tssn1611

I built a modular one-launch base designed to land on Minmus (but it could probably land on the Mun, too). More pics are here: http://imgur.com/a/BkdVY I realized after I landed and assembled everything that I forgot to actually find areas rich in ore and land on them instead of any ol' spot. So my harvester module is somewhat just for looks. Oh well. I guess that's why I'm not in charge of actual space programs.

Ah, okay, that's what "stowed" means. Thanks, all!

I had radial-mount parachutes and drogue parachutes each in six-way symmetry on a recent craft. When I went to deploy them, one of the drogue 'chutes and then two of the main 'chutes failed to deploy with the message "Cannot deploy while stowed!" It did that, even when I right-clicked and tried to manually-deploy the 'chutes. I'm not sure the meaning of this message, particularly since most of the parachutes deployed fine. Is that a bug or a design flaw in the craft?

Got all the way out to Minmus before realizing that there had been a ... we'll call it a mishap in the placement of the landing legs. Fortunately, the "landing" contracts only require that you touch down, so I just touched the surface and rammed the throttle before tipping over.

8 GB here; maxed out my laptop. I do lots of RAM-intensive stuff besides KSP, so my next computer will probably have RAM as a priority. It's worth noting (I'm not sure if someone's sad this already), but it's not just about the RAM that KSP uses. Having more RAM frees up RAM that the OS can use while KSP is running, so your computer is more responsive. Upgrading from 4 GB to 6 GB and then to 8 GB made a huge difference in that regard.

I landed a one-man lander on the south pole of Moho (and returned it to Kerbin). Actually, it was about 88° S. Eh, close enough. The mission profile was interesting: I aimed for a polar orbit around Moho to avoid as many plane changes as possible. The south pole landing site was chosen because it allowed me to launch back to the interplanetary stage in orbit at any time without huge plane changes, plus it's easier to land at the south pole than the north pole. Once it was time to return, I launched, docked with the interplanetary stage, transferred fuel, and dumped most of the lander in Moho orbit to save mass for the return trip. At this point, to align my trajectory for the return, I need to do an orbital plane change. To do this, I burned until my apoapsis was just inside Moho's SOI. The plane change was done at apoapsis, which was incredibly cheap. After that, there was just the nerve-wracking final transfer burn back to Kerbin (I wasn't sure I'd have enough fuel). All told, the mission was about 110 days, 50 of which were waiting for the transfer window back to Kerbin. Jeb went a little stir-crazy.

Any thoughts on adding graphical plotting of the transfer orbits, such as in Arrowstar's KSPTOT, instead of (or in addition to) the text readout? Seems like you might be able to display the same information in a much more intuitive fashion than a wall of text. BTW, as it is, it's a very nice, light-weight tool. I might try to make use of it for my Moho trip that I have yet to complete ... Also, a bug report (or perhaps just an oversight): in Chrome 28, the "Reset" button sets the "Latest Departure" field to Year 1, Day 1 and the "Time of Flight" fields both to 1 day.

Not that I really have time for this, but just for fun, I tried to preliminarily crank through the calculus using the starting point Wikipedia gave me. Turns out, at least in polar coordinates, if you assume tangential acceleration is zero (i.e. your engine is off), that lets a whole bunch of stuff be constant, meaning a lot of terms end up going away. Once you add tangential acceleration in there (as a function of time, no less), those terms stick around, and the equation is much more complicated. I worked on it until I got to a system of equations I don't think one can solve analytically.

I started getting into the mods around 0.19. Never anything too crazy, Kerbal Engineer Redux and KW Rocketry were my two most-used. I might download a few for the 0.21 update, maybe try NovaPunch and Quantum Struts. KW Rocketry produced some really nice looking crafts, but it tended to clutter up my parts list, and I already click around aimlessly when looking for parts enough with just the stock ones. (I understand NovaPunch is even worse than KW Rocketry from that perspective. I'll have to be choosy with the parts I use.) And all those things that Sean Mirrsen said, too. Geez, I sound like I'm sampling recreational drugs ...

