khyron42

Some people care about where they land (apologies to Werner von Braun & Tom Lehrer) and want to do so without using excessive fuel. In preparation for future missions where crew/part recovery will matter, I\'ve done some test flights to determine how to land roughly where you want using just a capsule and chute, plus either an RCS or a throttle-capable engine to deorbit you. With meticulous planning and an orbit calculator that included the calculus for atmopheric drag, you could do this perfectly. You also probably wouldn\'t have fun with it. Instead, you can reliably land NEAR a target area by following these steps: 1. First, get yourself into a roughly 100 km circular orbit that will pass over your target area. In this case, I\'ll use KSP as the example. This would work for any orbit, but the timing of the deorbit burn would be different and this is the one I figured out the timing for. 2. Switch to map view, hit tab to switch targets to Kerbin, and center your landing target in the view. 3. Zoom out until you can see your whole orbit easily. Then, right click and drag straight down on the map until you\'re looking at your orbit from above. Your landing target should be at the 6 o\'clock position if the planet were a clock. 4. Warp time until your ship reaches about the 10:00 position (120 degrees before it would pass over your target.) Then, repeat step 2 to correct for the planet\'s rotation, and get your ship lined up for a deorbit burn. 5. Ideally at the 9:30 (105 degrees) point, slow your ship down to have a periapsis of just 100 feet or so. The periapsis should be about at the 3:30 position. If you\'re not planning a powered landing, jettison anything you like here but don\'t activate the parachutes yet. Then you can warp time again for 5 minutes until your ship enters the atmosphere. In this example, I made the deorbit burn slightly too early - around 110 degrees/9:40 instead. 6. Just let atmospheric drag do its thing for 5 more minutes of the flight. Pop the chute when you get below 3000 feet or if you\'re going to overshoot your target. 4. Your ship should be within sight of your target when you pop the chute/light the engines for landing. Like I said, I was slightly too early. Still - I was within sight. You can see just how much I was off in the final orbit view. Your Kerbal\'s will only take about 2.5 G\'s of acceleration this way - way less than they probably took during launch. You could use this for pretty much any orbit if you line up to be at about 100 km altitude when you\'re at that 105 degrees before target location in the orbit; I used a circular example just to simplify things. The Really, Really Short Version: if you put yourself into a 100 km x 100 m orbit, you will end up landing about 105 degrees around the orbit from the apoapsis due to atmospheric drag.

Oooh, nice! I had forgotten that I could also sling engines (with fuel lines) under non-fuel-tank structures. Well done.

All right, as long as I don\'t care about a working altimeter or how bad the slideshow is, I can do even better. 48 tank refueling station. 3 propulsion stages (12 engine x 3 tanks each, 18 engine x 3 tanks each, 18 engine x 6 tanks each, fuel lined to run all engines from launch off the outer stages.) Deorbit stage is ASAS + RCS tank + 4 thrusters. I really should turn on vertical snap, hand-aligning all 48 propulsion stages to be level with each other so that they don\'t crush each other on the pad was annoying. Launch pad: Stage separations (I forgot to screenshot the final stage separation, but you can see the detached stage in the verification picture: Confirming 48 tanks in a 93x97 km orbit: I separated from the station and practiced RCS docking approaches, using the convenient hollow I designed into the 'top' end... It worked better after I went to 5x for a second to stop the station from spinning. I did some additional formation flying with it and then tried for a deorbit & landing near KSC. In the second pic, the little dot to the left of the Mun is the fuel station, 10 km above me and an unknown distance ahead in orbit. Landed safely, but no where near KSP. Full image gallery here. You\'ll see several 'end game' screens early on, because that was the easiest way for me to see what the current altitude was. 48 tanks = 3530 points.

You can also just radially attach the non-refueling fuel tanks, since fuel doesn\'t flow through radials. Here\'s the full image gallery for the flight I just finished. The highlights: On the pad. The staging is: capsule and parachute and the couplers holding together the fueling station, rcs and asas, 6-tank core of fueling station plus 5x6 surrounding tanks radially mounted, (couplers up in stage 1), 12 engines with 3 fuel tanks each radially mounted, 18 engines with 5 fuel tanks each and fuel lines inwards to feed the 12 inner ones during the first stage burn. It manages to do a pretty good job of clearing the tower. About every 300 feet I have to pause the game for a moment to keep the altimeter accurate. Stage separation, and a view up through the bottom to show the fuel station part. Circular orbit achieved, and even some fuel left. Ditched the engines and the remaining non-depot fuel. 36 tanks delivered to a 114 x 106 orbit. Time to head home. Safe and sound! JellyCubes delivered more tanks... but at least with mine they\'re all in one chunk to rendezvous with! 36 Tanks: 60 + 120 + 300 + 1800 + 50 for orbit = 2330 points.

