Jump to content

Search the Community

Showing results for tags 'delta-v'.

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • General
    • Announcements
    • Welcome Aboard
  • Kerbal Space Program 2
    • KSP 2 Discussion
    • KSP 2 Suggestions & Development Discussion
    • KSP 2 Dev Diaries
    • Show and Tell
  • Kerbal Space Program
    • The Daily Kerbal
    • KSP Discussion
    • KSP Suggestions & Development Discussion
    • Challenges & Mission ideas
    • The Spacecraft Exchange
    • KSP Fan Works
  • Community
    • Player Spotlight
    • Science & Spaceflight
    • Kerbal Network
    • The Lounge
  • Gameplay and Technical Support
    • Gameplay Questions and Tutorials
    • Technical Support (PC, unmodded installs)
    • Technical Support (PC, modded installs)
    • Technical Support (Console)
  • Add-ons
    • Add-on Discussions
    • Add-on Releases
    • Add-on Development
  • Making History Expansion
    • Making History Missions
    • Making History Discussion
    • Making History Support
  • Breaking Ground Expansion
    • Breaking Ground Discussion
    • Breaking Ground Support
  • International
    • International
  • KerbalEDU Forums
    • KerbalEDU
    • KerbalEDU Website


  • Developer Articles

Find results in...

Find results that contain...

Date Created

  • Start


Last Updated

  • Start


Filter by number of...


