GoSlash27

Actually, I think that's a product of the physics. Wings now create a lot more lift than they used to and the drag hurts you more around Mach 1. End result: Less wings. Best, -Slashy

Roger that! Thanks for the assist! Just for S&G, I'll see where 4 tonnes of fuel and oxidizer takes one of my current designs. Best, -Slashy

*shameless plug* This is how to make an effective SSTO spaceplane in 1.02. I haven't tried scaling it yet. http://forum.kerbalspaceprogram.com/threads/118728-Slashy-s-1-02-Spaceplane-recipe I'm just getting started. Hopefully some of you folks can chime in with helpful tips & recipes. Best, -Slashy

MunGazer, Try disabling your temperature gauge. It's got a memory leak and that may be why you're crashing. Best, -Slashy

A decent DV budget for 1.0 was around 3,400 m/sec assuming you calculated it with vacuum Isp. 1.02 has increased the drag, so I don't know what the new DV budget is. Haven't looked at that yet because I've been working on spaceplanes... Best, -Slashy

This guide is subject to change as we learn more about 1.02 parts, aerodynamics, and physics. Here's where I am at the moment... This design will get 4 tonnes of payload to LKO and still leave fuel for maneuvering, retro burn, and air breathing flight home. My basic rules of thumb: * 1 RAPIER per 13 tonnes of aircraft * 2 radial intakes per engine (or 1 ram per engine) * 1 CL worth of wing area per 4 tonnes of spaceplane * 650 units fuel per engine * 550 units of oxidizer per engine I'm having good luck with the strakes as wings. Adequate lift and low drag. Stacking the sections in series creates a low frontal area, but it's not actually necessary. I've also had good results with the FL-TXX series tanks in parallel, like this: I have noticed that 1.02 likes very minimal control surfaces. The control surfaces on the X-3 above are overkill and make the controls twitchy. Best, -Slashy - - - Updated - - - Basic takeoff profile: This is subject to change as we refine our techniques... *important*: Set an action group to manually switch the engine mode and toggle intakes. Auto switching is wasteful. Takeoff at half throttle and gear up once climb is established. Pitch up to maintain between150 and 200 m/sec airspeed. Throttle to max Pitch up to maintain between 150 and 200 m/sec airspeed. Try to maintain 5* angle of attack through the climb, gradually reducing pitch until level at 200 m/sec at 10-12 km altitude Accelerate at full throttle in level flight until supersonic and accelerating rapidly. At the first sign of compression effects, pitch as necessary to maintain weak fog. Aircraft should top out at about 1 km/sec airspeed and 25 km altitude. Switch to closed cycle and pitch as necessary to avoid overheating. Orbital velocity should be achieved at approx. 35km altitude. Best, -Slashy

All, I'm going to have to reset the competition in light of the atmospheric changes in 1.01 and now 1.02. I'm learning the new aero, so I may be a bit slower to respond here. Please bear with me! -Slashy

MunGazer, I love the slideshow! I picked the highest speed and altitude and went with that. Congrats on the circumnavigation. Impressive all the way around! Zekes, I've got you on the boards. I took the liberty of naming your entries. Just let me know if you'd like them changed. Best, -Slashy

Unfortunately, that's the problem. Ironman flights aren't allowed to have parts blow up at any point during the flight. They must return home safely and intact. Apologies, -Slashy

^ Turns out KER works fine and checks out empirically. The problem is the engines have been nerfed. Lower Isp means they burn more fuel for the same DV and lower thrust means that you have more gravity losses during circularization. There have been no changes to the bodies themselves. Best, -Slashy

Oh, okay. I picked that one uphere, but it's clearly erroneous. Disregard my last... Sorry for the confusion! -Slashy

I'm inclined to agree with this from what I've seen so far. The top "open" speed records have been established at near seal level; So low that I didn't bother logging their altitudes. It seems that low altitude and thermal mitigation trumps high altitude for all-out speed. Best, -Slashy

All, KER has not been updated to reflect the new Isp of the 1.0 engines. The numbers that it generates are invalid. ^ Not correct. KER works fine in 1.0. Best, -Slashy

It works great for me. I don't need tailfins and my efficiency is good. Plus I'm not having any problems with overheating. Best, -Slashy

Oh, poop. It didn't take. I gotta do it again -kickin' rocks, -Slashy *edit* all fixed. Leaderboard really updated this time. Apologies, -Slashy

A couple extra notes: Zekes, I'm thinking it's not any more difficult to achieve high speeds at low altitude than at high altitude, so I'd rather not split it. I'm... well, let's face it: I'm a lazy man! AngusJimiKeith, thanks for the correction. It's been fixed. Leaderboard updated! Best, -Slashy

