maltesh

On my Duna returner, I used one NTR on the lander (which came down primarily on three large chutes to save fuel) (Edited to fix the spoiler. Blast it, I was just told about that yesterday) It returned to Duna Orbit primarily powered by the aeropikes. I then decoupled off the aerospikes and the landing legs, leaving the NTR as the sole active engine. It rendezvoused with the spacecraft of a previous Duna astronaut and rescued him, then the two of them returned to Kerbin with plenty of fuel. It should be noted that the NTR /really/ doesn't like shear forces, so if you're going to stack it under anything massive, you're probably going to have to strut it something fierce.

Jool's synchronous orbit altitude is 15,010.461 km ( corresponding to a sidereal rotation period of 10 hours) Of course, Moho's synchronous orbit is well outside its SOI. Other bodies in the Kerbal Star System that have a synchronous orbit inside their SOI as of v0.17... The Sun (Sidereal rotation period 5 days, synchronous orbit altitude 1,508,045.286 km) Gilly (Sidereal rotation period 7 h 50 m 55 s, synchronous orbit altitude 42.138 km) Minmus (Sidereal rotation period 11 h 13 m 20s, synchronous orbit altitude 357.941 km) Bop (Sidereal rotation period 3 h 35 m 50 s, syncrhonous orbit altitude 154.420 km)

Well, I put a regular fuel tank into the Sunrunner3 and made a couple more modifications: Found the strut that was snapping on launch, which prevented the ascent corkscrewing. This meant the last stage of the lifter could be used to help throw Sunrunner 3 to my traditional 131Gm Bi-elliptic sundive distance. Jool and all the other planets were well out of the way this time, so I didn't have to spend any more delta-V avoiding them, and I went for a periapsis at a mere 13 km over the solar sutface. Maximum velocity was just under 98 km/s achieved at an altitude of about 55,000 km over the solar surface. 47670.2 m/s of that was carried out to 1Tm, for a time of 26 663.1 years. Guess that bad luck and poor building made the original Sunrunner fly suboptimally, even though it had that modded fuel tank. Sunrunner 3.craft - Mechjebbed, rest stock.

The KSP Sun has an escape velocity. Escape velocity is the minimum speed, for a particular distance from an object, that a second object would have to be traveling at so that, regardless of how long gravitational force has to act upon it, gravity can never force it to have a maximum separation distance. It's the velocity that matches up with a specific orbital energy value of 0 m^2/s^2 for that altitude. It has nothing to do with spheres of influence.

Ed Kieth's Innovative Asparagus Stalk Booster is described in </efficency.>Tom Logsdon's'Orbital Mechanics: Theory and Applications and pretty much nowhere else. As described in the book, its seven equivalent liquid fuel rockets stacked with six surrounding the central stack, like so. If you don't get the fuel lines right, you'll wind up with an unbalanced craft that will tumble. If you don't get the staging right, you'll wind up popping off a still burning stage with generally catastrophic results. If you strut down the boosters (and you probably should), and you don't attatch the struts symmetriclaly, it will probably will spin out of control. If you do get everything right provides a pretty efficient lift stage that gives you maximum thrust off the pad when you need it most, and gets rid of the empty tanks quickly, so that they aren't weighing down your spacecraft, cranking up your full mass/dry mass ratio each time you dump the empty tanks and resulting high delta-V. It's become a standby in my spacecraft design stable to get things into orbit. (edit) As for why it's called an Asparagus Stalk Booster...see Ziff's post below. Was wondering why the spoiler wasn't working. Thanks. (end edit)

Bi-elliptic is only cheaper than the Hohmann for certain circumstances. For instance, if your aim is to dive into the sun, a bi-elliptic sundive can be a heck of a lot cheaper than a hohmann sundive. If your intention is to reach any of the planets from Kerbin, Hohmann transfer is less expensive for all of them. For plane changes, while it's always less expensive to do a plane change when you're moving slower, the method of pushing the apoapsis out to a far distance, doing the plane change there, then returning to periapsis and recirularizing tends to only be worth it for extreme plane changes, on the order of 60 degrees or more.

