Goozeman

Here's my entry, the World Traveller. Mods used are FAR, pWings, and RealChutes. I had trouble landing the first time round, so I added a pair of drag chutes to the back to slow it down on the runway. As I recall Global Flier actually descended with drag chutes open. Anyways, I made it in 5:59:15 with 15.87 units of fuel remaining. The secret to doing this subsonically with FAR installed is displayed in some of the screenshots, but I'm not going to give it away. Anyways, without further ado: Attained cruise speed and trim screenshot3 by The Aviator 11, on Flickr About 1/2 way around. screenshot5 by The Aviator 11, on Flickr Beginning Decent. I actually started descending about half way across the ocean and still was on too high a glide path. screenshot6 by The Aviator 11, on Flickr Passing K2 screenshot9 by The Aviator 11, on Flickr Landed! screenshot11 by The Aviator 11, on Flickr Flight Report screenshot12 by The Aviator 11 My final score was 15.79 + 3-Point Landing for a total of 16.79

A challenge for the aerodynamically inclined. The rules are simple: circumnavigate the globe on a single Mk1 fuselage of fuel and land back at KSC (or the island base, if and only if traveling east). I do not know whether this is possible in vanilla KSP, as I don't play without Farram Aero. Research. Therefore the use of FAR is allowed and highly encouraged. If you can, by some miracle, do this in vanilla, you are awesome at figuring out arbitrary physics, have a cookie. For reference, I have completed this challenge except for the landing back at KSC part; I crashed trying to land. I had 13 units of fuel remaining, so I even had some margin for error. I am in the process of retrying the attempt, but since that proves that it is indeed possible, I wanted to get some feedback from the forum. The caveats: 1.) This is intended to be a challenge of aerodynamics, not propulsion tech. Only the stock engines and intakes are permitted. However, aerodynamics and structural parts from mods are allowed and encouraged. For example, I very much like PWings. Mods that are incompatible with FAR are not banned, but strongly discouraged. 2.) This challenge is intended for heavier-than-air craft. No balloons, dirigibles, or blimps please. Helicopters and autogiros are permitted. Lifting bodies are permitted as well. 3.) Aircraft that make sub-orbital hops are discouraged, and I reserve the right to not include any attempt that defies the spirit of the rules (aero, not orbital). Aircraft that exceed 60km will automatically not be included. Excessive intake spamming is also grounds for non-inclusion; as a general rule, at most two intakes per engine will be accepted. 4.) No dev console. Part clipping is permitted if and only if you can do it without using the dev console. 5.) Your entry MUST make a successful landing without damage. All entries must land at KSC, and eastward entries have the option of landing at the island base. Scoring: This is intended simply as a personal challenge, but I will keep score using fuel remaining after landing as a metric. Stock aerodynamics and FAR will be in separate leader boards. Bonuses: 3-Point Landing: Land on and remain on the runway at KSC. +1 unit of fuel Polar Express: Fly north or south instead of east. +0.5 units of fuel Sun Synchronous: Fly west, never see night. +1 unit of fuel Show-off: Land at the island base. May only be obtained with an easterly circumnavigation. +2.5 units of fuel Pratfall: Land at the island base, but miss the runway. -2.5 units of fuel. Stacks with above. In Stock We Trust: Do it will all stock parts. +2 units of fuel Slow Boat: Take longer than 12 hours. +2 units of fuel Fast Craft: Take less than 2 hours. +3 units of fuel Low'n'Slow: Never exceed 5000m. +3 units of fuel Cheapin' Out: Use a probe core. -0.25x fuel remaining. Good luck! FAR Leaders: 1. Traches with pWing Abuse : 83.54 (82.54 + 3-point landing) 2. Goozeman with World Traveller: 16.79 (15.79 + 3-Point Landing) 3. Stock Leaders: 1. zorque: 60.34 (52.34 + In Stock We Trust + Fast Craft + Show-off) 2. koshelenkovv 43.65 (54.20 + In Stock We Trust + Fast Craft + 3-Point Landing)xCheapin' Out 2. leafty with Minimi: 30.87 (25.87 + Fast Craft + In Stock We Trust + Show-off/Pratfall) 3. Rhomphaia : 10.91 (7.91 + Fast Craft)

A real quick question about units. The aircraft I'm currently flying has a single basic jet engine. While flying at 22km, the TSFC is listed as 0.750/s. This is absolutely absurd, as it would be consuming 3/4 of it's thrust in fuel every second. I'm guessing that this should be 0.750/hr, which would make sense and be inline with real engines.

Having the same problem, though it seems that it gives all three stages the thrust of the first stage. This is a little bit of a pain when I want the first stage to have high thrust and the next two to be low thrust.