All, I'm comfortable with you folks having a "gentleman's agreement" on what constitutes level flight. I don't want to make the rules so stringent that they turn off entrants who maybe don't have the skills to maintain tight tolerances. I'd say we can generally tell the difference between someone who's zoom- climbing/ diving and who's operating in good faith. If I miss an entry that looks suspicious, just hit me up on PM and I'll have another look at it. It will be strictly confidential and nobody will ever know who requested a review of a particular flight or even if the review was requested or if I just decided to review it on my own. "Level flight" to me means that it has achieved an equillibrium state where the altitude and speed will not degrade over time. This is your competition and I'm just housekeeping (and shamelessly stealing all of the tribal knowledge you're generating ). It's in your own best interest to keep it fair. With that said, time to update the leaderboard. Good job and excellent entries! Best, -Slashy

Now that 1.0 has dropped and rebalanced all of the engines, I thought it would be helpful to analyze the capabilities of the engines in their new form and see how they stack up against each other in various uses. A lot has changed and we have some surprising new "best" engines. They are placed in a standard situation with a given DV budget, and evaluated by their payload fraction. The lighter an entire stage is in comparison to it's payload, the less mass the preceding stages will have to lift. Generally, this results in small and inexpensive rockets on the pad and maximizes your capabilities. I start with the values in the config files for the engine's mass, thrust, and Isp. Based on the desired Isp and payload, I calculate how much fuel and tankage is required. I then adjust the payload and reiterate until it shows that one engine is required to accelerate the total mass at the desired G. Finally, I record the payload and total mass, and divide the payload into the mass to give payload fraction. "Best" engines exhibit payload fractions of >95% of the single best performer. "Good" are 90-95% "Fair" are 85-90%. All are shown with their payload per engine in tonnes and payload fraction in percent. Scenario #1: Single main core stage with SRBs. The DV budget 3,600 m/sec, vacuum Isp and 1.0 t/w ratio. "Excellent" engines [TABLE] [TR] [TD]KR-2L Rhino[/TD] [TD]47[/TD] [TD]23.1[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-L10 Poodle[/TD] [TD]5.7[/TD] [TD]22.4[/TD] [/TR] [/TABLE] "Good" engines [TABLE] [TR] [TD]LV-909 Terrier[/TD] [TD]1.28[/TD] [TD]21[/TD] [/TR] [/TABLE] "Fair" engines [TABLE] [TR] [TD]RE-I5 Skipper[/TD] [TD]13.6[/TD] [TD]20.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KS-25x4 Mammoth[/TD] [TD]83.5[/TD] [TD]20.5[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]T-1 Aerospike[/TD] [TD]3.76[/TD] [TD]20.5[/TD] [/TR] [/TABLE] Scenario #2: Two stage upper stage DV Budget 1,800 m/sec, vacuum Isp and 1.0 t/w ratio. "Excellent" engines [TABLE] [TR] [TD]KR-2L Rhino[/TD] [TD]98[/TD] [TD]48.2[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KS-25x4 Mammoth[/TD] [TD]188[/TD] [TD]46.2[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-L10 Poodle[/TD] [TD]11.6[/TD] [TD]45.8[/TD] [/TR] [/TABLE] "Good" engines [TABLE] [TR] [TD]RE-M3 Mainsail[/TD] [TD]69.3[/TD] [TD]45.4[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-909 Terrier[/TD] [TD]2.67[/TD] [TD]43.8[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]T-1 Aerospike[/TD] [TD]7.95[/TD] [TD]43.4[/TD] [/TR] [/TABLE] "Fair" engines [TABLE] [TR] [TD]KR-1x2 Twin-Boar[/TD] [TD]87.9[/TD] [TD]43.2[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]48-7S Spark[/TD] [TD]0.78[/TD] [TD]42.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-T45 Swivel[/TD] [TD]8.66[/TD] [TD]42.5[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-T30 Reliant[/TD] [TD]9.26[/TD] [TD]42.3[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]24-77 Twitch[/TD] [TD]0.674[/TD] [TD]41.4[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]Mk-55 Thud[/TD] [TD]5.01[/TD] [TD]41[/TD] [/TR] [/TABLE] Scenario #3: Three stage mid or upper stage DV Budget 1,200 m/sec, vacuum Isp, and 1.0 t/w ratio "Excellent" engines [TABLE] [TR] [TD]LV-909 Terrier[/TD] [TD]9.93[/TD] [TD]61.9[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KR-2L Rhino[/TD] [TD]122[/TD] [TD]60[/TD] [/TR] [/TABLE] "Good" engines [TABLE] [TR] [TD]KS-25x4 Mammoth[/TD] [TD]238[/TD] [TD]58.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-M3 Mainsail[/TD] [TD]88.4[/TD] [TD]57.9[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-I5 Skipper[/TD] [TD]38.3[/TD] [TD]57.9[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-L10 Poodle[/TD] [TD]14.4[/TD] [TD]56.8[/TD] [/TR] [/TABLE] "Fair" engines [TABLE] [TR] [TD]KR-1x2 Twin-Boar[/TD] [TD]113[/TD] [TD]55.