Reusables

Yes, I know. In my opinion, that's also what community can take part in.

Yes. That's why I said this: I'm certain that it's much harder to translate scripts than something like KSPedia. Also, how much degree of proof-reading is needed for a game? I think it doesn't have to be thorough. I suspect that codebase changes for localization took most of the time, since it needs many design decisions and considerations.

Yeah, I know. Though, every games with lots of scripts I see has more than 5~6 languages from the beginning. They can even get lots of help from the community.

4 to 5 languages... For 'Localization' update. ..What?

Yeah, that's exactly what I meant. I just realized that after reading the post.

So it varies per orbit of the asteroid? I didn't know that, I've never played with asteroids. Wow, aerocapture? That looks great solution for this one! If my calculation is right, Skipper is not very cost efficient for disposable lifter compared to Reliant. On the other hand, kickback is great for first disposable stage compared to the other choices. Though I think you can get a bit more advantage with dv. Yeah, SRBs are cheap. May I know your cost efficiency in lifter cost per payload mass? I think you would get TWR over 2~3, which will kill the efficiency (drag penalty will be heavy on transonic region). If you have the SRB with thrust limiter way down, you'd better have multiple SRBs, I think. Also, AFAIK you can get better result with other SRBs like Hammer and Kickback. Thumper has slightly better Isp than Hammer, but poor wet-dry ratio of Thumper compared to Hammer makes up the dv difference. By the way, experiments have shown that TWR of 1.5 is better than 1.4 for sufficiently aerodynamic rocket. I'll update the atmospheric stage information with that.

I think refueling should count as profit, so should not included in the lifter cost. By the way, is it practical(profitable) to get an asteroid to LKO and mine it? I was told that it costs too much, so lifting fuel to orbit is cheaper. Thanks, I like the challenge and the impressive results!

Wow, bypass? I couldn't think of that. BTW, is it possible to make efficient orbiter soly out of the solid boosters? Great analysis! This would be good starting point to analyze efficiency of a spaceplane. Probably more thorough analysis regarding L/D will give tighter bounds. I'll try it. Wow, that's impressive. Did you use reusable rockets or airbreathers? I think you should be using cheaper air intake (like diverterless) and doing more aggressive gravity turn. Ram intakes are just too expensive for a disposable craft. Also you need less initial TWR for the airbreathers. AFAIK whiplash has OP Isp (nearly no need to bother fuel usage) and decent TWR on supersonic speed..

Yeah, Twinboar is definitely one of the best. Besides, I discovered that Reliant could be reasonable choice for low dv. I couldn't ever expect this... this means they are great for application on small rockets! Wow, flea? Hmm, I should analyze efficiency of the solid boosters. And there goes airbreathers. I think they are too OP. Does they have high ISP IRL? Sorry for the messy and buggy formulae. I had hard time writing them here. I should fix those in some time... Thanks! And the Thud... i think some players might use them for side boosters. They are not that bad actually, as shown on the spreadsheet. (Better than Spark)

Spaceplanes will be in General category(III), as they are totally different thing in efficiency. Or, you can make a fully rocket-powered spaceplane. (For IIa) In the case, you can still transfer the fuel if you don'don't enabled 'fuel transfer obeys crossfeed rules' There are many utility parts which provides decent weight. Why don't you use them? Also using ore will be allowed if it doesn't have They will just deploy while staging if pressure is high enough. You should find a solutiom since they will be deleted if you are 1km away from the craft.

Here goes my (inefficient) entry, with fully recoverable TSTO with Nerv on the second stage (IIa, III): http://imgur.com/a/X0fSY Payload : 3.280t Total Cost : 33170 Recovered Cost : 30690 Net Cost : 2480 Cost per Payload Mass : 756.10/t P.S. There were significant loss from recovery(1550). Should perform more shallow gravity turn next time...

EDIT: Just realized that it can be strict for some launch profiles. (Probably with better TWR) Released the rule.

