The Cheap and Cheerful Rocket Payload Challenge 1.0.5

[Norcalplanner]

Welcome to the Cheap and Cheerful Rocket Payload Challenge! (2.0 Ruleset Edition)

This challenge grew out of some of the discussion on my Cheap and Cheerful (aka C&C) tutorial thread and elsewhere regarding various rocket designs which are optimized for cost-per-ton to orbit.  While Red Iron Crown's challenge for best payload fraction has yielded some incredibly capable and occasionally unorthodox designs, it's not the most helpful for those who don't enjoy spaceplanes but still want to get payloads into orbit in a cost-effective manner.  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: 1.0.5 only, with stock stats and costs for all parts.  The challenge will likely end when 1.1 drops.
• 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.
• 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. This is primarily a design challenge.
• 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. 
• 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.
• 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.

Leaderboard:

• A single leaderboard will be kept, with notes to point out any key characteristics of an entry.
• 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.

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 my Rules of Thumb for Building Cheap and Cheerful Rockets.

The Leaderboard (2.0 Ruleset)

maccallo - 645.93 funds/ton - 164 ton payload, refinement of previous design

GoSlash27 - 648.36 funds/ton - 137.3 ton payload, quasi-asparagus staging with a Twin Boar sustainer

maccallo - 649.98 funds/ton - 164.05 ton payload, quasi-asparagus staging with radial tanks on top of two big SRB clusters

GoSlash27 - 662.68 funds/ton - 135.7 ton payload, quasi-asparagus staging using more Mk3 plane parts for lowered cost and better aero

maccallo - 666.4 funds/ton - 160 ton payload, refined version of previous entry with drop tanks on top of larger SRB clusters

maccallo - 675.3 funds/ton - 139.6 ton payload, 3.75 meter entry, center Rhino sustainer with radial SRB clusters

GoSlash27 - 677.66 funds/ton - 19.7 ton payload, all SRB first stage, Poodle transstage

Nich - 730.1 funds/ton - 146.39 ton payload, 3.75 meter entry, center Rhino sustainer with drop tanks on top of radial SRB clusters

Norcalplanner - 738.26 funds/ton - 258.07 ton payload, combination of standard and quasi-asparagus staging with a Mammoth sustainer

 

Looking for the old 1.0 ruleset and leaderboard?  It's hidden below.

Spoiler

 

Welcome to the Cheap and Cheerful Rocket Payload Challenge! (old 1.0 ruleset)

This challenge grew out of some of the discussion on my Cheap and Cheerful (aka C&C) tutorial thread and elsewhere regarding various rocket designs which are optimized for cost-per-ton to orbit.  While Red Iron Crown's challenge for best payload fraction has yielded some incredibly capable and occasionally unorthodox designs, it's not the most helpful for those who don't enjoy spaceplanes but still want to get payloads into orbit in a cost-effective manner.  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.   

Scoring: Divide the cost of your lifter (in funds) by the final weight 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: 1.0.5 only, with stock stats and costs for all parts.  The challenge will likely end when 1.1 drops.
• Payload: The payload must be at least 2.25 tons, and must detach from the lifter before scoring.  Reaction wheels, power sources, and even engines (more on this in a moment) in the payload are fine.  Payload fuel tanks must remain full prior to the payload detaching from the lifter.  No fuel may be drawn from the payload to feed engines in the lifter. (clarified 1/28/16)
• 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.  No explosive staging. (added 1/28/16)
• Recovery: Not for this particular challenge.  We're looking for Cheerful as well as Cheap.
• Orbital Height: Pe of the orbit must be at least 80 km.
• Parts: Stock parts only.  One of the goals of this challenge is to showcase designs which anyone can recreate.
• 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. This is primarily a design challenge.
• Special Rule: An LFO engine or engines which are part of the payload may be used for up to 500 m/s of an orbital insertion and/or circularization burn after the payload detaches from the lifter. If an engine on the payload is used, then the final payload mass is the mass after the orbital insertion burn is complete. 

Regarding the special rule, it's intended to: a) encourage responsible launches (no Kessler syndome); b) encourage proper ascent profiles; and c) allow for more realistic use of lifters.  I thought about it a lot, and it may open up some exploits.  Nevertheless, C&C design is about practical rockets, and many rockets in both KSP and RL use the same engine for orbital insertion and for a transfer burn to the craft's final destination.

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. 
• 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. 
• If you use a payload engine for orbital insertion, show the m/s of the insertion burn via a maneuver node, or by keeping MechJeb or KER delta V panels open and doing some math.
• 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.
• 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.