The trick with nuclear engines in real life is that the tanks have absolutely absurd mass ratios. Because LH2 is so sparse, the tank can have a very thin wall (~1mm for 10mx30m tank made of titanium alloys.) With a basic support structure and some piping included, such an LH2 tank can have a mass ratio of 30-50:1 or better, much better than the BOTs in KSP (9:1). Mind you, such a tank cannot take significant axial load, so it cannot be used as a lower stage, but it works great if you put a couple in space and then dock them to an interplanetary stage. As far as Nuclear engines go, the best ever designed was a more recent PWR engine with a TWR of 5:1 and an ISP of 950s. NERVAs (the actual project) tested to ~820s with a 3.5:1 TWR. 1000s or so is about the limit for current material science tech.

It isn't so much higher Isp that we need, though I agree that a low-profile lander engine would be nice. It's a small, relatively high TWR upper-stage engine with ~30kN of thrust. Such an engine would weigh about .2mt and allow higher mass fractions for upper stages. Such an engine would also be conceivably small enough to mount on a lander with the standard landing legs. My upper stages typically have about a 1.5-2.25 TWR when using a Vesta engine. Ideally, upper stages should need a .5-75 TWR.

Hm. I took a look through the part files and I see your point. The Vesta does meet your criteria, though, in being a 120kN engine at .6mt, coming in at 21:1 (piss poor in real life), but this is actually better than the Wildcat-V.

I presume you mean 2nd stage engine in 1.25m, otherwise the Poodle fits the bill rather well. IMO, if you need that much thrust in a second stage, use an L or L+ engine. Otherwise, design your first stages to hit ~1500-1700 m/s at burnout, and you'll find that the low thrust of the upper stage engines isn't an issue. I don't suppose it would be possible to have a Sea Level/Vacuum option in configuring engines? Sometimes I find that I only need a 50kN engine in the sea level stage, or conversely as you pointed out, I need a 200kN 1.25m upper stage engine. The vacuum option would see a hit to TWR while giving a substantial increase in Isp.

I started using KW rocketry expansion pack with MFS a few days ago and noticed that the Maverick-1D is listed as an upper stage engine. What is the reasoning behind this? If anything, we need smaller upper stage engines, not larger. From its description, the M-1D is supposed to be a larger, 2-nozzle Wildcat-5. Shouldn't this make it a L or L+ at best?

I know this kinda goes against the whole Kerbal mantra of "MOAR POWAR," but is there a smaller 1.25m engine in the works? I find that the Vesta is massive overkill for some upper stages and even the LV-909 can be too much of a good thing. Something along the lines of the 48-7S but in a 1.25m package would be awesome.

Here's my entry. Score is 9.05mt. I manually controlled the throttle and used the Smart A.S.S. to control orientation.

That will allow your aircraft to fly with the engine more level, and thus pick up a small speed bonus, but will not provide any additional lift. Additionally, if you find that the nose wants to pitch down, tip the canard up more relative to the wing.

Do remember that the KSP aero model is incredibly... primitive? It doesn't really mimic what happens in real life. The Farram Aerospace Research mod does a very good job of implementing a realistic aerodynamics model. That said, take the following info with a grain of salt for KSP. Air intakes do cause a modicum of drag. It is usually insignificant compared to the amount of force applied by the control surfaces, so I wouldn't worry too much about it. It is more important that you line the thrust vector up such that the CoG lies on said vector. A little one way or the other isn't that bad, but the further off, the more torque it applies. I'm not sure what you're talking about for "horizontally angled wings." There are three angles that can be applied to a wing: incidence, dihedral, and sweep. Incidence is how far tipped up the leading edge is compared to the trailing edge. Dihedral is how far the tip is angled up from the root. Sweep is how far back the tip is from the root. An aircraft that needs severe nose up trim can benefit from some positive incidence. Positive dihedral can help an aircraft maintain its heading when disturbed from zero roll. KSP implements these affects decently well. However, sweep doesn't seem to affect handling all that much except to move the CoL (or Neutral Point in true aero speak) about. I'm not sure how KSP determines the vertical position of the CoL. The only effect that I can imagine it having is to return the aircraft to level flight. This isn't entirely realistic, but it works for the sake of the game. Finally, use the avionics part. It makes the aircraft fly much more realistically.

Thanks! I've been playing for a while, but lurking in the forums. I'm an aerospace engineer, so the first thought is to complete the requirements. Everything else is just wasted. I actually could have dropped the central tank and still had enough fuel to go around, but only just.

Here's my entry, the Global Flier 2. Climbout. screenshot7 by The Aviator 11, on Flickr Result screenshot4 by The Aviator 11, on Flickr