[1.1.3] The Cheap and Cheerful Rocket Payload Challenge

[linuxgurugamer]

Welcome to the Cheap and Cheerful Rocket Payload Challenge! (3.0 Ruleset Edition)

This challenge is an offshoot from the older version by @Norcalplanner (http://forum.kerbalspaceprogram.com/index.php?/topic/130730-the-cheap-and-cheerful-rocket-payload-challenge-105) with his permission.  It is very similar, but updated for 1.1.3 with the addition of rules to allow parts mods to be used.

This challenge is designed to mimic a typical rocket launch in a career game, and I fully expect that some entries will be players showing off their existing lifter designs. 

The Challenge: Launch a payload into an 80 km orbit with a rocket at the lowest cost you can.  The payload doesn't have to fully circularize - see the Orbital Height rule below for details.

Scoring: Divide the cost of your lifter (in funds) by the mass of your payload (in tons).  For example, a lifter which costs 30,000 funds and gets 20 tons into orbit would have a cost of 1,500 funds/ton.  Lower is better.

The Rules:

• KSP Version: 1.1.3 only, with stock stats and costs for all parts.  The challenge will not end when 1.2 drops.  However, unless there is no change to the physics, etc in 1.2, it will remain 1.1.3 only
• Payload: The payload must be at least 2.25 tons, and must detach from the lifter before scoring.  The payload may contain electricity and a probe core. 
• Reaction Wheels: 1.25 meter and 2.5 meter payloads may each have a single reaction wheel or manned capsule of that diameter.  Because there is no stock 3.75 meter reaction wheel, 3.75 meter payloads may have two of the 2.5 meter reaction wheels.
• Lifter: The lifter must be vertically launched and use only LFO engines and/or SRBs. 
• Staging: All staging must be accomplished with a decoupler, stack separator, or docking port.  Decouplers and docking ports used for staging may not remain attached to the payload.  Explosive staging is prohibited.
• Recovery: Not for this particular challenge.  We're looking for Cheerful as well as Cheap.
• Parts: Stock parts only.  One of the goals of this challenge is to showcase designs which anyone can recreate.
• You are allowed to use parts from a single mod only.  Clarification:  Stock is not considered to be a mod, so you may include stock parts as well.  For example, KW Rocketry Redux, SpaceY, etc. for anything which contributes to the actual performance of the rocket. I will consider SpaceY Expanded to be used along with SpaceY, since it is packaged separately but is merely an expansion of the original.   You may use other parts mods as well, to improve automation, for screenshots, etc.  For example, Smart Parts is allowed and recommended, as is Hullcam VDS.  Camera Focus Changer is useful for changing where the camera is pointing
• Mods: KER or MechJeb is recommended, as is Kerbal Joint Reinforcement.  Immersion and information mods, including Editor Extensions, are all allowed.  Anything besides KJR which alters physics (e.g. FAR) or parts (e.g. Tweakscale) is prohibited. 
• Cheating: No editing of config files, infinite fuel, hacking gravity, or any other such tomfoolery.
• Autopilot: MechJeb or other autopilot ascent is fine. So is using Smart Parts.  This is primarily a design challenge.  Gravity Turn is also allowed
• Orbital Height: Achieving a full orbit is not required for this challenge, as it is intended to simulate launch of a payload which can complete circularization by itself.  Score must be calculated when the payload Ap is a minimum of 80 km, Pe is a minimum of 1 m (i.e., you can see the Pe marker in map view), and altitude is at least 70 km.  In other words, you can detach the payload from the lifter while still in the atmosphere, so long as the payload still meets the Ap/Pe criteria after it exits the atmosphere.
• Payload Special Rule: The payload may not contribute any thrust to meeting the above criteria, and the payload mass must remain constant from launch until after the lifter detaches.  While the payload may contain an engine, using that engine is outside the scope of the challenge.  In other words, if you can't bear to see your payload fall back into the atmosphere, you can include an engine in the payload, so long as you score your entry before firing up that engine. (This is intended to accommodate OCD/completionist/roleplaying types, and also allow people to enter existing craft they've used in a career save.) 

Regarding the Orbital Height and Payload Special Rules, they're encouraged to: a) encourage responsible launches (no Kessler syndome); b) encourage proper ascent profiles; and c) allow for more realistic use of lifters.  C&C design is about practical rockets, and many rockets in both KSP and RL use an engine in the payload for final circularization.  If all the above seems too complex, simply launch your payload to an 80 km orbit and then detach the lifter at that point - such an entry will still comply with the rules, and you're only giving up a few dozen m/s of delta V.

Entry Requirements:

• Provide photos or a video showcasing your lifter design and launch.  Be sure to include shots in the VAB showing the total rocket cost, and then the cost of just the payload; the difference is your lifter's cost. 
• While not required, it would be helpful to upload your craft file to KerbalX and provide a link.
• Clearly show the final mass of the payload in orbit, after it's detached from the lifter, using KER, MechJeb, or the info button in map view, rounded off to two decimal places. 
• Include a brief description of your design, either in your post or in the captions for the photos. Be sure to note any particular techniques or parts which are used in your design.  Feel free to sell how wonderful it is on other criteria - low tech level requirements, limited part count, ease of piloting, or whatever else you like about your lifter.  If you do upload to KerbalX, please provide all the information there as well (cut'n'paste would work).
• Calculate your own score as part of your entry. Divide the cost of your lifter (in funds) by the final mass of your payload (in tons).  Round off to no more than two decimal places.
• If you are using a parts mod for lifter parts (engine, tank, SRB, etc), please be sure to mention that in the description of the entry, preferably in the title.

