ATEC

Stock Payload Fraction Challenge RE-BOOT

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Posted (edited)

THIS IS A REBOOT OF THE STOCK PAYLOAD FRACTION CHALLENGE FOR 1.05!
Original Thread: Here

So let's begin!

I was just scrolling trough The Heritage Challenges and there i found the fact that the original mission was shut down and/or abandoned by OP. That's why i decided that i could re-boot the mission and change her up a bit!

The Challenge:
You must build and fly the most mass-efficient lifter possible for flying to LKO
(Orbit must be 100,000 Equatorial, Circular orbit)

The Rules:
- Stock parts only. KSP version 1.2.2 only, (earlier entries (like 1.0.5) will not be allowed)
- No cfg editing, save editing, debug menu or anything else like that.
NO physics exploits, (like infini-glider). The craft must be lifted by trust and aerodynamic lift alone
- Payload must be mounted on a decoupler or docking node and separated from the lifter in a stable orbit with a equatorial orbit of 100,000m.(max 10% above or below the 100,00m mark) The decoupler/docking port must stay with the lifter
- The payload is allowed to have RCS trusters and/or SAS to fine-tune the orbit after decoupling (It may not be used when the lifter stage is still attached.)
- The payload MAY NOT have any form of engines (Lf + Ox, nuke etc. etc.)
- The payload MUST be a DEAD WEIGHT until decoupling and after that only the usage of RCS and/or SAS is allowed to fine-tune the orbit
- Entries must be a single launch, with no interaction with any other vessels already in flight or launched afterward.
- If you use the offset tool the part MUST be visibly attached to the rocket (attach a strut or something)
- The base of the lifter must be close to the pad surface, preferably touching it. No kilometer-high launch clamps please.
- Do NOT clip parts
- Please do not make a cargo bay the root part of your craft, to avoid a glitch/exploit discovered by Nao.

- Images or video of your design is required for entry, showing launch mass, payload mass in stable orbit, and enough in between to show how your vessel works. (Must be sent as a imgur picture library) Craft files would be the best so we can all learn from each other's building techniques
- You need images of the design in the VAB

- You need an image of the design on the Launchpad
- You need an image of the design in Sub-Orbital Trajectory
- You need an image of the payload in orbit (Mass of the payload MUST be showing (the kerbal button in the right of the HUD)
- Video of the full launch would be the best!

Permitted Mods:

- Visual mods (like scatterer)
- Informational mods (like KER)

Forbidden Mods:

- Anything that modifies stock parts or that adds new parts
- Anything that changes the games physics
- Any autopilot (like mechjeb's AR-202)

The Scoring system:

The maximum amount of points is 100 and you can define your score by doing:

PayloadMassInOrbit / TotalLaunchMass * 100

Higher is always better, and the score will be rounded to two decimal places.

All the categories habe been added so you can start sending in crafts!

Unlimited: Use any propulsion to get into orbit, no recovery needed

Unlimited Recovery: Use any propulsion to get into orbit, all stages MUST be recovered

Rocket Only: Rocket engines only (no ions, jets, or Rapiers in open cycle mode), no recovery necessary.

Rocket Only Recovery: Rocket engines only (no ions, jets, or Rapiers in open cycle) all stages MUST be recovered.

SpacePlane SSTOAll engine types are allowed, must be launched horizontally from the KSC runway. 

*just for SPH SSTO* You will get 10 points extra if you de-orbit and land ON the KSC runway (so maximum amount of points for the SSTO mission will be 110)

The Leaderboard:

For version 1.2.2

Unlimited Unlimited Recovery Rocket Only Rocket Only Recovery SSTO SpacePlane
   

@Zeiss Ikon With 12.67 Points

 @swjr-swis With 20.23 points

@Wanderfound  With 45.43 points

     

 @Abastro With 18.70 Points

 
         
         
         
         
         
         
         
         

 

Edited by ATEC
Leaderboard
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Posted (edited)

@SpaceBadger007 Are ya gonna make a try for any of the categories?

Edited by ATEC

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I may try this, though I'm not the most efficient at gravity turns? This is a challenge of piloting as well as design I see.

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12 minutes ago, Skylon said:

I may try this, though I'm not the most efficient at gravity turns? This is a challenge of piloting as well as design I see.

Yeah that is true...

You could just give it a shot...

You can still get those 100 points when you get it to a stable orbit and don't get that 100km orbit

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Posted (edited)

I am allowed NERV right? Or does that not count? It wasn't mentioned.

I don't have access to KSP right now.