Leaderboard:

• A single leaderboard will be kept, with notes to point out any key characteristics of an entry.
• 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.

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 my Rules of Thumb for Building Cheap and Cheerful Rockets.

Example:

As television chefs say, here's one I prepared earlier.  While not intended specifically for this challenge, my Orange Tank Refueler (used as an example in the C&C tutorial) still has enough info in the screenshots to score it as an entry.  58,880 fund total rocket cost minus 14,750 fund payload cost means the lifter costs 44,130 funds.  Final payload mass is 41.92 tons, for a cost of 1,052.72 funds per ton to orbit.

 

 

Have fun! I look forward to your entries!

The Leaderboard (1.0 Ruleset)

maccallo - 597.1* funds/ton - 102.6 ton payload, quasi-asparagus staging with LFO tanks above radial SRB clusters   *used explosive staging

nich - 628 funds/ton - 26.28 ton payload, all SRB first stage, used Poodles both for transstage and final orbital insertion

GoSlash27 - 650.97* funds/ton - 18.05 ton payload, all SRB first stage, used an aerospike for final orbital insertion     *used explosive staging

maccallo - 682.16 funds/ton - 26.34 ton payload, all SRB first stage, payload contributed only torque (no thrust)

maccallo - 734 funds/ton - 38 ton payload, radial SRBs with a center LFO sustainer, final insertion TWR of only 0.18

Nich - 759 funds/ton - 123.38 ton payload, quasi-asparagus staging with LFO tanks above radial SRB clusters

norcalplanner - 798.17 funds/ton - 96.22 ton payload, scaled up version of previous entry, abusing KJR and surface attachment with 16 Kickbacks on four decouplers

GoSlash27 - 820.78 funds/ton - 37.83 ton payload, optimized version of previous entry concept with better launch profile

SanderB - 828 funds/ton - 6.39 ton payload, used a single Kickback as the first stage, 1.25 meter leader and lowest cost lifter of any entry

GoSlash27 - 900.89 funds/ton - 37.13 ton payload, all SRB first stage with staggered thrust levels, used monoprop for the final orbital insertion

Temstar - 914.48 funds/ton - 262.5 ton payload, massive asparagused 3.75 meter entry, best LFO-only entry

Streetwind - 963.46 funds/ton - 7.01 ton payload, all SRB first stage with staggered thrust, very low tech requirements (25 science points will unlock all needed nodes)

norcalplanner - 1052.72 funds/ton - 41.92 ton payload, radial SRBs with a center LFO sustainer, payload is an unmanned refueling tanker

dragonaether - 3941.2 funds/ton - 5 ton payload, used as an actual working rocket with a fairing to deliver a rover to Minmus

 

 

 

Edited February 5, 2016 by Norcalplanner
updated leaderboard

[Nefrums]

Is the payload allowed to contribute to the launch to orbit?    So a SSTO payload would score infinitely?

[Norcalplanner]

33 minutes ago, Nefrums said:

Is the payload allowed to contribute to the launch to orbit?    So a SSTO payload would score infinitely?

Nefrums,

I'm not sure I understand the question.  A maximum of 500 m/s of the orbital insertion / circularization burn can be performed by the payload.  The first 2600+ m/s has to be performed by the lifter, which is not counted as payload. 

In re-reading my OP, I now see that the special rule isn't 100% clear.  I'll change it to specify that I'm talking about an engine which is part of a payload which has detached from the lifter. 

SSTO won't really generate any benefit under the current rules, as there's no recovery.  That said, if you and a number of other entrants really, really want to do SSTO rockets, then we'd probably use the stock recovery mechanic for any lifter that lands back at KSC and subtract any returned funds from the total lifter cost when figuring cost to orbit.  We'd definitely need to split the leaderboard in two if we go that route, since it would be an apples to oranges comparison.

Edited January 26, 2016 by Norcalplanner
Clarity

[Nefrums]

ok, I missed the rule about that the payload only can be used for the last 500m/s

[GoSlash27]

Nefrums,

 You should probably divvy up the leaderboard into different weight classes. There's a definite economy of scale in KSP that favors larger launchers.

