Brikoleur

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About Brikoleur

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  • Location Igwe, asteroid (6178) 1986 DA

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  1. Brikoleur

    What did you do in KSP today?

    Introducing the BAK Shahrazad, BAK Dunyazad, and BAK Super Shahrazad. They are currently undergoing final tests. The three sisters are based on a brand-new "magic carpet" design. They are roll-on, roll-off flatbed cargo atmospheric craft. They represent a new approach to solving the same problem as the BAK Pelican and its successors, the BAK Pelican 2 and the BAK Cyclone. Left to right: BAK Shahrazad (20-ton HTOL SSTO lifter/Kerbin), BAK Dunyazad (40-ton STOL/VTOL SSTO lifter and liaison craft/Duna), BAK Super Shahrazad (45-ton HTOL SSTO lifter/Kerbin) The BAK Shahrazad at left is an airbreathing light SSTO lifter, intended for use on Kerbin and Laythe. It is rated for a 20-ton payload on Kerbin. It will reach 1550 m/s surface velocity on its three RAPIER engines with the maximum rated payload, and will reach LKO with plenty of dV to spare for the return trip. The BAK Dunyazad is based on the same cargo platform but is intended for a completely different mission. It is to be the primary liaison craft for the planned Kosmodrome Aelita on Duna. Primary propulsion is a single RE-J60 "Wolfhound" engine, which boasts an unbeatable TWR and vacuum efficiency. VTOL/STOL capability is provided by five RV-1 "Cub" Vernier engines housed inside Mk 1 utility bays. It is expected to be capable of lofting a 40-ton payload to orbit from the Dunyan surface, with enough fuel left for a return trip. It has an invariant CoM when empty; with heavier payloads, some tuning of the "Cubs" may be necessary. The BAK Super Shahrazad is an uprated version of the BAK Shahrazad. It carries a total of five RAPIER engines, and has a rated payload capacity of 45 tons to low Kerbin orbit. It is worth noting that this is the same or slightly higher payload capacity as the older Pelican 2, which needed eight RAPIERs reach orbit with maximum payload. Such are the benefits of improved aerodynamic efficiency! The older Pelican 2, in orbit of Laythe. We expect to take the Shahrazad and Super Shahrazad into use as light/medium lifters on Kerbin as soon as the experimental RAPIER engines are cleared for operational use, and should the plan for another Laythe Kosmodrome be approved, intend to deploy one or both there as well. The first to be taken into operation is the Dunyazad, which is a key component of the planned Kosmodrome Aelita on Duna.
  2. Brikoleur

    Is this a good simple plane design?

    I thought you meant centre of pressure. And it doesn't have to be behind the CoM, it just mustn't ever be in front. Which means that that craft is marginally stable with full fuel load, and will get stabler as fuel drains. The centre of pressure could throw a spanner into the works though (or, conversely, could help, I can't tell just by looking at the picture).
  3. Brikoleur

    Is this a good simple plane design?

    How can you tell where the centre of drag is, just by looking at the picture?
  4. Brikoleur

    ISRU Cooling

    The fixed radiators work fine for me. Trick is, I bolt them to a fuel tank which is bolted to the ISRU, and the drill bolted to the same tank. The tank wicks out heat from the ISRU and drill, and the radiators cool the tank.
  5. I can comment on Eve's and Jool's atmosphere. Eve's atmosphere is not thick enough to cause any parts to fail due to pressure limits. Jool's atmosphere is. Dive into it, and if you don't burn up, you will get crushed by the pressure. (Haven't done any diving in Eve's oceans so can't comment on that.)
  6. Brikoleur

    What did you do in KSP today?

    So I needed to bring back a bunch of Kerbals from Minmus, with a lander that had touched down there. Contract. This seemed like a good idea at the time. What could possibly go wrong? The answer, O ye of little faith, is, nothing. Nothing went wrong. Everything went without a hitch. As anticipated, the glide down to KSC was on the extremely steep side because those craft stuck on the roof do generate a certain amount of drag, but that was not a problem at all, just something to plan for. I figured it might be a bit tricky to do supersonic flight in that ... thing, so I held a very steep attitude until I was down to Mach 1. After that it was an easy glid down.
  7. Brikoleur

    What did you do in KSP today?

    I know. But I forgot.
  8. Brikoleur

    Is this a good simple plane design?

    It'll fly. If you want to improve it, here are some things you could look at: Too much wing, unless you're going for some really esoteric mission. You should be able to do a decently easy landing with about half the wing surface you have now. This is gonna be really floaty! Too much fuel. Landing gear too far back. Also medium LG is overkill, small is more than enough for something this size. Wing is horizontal, should be pitched just a tiny bit: this way your body will be aligned with your vector and you'll produce less drag. It's gonna be squirrelly to fly. Consider adding either a tailplane or canards and putting the rudder as far back as it can go. Also set the control surfaces so only the wingtip ailerons control roll, and the rudder only controls yaw. The engine is way overpowered for something this size, but then again more power = more fun so I don't know if that's a problem really. Something this size would fly just fine with a single Juno. If you want more control on landing, consider adding an airbrake.
  9. Brikoleur

    What did you do in KSP today?