So I played with formulas to find the theoretical bound for LF/Ox rockets. There are 4(or 5) types of mass regarding rocket type propulsion: Payload, Fuel&Fuel Tank, Engine and Utilities(Probe/SAS, Aerodynamics and such). (WARNING: Wall of Formulae) There are certain requirements for a stage: It should have enough initial TWR and Δv budget. These constraints can be expressed with the formulas: Mass of each part has corresponding relations: NOTE: The propellant fraction used here is wrong; It's propellant mass per dry weight. (I think it's reasonable assumption that utility cost is proportional to dry mass, regarding the structural costs) Putting these together, upper bound of payload mass to total (wet) mass is given by this formula: (Apparently, payload mass is the remnant mass without Fuel&Fuel Tank, Engine and Utilities) Let's just deal with LF/O tanks, since Nerv has totally different profile. (Dawn? No) Then the formula becomes: (Actually, the last term should be α/(ζ_tot+1)) Now, let's calculate price. Usually, price of utilities can be ignored. For disposal lifters they are tiny fraction of the mass, and they just got recovered for reusable lifters. (There's one counterexample: Cheap solid fuel engines. I'll deal with them later) And, it's generally acceptable to say that dry price of fuel tank is same with the fuel cost for big enough tanks. (Look at the numbers!) Thus, (Inequality is inverted here) (φ is price per mass of each part; T is for fuel tank, F is for fuel itself, eng is for engine φ_F = 91.8/t for LF/O Tanks) For disposable lifters, lower bound of the price per single ton of payload is given by For reusable lifters, the lower bound is (Again, the last term should be α/(ζ_tot+1)) (Formulae end here) Here's a spreadsheet with these information for some engines: KSP Engine Specifications (Twin-Boar is regarded as engine + Rockomax Jumbo-64 fuel tank) These information is given for single stage rocket. This could be used to determine performance limit of simple multiple stage rocket. This wouldn't work for asparagus staging / drop tanks, though. I'll take care of it next time. PS. Twin-Boar seems to be OP for these purpose.

I don't have the photo right now. I just strapped radial parachutes and did shallower gravity turn. It's just a matter of timing: Give enough kick on the second stage to push apoapsis further, land the first stage to the ocean before second stage reaching apoapsis. Here are those (suboptimal) crafts, heavier ones are better. Besides, here's the rebooted challenge. Thanks for the great resource!

I wanted to see how rocket with airbreather performs. About the exact value, I found the pitch limit practically. (I should have been removed it from category IIa...)

This is reboot of @tseitsei89's economy challenge, which was for 1.1. Categories There is 4 categories each for Stock and Modded. I. DISPOSABLE LIFTERS - Recovery doesn't count IIa. REUSABLE ROCKETS - No airbreathers IIb. VERTICAL LAUNCHED VEHICLES - Vertical Launch with airbreathers III. GENERAL - Anything is allowed Score Score is given by {Expense for the Mission} / {Payload mass(t)}. Expense doesn't include the price of the payload. Recovery cost is excluded from the expense for categories IIa, IIb and III. Rules 1. No cheat menu, No clipping of fuel tank & engine. 2. For stock entries, the craft should work in the same way with stock installs. For modded entries, basically only stock-balanced mods are allowed. However, you can request adding new category for mods you want. It will be accepted if it's resonable for this challenge. 3. You must launch from launch pad or runway. 4. You must achieve a stable orbit. (Pe >70km) 5. Payload must be separated from the lifter once in orbit. Decoupler used for this can NOT be a part of the payload. 6. Payload can have 1 pod, cockpit or probe core but nothing else that contributes any thrust or control authority to your craft. Also no lifting surfaces in payload. 7. Payload mass count after it's decoupled. If you had fuel or something disposable on the payload, give enough proof that you didn't throw any of them away. (e.g. Show that initial payload mass and final payload mass are same) I. DISPOSABLE LIFTERS 1. Funds from recovery doesn't count. 2. You can use ANY parts you like. IIa. REUSABLE ROCKETS 1. You can use any parts except airbreathing engines. (This includes any kind of scooping) 2. You can recover any parts of your lifter that you can for a refund. 3. If you return parts of the lifter from orbit you don't have to land on runway or launchpad for 100% refund. Just land somewhere on kerbin and you can count 100% refund. This is because once you are in orbit it is trivial (but time consuming and boring/irritating) to land at KSC. 4. If you return parts of the lifter that are dropped while suborbital or in atmosphere you must land them somewhere in the KSC area (not necessarily on the launchpad/runway) for 100% refund (KSC must be within sight from your landing spot). This is because again precision landing is boring/irritating. If it is outside the KSC, recovery cost is calculated as default. IIb. VERTICAL LAUNCHED VEHICLES 1. You can use any parts, and at least one airbreather should be used in lifter. 2. You can recover any parts of your lifter that you can for a refund. 3. The craft should fly vertically to orbit - Pitch should be above 30 degrees under stratosphere(7km) 4. If you return parts of the lifter from orbit you don't have to land on runway or launchpad for 100% refund. Just land somewhere on kerbin and you can count 100% refund. This is because once you are in orbit it is trivial (but time consuming and boring/irritating) to land at KSC. 5. If you return parts of the lifter that are dropped while suborbital or in atmosphere you must land them somewhere in the KSC area (not necessarily on the launchpad/runway) for 100% refund (KSC must be within sight from your landing spot). This is because again precision landing is boring/irritating. If it is outside the KSC, recovery cost is calculated as default. III. GENERAL 1. You can use any parts. 2. You can recover any parts of your lifter that you can for a refund. 3. If you return parts of the lifter from orbit you don't have to land on runway or launchpad for 100% refund. Just land somewhere on kerbin and you can count 100% refund. This is because (IMO) once you are in orbit it is trivial (but time consuming and boring/irritating) to land at KSC. 4. If you return parts of the lifter that are dropped while suborbital or in atmosphere you must land them somewhere in the KSC area (not necessarily on the launchpad/runway) for 100% refund (KSC must be within sight from your landing spot). This is because again precision landing is boring/irritating. If it is outside the KSC, recovery cost is calculated as default. Submission - Submission should include enough screenshots or video to prove validity of the mission. - Username, brief explanation of the profile and characteristics will be listed. Craft file will be listed as well if it's given. - Up to 5 entries will be listed on the leaderboard. Leaderboards Stock: I) 1. 589.8/t, @maccollo, with Skipper augmented with Kickbacks. IIa) 1. 378.32/t, @Abastro, with fully recoverable TSTO w/o boostback. (Poodle on the second stage, Skipper&ReliantsX2 on the first stage) 2. 394.99/t, @Nefrums, with Shuttle second stage on SpaceX style first stage. (Rhino on the second stage, Mammoths&Vectors on the first stage) 3. 484.231/t (Craft file), @Avo4Dayz, with simplistic recoverable rocket SSTO powered by single Twin-Boar. 4. 756.10/t, @Abastro, with fully recoverable TSTO with Nerv on the second stage. III), 1. 88.46/t, @Wanderfound, with improved version of 'kerbotruck' - more boosters! (8 R.A.P.I.E.Rs and 4 Shock Cone Intakes) 2. 106.57/t, @OHara, with improved version of @NightshineRecorralis and giving it more cargo. 3. 109.02/t (Craft file), @Wanderfound, with mk3 cargo bus 'kerbotruck' powered by 6 R.A.P.I.E.Rs and 3 Shock Cone Intakes. with few wings - I guess, it's just not wingless 4. 113.69/t, @Clancy, with mk1-2 spaceplane powered by 2 RAPIERs supplied by and 1 NERV. (Just enough Oxidizer to push through the 30-40km, where the NERV can take its time getting to orbit.) 5. 159.29/t, @NightshineRecorralis, with mk2 spaceplane with 2 R.A.P.I.E.Rs supplied by single Shock Cone Intake. 6. 378.32/t, @Abastro, with fully recoverable TSTO w/o boostback. (Poodle on the second stage, Skipper&ReliantsX2 on the first stage) Modded: - Stock-Balanced - with FAR&AJE

