 600 km (or 600,000 m... be sure that all three numbers are in the same units!)
  • Payload fraction.  This is defined as orbital mass divided by launchpad mass.

 

A working example

Here's an example that I put together as proof of concept, just to get the ball rolling.  It's not trying to be "the best" at anything, it's just the first thing I built that actually gets to orbit by the rules above.

Spoiler

• Craft file
• Mass on launchpad:  9.87t  (Amusingly enough, pretty close to the 9.4t of the actual Ōsumi launch vehicle.) 
• Mass in orbit:  0.66t
• Pe: 84,963m
• Ap:  603,633m
• Eccentricity:  0.275
• Payload fraction:  0.0669

 

The winners:

A few categories here.  I'll update as people post results.

 

The "Just Do It" Award:

Just get to orbit, by the above rules.  Any orbit is fine.  There's no "rank" or "top" here, it's just a complete list of people who have done the challenge and posted their results, in the order received.  I'll include myself at the top of the list, due to my example above. 

1. @Snark
2. @ManEatingApe (entry)
3. @HydraZineSoda (entry)
4. @tg626 (entry)
5. @Starman4308 (entry)

 

The "Precision" Award:

Get into the most circular orbit, defined as having the lowest eccentricity.  Top 10:

1. 0.0208, @HydraZineSoda (entry)
2. 0.0699, @tg626 (entry)
3. 0.101, @ManEatingApe (entry)
4. 0.213, @Starman4308 (entry)

 

The "Efficiency" Award:

Get into orbit with the highest payload fraction.  Top 10:

1. 20.5%, @ManEatingApe (entry)
2. 6.52%, @HydraZineSoda (entry)
3. 5.47%, @Starman4308 (entry)
4. 0.36%, @tg626 (entry)

 

The "Pee Wee" Award:

Get into orbit with the smallest possible launchpad mass.  Top 10:

1. 11.65t, @HydraZineSoda (entry)
2. 22.265t, @tg626 (entry)
3. 30.6t, @ManEatingApe (entry)
4. 165.728t, @Starman4308 (entry)

 

The "Totally Kerbal" Award:

This is a completely subjective category, based on my personal opinion.  It's for listing people who go above and beyond the call of duty by achieving insanely ingenious things using only the above rules.  Landed on the Mun?  Orbited Kerbin and then landed on the runway?  Got to orbit without using any of the allowed SmartParts mentioned above?  Something else that makes people go, "holy heck, how did they do that?"  Here's your chance to show off! 

Items presented here in chronological order of submission.  Not gonna try to "rank" these.

• @ManEatingApe (entry), for submitting the first completely stock entry.  No timers at all, it's pure stock!  (I also like how his design manages to put no probe core at all on the launched ship.)
• @tg626 (entry), for a beautiful replica of the actual IRL Ōsumi satellite, including aerodynamic spin stabilization. (With style points for deorbiting the last booster stage.)
• @Starman4308 (entry), for an ingenious Rube Goldberg contraption. (Multi-stage... in pure stock!)

[Stargate525]

So, an SSTO, that's only SRBs?

Or do you also allow us to manually stage since there's no way to automate that in stock?

[Snark]

4 minutes ago, Stargate525 said:

So, an SSTO

No, doesn't have to be an SSTO.  It can have as many stages as you like.

5 minutes ago, Stargate525 said:

only SRBs?

Correct, only SRBs.  See Rule #2.

6 minutes ago, Stargate525 said:

Or do you also allow us to manually stage

This one's an absolute no.  Absolutely no player control over the ship under any circumstances, other than the instant of launch.  That's the whole point of the challenge. See Rule #3.

8 minutes ago, Stargate525 said:

since there's no way to automate that in stock?

See Rule #5.  There are a couple of specific parts from the Smart Parts Continued mod, which are allowed.  One fires a stage after a timer, the other fires a stage when an SRB burns out.  Between the two of these, you can automate the launch just fine.  It's just that these are all you're allowed to automate with.

[Jestersage]

So it's pretty much a mod only challenge, since a multistage rocket will give inherited advantages.