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]48-7S Spark[/TD] [TD]1[/TD] [TD]54.8[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-T30 Reliant[/TD] [TD]11.9[/TD] [TD]54.5[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]T-1 Aerospike[/TD] [TD]9.93[/TD] [TD]54.2[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]24-77 Twitch[/TD] [TD]0.877[/TD] [TD]53.9[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-T45 Swivel[/TD] [TD]10.9[/TD] [TD]53.8[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]Mk-55 Thud[/TD] [TD]6.43[/TD] [TD]52.7[/TD] [/TR] [/TABLE] Scenario #4: Long- distance interplanetary mass- mover DV budget 6,000 m/sec, vacuum Isp, 0.5 t/w ratio "Excellent" engines [TABLE] [TR] [TD]RE-L10 Poodle[/TD] [TD]3.16[/TD] [TD]6.2[/TD] [/TR] [/TABLE] "Good" engines [TABLE] [TR] [TD]KR-2L Rhino[/TD] [TD]22.9[/TD] [TD]5.64[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-909 Terrier[/TD] [TD]0.683[/TD] [TD]5.59[/TD] [/TR] [/TABLE] "Fair" engines Scenario #5: Short range spaceflight (within the Kerbin system) 1500 m/sec DV, vacuum Isp, 0.5G t/w "Excellent" engines [TABLE] [TR] [TD]KR-2L Rhino[/TD] [TD]230[/TD] [TD]56.5[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-L10 Poodle[/TD] [TD]28.3[/TD] [TD]55.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KS-25x4 Mammoth[/TD] [TD]443[/TD] [TD]54.5[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-909 Terrier[/TD] [TD]6.64[/TD] [TD]54.4[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-I5 Skipper[/TD] [TD]72[/TD] [TD]54.4[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]T-1 Aerospike[/TD] [TD]19.7[/TD] [TD]53.9[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-M3 Mainsail[/TD] [TD]164[/TD] [TD]53.8[/TD] [/TR] [/TABLE] "Good" engines [TABLE] [TR] [TD]LV-T45 Swivel[/TD] [TD]21.4[/TD] [TD]52.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KR-1x2 Twin-Boar[/TD] [TD]212[/TD] [TD]52.1[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]48-7S Spark[/TD] [TD]1.89[/TD] [TD]51.7[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-T30 Reliant[/TD] [TD]22.6[/TD] [TD]51.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]Mk-55 Thud[/TD] [TD]12.4[/TD] [TD]51.1[/TD] [/TR] [/TABLE] "Fair" engines [TABLE] [TR] [TD]24-77 Twitch[/TD] [TD]1.64[/TD] [TD]50.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-1 Ant[/TD] [TD]0.206[/TD] [TD]50.6[/TD] [/TR] [/TABLE] Scenario #6: Munar ascent or descent stage 800 m/sec DV, 1.5G Munar t/w, vacuum Isp "Excellent" engines [TABLE] [TR] [TD]KR-2L Rhino[/TD] [TD]607[/TD] [TD=width: 86, bgcolor: #7030A0]74.3[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-L10 Poodle[/TD] [TD]75.4[/TD] [TD=width: 86, bgcolor: #7030A0]73.8[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-909 Terrier[/TD] [TD]17.9[/TD] [TD=width: 86, bgcolor: #7030A0]73[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KS-25x4 Mammoth[/TD] [TD]1190[/TD] [TD=width: 86, bgcolor: #7030A0]72.9[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-I5 Skipper[/TD] [TD]193[/TD] [TD=width: 86, bgcolor: #7030A0]72.9[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]T-1 Aerospike[/TD] [TD]53.5[/TD] [TD=width: 86, bgcolor: #7030A0]72.7[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-M3 Mainsail[/TD] [TD]444[/TD] [TD=width: 86, bgcolor: #7030A0]72.4[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-T45 Swivel[/TD] [TD]58.6[/TD] [TD=width: 86, bgcolor: #7030A0]71.7[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KR-1x2 Twin-Boar[/TD] [TD]583[/TD] [TD=width: 86, bgcolor: #7030A0]71.3[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]48-7S Spark[/TD] [TD]5.23[/TD] [TD=width: 86, bgcolor: #7030A0]71.1[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-T30 Reliant[/TD] [TD]62.4[/TD] [TD=width: 86, bgcolor: #7030A0]71[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]Mk-55 Thud[/TD] [TD]34.7[/TD] [TD=width: 86, bgcolor: #7030A0]70.7[/TD] [/TR] [/TABLE] "Good" engines [TABLE] [TR] [TD]LV-1 Ant[/TD] [TD]0.576[/TD] [TD]70.4[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]24-77 Twitch[/TD] [TD]4.59[/TD] [TD]70.3[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]LV-1R Spider[/TD] [TD]0.561[/TD] [TD]68.6[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]CR-7 RAPIER[/TD] [TD]38.9[/TD] [TD]68[/TD] [/TR] [/TABLE] "Fair" engines Scenario #7: Tylo Ascent or descent stage 2400 m/sec DV, vacuum Isp, 1.5G acceleration on Tylo "Excellent" engines [TABLE] [TR] [TD]KR-2L Rhino[/TD] [TD]63.6[/TD] [TD]37.5[/TD] [/TR] [/TABLE] "Good" engines [TABLE] [TR] [TD]RE-L10 Poodle[/TD] [TD]7.48[/TD] [TD]35.3[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KS-25x4 Mammoth[/TD] [TD]119[/TD] [TD]35.2[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-I5 Skipper[/TD] [TD]19.2[/TD] [TD]34.9[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]RE-M3 Mainsail[/TD] [TD]43.8[/TD] [TD]34.4[/TD] [/TR] [/TABLE] "Fair" engines [TABLE] [TR] [TD]LV-909 Terrier[/TD] [TD]1.69[/TD] [TD]33.2[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]T-1 Aerospike[/TD] [TD]5.01[/TD] [TD]32.8[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]KR-1x2 Twin-Boar[/TD] [TD]54.6[/TD] [TD]32.2[/TD] [/TR] [/TABLE] [TABLE] [TR] [TD]24-77 Twitch[/TD] [TD]0.412[/TD] [TD]30.3[/TD] [/TR] [/TABLE] Best, -Slashy