Edited by Skylon

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@Skylon 
1) WHY WOULD YOU DO THAT EFFICIENCY MATE

2) It's only allowed on the launcher but not on the payload (payload must be brought to orbit by the launcher)

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Let's say my lifter was 15t, and payload was 3t. My orbit is 95*105. What is my score? I'm not entirely sure about the scoring system. 

1 minute ago, ATEC said:

@Skylon 
1) WHY WOULD YOU DO THAT EFFICIENCY MATE

2) It's only allowed on the launcher but not on the payload (payload must be brought to orbit by the launcher)

I haven't tested it, but I could have a tiny first stage to bring the NERV to around 10km or wherever the effiecieny begins to ramp up, then the second stage would be much larger and take the payload the rest of the way.

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Posted (edited)

@Skylon

Your score would be:

TotalLaunchMass, thats the mass of the lifter and the payload COMBINED!

PayloadMassInOrbit / TotalLaunchMass * 100 + 20 - (The percentage you are away from perfect equatorial orbit (periapsis and apoapsis)
3 / 18 * 100 + 20 - 5 - 5 = 16,67 + 20 - 10 = 26.667 points 

And about that NERV system: It depends on which class you want to join in... If you want to play the unlimited challenge its allowed

If you wanna play unlimited recovery its allowed (But you must recover ALL stages except payload) 
If you wanna play Rocket only mode you may not do that... (cuz only Lf + Ox rockets)
If you wanna play Rocket recovery you may not do that (and you must recover all stages)

etc

etc

Edited by ATEC

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9 hours ago, ATEC said:

@SpaceBadger007 Are ya gonna make a try for any of the categories?

Im away at the moment, but I will give ut a go, probably wont make it cause im terrible!:D

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Posted (edited)

One for the SSTO spaceplane category:

Score is 68,000/191,925 x 100 for 35.43, plus 20, plus 10 for the runway landing, for a total score of 65.43

Mechjeb is installed, but was not used

 

Edited by Wanderfound

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Posted (edited)

@Wanderfound Wanna share a .craft of it?

I would like to use it for my sandbox roleplay mode!

And i changed the scoring system so those 20 points won't be added...
Your total score is 45.43

Edited by ATEC

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Quote

The payload MAY NOT have any form of engines (Lf + Ox, nuke etc. etc.)- The payload MAY NOT have any form of engines (Lf + Ox, nuke etc. etc.)

Not really relevant if those engines don't get activated. 

On the other hand there is no rule against use fuel contained in the payload's tanks.  (I suppose that's intentional, just checking) 

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15 hours ago, ATEC said:

@Wanderfound Wanna share a .craft of it?

I would like to use it for my sandbox roleplay mode!

Sure: https://www.dropbox.com/s/anrsimfrzf40sor/Kerbotruck PFC.craft?dl=0

Action groups 1 to toggle engines, 2 for engine mode, 3 to set elevators and canards to climb. Spoilers linked to brakes.

As demonstrated, it can struggle up with 70 ton, but it'll be a lot happier if you keep it to 50 or less. You can afford to drop two engines if you do that, too.

If you make a similar ship with the cargo bay replaced with fuel tanks, you've got a good tanker. Use the two in combination and you can fling a payload up to escape velocity with the cargo ship before aerobraking it back down to KSC.

 

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@Spricigo Actually that wasn't intentional (The payload was supposed to be a dead weight until decoupling and then only allowed to use RCS and/or SAS to fine-tune orbit...

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Hmm.  I've got a vessel in my Sandbox save for this challenge.  Let me go make a couple minor mods (disabling engines in the upper stages to make them "payload") and take some pictures...  :)  I guess a crewed VTO LF/O SSTO with no stage recovery is "Rocket mode".

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@Zeiss Ikon You know that the payload stage cannot have engines (even if they are turned off...)

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23 minutes ago, ATEC said:

@Zeiss Ikon You know that the payload stage cannot have engines (even if they are turned off...)

Ugh.  That means I have to go back and delete perfectly good engines.  Even if I can show the rocket in the required orbit with the upper stage still attached to the booster (and hence upper stage engines never activated).  Not to mention multiple screen shots throughout launch showing RCS off...

 

Sigh.  Okay, one dead weight payload, coming up.

 

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4 hours ago, ATEC said:

@Spricigo Actually that wasn't intentional (The payload was supposed to be a dead weight until decoupling and then only allowed to use RCS and/or SAS to fine-tune orbit...

Well, IMHO engines that never get used are deadweight,  monopropelant and reaction wheels that get used is not. 