  • Start



Website URL



About me



  1. I usually use mods, but I've removed them all when this problem arose. Therefore I've put this into the unmodded section. No matter what part combo or fuel type, I cannot get any info in the editor or in-flight. it simply says 0 meters/s and when I click on it to get the more detailed info like TWR, it simply does not display any data within the box. Please help with this as it is making the game almost unplayable for me.
  2. I'm trying to make a rocket-only SSTO spaceplane that can get to orbit and dock to a station. I have managed the first part, but only with like 30 m/s remaining - not enough to get to a station and return home. My current design uses a few aerospikes, and has a vacuum delta v of around 4 KM/s. Why I decided to use a rocket SSTO: 1. easier to fly than a jet SSTO 2. noting to have to balance or otherwise deal with, compared to a shuttle 3. cooler than a rocket How can I increase the delta-V in orbit of my space plane to be able to dock to a station? Of course, if all else fails, I might be able to add a few drop tanks or boosters, but I'd like to try and go fully reusable.
  3. Not sure if im even asking the right question. Lets say for instsance, I build a massive ship designed to travel the solar system. And on this ship I have multiple engine groups that i can toggle via the actions menu. Some are for efficency and others are for high thrust and others even are for finetuning maneuvers. The problem is, no matter which engine groups are active the delta v available and the current twr readout over in the staging section remains the same which makes performing maneuvers kind of a guessing game at burn times, whether i have enough fuel, and when to start each burn. Am i missing something?
  4. KSP Visual Calculator Online tool that assists in playing Kerbal Space Program I have released a new tool for Kerbal Space Program to help players visualize and plan missions in-game. This calculates the delta-v requirements for a mission, and also CommNet constellations. For delta-v calculations, players can select multiple planets/moons as checkpoints and have the dv requirements automatically calculated for them. For CommNet constellations, players can add spacecraft with specific configurations of antennae, and then drag the spacecraft and planets around to mimic an in-game situation they would like to analyze. All spacecraft are linked with colored lines when a connection is established between them, showing their signal strength. Online tool: https://ksp-visual-calculator.blaarkies.com/ Checkout the github repo issues tracker Some details about the usage: Delta-v requirements are measured as best case scenarios. If you are not an Ace pilot yet, use the "margin of error" preferences control to add some safety to the final results. The trip details are a good way to learn optimal orbital mechanics When using the "Efficient" route mode in preferences, you might see extra visits in your journey because in total they will require less delta-v On the Delta-v Planner page, the location of planets on screen has no effect on the calculations. Feel free to move them around to better visualize your mission Antenna calculations have been tested against 30 in-game test scenarios with full accuracy Orbits in the app are not elliptical, and not in 3 dimensions Most orbits in-game are nearly circular anyway; inaccuracies are minor For CommNets, it does not account for any inclination in orbits. Most in-game orbits are flat enough (relative to each other) so that straight line distances do not differ too much due to this, but in certain situations like Pol <-> Bob this can be more obvious
  5. Community Delta-V Map 2.6 - KSP 1.3 View full size PDF versions (A4 & Letter) KSPedia Version (v2.6) Lights-out Theme (v2.4.1) (Thanks @Siege /u/s13g3!) Outer Planets Mod adaptation: By Swashlebucky; original by Misucat and his wife PDF version (v2.4.1) OPM - Lights-out Theme (v2.4.1) (Thanks @Siege /u/s13g3!) OPM - KSPedia Version (v2.4.1) (Thanks @AlexSheFF!) Changelog GitHub Check it for development, pull requests and other maps. All required tools for map editing are referenced there. How do I use it? It's simple! 1. Pick a planetoid you wish to visit. 2. From your initial position, add up the numbers between every checkpoint until you reach your desired checkpoint. 3. The total is the general Delta-V value needed to reach your destination. Example: - Kerbin surface -> Duna Surface 3400+950+130+10+250+360+1450 = 6550* *Aerobraking can reduce the needed dV to almost zero. Using it would result in the following: 3200+950+130+10 = 4490. - Eeloo Surface -> Kerbin SOI 620+1370+1140*+1330* = 4460 *Aerobraking can reduce this number to almost zero. *Numbers outside the stripes are the maximum dV needed to change between planets inclinations. Pay attention to them! Elliptical or Low Orbit? What's the difference? A Low orbit assumes a circular orbit 10km above the nearest obstacle/atmosphere. Elliptical orbits have the Periapsis at Low Orbit altitude and the Apoapsis at the planet's SOI edge. I added the Elliptical orbit checkpoint for two reasons: 1. It shows you the required dV needed to get your vessel grabbed into the planet's SOI, disregarding the value needed to circularize on a low orbit. 1a. It assumes you have set your encounter to the lowest periapsis possible, during the encounter maneuver. 