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

[tg626]

I generally wait for the camera to stop sinking.  And on angled launches, make liberal use of autostruts and rigid attachment.

I also find that with CPU heavy enhancements (Kerbal Konstructs, EVE) that it actually matters a bit which way the camera is pointed during ascent.

Edited December 17, 2016 by tg626

[HydraZineSoda]

I need to call this a night (or even a dawn) so here is the culmination of my quest for a perfect circle.

Link to craft file: https://drive.google.com/file/d/0Bwrp_eJ4c_vbQmdGVm5UWWpqWk0/view?usp=sharing 

Launch mass 11.65t / Orbit mass 0.76t / Payload fraction 0.065

Ap - 129,784 / Pe - 100,007 / Eccentricity - 0.0208261207 (Please check this as I am not used to this equation).

Link to screenshot as security settings are defeating me: https://drive.google.com/file/d/0Bwrp_eJ4c_vbbFZTUWctVF9CaUE/view?usp=sharing

Full Disclosure: I cannot reliably reproduce the same results with this craft. The difference between Ap and Pe varies from 20km at best to 40-45km at worst. The only mods on the ksp install I'm using for this are kerbal alarm clock and Smart Parts.The values given above are taken from a run that seemed closest to the mean result. If you are Snark and you are doubting this then please score based on whatever you can reproduce.

Flight Plan as it should work:

1, First stage BACC triggered by spacebar

2. Second stage rt-10 triggered by fuel depletion, thrust limited so that rocket continues to follow gravity turn.

3 Third stage 110 second timer triggered by fuel depletion, which then triggers another 90 second timer. Inertia from the gravity turn keeps the rocket pointing somewhere near the prograde vector as these timers countdown. I assume this is how stock physics works and I swear on the honour of my forbears I am not knowingly exploiting any glitches.

4 Circularisation burn triggered by second timer should occur within 5 seconds before or after Ap.

5 For best results, no phys warp, RW on the probe core is set to SAS only. 

Edited December 22, 2016 by HydraZineSoda
Images

[Snark]

10 hours ago, HydraZineSoda said:

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?

Sorry, just now saw this message, managed to miss it earlier.  Welcome to the KSP forums! 

If you can actually get something into a Mun assist, then that's totally fine.    Though in that case, for reproducibility, would really help if you've got a record of the exact time that you launch... otherwise other people will have trouble reproducing your results.

...And I can totally see wanting to have timewarp.  After all, even on 4X physics warp, the Mun is well over an hour away.  The problem is... the timewarp really does affect ship rotation and such, and the choice of when to timewarp can make a significant difference in the ship's orientation, which in turn makes a big change to what happens when you thrust.

Of course, that only matters if you're going to be firing any engines after timewarping.  If you're not, then timewarping doesn't affect your ship's trajectory.

So, how about this:  yes, timewarp is okay.... but only if you fire no engines after timewarping.  For example, if you finish firing all your engines to send yourself on a Mun-intercept trajectory, and then you're done, and the Mun flyby puts you into an orbit of Kerbin... then that is okay.

Does that seem reasonable?

21 minutes ago, HydraZineSoda said:

I need to call this a night (or even a dawn) so here is the culmination of my quest for a perfect circle.

Excellent, thanks!  I need to go offline myself here shortly, but will be adding your entry to the OP lists as soon as I have a chance (likely tomorrow).

[tg626]

https://kerbalx.com/TG626/SOSUEME

Stats:

• Mass on launchpad: 22.265t
• Mass after achieving orbit: 0.080t
• Periapsis altitude: 78,261m
• Apoapsis altitude: 178,740m
• Orbital eccentricity: 0.07
• Payload fraction: 0.36%

Vessel was designed following the real world example of Osumi 5, although my "4th stage" is actually a retro-disposal burn of the last SRB.

Here's a pic of the final satellite IRL and KSP.

 

Edited December 17, 2016 by tg626

[ManEatingApe]

10 hours ago, Snark said:

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...

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.)

Great point, thanks for debugging my ship!

 

5 hours ago, tg626 said:

Vessel was designed following the real world example of Osumi 5, although my "4th stage" is actually a retro-disposal burn of the last SRB.