0.13 didn't have any ability to use persistence files. If any version after 0.14 gets a persistence file whose format it doesn't understand, it will simply load a reset Kerbin star system (with whatever bodies that the game of that version knows about in their initial positions, and no spacecraft), and overwrite the file the next time it autosaves.

Land without fuel, landing gear, or parachutes? Okay. I'm afraid I don't have a picture of before launch, however.

At least, as of v0.16, there's actually a third Monolith near the north pole on the Mun. But yeah, the Monoliths are only a few meters high. You are exceeedingly unlikely to find any of the monoliths on the Mun without some sort of plugin-based addon helping you. I could see finding two of the five Kerbin monoliths without being told or using a plugin, but the other three... Yeah, really unlikely.

Thanks, but I'm afraid I'm going to have to request my own disqualification. Several days ago, I wound up making a second standard-sized liquid fuel tank, and doubled the number of fuel points in it so try to see if specific-impulse-based engines got their burn time directly from the empty and dry mass values in the .cfg file, or if they got it from some vague consistency with the liters value that you get when you right-click on a fuel tank. And like an idiot, I didn't give the modified fuel tank an obvious garish color to make it obvious to me that it was a modified fuel tank. I normally do that, but for some reason I didn't. So when I built the Sunrunner, the tank just under the pod wound up being a fuelTankBLARR instead of a fuelTank. I didn't notice this until I was checking the persistence file this morning. And as a result, in the middle of the powered slingshot, when the spacecraft was nearly the lightest it would get, it was burning a tank that had twice the fuel capacity it should have had, resulting in a higher velocity at 1Tm than it should have had. How much higher is an interesting question, I'd guess possibly as much as a dozen km/s. So, yeah. Definitely wasn't stock. I'll probably throw out another submission with truly stock + mechjeb parts in a few days.

Heading 270 is indeed West. Heading 180 is south.

Indeed. Bi-Elliptic Sundive followed by gravitational slingshot at under 100km from the solar surface. I'd tried a couple times to do this before the Kraken was slain. This is the Sunrunner. Mechjebbed, but all else is stock. [ Edit: Apparently wasn't stock, accidentally used one double-fuel tank.. See post later in thread. Requesting disqualification] Sadly, I didn't get any pictures of it on launch, because it was a fickle beastie to get into orbit, and had to restart about a half dozen times. THe lifter stage is asparagus-stalk staged, and yes, I did use Mechjeb, because keeping the ship aimed for 30 minutes during the eventual slingshot was not high on my priorities list. The orbit stage has six pairs of two-400-unit drop tanks arrayed around a central stack of two 400-unit drop tanks, powered by a nuclear thermal engine. It took four of those tanks to get from orbit to push my apoapsis out to 131Gm. 600 days later, At apoapsis, I then dropped the periapsis to about 100 km over the sun, though I had to do a bit of a plane-change as well to avoid sweeping through Jool's SOI. Then another 600 days back to Periapsis. At burnout, top speed was 98.4 km/s. And of that, 49048.8 m/s remained at 1TM. I was kind of hoping to get above 50km/s hyperbolic excess velocity, but wobbly steering on launch and the need to avoid Jool's SOI on descent probably were what prevented that. At any rate, that's a time of 29,215 years.

It's an ordinary text file, though you have to be careful to use a program that will preserve the carriage returns. I typically use Notepad++ to edit it.

For Munarl returns, getting into a hypoerbolic trajectory from very low munar orbit that points straight out the trailing pole of the Munar SOI (the point on the Munar SOI directly behind the Mun in its orbit), with a velocity that puts your spacecraft near the of the Mun's orbital velocity as you cross that SOI is going to be the most efficient way to do it, as it takes the best advantage of the Oberth Effect. If your low (10kmish) orbit around the Mun takes you eastward across its surface, you want to burn a little before you get the middle of the near face. If it takes you westward across its surface, you want to burn a little before you get to the middle of the far face. This video from a bygone era before Patched Conics illustrates the basic technique, except I didn't get into orbit first, and instead burned from the surface into an approximation of the desired hyperbolic path. Ideally, I would have wanted my departure course to be aligned parallel to the Mun's orbit for minimal fuel costs.