2. If your destination isn't the planet, but instead, its moons, you don't need to count the whole dV needed to circularize around the planet's low orbit, since you won't use that. Instead, a simple capture/elliptical orbit is enough to transfer to a moon. That way, you can reduce the needed dV for a trip drastically. I hope this helps. Enjoy! License This work is licensed under CC BY-NC-SA 4.0. You are permitted to use, copy and redistribute the work as-is. You may remix your own derivatives (edit values, design, etc.) and release them under your own name. You may not use the material for any commercial purposes. You must use the same license as the original work. You must credit the following people when publishing your derivatives in the material: JellyCubes (Original concept) WAC (Original design) CuriousMetaphor (Original vacuum numbers) Armisael (Additional vacuum numbers) Kowgan (Design, original atmospheric numbers) Swashlebucky (Design) AlexMoon (Time of flight) Official Wiki (Relay Antenna calculations) -- This was originally a continuation from WAC's Delta-V Map from KSP 0.23. Since then, a lot of people (credits above + advice from people in this thread and over the internet) have contributed to improve this chart and keep it up-to-date with the latest KSP version. I am very thankful to all those who helped make this chart possible. Seriously, thank you guys.
  6. It's not effective, either to have a single gigantic tank for Tylo and back, nor having two hundred separate stages for a trip to Mun. Is there a formula to calculate the minimum fuel to dead weight ratio for each stage in order to have a net delta-v gain for adding that stage?
  7. Jool 5 Delta-v Chart NOTE: This is based off of my flown mission but can be used to plan other missions to Jool. This chart is nowhere near perfect, but it should give you an idea of what to do or how much to build. I know circularization is not a word but I am trying, I am meaning it as making you orbit less eccentric. If you have any questions please ask me or someone else in the Jool 5 Challenge's main page listed here... The Chart Itself Action Rough Delta-v Requirement (meters per second) Launch to LKO (Inefficient launch) 3000 LKO -> Jool Transfer 2000 Jool Capture (moon assist) to Low Laythe Orbit This can range ALOT but I managed to do it with around 1500 Low Laythe Orbit -> Low Tylo Orbit Transfer 1400 Low Tylo Orbit -> Vall 800 Vall Capture 415 Low Vall Orbit -> Pol 800 Pol Capture 500- Including low Pol orbit circlularization Low Pol Orbit -> Bop 200 Bop Capture 190- including circularization Bop to 79,000 kilometer Jool parking orbit 660 Jool-> Low Kerbin Orbit 4110 FOR THOSE WHO MIGHT BASE A MISSION OFF THIS CHART - Do not base a mission only off of this chart, this does not include landing amounts yet - If I were you I would ensure that you have more delta-v that I have shown to be safe, especially for Jool capture as the moons are not always lined up to help you - I am basing all these values off my submission to the challenge (shown below).
  8. I am trying to design the a rocket that has the exact right amount of Delta-V required to get to the Mun and back. The first stage should be capable of getting the rocket clear of the atmosphere. I have looked everywhere for how much Delta-V the first stage needs and have found nothing. How much Delta-V should I be aiming for for my first stage to be able to get above 70 km?
  9. In one of Matt Lowne's videos I heard that to go to eloo your rocket need to reach a total delta-v of 4000 m/s. But what this mean? Is this means that that's the max deceleration or acceleration what you'll need to make, or what? He also stated out that his fuel just ran out before reaching that speed. I wanna make some rockets and put some stations on distant planets and an ssto that can send crew on them and back to kerbin, and i was just curious what could this total delta-v mean, and how it could help me make it.
  10. I understand the dV map to get from Kerbin to LKO is 3400, another 950 gets me to the sun and then 90 more will get me to a fly-by Eve with another 80 to get into orbit and 1350 to circularize just over the atmo. So to get into orbit of Eve I would need 5850 (plus margin) to simply get to the orbit of Eve. If I want to return from Eve to Kerbin what parts of that do I need to account for? Do I need to add the whole thing back or can I forget that 1330 that was used to circularize?
  11. I have been trying my hardest to design a lander that is capable of surviving an Eve re-entry, and being able to return from sea level. My main problems are first that the lander needs to be quite big and so I need big rockets to haul them into orbit. Sometimes they are not light enough to get into LKO. The second issue is that I am trying to at least land on actual land and not the ocean so Jeb can plant a flag and the rocket can stay upright on landing legs. The problem with that is mainly that I don't know how to do atmospheric precision landings on Eve. Any tips?