Leaderboards:

• A single leaderboard will be kept for stock
• There will be a new leaderboard created for each different parts mod used for lifter parts
• On each leaderboard, the entry will be listed with notes to point out any key characteristics.
• If there's a clamor of interest to add recovery, or to establish weight classes, we'll cross that bridge when we get to it.
• You may enter multiple times.  You can be listed on multiple leaderboards, but only one time on each leaderboard

Advice:

• Please launch your craft during the daytime.
• Kerbal Joint Reinforcement is highly recommended for larger craft.If you're stuck for ideas, take a look at the older  Rules of Thumb for Building Cheap and Cheerful Rockets.

 

Stock Leaderboard

1. GoSlash27 with 739.1 funds/ton

 

KW Rocketry Redux Leaderboard

1. maccollo with 544.5 funds/ton

 

SpaceY Leaderboard

1. Nefrums with 661 funds/ton
2. Norcalplanner with 742.53 funds/ton

 

Real Scale Boosters Leaderboard

1. Norcalplanner with 436.45 funds/ton

 

Edited August 24, 2016 by linuxgurugamer

[Norcalplanner]

Kudos to linuxgurugamer for reviving this challenge for 1.1.3.  I thought I would kick things off with an entry.

This is markedly different from most of the entries in the previous challenge.  It uses only SRBs, uses SpaceY parts, and has a 2.5m payload.

 

The lifter portion of the rocket is 23,735 funds, and puts 31.965 tons into orbit, for a score of 742.53 funds/ton.

Full album of images can be found here.

[Norcalplanner]

Well, I've created another rocket using SpaceY parts that's beaten my previous record of 699 funds/ton in the old challenge, but it will seem weird if I post two or three entries in a row.  We need more participants!  Paging @maccollo, @Nefrums, @GoSlash27, @numerobis, @Nich, and @Meithan - your rocketry skills are needed.

Edited August 22, 2016 by Norcalplanner
typo

[Nefrums]

Here you go a quick spaceY variant: http://imgur.com/a/L8sDu

661 funds/t

 

[maccollo]

are mixed parts allowed, like using both stock parts and KW rocketry in one launcher?.

[linuxgurugamer]

Yes, although it will be listed in the (in your example) the KW Rocketry leaderboard.  I added a clarification

Edited August 22, 2016 by linuxgurugamer

[GoSlash27]

Norcalplanner,

I really don't think I'm capable of doing any better than I did in the 1.0.3 challenge, but I'll see what I can come up with.

Maybe something ridiculously huge...

 

Best,
-Slashy

[maccollo]

Alright then, this allows me to beat my personal record with ease  KW rocketry has slightly different cost charateristics. The fuel tanks and more expensive, but have slightly better fuel fraction, while the engines cheaper but have slightly worse performance. Overall it seems cost difference is more significant than the performance for launches to low orbit, so mixing stock tanks with KW rocketry engines seems to be a good idea.

With that, here is my entry... It's another kickback boosted sustainer. Shocking! The core engine is the Vesta VR-9D from KW rocketry.

booster cost: 27820 funds

payload mass: 47.27 tons

cost per unit of payload mass: 588.5 funds/ton

Edited August 23, 2016 by maccollo

[GoSlash27]

Okay. This isn't the cheapest ride to orbit I've ever made, but it's the largest so far.

318 tonnes to orbit for $739.10 per tonne. All stock (no mods).

http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/BigCheep113

If I can swing it, I'll submit some cheaper entries at less- insane payloads.

Best,
-Slashy

 

 

[maccollo]

Found a very good combination using the big KW Thor II solids and the Maverick-V.

The Maverick brings the cost down quite a bit. 2650 funds for 1400 kN of thrust at an ISP of 315. That's about half the cost of a skipper. It's insanely good! (Though not quite good enough to replace the solids).

Comparing the Thor II to the kick back, Thor II has 20% higher cost per impulse, 15% higher cost per unit of thrust. However, it's structural mass fraction is much better, 7.5% compared to 18.75% for the kickback, so more of the impulse will actually go into the core. Not sure which one actually comes out on top, but one Thor II is certainly a lot less unwieldy than clustering 5 kickbacks together.

 

booster cost: 52820 funds

payload mass: 97.01 tons

cost per unit of payload mass: 544.5 funds/ton

 

To be frank, the cost balance in KW rocketry is a bit broken.

Edited August 23, 2016 by maccollo

[GoSlash27]

A new entry at the "cheap and light" end of stock.

17.2t at $891.28 per tonne. I did not optimize this one, so there's lots of room for improvement.

http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/Cheep17

 

Best,
-Slashy

[Norcalplanner]

13 hours ago, maccollo said:

To be frank, the cost balance in KW rocketry is a bit broken.

KW's balance has nothing on the "balance" in Real Scale Boosters.  Behold!

408.269 tons of payload at 436.45 funds/ton.

Full album can be found here.

Edited August 24, 2016 by Norcalplanner
Why is the "submit post" button next to the "insert other media" button?

[linuxgurugamer]

3 hours ago, GoSlash27 said:

A new entry at the "cheap and light" end of stock.

17.2t at $891.28 per tonne. I did not optimize this one, so there's lots of room for improvement.

http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/Cheep17

 

Best,
-Slashy

Interesting entry, but you are already on the leaderboard with a better ship (remember, only one entry on each leaderboard)

[GoSlash27]

5 hours ago, linuxgurugamer said:

Interesting entry, but you are already on the leaderboard with a better ship (remember, only one entry on each leaderboard)

Oh, that's fine. I'm just posting cheap designs that I didn't develop in the last challenge. These ones aren't as cheap as those, but I figure there's no point in resubmitting those since they still work.

Best,
-Slashy

[maccollo]

SpaceY entry
 

booster cost: 17600 funds

payload mass: 31.42 tons

cost per unit of payload mass: 560.15 funds/ton