Reusables

Well, I'm running relevant one: I don't think Mark Thrimm's SSTOs are efficient, it has many drag issues such as naked nodes. Thanks for actually giving me the figures! 1. So it's just a bit more expensive than my crew lifter (250/t) 2. That's so cheap! Though, I wanted figure under 300/t, as it tends to take time. + I wanted to use SSTOs for satellite deployment, which is often far from 'dense'. So it's not good for sats. Besides, my aim was on minimizing both game/IRL time spent. This is why reusable TSTO lifters was good compromise for me.

Right, except that expendable lifter wouldn't lift much more. It's difference of 16t and 18t in my experience. (I'm using reusable TSTO lifters) My playstyle is focused on stationkeeping and space tourism, this is why I want cheap lifters. To construct the infrastructure in reasonable price. So even in theory, each need 2715 and 2671 for an additional crew and 6.2t of payload. So over 390/t per payload. I won't make panther-based spaceplanes, then. I forgot that they could work as a rover. That's great point! Thanks! I'll try them.

This looks great! ..Though, my calculation gives 425 per crew. This figure is worse than my TSTO crew lifter, which can do 250 per crew. IDK how FAR affects here, but I don't think it doubles the cost. I wanted actual figure with payload mass and fuel cost.. Though I could calculate it with the resource tab. If the first one can lift 5~6t of payload(considering crew), its cost is under 350/t. Though it will be challenging to put some useful payload in the small space. The second one with Nerv costs 1663.2. As it can haul 1 additional crew, it only has to lift 4t for 350/t. This is a bit easier, till challenging. Towing payload should be easier and cheaper, but I think it gives certain restriction on payload. Not so reliable lifter, which is what I wanted. I'd better wait till Whiplash comes out. (which costs 550 sci points) Got it. I forgot that it takes nearly an entire orbit for climbing & reentry. Now I think I shouldn't bother with spaceplanes, especially with tech limit. Yeah, Twin-Boar SSTO is one of the best! Why did I bother spaceplanes? So how much does it cost? (Vertical-launched) Rocket with heavy cargo tends to be relatively cheap. With Twin-Boar&Poodle, it's easy to lift 20t to LKO in 7000. Now I got curious: Whiplash SSTOs are considerably cheaper, right?

Right! ... ..Sorry, but spaceplane is not always SSTO, and vice versa. P.S. I played with reusable TSTO rocket concept, which was promising. If you made a good lifter and made proper instructions, it's trivial and rewarding to fly.

Great! ... ..Sorry, but this one doesn't look low-tech.

It gets more challenging this way. For instance, in early game before getting spark and aerodynamics, the reusable system is hard to make and it's challenging to do so within 14t and 30 parts. Also the first orbiter should be SSTO because of the reason below. It could be a bit more grindy on the early game, since it is needed to upgrade the tracking station for reusable TSTO. But it costs only 3~4 SSTO launches with tourists to earn the enough money for the tracking station in my case. Agreed, it's just my rule for this career. I think current building cost is fitting well. (Especially since I want to involve some serious amount of tourism) I don't think it'll lag with 140 part limit. But wet noodle effect? That's great reason to aboid Panther SSTO. Oh well... Definitely not going for SSTO. This will definitely be what I'm going for. Though SSTO will still be challenging with it, right? Now this is a way! ..But it will spend much more time IRL, so I want to avoid this one. That's below 25km, I know this because I've played a lot with reusable TSTO lifters. I'd say this one looks promising! Besides, how much cost did you spent with the Panther-Nuke SSTO? Did it haul some payload, or a crew? If it's not under 300/t or 250/crew, I'll be going for rockets till Whiplash.

Hi, I recently started hard career with every parts reused except for heatshields, separators and fairing. I want to do it as cheap as I can, so I want to know if Panther-based spaceplane is cheaper than reusable TSTO. Basically these are what I want to know: 1. Cost per crew 2. Cost per ton of payload (does it beat 400/t easily?)

Just wow. . Now it's under 70/t, I can't even guess how cheap it is now. Also, mk1 parts are the best!

SSTO is single-stage-to-orbit. You can make one with conventional rockets, Just attach an orange tank to Twin-Boar and streamline it. If you want spaceplanes: There are several counter-intuitive points in KSP aerodynamics. With excellent explanation of Aerogav, I'd like to add this one: The central node of mk3 mount is 2.5m, and must be filled for minimal drag.

1. Elevons are, basically, airbrakes with decent heat tolerance. They provides sufficient drag when deployed on reentry. 2. 1.25m docking port is a cheap decoupler for low-stress environment. It has the same mass as 1.25m decoupler while being 120 cheaper. Great to use on orbit. 3. If you have a station with the big refinery, it's cheaper to launch ore.

I'm looking forward to it! This one is truly amazing, that's clever use of SRBs! Under a tenth of typical launch costs(rockets), It seems that it's really pushing the limit! Besides, what about trying with lighter payloads? I've changed the challenge to give bonus for transporters with lighter payload.

Sorry for being a bit off-topic, but Reliant is better than Swivel. 100 cheaper, 0.25t lighter and produce 12% more thrust for only 10s(3%) less vacuum ISP. Here is comparison between LF/Ox rocket engines: https://docs.google.com/spreadsheets/d/1FAWGoiUAasr3gukWhhTMjGIQSKcoWXPhvbyM_6E2u3U/htmlview Also it's shown on the sheet that SRBs and Vacuum engines are king of the efficiency. It may be better to have those two, if you are not using combinations like Skipper&Kickback. Swivel is not a vacuum engine, though. I personally think it's trainer engine for rookie pilots.