I\'ll just drop this here. From a challenge I posted back in 13.1, to go to the orbit of one of Nova\'s proposed planets, get a circular orbit there, and then return to Kerbin:

It\'s amazing how people keep finding ways to do this better! I\'ve updated the original post with the current best results.

Dash, we need the screenshot.

DonLorenzo - you do 'spoiler' in brackets to start a spoiler and /spoiler to end it, or just click the Radiation symbol in the post toolbar. Here was an attempt at just getting a good Option 2. I ditched the ASAS for a little less mass-to-orbit, but it\'s a pain to fly by hand for 6 & 1/2 minutes. I think the only difference between this one and DonLorenzo\'s was using gimballing engines for the slightly longer burn times. I\'m sure this can be improved further if people want to try. Let\'s see, total mass after burnout is 4.2. Speed 5.79 km/s at 716 km altitude. Kinetic energy: .5*4.2*5.79^2 = 70.4 Potential energy: -4.2*3530.461/1316 = -11.267 ? So, combined kinetic and potential of 59.133? or did I mess that up? Specific orbital energy = .5*5.79^2 - 3530.461/1316 = 14.079 I find it amusing that there\'s no mass-of-the-ship term in the last bit (intiuitively it feels like it should be a factor.) Also, I was assuming that the third equation was supposed to give the same result as adding the first two\'s answers, but I guess not.

I added the third category. I think we still have a lot more than can be done in the second category, but these are all looking fun so far!

Is there an easy way to calculate that, though? Besides, this is Jeb we\'re trying to please... but I could always add a third category if you can come up with an easy way to measure it.

While playing around with other challenges, I thought of an 'efficient design' one. Jeb #291 took every booster from the booster factory used them in a single ship... which he launched from inside the factory because it was just too much work to move them to the launch pad. Every ready-to-launch booster and the factory itself was destroyed. The liquid fuel tank factory was destroyed too in the ensuing mayhem, but 10 tanks survived the carnage. Jeb, of course, made it to space and died happy when the last 10 boosters exploded beneath him. Jeb #292 wants an immediate launch, and will settle for non-boosters if you can still get him moving really fast or keep the engines burning for a really long distance. The Challenge: [li]Option 1: Get the highest speed at burnout. (speed efficiency) Current leader - Dashcunning, 6685 m/s[/li] [li]Option 2: Get the highest altitude at burnout. (fuel efficiency) Current leader - Godot, 800 km[/li] [li]Option 3: Most efficient launch, as measured by some kinda rocket science, Jeb #292 doesn\'t care about the details (total energy) Current leader - Dashcunning, 18.369 MJ/kg 'Specific orbital energy'.[/li] Performance in the third category will need to be judged by plugging the numbers into this equation: .5*(final velocity in km/s)^2 - 3530.461/(600.00 + final altitude) = specific orbital energy (thanks, Kosmo-Not!) The Limitations: [li]You have 10 of the FL-T500 fuel tanks, plus an unlimited number of all other parts, subject to the other limitations.[/li] [li]Stock Parts only.[/li] [li]No Solid Boosters.[/li] [li]Continuous full-throttle burn. Obviously, we\'ll have to take you at your word on this one![/li] [li]Anything goes as far as staging, angling to take advantage of orbital speed, etc.[/li] This is kind of a combination of efficient design and efficient piloting. Post a screenshot taken just after burnout, ideally still showing the engine trail before it fades. My initial attempt, trying for speed:

yeah. unless it\'s perfectly rigid, you\'ll end up with, um, problems. from the poles, the full pressure of rock is still pressing down on the core. from the equator, the entire rock column has greatly reduced pressure. And the more it deforms outwards, the more of it is moving faster than orbital speed and wants to fly outwards, and pulls outwards on the bits it\'s still attached to. I think what you\'d end up with is cataclysmic plate tectonics, gradual loss of a portion of the planet\'s mass as things loosened and flew off.. a continuing process of that... and eventually a really thick, ovoid disk (like a round, flat pebble from a creek) with the old core sticking up through the middle and the outer edge of the disk just a little beyond orbital speed, being held to the disk by cohesion only. Is there anyone who can build a deformable physics model of it and record a video of the effects? I think this one would be fun to watch! A demonstration of Roche\'s limit as applied by a body\'s own rotation.

