ExaltedDuck

That was three. I was holding about 1600 m/s through most of the flight (about 40 minutes per lap), and flew twice over KSC before landing on the third approach.

Jeb and I have an understanding built on mutual respect. (And that was actually an expedition run, not grand. That thing HAULED. )

Maiden voyage of a new [unnamed] prototype turned into a successful expedition circumnavigation. I wasn't sure how it would handle. The power to weight ratio was better than I initially realized. It felt sluggish on the runway but got right up to mach speeds in the air. I was worried about fuel capacity after my first half lap. I though it might only have enough for 2 and a small fraction. It burnt about half by the first time around. But I still had about half of that at the end of the second lap. So I kept on truckin'. About 2/3 around the third lap, I started experience dutch rolls I couldn't quite trim out. But the speed held and fuel consumption didn't drastically increase. It threw me 2-3 degree off course by the time I reached the KSC, but it was still running strong on a bit more than fumes. I cut the power and autopilot and realized I'd done so way too late for comfort. But she's built for speed. So nose down, straight down, land or die trying. It was rough. I never did quite line it up but managed to steer it straight with a last second boost to the brake torque on the starboard gear. But once the smoke cleared, you would never have known the drama that had just unfolded. I really wish I'd been capturing a video. The landing was just harrowing. Three times around, in just over 2 hours, and with less than a third as much fuel as any of my smallest previous concepts (about 85% less than my biggest yet serious and nearly successful contenders). She deserves a good name. And one came to me. Mighty Steed.

Flipping in the low atmosphere is often a sign of you center of mass falling behind your center of drag. I'd add nose cones to every leading edge and set the fuel lines to pump from the top to the bottom. Extra fins down low on the booster might help too. Also, it almost looks like those axial docking ports are not placed symmetrically. If that's the case, they could pull the nose toward the side they're on.

I've been using pilot assistant. It's useful for helping to maintain steady flight and hold a course. When I started in the first thread, I had a very similar opinion to yours on mods. I have flown completely organically with times into the low 50 min. I even bought a flight stick to try out in the thoughts that analog control might let me compete better (it didn't. Huge deadzones in the stick made it worse than keyboard input. Or, rather, about as bad in terms of fine control but with the added disadvantage of the amount of time it took to move the stick side-to-side). I tried mechjeb first, but found pilot assistant to be a little more precise and way more tune-able (The PID approach they've used in its design is pretty handy). The way I use it is to lock the heading at or shortly after take-off then limit the ascent rate as I approach my top speed/operating altitude. The fun and exciting parts are still controlled manually, and the nod-off's that almost killed my first velocity contender on the first thread at about the 35 minute mark are no longer a problem.

lol, nice.

Xannari - Sub-40. Just barely. :-*

And because my friends were dismayed that the desert we were going to camp in was actually really hot on a summer day, I'm back a day early. So in the single engine top speed thread someone mentioned something about shock cones being fragile for speed. I got to thinking, maybe they could be used, if used with caution. So I came up with this craft. It might be capable of a supercruise above 1700 m/s. At least, the first one I made and took out was and made it all the way around on a 90 degree heading with about 40 fuel left in a position to begin a descent to KSC at about 37 minutes. BUT, I forgot to throttle down and exploded spectacularly at about 16000 m altitude. Then I started making little adjustments (trying to add drogue chutes and/or airbrakes, looking into lower drag lifting surfaces, etc.) and somehow only managed to get myself to where I could hardly exceed 1680 and couldn't get my fuel consumption low enough to make it all the way. I still prefer to use mid-body intakes. Axial and nose-mounted pieces just aren't slippery or hungry enough. But this does show that with the new aero in this version, a single shock cone can keep 2 rapiers running as long as speed is maintained. During ascent, there's not much room between terminal heating and adequate acceleration but it is possible to get it there and if you can walk that knife's edge, it will perform.

IMHO, refueling breaks the spirit of the challenge in that it's quite a bit like having drop tanks and that with well planned logistics, flight becomes effectively indefinite.

lol. beautiful. =D - - - Updated - - - I hope you do. That's gorgeous!

Aw man. I have my basic design together but had some gremlin to work out. Won't get a chance to run it till Sunday. I guess I'll have to try for 4 or 5 laps.

my advice for next time: lockwashers, double nuts, and whole lot of loc tite. ;p too fast, too low. If I dived sharp enough to avoid seeing a heating gauge, I might as well have been hitng the ground at around 16000m. No warning. just boom. This just gave me an idea for a new mkII design. >=] - - - Updated - - - And thanks, triop. This is a fun and intriguing challenge.

Yeah, if there were any oxider in the mix you would have burnt way more fuel. Weights before and after suggest total usage just over 470 for an average rate of a little less than .2 and usage between minutes 8 and 30 looks to have been at a rate of about 0.17. Doesn't look like any funny business. Like I said, my only real complaint is that I'll be away for a couple days and unable to try again until I'm back.

That is some crazy good fuel economy. It looks like it still took an oscar b or round 8 tucked away somewhere to make it home, though, judging by the parts count and before-and-after weights. Not complaining, just observing. I've seen some diagrams of military jets' fuel systems and it's impressive how they'll tuck away fuel anywhere they have a few gallons worth of void space in the airframe. It seems a totally valid approach in that regard. If I really wanted to be "that guy" I'd point out your runway parts count is greater than your landed part count. (but honestly, that doesn't bother me, either. I resorted to a nearly identical method while developing my high speed single engine entry when I ran into some landing gear instability before briefly setting it vertically on the runway for take off to preserve parts count. But landing problems led me to finally just fixing the rear gear to where a traditional take-off was only difficult rather than impossible.) The lack of resource display is a little more troubling, but the visible times and weights suggest a lack of any funny business. My only real complaint is that I'll be out of town until Sunday and won't get a chance until then to defend my title. Good job!

