Sordid Posted September 11, 2011 Share Posted September 11, 2011 Ladies and gentlemen, aviators, I have the ultimate aviation challenge for you!Fly an aircraft......around the world.Rules:Stock, NovaSilisko, C7, and SundayPunch parts only. And no cheating by editing stuff!Atmospheric craft only, no going into orbit! Maximum allowed altitude: 15 km.Detaching the crew capsule and landing via parachute is allowed, but bonus points are awarded for landing on the Kerbal Space Center runway in a conventional, airplane-like manner.Multiple-stage vehicles are allowed, but doing it with a single-stage craft will guarantee you super-ultra-mega-bonus points and a place in the pages of history.Document your journey with screenshots.They said it was madness.They said it couldn't be done.Prove them wrong! Link to comment Share on other sites More sharing options...
Rotten194 Posted September 11, 2011 Share Posted September 11, 2011 Flying at 2 km, the trip would be ~1890 km. Assuming you're traveling at a reasonable 500 m/s, this challenge would take about an hour. Good luck aviators! Link to comment Share on other sites More sharing options...
CombatWombat Posted September 11, 2011 Share Posted September 11, 2011 To be fuel efficient enough, you'd have to be cruising at maybe 75-100 m/s @ 15km. So... Many hours. Link to comment Share on other sites More sharing options...
foamyesque Posted September 12, 2011 Share Posted September 12, 2011 Flying at 2 km, the trip would be ~1890 km. Assuming you're traveling at a reasonable 500 m/s, this challenge would take about an hour. Good luck aviators!500m/s is not a reasonable speed for 2km up. Link to comment Share on other sites More sharing options...
comradephil Posted September 12, 2011 Share Posted September 12, 2011 You're on. Link to comment Share on other sites More sharing options...
sirmonkey Posted September 12, 2011 Share Posted September 12, 2011 actually the best way to do it is to get as close to the atmos line.. around 30k meters.. gain as much speed as possible and then drop the throttle.. the distance traveled is much further but theres less air resistance, more efficiency and higher speeds. Link to comment Share on other sites More sharing options...
UmbralRaptor Posted September 12, 2011 Share Posted September 12, 2011 500m/s is not a reasonable speed for 2km up. Also, the distance is closer to 3770 km. (600 km radius, not diameter...) Link to comment Share on other sites More sharing options...
Rotten194 Posted September 12, 2011 Share Posted September 12, 2011 Also, the distance is closer to 3770 km. (600 km radius, not diameter...)Yeah, redid my math and you're right. So assuming 3770 km and 200 m/s, it would take about 5 hours. Link to comment Share on other sites More sharing options...
comradephil Posted September 12, 2011 Share Posted September 12, 2011 As it turns out, I could probably achieve this, but I'd need less engines.I've calculated it roughly, and I'd only get around 616km out of my current design. I'd need five times as much fuel and a constant speed of 400m/s to make it around kerbin. It's madness, basically. Link to comment Share on other sites More sharing options...
CarolRawley Posted September 12, 2011 Share Posted September 12, 2011 I've done it, and unpowered(apart from 20 seconds for takeoff) as well. Link to comment Share on other sites More sharing options...
Causeless Posted September 12, 2011 Share Posted September 12, 2011 I've done it, and unpowered(apart from 20 seconds for takeoff) as well.So have I! Hint: Winglets EVERYWHERE, means the thing practically floats. I'm talking about 21 winglets. Link to comment Share on other sites More sharing options...
Sordid Posted September 12, 2011 Author Share Posted September 12, 2011 Pics or it didn't happen. > Link to comment Share on other sites More sharing options...
Arthree Posted September 12, 2011 Share Posted September 12, 2011 I think the point of this challenge is to make an actual spaceplane that actually flies (under power) around the world, not to see who knows how to bug out the winglets and float around at 10m/s. Link to comment Share on other sites More sharing options...