Post a warning next time you want to skew a challenge for people who use mods, so stock only players can avoid having their hopes up.

Edited December 15, 2016 by Jestersage

[Starman4308]

Quick question before I try it out; would a kOS script whose sole purpose is to stage when resources are depleted be acceptable?

I mean, the rest of the mods I use would rule it out of any coherent scoring (6.4x scale, FAR, Real Fuels, etc), but there may be other players with stock physics who are more familiar with kOS than Smart Parts.

[Snark]

40 minutes ago, Starman4308 said:

Quick question before I try it out; would a kOS script whose sole purpose is to stage when resources are depleted be acceptable?

In principle, I don't have a problem with the idea of a mod that can do the two things that the Smart Parts parts can do (namely, "stage when empty" and "stage after countdown")-- as long as that's the only thing it does, and it doesn't apply any other sort of control input (no torque output; no use of sensor readings for timing; etc.

However... one of the things I'd like to be the output of this challenge is, each person links to their .craft file, and anybody who's participating can try out anybody else's .craft, without having to install any mod at all other than the one (Smart Parts) that's already listed.  Also, the Smart Parts are really limited, they can only do those two things... I really don't feel like having to get into a lengthy technical discussion with someone about whether this or that kOS function is allowable.  Having the physical limit built in to the hardware itself just seems to keep things straightforward.  So I'd really prefer just sticking to this one.

FWIW, they're really easy to use.  The one part will cause the next stage to fire when the SRB it's attached to burns out.  The other one, the timer, is a stageable object itself. When its stage action fires, it counts down for a set interval and then activates the next stage.  They're pretty intuitive; I found that just sitting down for a few minutes and fiddling with them was enough to get a general feel for how they work.

[Jestersage]

@Snark, you still haven't address my concern that this challenge is skewered toward modded game.

I would rather you just be honest about that as a fact, or do something for stock -- you should know that without the CHEATS from the mod, stock games cannot stage and will always lose out due to TWR (and delta-v -- 32 seperatron + 1 KD-25K just barely have 3467 dv) and etc.

Or are you just trying to promote a mod? Just be honest, will ya?

 

EDIT (x time) Checked your file: It requires mods. No go for stock.

Edited December 16, 2016 by Jestersage

[tg626]

I gotta admit, I *was* interested until I hit the smart parts requirement.  And truthfully it is a requirement.  Perhaps there should be with and without smartparts categories?

I did it anyway, and somebody else did it all stock!  Shows what I know 

Edited December 27, 2016 by tg626

[Starhawk]

I spent a couple of hours last night working on a pure stock entry.  No luck so far, but I'm convinced it's possible with the right adjustment of tweakables and geometry.

Happy landings!

[Gaarst]

7 hours ago, Jestersage said:

@Snark, you still haven't address my concern that this challenge is skewered toward modded game.

I would rather you just be honest about that as a fact, or do something for stock -- you should know that without the CHEATS from the mod, stock games cannot stage and will always lose out due to TWR (and delta-v -- 32 seperatron + 1 KD-25K just barely have 3467 dv) and etc.

Or are you just trying to promote a mod? Just be honest, will ya?

 

EDIT (x time) Checked your file: It requires mods. No go for stock.

It never killed anyone to download a mod for a challenge you know? No one says you have to corrupt your precious stock career to do it.

 

Cool challenge, but unfortunately I won't have the time to attempt it in the next weeks. I'm still going to follow the entries!

[Matuchkin]

16 hours ago, Jestersage said:

So it's pretty much a mod only challenge, since a multistage rocket will give inherited advantages.

Post a warning next time you want to skew a challenge for people who use mods, so stock only players can avoid having their hopes up.

I have absolutely no idea why you are so upset about this. Mod challenges are completely legitimate, and are not meant to be malicious towards stock players. Also, Snark is a moderator, so he cannot give a warning to himself. Please learn forum etiquette before posting such comments.

[Starman4308]

8 hours ago, Jestersage said:

@Snark, you still haven't address my concern that this challenge is skewered toward modded game.

You are being extraordinarily combative. Also, it's "skewed", not "skewered".