All right, which one of us contacted the guys who write Doghouse Diaries? or are they members here?

That was interesting to dig up some high school trigonometry to figure out the minimum altitude orbit for an equilateral triangle of satellites to see each other around a 600km sphere in the center. If you\'re working from a single ground station on the Mun and trying to talk back to KSP without a series of ground stations, you\'ll need three sats on each end. If you\'re going for lowest possible three-comsat constellation, for Kerbin you need three equally spaced (120 degrees apart) in orbit at about 1500 km. For the Mun, the triangle arrangement needs to be at about 500 km altitude. You could, if you use Keosynchronous satellites on the Kerbin side, get away with using just two of them with about 1200 km separation from each other. One could be directly over KSP and one offset just enough that it\'s always visible when the KSP one is blocked by the planet. However, then your Munar relays end up sending signals across 3000 km some times and 19000 at other times; better to relay across a more predictable 11000 km distance to a lower-orbit 3 satellite setup, I think. You can also go with lower-altitude comsats if you add more than three, but the calculations of just how low get more complicated fast. Lastly, you could park a single Munar one 2500 km ahead of the Mun in the same orbit and use it, if your Munar base can see that point in the sky at all times.

Perhaps the 'any technical job' part of my post would apply to that too. I\'ll leave it to you to prepare for your chosen career in whatever way you see fit, though! Your Mom - someone\'s going to be launching things but it might not be NASA, or even US-related. It depends on whether nasa123 considers a satellite a 'spacecraft', but I know first-hand that at least one of NASA\'s unmanned items (SOHO) gets called a spacecraft by the operators. I\'ll stop derailing the thread now!

You would be spending vast amounts of your time 'tpye'ing at almost any technical job, including even being an astronaut. You will be expected to understand spelling, grammar, and punctuation - spellcheck can only save you from the first of those. You might want to work on those skills. On the other hand, I know you probably could type clearly if you made the effort, you\'re just sending quick responses on a game forum.

2-stage stock with no solids in 1:44, but I\'m still working on improving it. Fuel lines are magical. --- Trimmed it to 1:41 with some solids. It\'s not going to win any records, but I\'ll post it anyway in case it\'s useful to someone else to see how I\'m using fuel lines. inner stage: capsule, ASAS, LV-T30 engine under ASAS, 6 fuel tanks in a circle around ASAS, 6 fuel lines to central engine, 6 LV-T45 engines under fuel tanks. middle stage: 12 decouplers, 12 fuel tanks, 12 LV-T30 engines, 12 struts, 12 fuel lines inwards to the 6 inner-stage tanks. Burns out around 40 seconds into flight. Outer stage: 12 decouplers, 12 SRBs. I may try this with just two SRBs per decoupler. Burns out at 25 seconds into flight. Image gallery Here, to save the forum screen space. The important part is that all 19 engines burn through the outer 12 tanks and then they\'re dropped along with 12 of the engines. Throughout the launch the central engine can help burn without having any fuel tank weight attached to it. As you can see in the final screenshot, this design runs out of fuel literally at 100 KM altitude - You can just see the tail of the flame still in screen. So more engines with less fuel might do even better. I\'ll see if a similar approach will work with NovaPunch.

Thanks for fixing my problem as well! I hated distracting you from the real work of packing more awesomeness into the bursting seams of KSP.