Unfortunately, no. The moon landings were about 20 years before my time.

Well, you're right that water provides a strong moderating influence on local temperature. However, the air temperature over the water on Earth is usually a lot closer to the water temperature than that, assuming it's liquid and not solid in the case of the arctic. Kuala Lumpur, Malaysia (3 N) has average highs of 32-33 C year-round, and Reykjavik, Iceland (64 N) is surprisingly balmy in the winter (average lows just below 0 C). Furthermore, Quito, Ecuador and Kuala Lumpur are both near the equator and near the ocean, but Quito's highs are consistently about 20 C. Why? Quito's temperature is being influenced by the cooler south Pacific current, whereas Kuala Lumpur's temperature is influenced more by equatorial ocean currents that are much warmer. As for water laced with ammonia, the primary reason for water's moderating influence is its heat capacity. If I've done my math right, ammonia has a slightly higher heat capacity than water does, so oceans of water and ammonia should have slightly more of a moderating influence on temperature than just water. Conclusion: Laythe's ocean temperatures and near-sea-level air temperatures are probably pretty close overall. Also, if the diurnal temperature range on Laythe is 6 C to -40 C, that seems pretty large for a planet that's mostly water and ammonia. On Earth, the diurnal range for coastal cities is usually not more than about 8-10 C. Is there an elevation component to the temperature readings in KSP? Because being on a mountain seems much more likely to be the cause of -40 C readings than being on the night side of the planet.

Do you think continuing to complain is going to get it changed any quicker? If this is bothering you that much, maybe do something not KSP-related for the evening? My guess is that the issue is a combination of some sort of phantom torque (a bug) and peoples' expectations of what SAS should do. If there is a bug, I'm sure Squad will get it sorted out, and there will be a patch in the next couple days. Peoples' expectations ... well that's more of a philosophical question that I'm not going to pretend there's a correct answer to. I should note that I haven't played 0.21 myself yet. I'll attempt to post a video, per Ted's request if I see any issues.

Tried it a couple times and got 7.74 L of liquid fuel left. My orbit could probably have been a bit lower, but I was having a hard time properly circularizing my orbit such that the periapsis was above 75 km. Anyway, I guess this would put me in 9th place currently? Oh, and this was completely stock. Munfrod knows something's up. They forgot to pack parachutes ... this won't end well for him.