8 hours ago, Jestersage said:

I would rather you just be honest about that as a fact, or do something for stock -- you should know that without the CHEATS from the mod, stock games cannot stage and will always lose out due to TWR (and delta-v -- 32 seperatron + 1 KD-25K just barely have 3467 dv) and etc.

Two comments here: #1, Sepratrons are a bad idea for providing main thrust in this challenge (poor specific impulse), and #2, stock games can stage, you just have to be creative about it. I'm imagining, for example, a ring of SRBs around a central core, held in by creative abuse of struts and their own thrust. Will illustrate later, need to go to work now.

8 hours ago, Jestersage said:

Or are you just trying to promote a mod? Just be honest, will ya?

See #1 about being needlessly combative. Yes, it's a challenge in 100% stock due to Mr. Tsiolkovsky and the inability to conventionally stage, but all Smart Parts does is reduce the necessary strut/other-creativity abuse.

[Jestersage]

40 minutes ago, Matuchkin said:

I have absolutely no idea why you are so upset about this. Mod challenges are completely legitimate, and are not meant to be malicious towards stock players. Also, Snark is a moderator, so he cannot give a warning to himself. Please learn forum etiquette before posting such comments.

Mod-based challenge need to be upfront -- this challenge is written as if stock games have a similar chance when it is not. Also, mods tend to break not just a save, but the entire game, and with KSP now at 1.2.2...

And the warning is more for that "Yes, this challenge will be skewed toward modded games." As long as they are upfront I will be fine.

Edited December 16, 2016 by Jestersage

[Hoody]

Solve the dispute by adding a "Stock only" category and give it the most prestige seeing as it's harder — job done. 

[Red Iron Crown]

@Jestersage There is no requirement that stock has to be a playable option for a challenge, lots of challenges require FAR or BD Armory for example.. There is no reason to imply that the OP is somehow being dishonest or has an ulterior motive by requiring a mod.

If you don't like this challenge you are free to not participate; I'll ask you to not post about the mod requirement any further here as it is distracting from the actual challenge itself.

[HydraZineSoda]

I have two queries. If I get my dumb booster onto a mun assist and orbit after said assist is less eccentric than my initial transfer orbit, which orbit is admissible? If post assist orbits are admissible,  please may we use time warp AFTER the rocket is out of fuel?

[tg626]

On 12/15/2016 at 7:39 AM, Snark said:

A working example

Here's an example that I put together as proof of concept, just to get the ball rolling.  It's not trying to be "the best" at anything, it's just the first thing I built that actually gets to orbit by the rules above.

Um, first attempt to use your craft file resulted in 552,435m x -399,421m "orbit"...  interesting use of timers tho.

EDIT:

Genuinely assuming it was me and not you I then moved SmartParts and your craft file from my modded install to my plain vanilla install.  That launch yielded 582,241m x 84,304m.

That raises 2 questions.  One, why didn't I get EXACTLY the same thing you got?  Why is my modded install resulting in a WILDLY different result?  (None of my mods are atmospheric (IE no FAR) and all guidance mods were inactive...)

I shall continue to investigate

 

Edited December 16, 2016 by tg626

[Snark]

21 minutes ago, tg626 said:

Um, first attempt to use your craft file resulted in 552,435m x -399,421m "orbit"...  interesting use of timers tho.

Interesting, it's pretty consistent for me. I've run it a few times and it was nearly same results each time, within a few percent anyway. Even running the whole thing in "realtime" gave very nearly the same result as doing quite a bit of 4x physics warp.

Wonder what's different in your case?

When I get to a KSP computer and have a little time, I'll post a screenshot sequence showing the trajectory that I observe. Will make it easier to see at what point your experience diverges from mine.

[tg626]

Roughly, I get the following pitches which seem to be the critical parameter...

• 60^o @ 3km
• 50^o @ 5km (maybe 9km, my handwriting sucks)
• 45^o @ 20km (MECO)
• 40^o @ 40km
• 31^o @ 70km
• 25^o @ 80km

If I pull ALL my mods from my modded install I get near the same performance.  Now I add them back, one by one, until I find the culprit.  

