Abastro

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Everything posted by Abastro

  1. 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?)
  2. While testing a pseudo-aerostat, discovered that fairing has basically infinite impact tolerance. It won't break apart as long as the base part won't. I think this means that one can cheat with fairings and abuse them as landing strut / splashing buoy or rover cover, as it is the lightest part with that kind of tolerance.
  3. These comes to my mind. I. Simple & Economic (Unhealthy) 1. Wait for Duna -> Kerbin transfer window. 2. Get Val out of the cozy cabin. 3. (Optional) If the plane has a probe core, point one of the nuke engines to the Val and turn it on. Val should gain reasonable speed with it. 4. Use jetpack to plot a nice Ike gravity assist to escape Duna and intersect Kerbin. (Ike flyby costs about 400m/s, so doable) 5. Let Val wait for countless time during the transfer. 6. Rendezvous and catch Val with rescue ship. II. Fast (ingame time) 1. Design a seat with Ant engine, which will grant you lots of dv in a small package. (~3km/s) 2. Attach Spark engine stage to the seat, which will give you extra 3km/s of dv or so. 3. Design asparagus-staged nuke interplanetary ship to haul the seat above. 4. Lift the above spaceship to LKO. 5. Shoot Duna with it. Literally. (*Effective when Duna is close / If you unlocked an ion engine, use it instead of Ant/Spark) III. Reusable 1. Launch a Reusable SSTO with klaw. The same spaceplane with a klaw attached would work. 2. Reach Duna orbit. 3. Rendezvous and grab Val's plane. 3. Tug the spaceplane back to Kerbin. With proper aerobreaking, I think dv needed is about 2.6km/s on LKO. (Considering the increased mass after grabbing) Though, these are just suggestions. Do what you want
  4. Right! Gosh, I should be bad at communication. I'm sorry. (Besides, I was confused because you mentioned numbers; A number can be either scalar or 1-dimension vector)
  5. Started playing with airships, ended up with amphibious seaplane which can land on belly. Fairing is really OP, it has basically infinite impact tolerance. Structural failure is the only possible cause of explosions given that all parts are shaded in the fairing.
  6. This is contradiction. What do you mean? Multiply u and v? Why?
  7. That's scalar... scalar does not contain direction while vector does. Yes it is. Also, if it works on some system, it works on every system since reflection/rotation/translation are linear. If there were contradiction like this, nobody will be using vector arithmetics. (Also similarly one can deduce a=b for any number a,b - the secret is dividing by zero which is packed up with formula, it is hard to realize that it's actually zero)
  8. Amazing video! I have a question, why did you limited the throttle during the ascent till 5.6km?
  9. I got over 22.34% with this rocket: Quite surprised that high TWR can greatly improve fuel economy! I'll post this as an entry after adding wings to the second stage.
  10. Well, the velocity difference is always -2(u+v) in vector when planet vel = -u & ship vel = v.
  11. I think you got a mistake here: (-2u-v)-v=-2(u+v).
  12. Hmm... then, please update the OP to include the unit (km). This one was confusing as you said: I thought this means the result was in meter. Besides, screenshots would be great for verification.
  13. You reduced the amount of solid fuel, right? Because a Kickback surely can go much further than few hundred meters when fully fueled... (They can get to LKO on their own) Did it go supersonic, where most of the aerodynamic drag comes from? Also, would you post the screenshots of the test rockets?
  14. Well, I don't care about it, because I'll abus- -e it. I'll apply this to a robust rover. Maybe it could work well as rover wheel! (+ tried lithobraking, fairing does survive 200m/s but the other parts often get ripped apart by the stress. Maybe it would work well with spaceplane parts which have high impact tolerance)
  15. Shoot the mun and bounce intact. (50m/s bounce should be possible - would bouncing back to kerbin be possible?)
  16. I thought I might need some weight over 50t, but just found out that there's no payload part which weighs that much... The most massive part which is neither fuel nor engine is 6.5t passenger crew cabin, as far as I can find. So there's no point for panther spaceplane as spaceship. I've been looking at it. I really liked it, actually I borrowed some designs and ideas! Probably I'd never come to the concept of recoverable rockets if you didn't post it. Thanks! It was great, and I guess it should work in current version as well. Though I think my recoverable rocket TSTO is more efficient as it's staged design. (I could get 380/t with 15t payload) Still it could be the case that lifters work better in 1.2.
  17. 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) 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:
  18. Wow, Skipper SSTO for lifting under 2t, in 811/t? This is far from my expectation, as I had similar one(skipper ssto) which was quite expensive. I'm going to try light lifters! (2t first, since I can't think of a way to lift something lighter than that)
  19. Hi, I tried to make a streamlined VTOL cargo SSTO, but there was an issues in my mk3 engine design: Mk3 to 2.5m adapter holds too much LF+Ox, so it's going to be horribly big.. (Besides I just can't make anything look aesthetic. Begging for advice, please help me!) I have couple more questions: 1. Is there heavier and reliable hinge than Thermometer-OscarB hinge? I think it reached its limit. 2. I'm using airbrakes to swivel the engine-wing section, but it seems that it is pretty generous with clipping, resulting in pendulum motion. Is there something which can hold the engine? I want ones which can move 90 degrees, and strong enough. Added pics for more explanation.
  20. I don't think 5s difference for spaceplane would matter much. The drag loss due to relatively low TWR should be bigger in most cases. For LKO station, 300m/s you gained is enough.
  21. Oops, so you should perform speedrun (gain speed) on about 16km. You get to 1.2~1.3km/s while airbreathing mode, right? Also single Terrier won't work on the case, did you used 2 Terriers? Besides, Aerospike is indeed good choice for spaceplane engine; just land on the runway(launchpad) or you'll lose several bucks.
  22. Did you placed the engines without symmetry? Or you mean the number of engines?
  23. But in the case, it's hard to match CoL and CoM. That's fundamental problem of the design, and it diminishes the performance. Also it's just barely better than reusable rockets, I guess..
  24. In my opinion, not pitching up at all won't worth it. I didn't experience cost of over 30m/s pitching up 5 degrees, and it means staying longer in low atmo which makes the ship easy to overheat. Also low TWR efficient engines could be used in this case. Typically it's Terriers, but sometimes even Nukes can be used.
  25. I design mine 0.4 TWR, usually I don't bother with it much. 0.7 TWR is too big for that, and 0.4TWR for circularization is usually not enough. I forgot to mention that 'spaceplane' has relatively less mass. But I got your point, one usually don't need that kind of mass. Nuke & Panther could make great combination for long-range spaceplane. It's great for giant spaceships in 140t limit, providing lots of payload mass. It's just too big for usual applications. The problem on hard career is usually funds for upgrading buildings, it takes lots of time and effort. Especially, that R&D building takes a lot to upgrade to 3 tier. so I can't have much options with it. And I want to do it in relatively short ingame time. Besides, I don't think there's much to replace pre-existing parts after unlocking nuke. Those in higher tech which are useful to me are only Gravioli & Refinery, Relay dish and Docking port Sr & Structural parts. Other parts looks like cosmetic bits for me. The two prior ones usually need ships for its own niche, so the only thing matter is big structural parts for bigger station. Even then previois station can dock to the new ones with normal docking port. (Also it's not bad to have more stations, I think) Personally, many techs just look obsolete, e.g. precision propulsion. (those radial engines... ;-P) @Spricigo, is it about disposable middle stage? I can't exactly get the idea. Disposing empty fuel tanks didn't save much in my experience.