Efficiencies of Munar Landing Trajectories tssn1611 and Edfel Kerman Submitted to the Journal of Kerbal Spaceflight Introduction Achieving an efficient landing trajectory on a Munar mission is important for mission efficiency, cost and ultimate crew survival on a mission. Which trajectory is most efficient has been somewhat up for debate, however. Some prefer a steeper trajectory, even going so far as to eliminate all horizontal velocity on the deorbit burn and focus on destroying vertical velocity on final landing approach. Others prefer a shallower trajectory that removes horizontal and vertical velocity at the same time. The purpose of this entry is to offer insight into which of these landing profiles is most efficient. Craft and Procedure The craft used in these experiments is a Betelgeuse A lander (see Figure 1) manufactured by Koeing Spacecraft Corporation. It has a mass of 8.48 tons fully loaded and has 3832 m/s of ∆v, enough to conduct missions with potentially large ∆v requirements and ensure crew return. Its main descent engine is an LV-909 model manufactured by Jebediah Kerman's Junkyard and Spaceship Parts Company, whose vacuum Isp is 390 s. In addition, it has MechJeb 1.9.7 installed for automated maneuvers. The craft was launched by a Klaturn booster on Year 1, Day 131 at 2317:49 UTK and placed into a 75 km Kerbin orbit. After booster jettison, a Hohmann transfer orbit to the Mun was initiated, and the Betelgeuse was placed in a 30 km x 30 km Munar orbit. Figure 1: Photograph of the Betelgeuse landing craft. From this 30 km orbit, various tests were conducted varying the size of the deorbit burn. The spacecraft's MechJeb module was used to keep the craft pointing retrograde for the duration of the burn. After deorbit burns were complete, MechJeb's landing autopilot was engaged for the remainder of descent. After each descent, the Almighty Quickload was invoked to bring the Betelgeuse back to its 30 km orbit in preparation for the next test. The sizes of the deorbit burns ranged from 50 m/s to 500 m/s. Additionally, a test was conducted using a "skimming" burn, one that barely lowers the periapsis of the orbit below the surface (12 m/s from a 30 km orbit), and a test was conducted in which the deorbit burn removed all velocity relative to the Munar surface (521 m/s at a 30 km orbit). Finally, a test was conducted using the MechJeb's "Land at Target" feature, which performs its own deorbit burn. Each trajectory was scored by its ∆v used, as obtained from MechJeb's Vessel Information readout. It is known that the elevation of the landing site has an effect on ∆v requirements for the landing. For these experiments, the test was repeated until a landing site was obtained that is near 1500 m elevation, though the actual landing site may differ in elevation by up to 250 m for reasons of pilot sanity. Results In examining Figure 2, it is apparent that the lower ∆v deorbit burns give a lower ∆v for the overall landing maneuver. However, the effect is non-linear such that deorbit burns of less than 250 m/s do not use significantly different amounts of ∆v. The KHV burn is easily the least efficient of all the three, requiring 852 m/s of ∆v, and as such, that strategy should be avoided when landing on the Mun. The "Skim" burn and the 50 m/s burn are the most efficient, requiring 682 m/s of ∆v. The difference between the most and least is 24.9%, which is a significant difference in ∆v. Figure 2: Plot of ∆v as a function of burn size. "Skim" denotes a skimming burn (12 m/s), and "KHV" denotes a burn to kill horizontal velocity (521 m/s). As a comparison, the MechJeb "Land at Target" feature used 755 m/s ∆v, which places it between 350 m/s and 400 m/s burns. However, its landing strategy was less efficient overall, as it was constantly running the engine at at least a low level. Additionally, on final descent, it forced the craft into large yaw oscillations about its intended trajectory, which wasted fuel. Conclusions We have demonstrated that, at least for Munar descent, shallower trajectories are more efficient. However, for deorbit burns less than about 250 m/s, the difference in efficiency is relatively minor. Conversely, there is a large difference in efficiency between the most efficient ("Skim" deorbit burn) and least efficient ("Kill Horizontal Velocity" deorbit burn). For future work, we plan to try different starting orbits and descents different bodies. Of particular interest are Duna and Laythe, as they have atmospheres that help to slow the craft.

I plan to submit an entry about the most efficient landing profile from Munar orbit (assuming you don't really care where you land). Preliminary results: MechJeb "Land at Target" takes 755 m/s of delta-V from a 30 km orbit. More to come tomorrow (it's 4:45 AM here ...)

I am in a five-piece band, for which I play guitar and occasionally sing. Genre? For our covers, mostly classic rock and jazz. Our repertoire includes Electric Light Orchestra, Santana, Ray Charles, The Moody Blues, the Doors, and a few others. For our originals? Well, I write most of the songs, and I've been influenced by Kansas, Rush, Genesis, Pink Floyd, and similar artists, so a lot of my songs kind of sound like blends of them. Not sure what you'd call that. We're not very organized, either. I finished my Master's thesis last fall, so I had very little time to practice, and our keyboard player is finishing is thesis currently, so he has very little time to practice now.

Question regarding the periapsis kicks: that works fine when your orbit stays inside Kerbin's SOI, but what about the last one (the one that takes your periapsis outside Kerbin's SOI)? For transfers to Jool or Eeloo, nearly half your delta-V needs to be expended on the last kick, and for some of my interplanetary ships, this is a 10-minute burn (or longer). Any thoughts on how to do that efficiently? Two days old doesn't count as necro-ing does it?