Best,

-Slashy

[dragonaether]

this is my entry, i hope to have respected all the rules. my payload is a rover for minmus.

http://imgur.com/sqjc5os&TTDWa4E&8zVjKKv&YuZ2qEu&UGeACGB&SsQEU9Y&LIJy7yQ&G3hIBLb&akmdIkV&nYIXhFo&tXaYWpo&asG2hLD&kSMlPDd&oAmw5a3&r99J32o&DnEevYN&eCfoInt&9MlCGee&kvl9a0Q

the lifter cares 3 tons and the cost 19706, plus the payload (the science and the rover cost quiet enough) the total is 40410

Edited January 26, 2016 by dragonaether

[Norcalplanner]

3 hours ago, GoSlash27 said:

Nefrums,

 You should probably divvy up the leaderboard into different weight classes. There's a definite economy of scale in KSP that favors larger launchers.

Best,

-Slashy

Slashy,

I'm holding that idea in my back pocket for now. Let's wait and see if there's a clear difference among entries before splitting things up.

And I look forward to your entry. :-)

1 hour ago, dragonaether said:

this is my entry, i hope to have respected all the rules. my payload is a rover for minmus.

http://imgur.com/sqjc5os&TTDWa4E&8zVjKKv&YuZ2qEu&UGeACGB&SsQEU9Y&LIJy7yQ&G3hIBLb&akmdIkV&nYIXhFo&tXaYWpo&asG2hLD&kSMlPDd&oAmw5a3&r99J32o&DnEevYN&eCfoInt&9MlCGee&kvl9a0Q

the lifter cares 3 tons and the cost 19706, plus the payload (the science and the rover cost quiet enough) the total is 40410

Dragonaether,

First entry! I'll review this in detail later today - I'm  on my phone right now, which isn't the best for this sort of thing. If everything looks good, you'll be added to the leaderboard.

Edited January 26, 2016 by Norcalplanner

[Streetwind]

Are you specifically looking for cheapest cost only? I have sort-of scalable lifter architecture specifically made for earlygame launches, where you are limited more by science points than by cash (which the game throws at you in large amounts through starter milestones). Basically, as soon as you unlock the Terrier (and well, struts do help...), the only limits are those of the VAB and Launchpad. Which obviously don't apply in Science Mode games.

But it doesn't win prizes for cheapest cost to orbit, since 1.25m liquid engines simply have noticably worse stats than 2.5m and up...

[Norcalplanner]

15 minutes ago, Streetwind said:

Are you specifically looking for cheapest cost only? I have sort-of scalable lifter architecture specifically made for earlygame launches, where you are limited more by science points than by cash (which the game throws at you in large amounts through starter milestones). Basically, as soon as you unlock the Terrier (and well, struts do help...), the only limits are those of the VAB and Launchpad. Which obviously don't apply in Science Mode games.

But it doesn't win prizes for cheapest cost to orbit, since 1.25m liquid engines simply have noticably worse stats than 2.5m and up...

Streetwind,

Funds per ton to 80 km orbit is the scoring mechanism. Cheaper is better. I'll add notes next to each entry based on what you call out in your description, so if one of the things you like about your lifter is low tech requirements, or that it can be launched from a Level 1 pad, go ahead and mention that in your description.

Please submit what you've got and we'll see how things stack up. If a clear divide develops based on engine diameter or payload weight, then I may end up splitting the leader board.

I look forward to your entry!

Edited January 26, 2016 by Norcalplanner
Elaborated a bit

[maccollo]

I really enjoy tinkering with my launchers to make them cheaper, so this is right up my alley =)
Here's my first entry, a skipper powered sustainer core boosted by 4 kickbacks, and an terrier on the payload for circularization.

Total cost: 44066 funds
Payload cost: 16170
Launcher cost: 27896
Payload mass in LEO: 38.0 metric tons
funds per ton: 734

VAB screen dumbs:
https://dl.dropboxusercontent.com/u/22015656/cheapLaunch/launcher.png
https://dl.dropboxusercontent.com/u/22015656/cheapLaunch/payload.png

Launch video:
https://www.youtube.com/watch?v=vA31JnjrbFE&feature=youtu.be

Edited January 26, 2016 by maccollo

[Norcalplanner]

4 hours ago, maccollo said:

I really enjoy tinkering with my launchers to make them cheaper, so this is right up my alley =)
Here's my first entry, a skipper powered sustainer core boosted by 4 kickbacks, and an terrier on the payload for circularization.

Total cost: 44066 funds
Payload cost: 16170
Launcher cost: 27896
Payload mass in LEO: 38.0 metric tons
funds per ton: 734

VAB screen dumbs:
https://dl.dropboxusercontent.com/u/22015656/cheapLaunch/launcher.png
https://dl.dropboxusercontent.com/u/22015656/cheapLaunch/payload.png

Launch video:
https://www.youtube.com/watch?v=vA31JnjrbFE&feature=youtu.be

Great looking entry, maccallo. I'll review it in detail and put you on the board tonight.

