GoSlash27

Apologies, I'm still figuring this out as I go along After review, I pulled the Roadrunner 2 for disintegrating during the record attempt. I also updated the leaderboard (if I missed anyone, give me a holler) The rules for ironman are more strict than open. Ironman class: The aircraft must remain intact throughout the entire flight and recover safely at KSC. Open class: The aircraft must remain intact during the submitted run, but not necessarily the entire flight. That is; I will accept the record as valid so long as the submitted screen cap shows no destroyed parts at the time. After that, it's okay for the plane to go all explodey. HTHs and sorry for the confusion! -Slashy

Starhawk, Thanks for doing the work on this! It's about where I expected it to be, so the Mammoth is also a viable Eve booster, possibly able to edge out the aerospike for max DV. If my math holds true, these are the only 2 engines that don't outright suck on Eve. There will be others that can generate some thrust (at horrible Isps), but they're not competitive with these. Thanks again! -Slashy

My first launch (and also first successful launch) was an SSTO sounding rocket. I used it to figure out the DV budget to orbit and explore launch profiles. SSTO spaceplanes aren't "dead", it's just that the old method of making them won't work anymore. Best, -Slashy

A reminder to everyone: Sorry, but I can't accept entries that have had failures (parts exploding/ breaking off) during the flight. Also, I cannot accept SnakeDoctor's submission since it is the result of a ballistic trajectory rather than level flight. Best, -Slashy

This is the important part; a limit is only so useful for planning purposes if people can't achieve it. MechJeb can be easily confused by multiple stages, so it may not be giving you an accurate reading (even though it's consistent with itself). Also, the 3400 m/sec figure is assuming vacuum Isp throughout the flight, which would yield a DV budget somewhat higher than what's actually used. I'll try and see if I can reproduce your results with my sounding rocket. Best, -Slashy

It's vacuum Isp, isn't great, but it's sea level Isp is atrocious. That is normally a hallmark of an upper stage engine, not a booster. Best, -Slashy

Geschosskopf, Thanks for the info and rigorous testing. I'll get the OP updated. Best, -Slashy

I just went and double-checked the .cfg when you said that. Yeah, I made a transcription error. The LV-909 is okay. The Rhino numbers are definitely screwy, tho'. Thanks, -Slashy

It would require actually landing at KSC. Maybe cruise out West for a bit and then make your speed run heading home? The division's wide- open at the moment. Best, -Slashy

I have no problem with setting that up, but I will need to know that detail about the submissions. I will put up an "ironman" division, and entries for that board will have to show proof of their record *and* successful recovery at KSC afterwards. That should definitely increase the difficulty... Best, -Slashy

Rodyle, Congrats, I'll get the leaderboard updated. Don't feel bad about edging others out; this is how these things generally go. Best, -Slashy

Rodyle, Could you resubmit this run with less explosions or maybe pull the solar panels off? I can't accept this run because it violates the "ship must remain intact" rule. Apologies, -Slashy

I was going through the config files and noticed that the Rhino has a very odd Isp curve. While clearly intended to be a heavy lifter, it has an Isp curve that's better suited to a pure vacuum engine. Isp falls from 305s in vacuum to 170 at sea level. Was this a goof and it's supposed to actually be 270? I also noticed that the LV-909 Terrier has spectacular sea level Isp, yet it falls off to zero precipitously afterwards. This would make the LV-909 an excellent engine for a booster, and I'm pretty sure that's not what you had in mind. *edit* The LV-909 is okay. Transcription error on my part. Thanks, -Slashy

It was a good video (from a sales perspective). He made a lot of newbie mistakes, blew up a lot of rockets, and eventually made orbit. Most importantly, he said he really got into it and had fun with it.

FlipNascar, Your word is good. Updating the leaderboard now. Congrats! -Slashy oriramikad, That would have to be registered as a "gatecrasher".

Starhawk, That exceeds my prediction for the aerospike on Eve at sea level. My math said it would generate 230s and 107 kN. Could you do me a favor and check out the Mammoth? My math predicts 186s and 2,210 kN. If it beats my estimate like the Aerospike did, then it can (at least in theory) generate more total stage DV than the aerospike. Thanks, -Slashy edit... Physics: Based on the change in DV requirements for Kerbin LKO, I expect Eve to require 7,300 m/sec from sea level.

Aerodynamics: It looks like wing loadings should be much higher than before for best results in spaceplanes; somewhere in the neighborhood of .25. Engines run out of steam in a hurry above 20 km and you'll run into thermal problems at mach 3-4. You really just need enough wing to fly level at that altitude/ speed range. Flaps can be used to make it behave a little better around the runway. Best, -Slashy

Joker, Yes, absolutely you can enter as many submissions as you like. As for #2, I will tentatively allow it and see where it goes. Hot tip: The RAPIER is better than the turbo ramjet for this work. I just had one up to 26 km at 1200 m/sec. Good luck! -Slashy

allmhuran, I'm not knocking your achievement, so apologies if it came off that way! My point is that the difference is very little as compared to where you need to be to hit orbit. Since we need to be at 2.3 km/ sec and 70km altitude to establish orbit, the difference is relatively small. The extra thousand-odd m/sec DV to make orbit requires fuel and rockets. At what point is the extra mass better- spent on those than more jets? Best, -Slashy

giltirn, I recommend ditching all the stuff about "moar struts and SAS". Your ship is adequate to hold it's heading as it is if you fly it correctly. You just need to be gentle with it. If you can keep an eye on the acceleration, "feel" when it's starting to approach it's limits, and throttle accordingly, you'll be fine. 1.0 is placing a higher demand on your piloting skill and you probably won't be able to crutch it through design. Best, -Slashy

NathanKell, I know you're the go-to source on FAR aero, so glad to have you aboard! While 2G is unlikely to catch Vt vertically, it should still be a hard limit for any angle short of vertical. The aero FX are rough for the job, but IIRC they kick out early enough to be useful. It's sort of a "feel" thing. Best and thanks! -Slashy

TheJoker, Congratulations! You are the owner of both records! During my testing I was able to match that speed and nearly double the altitude, so I know there's a lot more room to shatter records. Good luck, everyone! -Slashy

NathanKell, I'm actually estimating it by the acceleration/ time and visual cues rather than calculating it, since I don't know exactly what my Cd is. Acceleration/ time: If you exceed 2G acceleration long enough, you will eventually exceed terminal velocity. Visual cues: As you approach terminal velocity, you see the formation of shock waves from the pressure shift. The more you push it, the heavier the "fog" gets and the more unstable the craft becomes. I use these cues as a warning. As the fog gets heavier and stability starts to weaken, I throttle back. I also use the sine of my pitch angle to set my peak acceleration. 2G when vertical, 1.5G at 50* pitch, and .5G at 30* pitch. Best, -Slashy

giltirn, Not if I engage SAS, but it tumbles if SAS is off. If it exceeds terminal velocity, it goes squirrelly. I'm able to easily keep it in line by keeping the acceleration under 2G. Best, -Slashy - - - Updated - - - *edit* It tumbles at about 6km altitude and 400m/sec without any control inputs whatsoever. If I limit the throttle to keep acceleration under 2 G, it flies fine. If I engage SAS, it holds on, but struggles a bit. Your aerodynamics will go hinky if you don't watch your acceleration. Just keep it under 2G and you should be fine. Best, -Slashy

It ran a little hot on launch, so I throttled back. That was probably your problem. Best, -Slashy