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Posted (edited)

Okay, I've "adjusted" the vessel -- there is no engine other than RCS quads on the payload, and the RCS wasn't even activated during launch and circularization (I included it mainly to have the ability to dock and recover the pod -- this is, at this point, effectively a light refueling ship, carrying 1800 units of LF/O with a docking port to permit transferring the fuel to another similarly equipped ship).  I have screenshots of the complete vessel and "inert" payload (which includes Jeb in a Mk. 1 Command Pod, along with parachute to get him home -- I think I forgot a heat shield, but these can reenter from low orbit without one, if you keep your periapsis high).  I've also got a screenshot of the complete vessel, in orbit, prior to staging away the booster.  Here's the craft file.  See below...

"Payload" mass 14.690 t (Mk. 1 Command Pod, Mk. 16 parachute, 1.25 m decoupler, 1.25 m monoprop tank, 12x RCS quads, 2x800 size tanks, 200 size tank, two fuel cells, inline docking coupler, and 1.25 m probe core).

screenshot37_zpshlyojinx.png

Launch Mass 116.110 t (includes .2 t of launch clamps; also adapter tank (800 fuel units), 3200 tank, 6400 tank, and the integral 6400 tank for the Twin Boar)

screenshot36_zps5lxctye5.png

Obligatory launch pad shot...

screenshot32_zpsot4hsull.png

After MECO, waiting for apoapsis to circularize.

screenshot33_zpsq2m9j24l.png

Circularizing complete -- just a whisper of fuel left in the booster, payload fuel untouched.

screenshot34_zpsksespoqp.png

Map view showing both apses, verifying orbit within tolerance on both.

screenshot35_zpsw49rte2b.png

Assuming I'm allowed to deduct the launch clamps, I get payload 14.690, GLOW 115.910, or a final payload fraction of 12.67% -- which I don't think is bad for a rocket-only SSTO.  I'll be very disappointed if someone doesn't beat that figure with a multi-stage rocket (in fact, I might come back and do so).

 

Edited by Zeiss Ikon

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@Zeiss Ikon Really nice build! I tested it out on my sandbox and it works reaallly well... The only thing I would change ( to make it better for use) is add some monoprop tanks on the mk1 pod so it can de-orbit with those rcs thingys

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Posted (edited)

11 minutes ago, ATEC said:

@Zeiss Ikon Really nice build! I tested it out on my sandbox and it works reaallly well... The only thing I would change ( to make it better for use) is add some monoprop tanks on the mk1 pod so it can de-orbit with those rcs thingys

It does have the 10 units internal to the command pod; in my experience, that's plenty to deorbit from as low as 100 km.  That's only about 40 m/s dV, as I recall, and with just 4 quads on the command pod, the 10 units of RCS fuel lasts thirty seconds or more.  I usually set my PE around 40 km anyway, that seems to be the sweet spot between being too low and burning up, or being too high and either skipping or getting a lot of heat without much deceleration.

Of course, if you're willing to give up the ability for the tank to dock itself, you could move the decoupler below the RCS tank and get a capsule with almost enough dV to make  Munar flyby...  :wink:

Edited by Zeiss Ikon

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Just now, Zeiss Ikon said:

It does have the 10 units internal to the command pod; in my experience, that's plenty to deorbit from as low as 100 km.  That's only about 40 m/s dV, as I recall, and with just 4 quads on the command pod, the 10 units of RCS fuel lasts thirty seconds or more.  I usually set my PE around 40 km anyway, that seems to be the sweet spot between being too low and burning up, or being too high and either skipping or getting a lot of heat without much deceleration.

That is true but I like to play my games a more role play kinda way... so I won't send some Kerbal (prolly Jeb) on a 100% dead rate misssion and then I would like a couple of units of rcs extra... you know, for reasons.

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1 minute ago, ATEC said:

That is true but I like to play my games a more role play kinda way... so I won't send some Kerbal (prolly Jeb) on a 100% dead rate misssion and then I would like a couple of units of rcs extra... you know, for reasons.

I do the same -- but there's not a docking port on the command pod here, so the only thing you'll be doing after staging the pod off the tank is deorbiting; there's not enough fuel here to get a much higher orbit (sure, you could probably kick it up another 100 km with the RCS on the tank, not to mention the whisper of LF/O left in the booster, but why would you bother unless you're on a rescue mission?).  Beside, go much higher and you'll have a hard time getting the pod back without burning up.

 

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Posting to subscribe, nice to see someone pick this up even if the rules are slightly different.

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