In looking at the video on my phone, I couldn't see how many m/s your insertion burn was. What's the figure?

Edit : got it, 332 m/s, thanks

Edited January 26, 2016 by Norcalplanner

[maccollo]

The insertion burn was 332 m/s

[Streetwind]

2 hours ago, Norcalplanner said:

Streetwind,

Funds per ton to 80 km orbit is the scoring mechanism. Cheaper is better. I'll add notes next to each entry based on what you call out in your description, so if one of the things you like about your lifter is low tech requirements, or that it can be launched from a Level 1 pad, go ahead and mention that in your description.

Please submit what you've got and we'll see how things stack up. If a clear divide develops based on engine diameter or payload weight, then I may end up splitting the leader board.

I look forward to your entry!

 

I'm not worried about scoring at all, to be honest. There aren't even screenshots showing each of the various configurations in orbit... I just thought it would fit the spirit of the "cheap and cheerful" idea I described the system in detail here:  http://forum.kerbalspaceprogram.com/index.php?/topic/128943-how-to-play-without-asparagus-staging/&page=4#comment-2354353

Tier 1: One stage, 1.9 tons for 3200 funds; 1684 funds/ton. Tech level: General Rocketry required.
Tier 1B: One extended stage, 2.6 tons for 3850 funds; 1480 funds/ton. Tech level: General Rocketry required.
Tier 2: Two stages, 10 tons for 12,350 funds; 1235 funds/ton. Tech level: General Rocketry required, General Construction recommended
Tier 3: Three stages, 36 tons for 42,375 funds; 1177 funds/ton. Tech level: General Rocketry required, General Construction required

For reference, by the way: unlocking all of tech level 2 as well as General Rocketry costs a grand total of 25 science. That's how early-game these launchers are. Struts unfortunately cost another 45, but only tier 3 really cannot make do without. The example screenshots I provided show FL-T800's, but the concept works with smaller tanks just as well, with the caveat of increased part count.

And yes, 36 tons payload is really quite oversized for a 1.25m stack. But you can also carry less, and instead benefit from a lot of spare dV for a high speed trip somewhere far away. Moho probe during the very first transfer window after game start? Can do!  

Finally, let me present you this "Tier 1 Block II" variant: 4.3 tons of payload for 4725 funds; 1099 funds/ton. It's literally just strapping a BACC (also unlocked in General Rocketry) below a slightly extended common booster as an additional launch stage. Shouldn't need any fins, much like the rest of the series, since the solid motor emptying itself will result in a center of mass plenty far forward, and after staging, the Swivel has its trusty gimbal to steer with.

 

Edited January 26, 2016 by Streetwind

[Norcalplanner]

2 hours ago, Streetwind said:

 

I'm not worried about scoring at all, to be honest. There aren't even screenshots showing each of the various configurations in orbit... I just thought it would fit the spirit of the "cheap and cheerful" idea I described the system in detail here:  http://forum.kerbalspaceprogram.com/index.php?/topic/128943-how-to-play-without-asparagus-staging/&page=4#comment-2354353

Tier 1: One stage, 1.9 tons for 3200 funds; 1684 funds/ton. Tech level: General Rocketry required.
Tier 1B: One extended stage, 2.6 tons for 3850 funds; 1480 funds/ton. Tech level: General Rocketry required.
Tier 2: Two stages, 10 tons for 12,350 funds; 1235 funds/ton. Tech level: General Rocketry required, General Construction recommended
Tier 3: Three stages, 36 tons for 42,375 funds; 1177 funds/ton. Tech level: General Rocketry required, General Construction required

For reference, by the way: unlocking all of tech level 2 as well as General Rocketry costs a grand total of 25 science. That's how early-game these launchers are. Struts unfortunately cost another 45, but only tier 3 really cannot make do without. The example screenshots I provided show FL-T800's, but the concept works with smaller tanks just as well, with the caveat of increased part count.

And yes, 36 tons payload is really quite oversized for a 1.25m stack. But you can also carry less, and instead benefit from a lot of spare dV for a high speed trip somewhere far away. Moho probe during the very first transfer window after game start? Can do!  

Finally, let me present you this "Tier 1 Block II" variant: 4.3 tons of payload for 4725 funds; 1099 funds/ton. It's literally just strapping a BACC (also unlocked in General Rocketry) below a slightly extended common booster as an additional launch stage. Shouldn't need any fins, much like the rest of the series, since the solid motor emptying itself will result in a center of mass plenty far forward, and after staging, the Swivel has its trusty gimbal to steer with.