So under 100/t

Again, looks great! However, it does not fit in this challenge as it's using FMRS. Could you get rid of it? If you can, I'll list it ityou as special entry! Besides, I'm going to switch to cost per payload mass, considering that it could be better to launch smaller payloads more times if it's more efficient. Then the list(hall of fame?) will be cleaned up! EDIT: Copied the leaderboard from the previous challenge, once more.

Long time no see, Sorry for late reply. Wow! As it's the same ship, I'll update your score! Did you copied from 'his pictures', and got 107/t? Great job! Now this is getting competitive! Looks like adequate SSTO planes for small landers. I'm looking forward to the improved one! I'll add a new category for those mods. It looks much harder! (Isn't it challenge to get to orbit there?) I should say that this looks great. It's more practical IRL, too. Though, I'm not going to allow neither StageRecovery nor FMRS, as they are not balanced with stock, especially with Reusable Rockets. EDIT: Could you get rid of it? If you can, I'll list this as special entry! (Copied from another thread)

So it's not only me! In my case, 99.9% of launch failure comes from kerbals sneaking inside the cabsules. Which greatly decreases efficiency of my reusable TSTO vehicles... while gravity turn and reentry comprises 0.05% each. Kerbals, root of accidents.

I did some math on cost efficiency of engines(including the fuel tanks), check it out. KSP Engine Specifications Generally bigger engines are better, with exception of the cheap Reliant.

I always forget it and ends up with Jeb sitting in there. This is painful in combination with tourist contracts. I even launched a rocket and found out that Jeb is just sitting in there. Alone. Doyou have similar experiences?

This, and bigger fuel tanks are cheaper as well. (Nearly every parts in ksp obey this 'economy of scale'.

Should be corrected this time.

Oh, sorry. EDIT: Immediately fixed it.

Continuation of economy challenge 1.2 with rules changed. Categories There are 3 categories each for Stock and Modded. I. DISPOSABLE LIFTERS - Reliable Disposables II. REUSABLE ROCKETS - Reusable Vertical Launch Vehicles III. SPACEPLANES - Cargo Planes got to orbit Scoring Score is given by {Expense} / {Payload mass} for the mission, for given Payload mass. - Expense doesn't include the price of the payload. Recovery cost is excluded from the expense for categories II and III. - All lifters listed will be the most efficient one among lifters with the same or lighter payload, in terms of the score given above. - i.e. a lifter won't be listed when it haul heavier payload than another lifter, and has worse score than that. 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, only balanced mods are allowed. 3. You must launch from launchpad 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. II. REUSABLE ROCKETS 1. You should recover at least one part of your lifter. 2. The craft should fly vertically to orbit - Pitch should be above 30 degrees under stratosphere(7km) 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. III. SPACEPLANES 1. Feel free with recovery - you can either recover or dispose any parts. 2. The craft should fly horizontally to orbit. Perform horizontal flight (pitch < 30deg) at least once before reaching stratosphere(7km) 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. - Payload mass and cost should be presented clearly. - Username, brief explanation of the profile and characteristics will be listed. Craft file will be listed as well if it's given. Leaderboard Stock: I) - 1.77t in 1720/t (3046 funds), @WanderingKid, with Thumper on the first stage and Terrier on the second stage. 3.2km/s to orbit! - 61.87t in 589.8/t (36488 funds), @maccollo, with Skipper augmented with Kickbacks. II) - 1.770t in 811.86/t (1437 funds) , @WanderingKid, with recoverable rocket SSTO powered by Skipper. Protective Fairing Included to protect the payload. - 3.280t in 756.10/t (2480 funds), @Abastro, with fully recoverable TSTO with Nerv on the second stage. - 13.42t in 378.32/t (5077 funds), @Abastro, with fully recoverable TSTO w/o boostback. (Poodle on the second stage, Skipper&ReliantsX2 on the first stage) - 140.1t in 290.94/t (40761 funds), @Abastro,with fully recoverable TSTO w/o boostback. (Rhino&PoodlesX4 on the second stage, Mammoth&TwinboarsX4 on the first stage) III) - 7.000t in 159.29/t (1115 funds), @NightshineRecorralis, with mk2 spaceplane with 2 R.A.P.I.E.Rs supplied by single Shock Cone Intake. - 10.50t in 69.00/t (725 funds), @OHara, with mk1 spaceplane with the payload between docking ports. Powered by 1 R.A.P.I.E.R and Shock Cone Intake. Suboptimal Entries: Modded:

That's so economic! Looks great. I thought it'd be better to have as less engines as possible, due to their mass. Now this one teaches me a lesson! Also, I couldn't expect Nerv for LKO Lifter. Thanks! Besides, I'm going to start the new challenge, with the entries given here included. Please take a look on it.

Simple: https://en.m.wikipedia.org/wiki/Kepler's_laws_of_planetary_motion#Third_law Rather tham fiddling with the constants, comparing with the planets/moons works better. (E.g. for Kerbin orbiter, compare with Mun)

Yeah, like that, but in much better form! Let me give an example. If there are submissions for 1000 for 0.5t, 1200 for 1t, 1700 for 1.8t, 1600 for 2t, 3000 for 3t, 3500 for 5t, 7500 for 8t, 7000 for 10t, 10000 for 14t, 10000 for 15t 1700 for 1.8t, 7500 for 8t, 10000 for 14t will be excluded on the list because there is a better(cheaper) entry. The rest remains in the list, comprising the cheapest lifters for the region of payload.