Great looking entry! I really like the attention to detail of the original mission, particularly spinning at the start and the recreation of the satellite

 

Edited December 17, 2016 by ManEatingApe

[Starman4308]

This took way too much effort. Stock only, probably mostly because people said it couldn't be done in stock. 2-stage, because people said you couldn't stage in stock without the spacebar. It may or may not take a couple tries to get to stable orbit; it's a slightly wobbly craft and periapsis narrowly misses the atmosphere. To be fair, though, I just did it a second time and again successfully missed the atmosphere... by less than a kilometer, yes, but it still 100% counts.

EDIT: Oh, and to be 100% super-duper-clear, the second stage in the staging order would only release the payload; the decoupler separating the two rocket stages is on the first stage. I just realized having a second stage in the staging order may make it look cheaty (note: rocket stage != "stage" here).

The "genius" comes in two parts. The staging occurs by staging all the decouplers at launch, and using shenanigans (a cage of struts and I-beams that violates all sound principles of engineering) to keep the first stage at 100% throttle attached to the second stage at roughly 40% throttle. How it manages to circularize is via the monopropellant tanks at the top: the westwards tank is empty, while the eastwards tank is 10% full. This slight off-center mass induces off-center thrust that, in the final stages of flight, pulls the nose down enough for circularization.

Craft file: http://kerbalx.com/Starman4308/TestifierV

Periapsis: 72,682m

Apoapsis: 1,119,017m

Eccentricity: 0.306882 0.10463 (EDIT: goofed on my spreadsheet calculating eccentricity).

Mass at launch: 165.728t

Second-stage mass: 31.693t

EDIT (SO MANY EDITS): Nominal payload mass: 7.91t including spent second stage.

"Payload" mass: 3.265t. Change at your own risk; the craft is a finely tuned precision instrument of quasi-usefulness.

Payload mass minus monopropellant tanks for off-centering the mass: 2.905t

The strut-cage-of-doom:

Extended launch clamp system:

On the pad:

EDIT: On closer inspection, I'm 99% certain this screenshot came from earlier in the design process.

Edited December 18, 2016 by Starman4308

[Snark]

10 hours ago, HydraZineSoda said:

I need to call this a night (or even a dawn) so here is the culmination of my quest for a perfect circle.

Sweet!  We have a new leader for both the "Precision" and "Pee Wee" awards. 

 

8 hours ago, tg626 said:

Vessel was designed following the real world example of Osumi 5, although my "4th stage" is actually a retro-disposal burn of the last SRB.

*snif*   That's just... beautiful!  Right down to the aerodynamic gyro-stabilization.  (And I love how you not only deorbit the last booster, but spin-stabilize it while doing so.)

 

1 hour ago, Starman4308 said:

Stock only, probably mostly because people said it couldn't be done in stock. 2-stage, because people said you couldn't stage in stock without the spacebar.

But... I don't even... I mean....

Okay, see, now this is why we don't let Wernher anywhere near the VAB after he's been into the eggnog at the office Christmas party!

Utterly insane. I love it. 

[HydraZineSoda]

18 hours ago, Snark said:

So, how about this:  yes, timewarp is okay.... but only if you fire no engines after timewarping.  For example, if you finish firing all your engines to send yourself on a Mun-intercept trajectory, and then you're done, and the Mun flyby puts you into an orbit of Kerbin... then that is okay.

Does that seem reasonable?

Perfectly fair. And if I did attempt this launch time would be straight away from fresh save. Getting any old mun flyby wasn't a problem. Getting a free circular without fine controls however...

[Vanamonde]

Some posts have been removed from this thread. To repeat what Red Iron Crown said earlier, if you don't like the terms of the challenge, don't play it and/or go make your own. 

[Starman4308]

Since it got nuked along with the moderated posts, I'll repeat this question:

@Snark, what precisely counts as "payload"? I hadn't included the mass of the expended second stage, as it wasn't "useful payload". The expended stage would mass in at 4.698 tonnes, with an empty Kickback SRB, four fins, and a 1.25m decoupler. If that counts, that'd bring my payload-to-orbit fraction up to 4.8%. Still execrable relative to certain homonid-consuming primates (@ManEatingApe), but the goal of my entry was to prove that A, it was possible in stock (ninja'd by said primate), and that B, staging doesn't technically require staging equipment or even the staging button, just sufficient creativity and the fine Kerbal traditions of "moar boosters and moar struts".

Edited December 18, 2016 by Starman4308

[Snark]

12 hours ago, Starman4308 said:

@Snark, what precisely counts as "payload"? I hadn't included the mass of the expended second stage, as it wasn't "useful payload".