  12. From Kerbin to Beyond Delta-v Hey folks, I got a little case of OCD today and decided to make a spreadsheet (link above) of all the Delta-v to get around the solar system when Kerbin is the starting point. This and the KER add-on works together beautifully to figure out proper staging and TWR for any given mission you are planning. This is by far my favorite Launch Window Planner for the nitty gritty. With a little research and elbow grease multiple landings can be had on a single celestial body. Be sure to pack an experiment storage unit if you do. And above all else, remember to pack all the other things you might forget or didn't know you needed. Notes* Downloading or copying spreadsheet may lead to happy accidents. There is a lot of delta-v wiggle room so feel free to adjust all the numbers if you also have OCD. Spreadsheet is linear from left to right. Kinda like how we read. LO = low orbit 2LO = to low orbit. Sources - https://wiki.kerbalspaceprogram.com/wiki/Main_Page https://alexmoon.github.io/ksp/
  13. Is the delta-v map showing the min or max delta-v usage?
  14. Space - the Kerbal playground. These are the voyages of a rescue space program. It's noble mission: to explore recently visited worlds, to seek out new science and new anomalies, to boldly rescue every kerb who tries to go where they haven't gone before - and fails. Recover Obemy and His Debris from Low Sun Orbit I posted this in the "Self imposed KSP rules. Things we do that make things more difficult." thread: So, of course, a few days ago I pop into Mission Control and accept a rescue mission... The words "low Sun orbit" seemed very ominous. In the tracking station I saw this.... Other than a string of expletives, I was at a loss for words. How would you approach this? Happy landings!
  15. Does anyone knows how much delta-v total do i need to get to duna and back? if there is already an answer can anyone send me a link? pls
  16. I have had KSP for the PS4 a total of 4 days now, and it's complexity and intricacy exceeds what I prepared for. I am happy in this, but mortified as well. I have started a science save file, and have only researched 4 additional groups including: basic rocketry, engineering 101, general rocketry, and survivability. With the new parts acquired from researching these groups I built a simple, 3 stage ship, and have decided to try to achieve LKO. To do so efficiently, I delved into the KSP wikis and forums to find the relevant information. I understand to a certain point the rocket equation, or the "*dudes name I can't spell*'s equation". Anyways, I found the ISP of the rockets used in each stage, and I wasn't going for complete accuracy at first, using the ATM ISP for every equation done. Then, I found the total mass of each individual stage, as well as the dry mass of the stages by themselves. In order to do so I had to take the first to stages off, and measure the total and dry masses for the last stage, then add the second stage and subtract the total mass of both stages my the total mass of the last stage to get the total mass of the second stage. Then I proceeded to do so with the first stage attached as well. I found both total and dry this way for the first and second stages. Now that I have the ISP, M_FULL, and M_EMPTY, I figured I could calculate and add the answers together to find my overall delta-v, granted I SHOULD have more than I calculate based on the idea that my ISP for each equation will be the atmospheric ISP. My work: (weights are rounded) Stage 1 (final stage): pod, fuel tank, and 'reliant' thruster. - Dv = 265 * 9.8 * In (4/3) = 747 Stage 2 (second stage): 2 fuel tanks and 'reliant' thruster. - Dv = 265 * 9.8 * In (3.5/1.5) = 2,200 Stage 3 (first stage) 2 BACC thrusters, and 1 'hammer' thruster, with added radiator panels. Dv = 520 * 9.8 * In (19.5/4.5) = 7,472 I am now realizing that each stage must also push the weight of the stages above them, meaning I must carry the mass of those stages into that equation, adding to the total and dry mass of the stage being figured. If this is not so and I have created a false solution, please let me know, thank you.
  17. Personally, I will continue to use Kerbal Engineer as it has a HUD that allows me to see things at-a-glance rather than having to go into and out of the map screen to check my apo- and periapsis. I also perdict that in the future, it will save me from having to scroll through long staging lists to check dV.
  18. Does anyone have a table or list of calculator with the upper limits of the Delta-V require to go from say a 50-100km orbit to a safe landing. I get it wrong too often. I just landed a base segment on Minmus with literally 10 times the Delta-V it needed. I ended up just throwing away all that fuel because it was late at night and I had to get to bed. It would also help if the resource you supply me with also listed optimal acceleration figures for landings. That's been on of my problems in these 155 years too. Help me improve my game, please.
  19. When calculating Delta-V manually the equation would be DeltaV=ln(m_start/end)xISPx9.8m/s^2 Now my question is when traveling to the moon would you change the 9.8 to calculate delta v? Im just confused as 9.8m/s^s is acceleration of gravity on earth. Thanks, Jonda
  20. Hello! Could somebody please explain what Delta-V is, but simply? Currently I think it is how much total thrust my craft can produce with the fuel it has. Now, I do not want a paragraph of mathematical and scientific stuff, I would just like a simple explanation.