This could have far ranging implications, at least for me...

Edited December 16, 2016 by tg626

[ManEatingApe]

Let's get the ball rolling with a "Just Do It" stock only entry. The video is speeded up but the entire run was at x1 time warp.

Craft File

Vital Statistics:

• Mass on Launchpad 30.6t
• Mass in orbit 6.3t
• Payload Fraction: 20.5%
• PE: 112km
• AP 272 km
• Orbital Eccentricity: 0.1

Edited December 16, 2016 by ManEatingApe

[tg626]

@Snark

Found it.  It's "Real Plume".  Examining it's files shows that it switches "ModuleEngine" to "ModuleEngineFX" but does not alter any parameters.  

The result is higher thrust, I get higher speeds (and therefore more weather vane effect, by which I mean the fins keep it flying straighter) and sometimes even loose 1 or more of the small fins at the top of the craft on ascent.

If I remove only realplume-stock which is what applies the effects to the engines, I get the same flight as you did.

I would suggest specifically forbidding Realplume since others may, as I did, assume "It's only a visual mod" and would have no effect on anything.

FWIW, with RealPlume, your craft was pointing at 50^o on the nav ball when the 2nd stage fired, without it's at 10^o.

The TRUE cause is that RealPlume triggers a reset of any limited thrust to 100%.  It's stated in the release thread that RealPlume will cause this issue with in game tutorials and scenarios, but as it turns out it also affects saved craft. I assume, and I stress this is an assumption, that the issue arises when a player saves a craft file with thrust limited and without RealPlume installed and then shares that craft file with someone who DOES have RealPlume installed. But in any case, we should add "Check yo thrust" to the same list as "Check yo stagin'" as Mr. Manley says.

I deeply regret and apologize for any dispersions I may have inadvertently cast upon RealPlume - I truly wish only that this thrust reset issue could be solved for all cases as I LOVE that mod and visual realism it adds to the game.

Edited January 13, 2017 by tg626

[Snark]

2 hours ago, ManEatingApe said:

Let's get the ball rolling with a "Just Do It" stock only entry.

Woot!  First person to take up the gauntlet!    Lemme go add that to the OP.

 

1 hour ago, tg626 said:

Found it.  It's "Real Plume".

Excellent, thanks for running that down!  I'll add that to the OP.

[Starman4308]

A question that is becoming increasingly relevant for the most... interesting booster I have designed: is a hyperbolic escape orbit of Kerbin acceptable so long as periapsis is > 70 km?

[Snark]

15 minutes ago, Starman4308 said:

A question that is becoming increasingly relevant for the most... interesting booster I have designed: is a hyperbolic escape orbit of Kerbin acceptable so long as periapsis is > 70 km?

Nope, has to be an actual orbit.  Mainly because the precision of getting to elliptical orbit (especially one that's close to circular) is harder than an escape trajectory (or at least, so it seems to me).

[Snark]

3 hours ago, ManEatingApe said:

Let's get the ball rolling with a "Just Do It" stock only entry.

Good grief, just now had a chance to actually look at your ship.  10/10 for style, dude.  You did it in pure stock, and SSTO!  No timers at all.  You, sir, are a steely-eyed missile man.  Hats off.

I also really like what you did by arranging it so the launched craft actually has no probe core on it at all (by sticking the core to the launch clamps).  That's a real touch of class, there. 

One interesting thing I discovered when flying your ship, though:  when launching, it's important to wait a few seconds before activating the launch-from pad.  When I flew it the first time, I was so eager I hit the space bar at the earliest possible instant.  Result:  it didn't actually make orbit.  Climbed a hair too steeply, ended up with its Ap out at like 400 km and its Pe underground.

Moral of the story:  for this sort of hands-off launch, a tiny difference in launch angle at the start can make a huge difference down the line.  When a ship first goes to the pad, it wobbles a bit as the physics ease in, and that effect is magnified for this particular ship since you've got the launch clamps way down at one end.

So, advice for future adventurers:   make sure you wait a few seconds after going to the pad before taking off, so that the oscillations have a chance to die down.  (I've added a "gotchas" section to the OP and called this out.)