When it happens with stars, the situation is called a Contact binary. There are a number of asteroids believed to be contact binaries as well (though being asteroids, they aren't massive enough to have atmospheres, and are in presumed physical contact). Robert L. Forward's Rocheworld series features a double-planet system. Haven't read it myself, though.

While Duna a pretty small SOI (48 Mm radius) , Moho's is smaller, both in radius (11.2 Mm) and as a fraction of its semimajor axis(Duna 0.23%, Moho 0.21%). Moho has the added issue that it's moving so much faster that it can cross a distance equal to the diameter of its SOI in as little as 20 minutes. Largest moon SOI is Tylo's at 10.8 Mm radius. Also, Duna's eccentricity is fairly low, at 0.051. Moho, by comparison, has an eccenricity of 0.2.

Tylo's larger than both Laythe (500km radius) and Duna (320 km radius). It has the same radius as Kerbin (600km) , though it's a bit less massive. As far as having nearly the same surface gravity, I expect the gravitational parameter, and thus mass, were chosen to specifically produce planets with 0.8 gees of surface gravity at the decided radii. Ultimately, the only thing in the Kerbal star system that has characteristics reasonable for a real-world celestial body (assuming the standard value for the Newtonian Gravitational Constant) is Jool, if you politely ignore the gas giant thing.

I don't think I've ever met a physicist who'd agree with that statement.

Correct. It's not Fannee Doollee, it's Maresy Doats.

It's not per liter of fuel. When specific Impulse winds up being measured in seconds (as it does in the game stats) its' "Per Newton of fuel weight measured under a standard gravity". Newton * second / Newton cancels out to seconds, and can be thought of as "The amount of time for which 1 Newton's weight of fuel can produce 1 Newton of thrust with this engine." As for why you'd use weight under standard gravity here instead of mass, in the real world, rocket manufacturers have to deal both with clients that use the imperial system, and clients who use the metric system, and if you calculate "The amount of time for which 1 pound of fuel can produce 1 pound of thrust" you wind up with the same value in seconds. If you go by unit mass of fuel instead, you wind up with Newton * second / kilogram, and since a Newton is a kilogram * meter / second ^2, you wind up with units of meters/second, which is the Effective Exhaust Velocity.

The REF = values for 0.17 are as follows: Kerbol = 0, Kerbin =1, Mun = 2, Minmus = 3, Moho =4, Eve = 5 (Gilly = 13), Duna =6 (Ike = 7), Jool = 8 (Laythe = 9, Vall = 10, Tylo=12, Bop = 11)

Here's a spreadsheet I threw together based on information extracted from the game by Nadrek: https://docs.google.com/spreadsheet/ccc?key=0AuySrGPsDeq2dFVpTkJUNTktT19xNFVOTTVuZE1ZQWc#gid=0

Convert those numbers to seconds, and you'll have values you can set the UT= parameter in the Flightstate section of persistent.sfs file to, instead of waiting.

Duna's orbit is elliptical, with an eccentricity of 0.051. Its distance from the center of the sun ranges from 19.4 million kilometers at periapsis to 21.4 million kilometers at apoapsis.Blast, beaten. At any rate, of all the planets, only Kerbin is in a truly circular orbit. Kerbin's moons and the three innermost moons of Jool are also in circular orbits. The black figure is a circle with radius 1 and center (0,0). The red figure is an ellipse with semimajor axis 1 and eccentricity 0.051. Its foci are (0,0) and (0, 0.102).

Which bodies have you tried parachuting to? Personally, I've used parachutes on Duna and Laythe landings, as both have atmospheres.. Also, for parachutes to work, they have to be manually activated, typically by pressing space to activate the stage they're currently in. Are you making sure that the stage of your planetary parachute is somewhere it won't cause problems?