"Bob! Hey Bob! Look what I found out behind the Dreamliner plant. Totally good batteries someone tossed out. Never heard of this of this brand, though... NFG? They were just sitting there by the dumpster. But they test out just fine, like new."

Sounds like fun. Here's my shot with a whiplash. Managed to capture my highest in-game speed (1495.5) I think I hit it in both directions but didn't manage to screen cap it on the eastbound pass. For whatever reason, mission summary shows 10 m/s lower.

erm... My timing is impeccably poor. I'll just set this here and be on my way.

Triop, on that drawing board, select the rotation tool, then your master part, then turn it 180 degrees (which should point the whole craft to 270 on the runway). I have a good feeling you'll not only make it but post a really killer time.

don't climb too soon/fast to be able establish/maintain mach speeds. At the same time, climb fast enough that you don't melt in the lower atmosphere. Try to do most of your accelerating in the transitionary zone between thick/thin atmosphere (8000-12000m). Try to hit your top speed below 20000m then climb to cruising altitude. And to get down, when you're 50-100km out, just cut throttle and point prograde then make any glide adjustment you need once you're down to about mach 2.

I ain't skeered. My ascent was hasty and my landing was sloppy. I'm sure I could shave a few seconds off its time, possibly even below 50 minutes if I ditch the excess fuel capacity. Might be worth trying just because it's a single engine. But really, I'd be more apt to tune the flight profile of my twin rapier Mk II chassis'ed craft. I expect it'll be capable of better than 44 minutes.

lol, no worries. My keyboard does stuff like that all the time, too.

I guess it could be a pretty good basis for endurance. One more Jet fuselage and it should be able to make two laps. But I think I'm sitting on something even better (getting about 1550 m/s at 0.45-0.50 initial cruising consumption). I noticed the leaderboard comment says my entry used a rapier. Might be worth noting it was a whiplash. That might explain some of the fuel consumption concerns. (the rest, I'm sure, is a combination of big wings, low drag, and high altitude). Initial cruising consumption was was high as 0.37, and during the ascent I think I spent some time around 2.4-ish. I'm totally willing to post the craft file if there's any question. It's fully vanilla, fully legit. Thanks for the badge. edited to add: So my twin rapier mk II is showing a ton of potential. But a poorly chosen launch time put me in a twilight landing. I hit my descent a little too early then botched the landing. And now it's about bedtime so no retry until tomorrow or or Sunday. But here's a quick teaser:

Ok, that was not easy. FInally got her back on the ground, intact. First three attempts (no save states) ended with a burnup during descent. Finally got wise with the throttle and the F5 and niner things. Ship is pretty straightforward. I probably could have used just one jet fuselage instead of two, but I have the scrawled envelope to prove that I really thought I'd need two. Basic plans are mkI pit, jet fuselage x2, precooler, whiplash. Wings are Big S delta, swept to where they nest to parallel edges, completely fueled up. 3 small landing gear underneath, two fuel lines in the precooler connecting the wings to the second jet fuselage. No funny business beyond the obvious and mostly-for-cosmetics clipping. Dubbed her "Simplicity" Cruising speed was around 1320-1340, altitude roughly 19200. Fuel consumption was as low as 0.25/s. I aimed for an altitude that would get it down to 0.30 or less, figuring that would give me a solid hour of cruising. (1200 fuel left after ascent x 0.3 fuel/s = 3600 seconds). Heating nearly killed me on the way up (between 10000 and 13000 m, 'pit temp rose from 1/3 to maybe 4-5 pixels shy of death, then just started cooling at about 13500. Cruise was unremarkable, except for the amazing views. Especially the sunrise. Landing was rough. almost went back to the drawing board. Rear gear desperately needs a wider track and the big s elevons I used are really twitchy at low speeds and without the extra weight of fuel. I opted for them after the normal swept wing elevons proved to be inadequate for initial lift. Might be more of a lift/weight balance issue. Regardless, got 'er down (eventually) after a whole lot of crashes. Here's the album: Final time 51:24. Fuel consumption just under 1000, with about 480 remaining. Definitely room for improvement. Next ship will likely be a twin engine MkII similar to the one I called Magellan in the previous thread.

well, I suppose I'll be taking a crack at about a 55 minute single run tonight. I'm still bummed about my expedition contender. Its various revisions carried as little as 18000 and up to as much as about 45000 units of fuel feeding as few as 4 turbojets for the light ones and were surprisingly zippy with 12 engines on the real behemoths even as the runway weight exceeded 200 tonnes. The night before the patch dropped, I came to rest about 48 km short of the runway on my 3rd lap, needing maybe 100-150 more fuel to have made it. Only to find out my 3 pairs of big s delta were never filled meaning I'd shorted myself by 1800. I told m myself I'd do right the next day but couldn't get my fuel usage low enough to make 2 full laps let alone the three I boned myself out of. =\ oh well, c'est la vie, right?

however it goes, thanks for the work you put in on this one, Fengist.