 

Streetwind,

These are some nicely optimized low tech lifters - definite Cheap & Cheerful. I'd encourage you to pick your favorite, then modify it to turn it into a full-blown entry - I think the special rule should bring your cost per ton down even further. If you'd rather not, there could certainly be an "honorable mention" section added which would be appropriate for your lifters.

[GoSlash27]

Norcalplanner,

 This is one that you've already seen before. It wasn't really intended to put a payload into an 80x80 orbit, so I just used some of the payload to circularize. It's just a basic no- frills medium lifter.

The entire lifter is $52,200 at launch.

Less the $18,750 that will be left in orbit leaves $33,450 expended.

It took a tonne of MP to circularize, so final payload is 37.13 tonnes. That works out to $900.89/ tonne.

Entire slideshow is here (probably jumbled because Photobucket sucks). http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/CnCRocketFactory

Best,

-Slashy

[Temstar]

19 hours ago, Norcalplanner said:

Payload: The payload must be at least 2.25 tons, and must detach from the lifter before scoring.  Reaction wheels, power sources, and even engines (more on this in a moment) in the payload are fine.

It's this bit that doesn't sit well with me. Usually my criteria for design rocket is that I have to assume payload is a dumb lump of lead without any capability at all, which means I build the guidance package on the upper stage.

It's probably overly restrictively as in practice I've never launched completely dead weight payload into orbit. The closest is propellant depots which don't have engine but have plenty of reaction wheel which then helps the rocket steer.

Putting guidance into the payload, particularly reaction wheel and engines that complete the final orbit insertion starts to get into the grey area of "what's an upper stage and what's a payload" like Saturn V's upper stage. It also strongly couples payload to rockets in the manner of "this rocket can put your payload into orbit, assuming your payload can supply 500m/s of delta-V and 30 unit of torque in all three axis".

But if you insist it's certainly doable as a challenge. In fact I have a rocket in mind already, I'll just get rid of the decoupler to merge the upper stage with the usual payload:

[maccollo]

2 hours ago, Temstar said:

Putting guidance into the payload, particularly reaction wheel and engines that complete the final orbit insertion starts to get into the grey area of "what's an upper stage and what's a payload" like Saturn V's upper stage. It also strongly couples payload to rockets in the manner of "this rocket can put your payload into orbit, assuming your payload can supply 500m/s of delta-V and 30 unit of torque in all three axis".

My second entry is basically exactly that. Why have expensive liquid propulsion in stage one when you can just use reaction wheels on the payload to wrestle the rocket? It doesn't really matter how much you use since all payload cost is subtracted.
Actually it wasn't that big of a difference, only about 50 funds compared to my first entry. But I did manage to breach 700, so there's that.

 

Total cost: 34864
Payload cost: 16896
Launcher cost: 17968
Payload mass in LEO: 26.34 metric tons
funds per ton: 682.16

VAB screen dumbs:
https://dl.dropboxusercontent.com/u/22015656/cheapLaunch/launcher2.png
https://dl.dropboxusercontent.com/u/22015656/cheapLaunch/payload2.png

Launch video:

https://www.youtube.com/watch?v=5UQfV17VQnM

Edited January 27, 2016 by maccollo

[Norcalplanner]

3 hours ago, Temstar said:

It's this bit that doesn't sit well with me. Usually my criteria for design rocket is that I have to assume payload is a dumb lump of lead without any capability at all, which means I build the guidance package on the upper stage.

It's probably overly restrictively as in practice I've never launched completely dead weight payload into orbit. The closest is propellant depots which don't have engine but have plenty of reaction wheel which then helps the rocket steer.

Putting guidance into the payload, particularly reaction wheel and engines that complete the final orbit insertion starts to get into the grey area of "what's an upper stage and what's a payload" like Saturn V's upper stage. It also strongly couples payload to rockets in the manner of "this rocket can put your payload into orbit, assuming your payload can supply 500m/s of delta-V and 30 unit of torque in all three axis".

But if you insist it's certainly doable as a challenge. In fact I have a rocket in mind already, I'll just get rid of the decoupler to merge the upper stage with the usual payload:

Temstar,

I look forward to your entry!  You've definitely built some nice rockets previously.