Payload is simply the total mass of your ship while in orbit.  It says nothing at all about what that mass consists of, or how "useful" it is.  To quote the rules,

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

Payload fraction.  This is defined as orbital mass divided by launchpad mass.

In your case, the spent Kickback and its assorted paraphernalia are certainly part of your payload, since they're part of your ship while it's in orbit.  By the same token, the monopropellant "ballast" also counts as payload.

Just now flew your ship again (it's so much fun to watch).  I make your payload mass to be 7.91t, rather than the 3.265t that your post quotes.

(Sorry I didn't catch this earlier.  I don't bother checking the numbers unless someone asks me to, e.g. if they're not sure of their calculations or their rule interpretations.  I just take whatever the person provides.  We're on the honor system here, which is easy when everyone has to post their actual ships and anyone can check anyone's numbers.)

Anyway, given your launchpad mass of 165.728t, that puts your payload fraction as 4.77%.  I'll update the leaderboard in the OP for this thread.  If you like, you're welcome to go update your post with the corrected numbers.  (Perhaps best just to stick an "[EDIT]" comment on the end rather than just silently fixing the numbers, just to prevent confusion for anyone who may be reading this thread in chronological order.  But it's up to you.) 

 

[Starman4308]

Now presenting, the Testifier VI. Designed after complaints that "your new booster literally just takes a random assortment of parts to low Kerbin orbit", E-Z Rockets Inc. presents a new booster.

Features:

9.13t to orbit

A docking port

Full RCS control

1000% more monopropellant

A Terrier engine

Two relay antennae

Even more fins in space!

Self-damping Anti-Wobble-Cage technology

The same, familiar, "so easy my cat could do it" launch procedures!

Vital stats:

Apogee 435,382m

Perigee: 71,377m

166.933t on the pad

Eccentricity (please let me have done this right this time): 0.213

Payload fraction: 5.47%

"Useful" payload (now including ballast on account of non-imaginary RCS thrusters!): 4.39t

"Useful" payload fraction: 2.63%

I'll be completely honest, this was done because I was bugged that my original "payload" was more or less just a randomish assortment of parts to match an approximate target mass. That it scores better was irrelevant to me; I just wanted to put something useful-if-you-squint up there, ergo the docking port (for something approximating a fuel depot), RCS for maneuvering/docking, relay antennas (because who doesn't want more relays), etc. The one downside appears to be that it's a bit more wobbly than the Mk. V, leading to less consistent results; whereas I'm 5/5 on launching the v5, the second trial run of the Mk. VI had a perigee around 66 km. Maybe it just needs slightly more off-center ballast and/or lower 2'nd stage thrust.

Satellite deployed and ready for operations:

Edited December 20, 2016 by Starman4308

[Snark]

On 12/18/2016 at 11:01 AM, Starman4308 said:

Now presenting, the Testifier VI.

This looks great... but can you add a .craft download link to your post?  (Apologies if it's already there somewhere and I've overlooked it.)

[Starman4308]

1 minute ago, Snark said:

This looks great... but can you add a .craft download link to your post?  (Apologies if it's there somewhere and I've overlooked it.)

Roger! The title is now a hyperlink to the craft.

Sorry about forgetting it.

[Snark]

14 minutes ago, Starman4308 said:

Roger! The title is now a hyperlink to the craft.

Excellent!    This breaks your previous records for both precision and efficiency-- I'll update your entries on the leaderboard.

[Snark]

So, just to mix things up a little, I decided to try my hand at doing the challenge, spaceplane-style.

So, I give you:  the Osumi-X:

• Link to .craft file
• Runway mass:  44.723 t
• Orbital mass:  4.42 t
• Periapsis:  74,160 m
• Apoapsis:  876,050 m
• Orbit eccentricity:  0.373
• Payload fraction:  9.88%

It's not exactly a record-breaker for spaceplane payload fraction, nor is it an SSTO.  And the orbital eccentricity's nothing to write home about.  And I suspect that horizontal takeoff is probably not a good way of playing to SRBs' strengths.

But it takes off like a spaceplane, and it flies like a spaceplane (shallow, then steep, then shallow; never climbs more steeply than 45 degrees), and it reaches orbit consistently.   

[Starman4308]

22 minutes ago, Snark said:

So, just to mix things up a little, I decided to try my hand at doing the challenge, spaceplane-style.

So, I give you:  the Osumi-X:

It's not exactly a record-breaker for spaceplane payload fraction, nor is it an SSTO.  And the orbital eccentricity's nothing to write home about.  And I suspect that horizontal takeoff is probably not a good way of playing to SRBs' strengths.