Herra Tohtori Posted September 12, 2011 Share Posted September 12, 2011 Guys, the only way to do this in sub-orbital flight are engines that use air as main propellant and fuel as energy source. In other words, we need turbofan engines with high bypass ratio.Secondly, the most economic wing for this is one with high aspect ratio, which produces high lift/drag ratio. Either swept or straight wing can work; Airliners use swept wings due to their operations near transsonic speeds (Mach 0.8-0.9); U-2 used long straight wing because it was designed to fly high at slower speed to improve photoreconnaissance quality.The first aircraft to fly around the world without re-fuelling or landing was the Rutan Model 76 Voyager which was superficially not similar at all to U-2 but it does share significant design principles - most important being high-performance, high aspect ratio wing. The Voyager just happens to be a propeller driven engine with dual pull/push prop setup.If we ignore the fact that Rutan chose not to use jet or rocket engines, there is a lot of Kerbal attitude in the story of the Voyager:Voyager's takeoff took place on the longest runway at Edwards AFB at 8:01 am local time with 3,500 of the world's press in attendance. As the plane accelerated, the tips of the wings, which were heavily loaded with fuel, were damaged as they scraped against the runway (the pilot wanted to gain enough speed that the inner wings would lift the plane, not the fragile outer wings - in 67 test flights, the plane had never been loaded to capacity before), ultimately causing pieces (winglets) to break off at both ends. The aircraft accelerated very slowly and needed approximately 14,200 feet (2.7 mi)(4.3 km) of the runway to gain enough speed to lift from the ground, the wings arching up dramatically just before take-off. During the flight, the two pilots had to deal with extremely cramped quarters. To reduce stress, the two had originally intended to fly the plane in three-hour shifts, but flight handling characteristics prevented routine changeovers and they became very fatigued.The plane also continuously reminded the pilots of its pitch instability and fragility. They had to maneuver around bad weather numerous times, most perilously around the 600-mile-wide (1,000 km) Typhoon Marge. Libya denied access to the country's airspace, forcing precious fuel to be used. As they neared California to land, a fuel pump failed and had to be replaced with its twin pumping fuel from the other side of the aircraft.The other aircraft that has flown around the world is the Global Flyer, also designed by Burt Rutan, and flown by the late Steve Fossett. It shares the long thin wing, but is powered by a single turbofan engine.Both aircraft are fairly small, whereas if we attempted to build an aircraft in KSP with sufficient fuel duration to last for the global flight, it would be huge. As an added problem it also needs to have thrust/weight ratio higher than 1, which is only required for planes that take-off vertically (which is the only option for now).Currently, I don't think if it's possible to make a flyer (not floater) that can reach around Kerbin and land safely. Link to comment Share on other sites More sharing options...
Sordid Posted September 12, 2011 Author Share Posted September 12, 2011 Well yeah. That's why it's the ultimate challenge and all that. But then where would Kermankind be if upon encountering some slight difficulty, such as the fact that the task at hand is impossible, everyone threw their arms up in the air and buggered off to the pub instead? Link to comment Share on other sites More sharing options...
millsw Posted September 12, 2011 Share Posted September 12, 2011 To the VAB! I shall attempt this insane challenge. Wish me luck. Link to comment Share on other sites More sharing options...
foamyesque Posted September 12, 2011 Share Posted September 12, 2011 Screw reality, this is KSP. I'll give this a shot. Link to comment Share on other sites More sharing options...
Sordid Posted September 12, 2011 Author Share Posted September 12, 2011 Good man! That's the spirit! Link to comment Share on other sites More sharing options...
Ferrit Posted September 12, 2011 Share Posted September 12, 2011 Good speed to you all, brave/foolish Kerbals! Link to comment Share on other sites More sharing options...
Tiberion Posted September 13, 2011 Share Posted September 13, 2011 I saw somewhere on the forums today someone who made a 'solar panel' that 'charged' a fuel tank over time - it might allow you to stretch the fuel out and make it, though its pretty cheat-y.. but then again that might be the only way given the current game's tools. Link to comment Share on other sites More sharing options...
millsw Posted September 13, 2011 Share Posted September 13, 2011 Yeah, A crapload of those refuel panels is sure to keep you going. Link to comment Share on other sites More sharing options...
MaxSchram Posted September 13, 2011 Share Posted September 13, 2011 Ladies and gentlemen, aviators, the first documented long range flight was ... errr ... quite successful.I bent the rules somehow and choose a traveling altitude of around 19km, which allows greater velocities and lower atmospheric drag. Nevertheless, it took more than an hour to travel roughly a quarter of the distance when finaly the engines went dry. It defenitively needs more fuel and even higher altitudes, maybe around 25km, to fly a full round.1st pic is at liftoff and 2nd some random impression on the trip. In the center of the 3rd is the final position and the last shows the traveled distance (red line). Link to comment Share on other sites More sharing options...
Sordid Posted September 13, 2011 Author Share Posted September 13, 2011 Very nice, definitely a good effort. Link to comment Share on other sites More sharing options...
Arthree Posted September 13, 2011 Share Posted September 13, 2011 Well, I managed to get about 450km on half my fuel the other day, at 300m/s and 13.5-14.5km. I figure it's possible to make it the whole way; the plane would just have to be scaled up 4-5x. The big hurdle with these is that as fuel burns in LFTs, the cg shifts aft and you end up with a plane that just wants to do flips by the time you're on the last tank. Link to comment Share on other sites More sharing options...
Herra Tohtori Posted September 13, 2011 Share Posted September 13, 2011 Well, I managed to get about 450km on half my fuel the other day, at 300m/s and 13.5-14.5km. I figure it's possible to make it the whole way; the plane would just have to be scaled up 4-5x. The big hurdle with these is that as fuel burns in LFTs, the cg shifts aft and you end up with a plane that just wants to do flips by the time you're on the last tank. I typically solve that by making a duplicate of the fuselage parts I use, with fuel storage set to zero. Then I just put fuel-containing parts near centre of gravity, and empty fuselages elsewhere.The problem, obviously, is reduced fuel capacity relative to the plane's size.Ideal solution would be ability to cross-feed fuel tanks so that they all drain at the same rate, which would negate any movements of the centre of gravity... Link to comment Share on other sites More sharing options...
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