NathanKell, Thanks, I kinda figured that had to be the case since the Aerospike had noticeably better Isp than I expected. Best, -Slashy

Yeah, somebody had asked me earlier how I'm following the terminal velocity and I forgot to answer. I'm surfing the Mach effect and keeping my acceleration at 2*sin(pitch) as I go until I hit 1G acceleration at 30* pitch. for rockets, if I'm getting heating effects, I'm not doing it right. Best, -Slashy

According to my numbers the mainsail would be worse on all counts. But of course, my numbers are just numbers at this point.... Feel free to check stuff out to make sure. I could easily be mistaken. *edit* What I did was start with the Kerbin sea level Isp numbers and then project them to their cutoff points in the config files. Interpolating at 5 Atm and multiplying by full-tilt thrust allows me to guesstimate the Eve sea level Isp and thrust, although these appear to be spline curves rather than linear functions.. The only 2 candidates I saw by that method was the aerospike and mammoth. Best, -Slashy

Kaboom, I'm not certain at this point that a launch from Eve is possible at all at this point. At least from sea level. The only engines you have to work with are the aerospike and the Mammoth. Either can produce a theoretical max of 2000 to 2300 m/sec, but I'm not sure it's possible to break 7300 m/sec no matter how you stage it. We'll be looking at it more closely as we learn new stuff. Best, -Slashy

Excellent challenge! I'm in the process of analyzing this very problem, and (like a dope) I left the results at work! Hopefully I won't brain-fart tomorrow and can submit a competitive entry. Best, -Slashy

Starhawk, I'll have to re-run the numbers, but basically the improved t/w of the Mammoth allowed it to lift more fuel and tankage for a given payload than the aerospike. The improvement in wet/ dry ratio allowed it to overcome it's disadvantage in Isp and deliver more DV total. The advantage amounted to 300 m/sec in extremis, and improving as the payload fraction increased. Best, -Slashy

Exactly so, which is why we're using the value that we are. If you build an "average" rocket with the vacuum Isp figure in the VAB, 3,400 m/sec should be about what is required to make LKO. The absolute minimum expended during the launch is a nice figure to know (especially for learning how to operate efficiently), but less useful for planning purposes. Incidentally, I was unable to shave off any waste by running your profile. I still wound up in the 3,400m/sec ballpark (although the *true* figure probably lined up closely with yours). I was running a constant curve right off the pad, reducing the t/w as a function of 2sin(pitch) until I reached a hard minimum of 1G. Best, -Slashy