  21. We've all heard it...there's frustratingly no working ALT code for a capital Delta on Windows. Every other Greek letter works, except for the one you and I would type consistently on this forum. We have to Google it, and copy and paste it from some website every time. But that's not true! You can make the delta symbol work with the Alt key! I found it here: https://www.reddit.com/r/windows/comments/18joaq/how_do_you_get_the_delta_symbol_on_a_windows/ Go to the Command Prompt, and enter this sequence: reg add "HKEY_CURRENT_USER\Control Panel\Input Method" /v EnableHexNumpad /t REG_SZ /d 1 Then, log off and log back on. Open a text editor. It can even be this forum. Hold [ALT] and [NUMPAD +] and type '0394' on the keypad. Δv
  22. Hey there! So I bought the DLC and apart from all of the other bugs and issues mentioned in many other threads, I have come to notice something: I'm not actually having any fun playing the Stock missions, and generally the stock game. I would dare to call myself a KSP veteran, having started out a few years back. Building rockets that can go to the place you want to go is quite a hit and miss, until you discover the concept of Delta-V and TWR. After my discovery, I started calculating them with pen, paper and a calculator. Then I switched to Excel, but that still got tedious real fast. Luckily I discovered MechJeb (and later KER) that calculated the TWR and the stages for me. I got used to them, and building rockets became second nature to me. When Making History was released, I thought to myself: "OK, let's play these missions as they were intended: with just the Stock game, no mods". I finally got to the third part of the mission (building Jebnik 1), and I come to realize: Wait, how the hell am I supposed to know if this is going to space or not??? I don't have a dV readout, I can't even do trial and error, because there is no Revert to VAB after I've launched the thing. My options are: Build the most "Kerbal Rocket" and create a giant behemoth that by my *guess* will probably make it to space Do trial and error by cheating Get it right by copying an existing design from the forum Go back to my days of calculator usage, calculate the dV of 3 stages by hand None of these is fun for me. Option 1) just isn't my style, and it's not even a guarantee that it will work. Option 2) feels cheaty, and also doesn't work very well. 3) is plain lame, and I'm just too old to do 4), I have moved past this years ago, and it's way too much work for a game meant for recreation. So what now? I'm usually a critic of statements like "this mod should be stock", but I'm coming to realize that the game really, really needs a Delta-V and TWR readout. What are your thoughts about this? How do you deal with building rockets without KER/MechJeb? ps.: inb4 "Just install KER/MechJeb": I know I can do that, and probably will. But in this thread I want to talk about the *Stock* experience that the game provides and that the developers intended.
  23. I have this monstrosity I've constructed a couple of times now. First by four Kerbal-X rocket launches, and later by three cargo SSTO trips. Since this first iteration, I've removed the Mk1 inline cockpit and added three more Liquid Fuel tanks. I also removed a little bit of mass here and there, used smaller parts where I could, and lightened the load as much as I could while still being reasonably comfortable to a six-kerbal crew. Aside from KER, I have DMagic's EVA Struts in use. If I just cheat this monster into orbit, I get slightly more than 3500 m/s according to KER's estimate. Enough for Duna and back. If I launch it as intended, the first module containing the Mk1 crew cabin and engines will have in excess of 7200 m/s. But then I start piling on modules, and the estimated delta-v doesn't seem to change once it's fully assembled. I have one of these out at Duna in a career play-through that has slightly less than half of its fuel, and has landed the rover package on Duna's surface. Yet KER thinks I still have 3700 m/s. First off, the Iktomi II, in Duna orbit, has 257 parts, 56.57 tonnes, and 1866 / 4800 Liquid Fuel. This is the ship that already dropped off its rover kit. Supposedly I have over 3700 m/s. Assuming one unit LF = 5 kg, that's 9.330 t fuel, making dry mass 47.34 t and dV = 1397 m/s. Enough to get home, barely, if I'm careful with Ike and Mun assists, or I could dump a lot of hardware first. Second, the Defrahnz, in Kerbin orbit, is prepared for departure to Eve. This has 306 parts, 75.92 tonnes, and is fully fueled at 4800 / 4800 Liquid Fuel. Supposedly I have just over 7400 m/s, but in reality with 24 t fuel I have only 2980 m/s. At least this craft could reach Gilly and land on RCS alone, and refuel. Is KER not taking into account the added mass of modules as I assemble this thing? Have I missed a setting somewhere?