    From the "let's not get cocky" department. The mission: crew rotation from Munar orbital station. Three crew out, four crew in, including a surface rescue. The solution: MUNBUS-5. A rocket-powered SSTO carrying a 5-kerbal craft. SSTO flies to orbit, deploys Munar shuttle. Munar shuttle flies there, swaps crew, flies back, docks with SSTO, SSTO re-enters, lands. Recovered, everybody's happy, including the beancounters. Simple thing, huh? The Brikoleur must've built a hundred, no two hundred, light SSTOs by now. No need for a lot of test flights; let's just slap one together, tune the CoM and CoL, and we're off. What could go wrong? On the way out, nothing went wrong. SSTO flew up, deployed the Munar shuttle... ... the shuttle did its thing, came back, RV'ed with the SSTO with about a football field's worth of dV to spare, docked neatly. Nothing left but a routine re-entry. Ouch. Turns out our SSTO has the hypersonic aerodynamic stability of a maple leaf. Bit of a roller coaster ride down. The captain orders the passengers to prep for bailing out, but after some white-knuckle wrestling with the yoke, the craft is back under control -- if in a steep dive -- at around 10k altitude. A gradual pull back, and we're in a nice, shallow descent, although faaar from KSC due to the maple-leaf thing. Lining up for a bush landing in the desert. Nice and flat, plane glides well, has plenty of wing for a sub 50 m/s landing. Home and dry! Uh, no. We have a landing gear malfunction. Specifically, "cannot deploy while stowed." What in the...? I've heard it said that there are two kinds of pilots, those who have made a gear-up landing, and those who are going to. Ronster Kerman just joined the former group. Only damage was the nose cone. All's well that ends well -- but this was a tense one!
  10. Whosoever hath not had a tailstrike, hath not designed a plane in KSP.
  11. Brikoleur

    How do you SSTO to duna?

    If you want to use a plane on Duna, it'll have to be a rocket-assisted VTOL or STOL. Otherwise you'll just plow straight into a dune; the air is too thin and the gravity too low to slow down to a safe landing speed otherwise. Else just use a conventional lander that slows down with parachutes and fires a puff of retro rockets for the final touchdown.
  12. Without seeing pictures it's hard to be sure, but I get the impression you're having a CoM problem, or just possibly a stubby nose problem. These are the most common causes of rockets being unstable. On the way up, your rocket has to be nose-heavy and have a pointy nose. That way aero forces will keep it pointed the right way. On the way back, assuming you're re-entering tail first, you have to have a heavy tail. Normally this sorts itself out by itself because your engines are heavy and your body will be light, since you will have burned all your fuel. If you want to re-enter nose first, you'll have to do a quite a bit of somewhat intricate balancing -- you'll have to design your craft so that it has a pointy and heavy nose even with empty tanks. (This is in fact one of the harder challenges in designing reusable SSTO aircraft.)
  13. Brikoleur

    Oberth > Isp?

    I'm sure somebody could run the numbers, but I'm fairly certain that a one-minute longer burn will only cost single-digit m/s. You won't be that much higher at the end of the burn. The orbital period for LKO is about a half an hour; if your burn was 10 minutes as opposed to 1 minute then you'd see significant Oberth losses, and in that case you should split it into three 3.3 minute burns anyway. If we're talking efficiency, I have to ask though, what are those other engines you might or might not burn for, and could you eliminate them from your design? Getting rid of that dry mass would net you a far bigger efficiency gain than a slightly shorter burn.
  14. Brikoleur

    What did you do in KSP today?

    Career is progressing nicely. I just got back from my first interplanetary mission (Duna flyby with a quick visit to Ike's surface since I had the dV budget), and have some more permanent assets on their way there -- a relay constellation, a survey sat, and a space station with a lander. Two launches. Next I'll need to grind some missions to have enough funds to upgrade my science centre to level 3 -- I want that ISRU and now have the Sci for it, but am lacking a few hundred grand in Funds. I will use these missions to develop a set of fully recoverable launchers (I now have the tech for that). Next transfer window, I want to have a Duna ground base ready to go: that means a STOL liaison / cargo shuttle, a command centre, ISRU + tanker, and a couple of science rovers. I also want to send up an intra-system shuttle / return vessel I can use to do rescue missions in the Duna system. I've also got the Outer Planets mod installed this time. Once the Duna base is established, I want to build another one on Laythe or perhaps Val. They can be waystations towards the Outer Planets, or, more likely, for return missions from them -- I remember all the trouble I had bringing my kerbals back from Laythe last time, and my Duna base was vital to that. KIS/KAS rules by the way. It's loads of fun to bolt things on, and I can't wait to set up a surface base where I can refuel things with hoses like a normal person would.
  15. Brikoleur

    Are SSTO's worth it?

    Pretty much that yeah. I think it's fairly uncontroversial to state that SSTO aircraft rule for - exploring Laythe - lofting modestly-sized, compact cargoes (or Kerbals) off Kerbin Anything more ambitious than that is squarely in the "because you want to" category. Which isn't to say that they can't be good -- again, I have made high-mass, high-volume SSTO lifters and they work great -- but they are a lot of work, and require a lot of fine-tuning to get right. Rockets are unquestionably easier, even recoverable SSTO rockets.