That\'s an interesting bug that this found. The real 'ground speed' for a retrograde orbit should just be rotational speed of the planet (about 174.5 m/s) + your orbital speed, but instead it works like Kosmo-not said (comparing your current speed vs. how fast you would have to be going at that altitude to stand still over the ground.) This may be needed to give accurate measures if you were travelling prograde, but gives these huge numbers on distant retrograde orbits. Flixxbeatz - I did a lot of orbit testing tonight. Prograde: 1 day at 2868km = 194 km additional 'Ground distance covered.' No orbit\'s perfect. Switching to 'surface' indicator on the speed showed 2.7 m/s. Retrograde: 1 day at 200km = 201,618 km - that\'s pretty close to the 196,500 km that it should be, and it should actually go downwards in any higher orbit since the orbital velocity part would go down and the planet\'s rotation is always the same. 1 day at 2000km = 167,099 km - should be 107,093 km, based on orbital speed of 1165 m/s + 174.5 m/s planet rotation * 86400 seconds/day. 1 day at 2868km = 174,170 km - displayed surface speed 2017.5, pretty much double the 1008.9 orbital speed and showing that the game uses the expected 'steady over ground' speed at a given altitude to calculate the apparent surface speed. 1 day at 50000km = 1,305,000 km 1 day at 81000km = 2,071,008 km - with 208 m/s orbital speed, this should be 33,048 km or so. Unfortunately, my attempt to do the 1 year 81,000 km orbit and then land back at ksp with only stock parts failed - as I was preparing to start a powered reentry, my stage separation went wrong and the orbit stage broke the engine and a fuel tank off of the landing stage, leaving me stuck in a 124 x 1000 km orbit. By doing the orbit at 81,000ish, I got a little more distance - I\'ll have to try it again when I have a time to sit through another year at 10000x compression.

It\'s been over a month since I pre-ordered and I don\'t see anything on my store profile to indicate that the pre-order is in. Is there still a backlog being processed? I\'m not in any rush to see the confirmation in the store profile (until 0.14 comes out, that is) but I wanted to make sure whether the long time to show up is normal. Plus, I figure having the 'time to process' show up in this thread will limit future asking of the same question!

Complaining about my laziness/lack of effort would make sense, except you two seem more interested in complaining than doing the challenge... how\'s that for lazy! Ignore my result, and show us what a non-lazy design can do.

I\'m not sure why you thought SE is involved at all. This was NovaPunch+kw+rediculous fuel tank. He said in the OP 'any parts' so I did this, to show that even very low effort on my part I could hit that speed. The cheatish fuel tank that was included in the FTL drive pack (9999 fuel, 3 mass) is what made that work - you should probably change the challenge, the same method I used could easily break 100 km/s.

Since you said 'any parts' I decided to dabble in cheatish parts for the first time in a while. Spoilered to save people\'s screens. Capsule with parachute and light decoupler, 8 FTL drive fuel tanks, and a KW Hercules X. Launched it and made sure it was on a truly straight-up orbit with apogee at 83,000 km. They spent just less than one of the fuel tanks doing that. Just after it starts falling back in, Jeb tells the other two it\'s time to go home quick; 'let\'s see what this baby can do!' They line up carefully aimed at the planet... 5 days, 7 hours, 11 1/2 minutes after they launched, they throttle up to full, and watch the orbit view carefully to make sure they\'re not going to miss re-entry and drift off into space. As soon as it\'s confirmed they\'re aimed straight at the planet... Jeb locks the controls. 'Guess it\'s time I explain why I named this one the Planet Buster. Y\'all thought I was joking - the joke\'s on you!' The next 23 minutes consist of frantic efforts from the other two to override Jeb\'s lockout, but it\'s all for nothing. At the end of that time, they\'re going 61.6 km/s, they\'ve already covered half the distance they took the last 5 days travelling, and there\'s absolutely nothing they can do but wait for the next 12 minutes, which is all that it will take to re-enter and die. At those speeds, travel time from the Mun to Kerbin is 3 minutes. Jeb spends the last minute promising that the parachute and heat shielding can handle it! Jeb\'s tombstone would read 'It can handle it!', if only they could find enough parts to bury. Full image gallery here.

See this post (click the spoiler tab.) Made it from Kerbin to a 9.7 million km circular orbit around Kerbol, returned to an orbit slightly wider than Kerbin\'s and made that one circular, then returned to Kerbin and landed. No need for mods, it\'s all stock parts. Manned ship, and it had plenty of fuel left when I ditched the tanks for re-entry. Screenshots and information are in that post. I had to rebuild the craft for 13.1 with the reversed fuel lines, I\'ve attached it. 128 fuel tanks, 25 LV-T45 engines, and a ton of struts and decouplers.

I didn\'t like all the land ownership stuff, but decided to fight it through RP of a socialist rebellion instead of just ignore it or complain about it. I decided it would also be against all the fancy titles and such that people were making up for themselves. But since this challenge has a huge crossover into the roleplay threads, let\'s go with the RP response... The people will triumph! Down with the nobility/robber-barons/oligarchs/1%! (pick whichever applies in the current century and country) Support the PDLKP and OCCUPY MAKAVI! Booster-tron activate! Umm... let me get back to you after someone smuggles me a strut or two.