  24. For just about every journeys there are questions that need to be made. Just about all of us have taken off from Kerbin with 10k dV in the Moho's orbital direction and finding out, when we go close to Moho that we did not have enough fuel left to circularize (or some other nice oversight like pointing the solar panel in the direction of the sun for 6 months). Can we sit down with a spreadsheet and make decisions that factor the choices that are presented. I decided to basically write these posts because of the eccentricity thread in order to illustrate what the real value of eccentricity is when all is said and done. To make the answer short, energy is much more important, but eccentricity gives us on the fly information. For example if you are circularizing from an eccentric orbit close to Pe or Apo (whichever is the burn point) and your delta-e/t is too low compared to time to pe/apo, this informs you that you need to increase thrust or should have carried a more powerful engine. Another situation is during reentry from distal targets, the delta-e/t tells you how rapidly or effective your entry-theta was. If your ship is overheating and your e is not likely to approach zero at some point during reentry then you probably should have used a bigger shield(or kept some retro fuel) and choosen a steeper entry angle (lower no-ATM Pe). The eccentricity argument has an effective range of 0.0005 to 1.0000 below or above which are meaningless in the game. In this case an eccentricty of 0.5 = 0.4995 to 0.5005. This differs from other stats such as dV which are accurate over a 100,000 fold range in the game, altitudes are accurate to >10 decimal places. IOW, the values used to derive e are much more precise than e itself. Does it make a difference, yes and no, theoretically if you had a TWR = infinity, an exactly angle to prograde for a perfect burn (with perfect thruster control) there is no wasted dV and you end up intersecting the minimum orbit of the target planet. In reality the dV calculated at best puts the craft in a range were RCS thrusters in the departure orbit can be used to get within about 5000 meters of the perfect arrival orbit (on a good day). However knowing energy makes some logical sense of what is going on, for example by the Oberth effect works, why burn from low orbit, why use kicks on lowTWR craft in low orbits (versus spiralling away from the celestial). When we are using e for on-the-fly decision making accuracy is not really an issue, however in the formulation of travel strategies we do want to use as accurate as possible starting information. So what about everything else? The procedure is this. Step one. For a target planet orbital ap _and_ pe (meaning two parallel analyses), assign a departure and arrival altitudes relative to kerbol, transform to radius, derive a. Step two. Assign u/a (Escape energy) and u/2a (SKE at a) Step three. Assign SPE changes from kerbin-to-a and from a-to-target. Step four. Assign deltaSPE changes (changes in Kinetic energy) from a to kerbin or target. Step five. Calculate SKE at kerbin or target. Step six. determine dV required to achieve kerbin or target orbits without entering kerbin or targets SOI. Step seven. determine the SKE at planets SOI entry or exit based on step six. Step eight. Add this to planets minimum orbit radius escape energy, this give energy to reach minimum orbit around the planet and free fall to planet. Step nine. Convert this to dV required to free fall from minimum stable orbit Step ten. Subtract the circular orbital velocity from freefall at minimum orbit dV requirement. Step eleven. Add the two dV (kerbin and target planet) together and get total dV. At 6 specific points in the 11 step process unique energy parameters were used to derive decision making information. The table below compares the Total dV (m/s) cost of intersecting orbits (values rounded for clarity) and also compares to inclination dV performed in circumkerbol orbit. Planet Target Intrcpt δV inclination at Apo at Pe dV at a Moho 4724 4001 723.1 1818 (Depart from Kerbin at the Kerbin-Moho inclination node closest to Moho's Apo, inclination nodes are priorities) Eve 2911 2913 002 400 (Eve's orbital inclination nodes are priority) Duna 1928 3009 1081 78 (Depart from Kerbin close to Duna's Pe) Dres 2819 4837 2081 466 (Depart from kerbin closest to Dres's Pe, inclination nodes should be also considered) Jool 5202 5686 484.0 79 (more analysis of satellites requires) Eeloo 3416 3449 32.7 386 (Eeloo's orbital inclination nodes are the priority). As we can see above the analysis is devoid of any consideration of the e parameter, although it is easily obtained from the information we have. How can we get those pesky inclination nodes. One way is to place a satellite in a Kerbinesce orbit at theta = 2/3 pi and 4/3 pi relative to kerbin (in the same orbit as Kerbin but at maximum distance. Then target a planet, the nodes will show up also relative to kerbin. Such satellites can have a dual function since one can also place a deep space array on the satellite. That allows communication to objects that current orbit is on the other side of Kerbol. [Another set of energy and dV calculations that involve the equation The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit. in which we create an orbit a which is 2/3 or 4/3 the period of kerbin by generating a periapsis or apoapsis (respectively) whose average with kerbin orbit gives us a]. Disclaimers. Above assumes two sets of reciprocal process, launch/ascent & descent/land and transfer commence and complete that have a boundary at the minimum stable orbit of both planets. 