Regarding the ability to use the payload to circularize, I definitely hear where you're coming from, as the rule makes it difficult to compare the results of this challenge to other, more traditional lifter challenges.  In the end, however, I wanted this challenge to be about practical lifters that are useful in a career save, and that means an orbital insertion engine which has the option to do double duty as part of a transfer stage.  I figure if the Saturn V used the first burn of the S-IV to reach orbit, and the Shuttle used the OMS to reach orbit, then there's adequate precedent for blurring the lifter/payload line a little.

I would point out that using the payload for the final push to orbit is optional - maccallo's second entry, currently sitting atop the leaderboard, delivers a payload that only contributed torque, power, and guidance - no thrust.

 

Edited January 27, 2016 by Norcalplanner
typo

[Norcalplanner]

Congratulations to maccallo, Slashy, and dragonaether!  All of your entries have been placed in their respective slots on the leaderboard.

 

[Pds314]

*realizes maccollo has private videos that aren't visible on their channel.*

[SanderB]

In the spirit of norcalplanner's SRB 1st stage LFO 2nd stage I've made this thing that launches to orbit at about 842$ / ton to LKO.

The 1st and 2nd stages together cost 3,802.8 + 1,590 = 5,392.8

Divided by 6.4t of payload, comes out to about 843$ / t.

On a minor note, I did use tweakscale to enlarge the fins at the bottom... but that is the only part that's modded and the extra cost is added into the equation. I've also relaunched the rocket with 8 stock basic fins and that even shaves off 15m/s of dV.

Edited January 27, 2016 by SanderB
clarification

[Norcalplanner]

Oops - accidental voice recognition post

Edited January 27, 2016 by Norcalplanner
Oops

[Norcalplanner]

2 hours ago, SanderB said:

In the spirit of norcalplanner's SRB 1st stage LFO 2nd stage I've made this thing that launches to orbit at about 842$ / ton to LKO.

The 1st and 2nd stages together cost 3,802.8 + 1,590 = 5,392.8

Divided by 6.4t of payload, comes out to about 843$ / t.

On a minor note, I did use tweakscale to enlarge the fins at the bottom... but that is the only part that's modded and the extra cost is added into the equation. I've also relaunched the rocket with 8 stock basic fins and that even shaves off 15m/s of dV.

SanderB,

That's a good looking rocket - I was playing aeound a bit with single Kickback designs, but yours is better than anything I came up with.

In looking at the video, it appears that you're not quite high enough. Pe needs to be at least 80 km, so I can't put you on the leaderboard just yet. Please feel free to polish the design a bit, omitting the tweakscaled fins, and resubmit your entry.

[Streetwind]

On 26.1.2016 at 10:32 PM, Norcalplanner said:

Streetwind,

These are some nicely optimized low tech lifters - definite Cheap & Cheerful. I'd encourage you to pick your favorite, then modify it to turn it into a full-blown entry - I think the special rule should bring your cost per ton down even further. If you'd rather not, there could certainly be an "honorable mention" section added which would be appropriate for your lifters.

Alright, I'm currently strapped for time at home, so forgive me for a bare minimum submission.

The "25 Science Lifter" in the VAB. The side-mounted SRBs are throttled to 72.5%, the center is 100% (this smoothes out the TWR curve). Surprisingly enough, this thing doesn't noticably wobble even without KJR installed. Lifter cost is 2,950 + 3,800 = 6,750 funds. Payload is 2,458 funds. Total cost is 9,208 funds.

The payload in orbit. It's an arbitrary mass simulator, not constrained by the tech limit the lifter has. It has an engine though, since this challenge heavily favors using the payload to contribute dV. That's why I didn't use one of the common booster setups I displayed before - those would simply not have the TWR to increase the payload further, even if the payload could contribute dV.

Payload contributed 4,616 - 4,142 = 474 m/s dV. Final mass in orbit is 7,006 kg out of an initial 8,060 kg. Periapsis altitude is 80,020 m.

Score comes out at 6,750 / 7.006 = 963.46 funds/ton, showing that it's quite possible to get into the triple digits even with only General Rocketry unlocked

 

Edited January 27, 2016 by Streetwind

[GoSlash27]

I made a couple minor adjustments to the Cheep 38 and had another go at it. I removed the fins and added a reaction wheel to the payload. Got a slightly more efficient launch profile.

 The entire vehicle is $51,900 on the pad and $20,850 in orbit, which leaves $31,050 expended. 
Payload on orbit is 37.83 tonnes, for a final cost of $820.78 per tonne.

I think that's about all I'm gonna get out of this design, short of gaming it. I'm going to try something different for the next one.

Best,
-Slashy