Profit doesn't count as reduction of cost.

Hmm, so SSTO spaceplane looks definitely better. (Form factor of the cargo bay seems fine) There's one with 84/t on the extreme end, on 1.1

Wow, this one is exactly what I was thinking. I'll post a reboot of the challenge with my own entry. This thread will be edited to be on the theoretical limit of the cost efficiency. It's fully reusable TSTO craft made for practical use. Thus not so competitive...

What is the current theoretical limit of the cost efficiency to orbit? For stock 1.2 without cheats, in terms of cost per ton, for these cases: 1. Without any recovery 2. Including recovery, without airplane flight path 3. Including recovery, with airplane flight path Practically, there was an orbiter capable of 600/t without any recovery a few versions ago (AFAIK). For the reusable case, I got 500/t with TSTO rocket in 1.1.3 and 1.2, and there should be better one. Here's a challenge to find the practical limit of the cost efficiency to orbit. Here's a spreadsheet with optimal cost efficiency for each engines

This one should be considerably easier, as there is less possibility of any danger. Also there are more open technology to use and more experts to get help from. Much more peaceful, too. What about starting with Phonesat? It's proven to work with some additional devices. AFAIK NASA also supports this one. I think if you are decent with programming and know a bit of engineering, it will be possible to design one. (Maybe)

Yes, it introduces tilted ecliptic to minecraft as well. And.. I had plans of patching minecraft world on sphere. That's why it's spherical, plus sphere is easier to deal with.

I'd like some feedbacks and suggestions for this one: (Sorry, this one is adapted on minecraft; Though I think these sky/space-related things is appropriate here in ksp forum) On high altitude(stratosphere ~ mesosphere)

Yeah, here goes the improved version. Craft file Images : http://imgur.com/a/5xhRA Action Groups: Instructions:

Ion engines won't work since it has high gravity of 1.7g. Also the thick atmosphere makes every engine aside from aerospike, vector and mammoth unable to use. It's hard to flight that way... You can use propeller planes if you are okay with its complexity and extreme price.