1. There is a simpler mechanic, single step "star trek" mechanic, in which your ship has so much power that you travel from departure x,y,z, vx, vy, vz to arrival x, y, z, vx, vy, vz before either of which have significantly changed position (arrival point and departure points are oriented to each other). Given that human life could never survive the dV/dt and the dV & TWR required do not exist this scenario can be disregarded and physically impossible and should not be considered. Deep space probes such as New Horizons need not depart into a circular orbit. That if they reach an angle to prograde of theta>090' while still in upper atmosphere while at the same time burning the dV required for a highly eccentric orbit does not require circularization and may use less dV. In such a burn the base assumption is that the best delta-SKE on hill sphere exit is obtained from the lowest altitude burn even if that burn starts at a suborbital trajectory with pe always below safe circular orbit altitude. To convert this to KSP the ascent angle is say inclination is at >15' and you are at alt=45 you simply can burn to Eeloo Apo intersect as you are crossing some theta~90 and have a large plume of overheated gas momentarily burning through the fairings before they are deployed. 2. KSP provides perfect examples, kerbin is in a zero inclination, zero eccentricity orbit about kerbol and as it so happens it common departure planet or arrival planet for most of the transfers. The argument of periapsis differs for all other planets so you are not going to be able to match a Apo/Pe angle of a planetary departure with 180 degree Pe/Apo of a planetary arrival except from Kerbin because kerbins orbit a=Pe=Apo. This has some relevance for the Eeloo, Jool transfer which is damn cheap relative to traveling back to kerbin and traveling to Jool (given some dV spent on plane matching). 3. The smallest-sweep area stable orbit about a planet may be unpreferential. Jool being the example. This infers there is complex decision making involved in getting to a system moon in which the planet is not the target. mechanical thermodynamics can be used to burn less than the amount needed to circularize at the planets rMin, that dV would be used to circularize at an apo that intersects the moons orbit. In the case of Jool, all three inner planets have a=pe=apo, so this is not too much of a problem. In these instances you want to compare intersecting the moons orbit directly (using a different planetary Rx,orbit) versus a hohmann transfer to 200k Jool-altitude and a partial circularization burn to intersect the target orbit and circularize. 4. If we make the assumption that inclination nodes are approximate to r = a (semi-major axis), that the dV required for inclination burn (see table) is low enough not to be a priority. In these cases we can, if we desire burn at a bearing above or below the departure planets equitorial plane on depart to send the inclination node to r = a and get rid of some inclination. In comparing the table below the difference between an Kerbin-Moho transfer Pe-target and Apo-target is delta-dV = 724 but the inclination change dV averages at 1814. Therefore its simply intelligent to set a priority on changing planes over departing theta = Moho's apo theta (fortunately Moho-apo is relatively close to the inclination node). The cost of changing inclination at kerbol is reduced by 100s of dV. The same logic is also true for Eve, and Eeloo. For the other planets a departure window closest to the target planets periapsis is a better choice than choosing a departure window closest to an inclination node. 5. Entry burns particularly on planets like Jool need transfers that seldomly overlap with their pe or Apo, consequently there is a triangulation between time to get good window for efficient inclination change, or close to Jool theta. In other instances like Moho, which is so small oberth effect is minimal, free burn times at pe near a kerbin inclination node is going to occur separately than the moho circularization burn. 6. Depending of kerbol relative altitude of the target the true burn altitude is different from the planets altitude. Our burn starts 670,000 meters closer but a maximum efficiency burns leaves kerbin's SOI at the moment of crafts circumkerbol Apo or Pe (depending on an interior or exterior target). We always want the exit trajectory to be parallel to kerbins path of travel even if the line is not identical with Kerbin, otherwise predicting intercept could be off and correcting dV would be required. This occurs both on kerbin exit and on target arrival. For example a the flat part of the escape curve to moho should generally be at a final angle to prograde ever so slightly more than 180 at kerbin SOI otherwise the Apo for the circumkerbol orbit will occur in the future. This means that the numbers for apo and pe differ slightly relative to the calculation. If the target was exactly one SOI in front or behind Kerbin, the difference would be zero, on an interstellar trajectory that the difference is nominal, from Kerbin 670,000 radius is 0.99995 that of the calculated. On such a trajectory 670000 = 85000000 sin theta, translates to an angle to prograde of is 180.45'.
  25. I'm playing a Career mode game with no mods (except MechJeb), and this is the largest rocket I've been able to build. It works well for traveling within the Kerbin system so far, but I want to start going to other planets, but it clearly lacks enough Delta-V to do so (only 7500 m/s). I only have all the 90-Science nodes of the tech tree researched, plus Heavier Rocketry and Command Modules. I would like to increase its Delta-V to (hopefully) 10000 m/s, but am unable to do so. Adding more boosters renders its TWR too small to lift itself. Any ideas? Picture here
  • Create New...