But it takes off like a spaceplane, and it flies like a spaceplane (shallow, then steep, then shallow; never climbs more steeply than 45 degrees), and it reaches orbit consistently.   

You know, this is the first entry to the Osumi challenge that is capable of taking Kerbals to space, which I think is kinda neat.

You also might want to update the leaderboard; in particular, you're #2 on the efficiency board, as well as #5 of precision and #4 on Pee-Wee.

[Snark]

7 minutes ago, Starman4308 said:

You know, this is the first entry to the Osumi challenge that is capable of taking Kerbals to space, which I think is kinda neat.

Thanks. 

7 minutes ago, Starman4308 said:

You also might want to update the leaderboard; in particular, you're #2 on the efficiency board, as well as #5 of precision and #4 on Pee-Wee.

Yah, deliberately didn't.  Since it's my challenge, and I'm the final arbiter of the rules, it seemed to me to be a bit of a conflict of interest to put myself on the leaderboard.  The referee shouldn't participate in the game.

Nothing that says he can't kick the ball around on the field a little during the halftime break, though. 

 

[Nhawks17]

On 12/16/2016 at 6:26 PM, tg626 said:

@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.

I will be looking into this report and seeing what I can find on the matter. If values are changing, they are not intentional.

[tg626]

6 minutes ago, Nhawks17 said:

I will be looking into this report and seeing what I can find on the matter. If values are changing, they are not intentional.

I'm sure.  I think it's Squad's "fault" - my perception is that moduleengine and moduleenginefx are NOT equal.  That is to say, when you use the same parameters in each, you get different thrusts.

[sarbian]

On 20/12/2016 at 9:54 PM, tg626 said:

I'm sure.  I think it's Squad's "fault" - my perception is that moduleengine and moduleenginefx are NOT equal.  That is to say, when you use the same parameters in each, you get different thrusts.

Nope. engineFx extend engine and contains only the fx code. The trust is handled by the base engine code.

Which version of SmokeScreen are you using ?

(it may be a good idea to open a thread about this problem only ?)

[tg626]

Ill take this over here:

 

Edited December 22, 2016 by tg626

[ManEatingApe]

Driven into an uncontrollable space exploration frenzy by an excess of holiday sugar, I couldn't resist giving this another try. This time the goal was to deliver and return 2 hapless tourists (more or less) intact from Kerbin orbit completely hands off, inspired by this challenge here.

• Pure Stock
• 2 out of 3 launches were successful, so 66% of the time it works every time
• Lesson learned from last attempt, extra clamps.
• @Starman4308 I really liked your ingenious girder cage for the 2nd stage, so I shamelessly pinched the idea.
• Central booster thrust was carefully tweaked to keep the 2nd stage seated inside its cage, and to give the Separatrons time to force the nose down
• 2nd stage spin stabilization worked surprisingly well

Figuring out how to land safely was an interesting problem. Parachutes were out as they would immediately deploy on the landing pad. Instead the 2nd stage was designed to resemble a Sycamore seed. By making it deliberately aerodynamically unstable it auto-rotated during descent, slowing to a survivable speed.

Mission Control were briefly worried that the violent rolling and yawing would make the interior of the capsule look like a Jackson Pollock, but our 2 tourists remained unperturbed throughout.

Here's the video, enjoy!

 

Download Craft file.  Payload fraction and orbital eccentricity are woeful, so this entry is just for fun!

Edited December 26, 2016 by ManEatingApe

[tg626]

38 minutes ago, ManEatingApe said:

Driven into an uncontrollable space exploration frenzy by an excess of holiday sugar, I couldn't resist giving this another try. This time the goal was to deliver and return 2 hapless tourists (more or less) intact from Kerbin orbit completely hands off, inspired by this challenge here.

[SNIP]

That's so KERBAL!  I love it!

 

Edited December 26, 2016 by tg626

[MarvinKitFox]

WEEP!

WAIL!

Beware all ye faithfull, for the devil is among us, and his name is ManEatingApe !

 

This miscreant doth defy the very laws of fizzics, yeah I tell unto you my brethren, he invokes the very Kraken Himself with his blasphemous ways!!

There are thing that no mere Kerbal can do, indeed things no Kerbal dare *dream* of doing, yet this ManEatingApe not only dream, not only does, but then goes forth and **spreads the word** on how to violate the very fabric of Kerbality

 

Repent and turn away from such Witchcraft!