LongbowEOD

I saw it! It was awesome! It climbed up out of the south, leaving a bright orange flame behind, arcing up and "leveling off" as it passed to my southeast and started to dim. I thought it might be getting far off that fast, but nope, it was just the first stage burning out. It jettisoned and the second stage lit up bright and the velocity really picked up as it flew to the northeast and back down toward the horizon. It started dimming out and I thought I might get to see the third stage light up (this rocket has FIVE stages) but it dipped behind the trees first.

Ooh! I'm gonna give this a try.

Way back before persistence, landing legs, or even the venerable LV-909, I managed to graze the lunar surface with a craft relying on the old workaround of winglets mounted to radial decouplers. Jeb managed a pretty good approach, but was unable to perfectly kill his horizontal velocity. Predictably, the first winglet to contact the surface snapped right off, but unpredictably, Bill was able to restrain Jeb long enough for Bob to punch whiskey throttle to abort back to orbit and a successful return to Kerbin.

First thing I did when 0.20 came out:

So not as much "lunar slingshot" as "encounter without capture." I guess for me, "slingshot" implies getting to somewhere else. Still, effective way of gaining a few hundred m/s delta-v to get to heliocentric orbit.

I don't know if it's exactly a "balance" problem, but I'd like to see engine gimbals become smart enough to guide a tractor-configuration rocket. Right now they can only correctly control a pusher-style rocket.

Quick answer to your question: I don't know how to get that, without being in the Mun's SoI. Long answer: So do you want these 2 satellites to orbit Kerbin at the same altitude as the Mun? Otherwise, it seems the distance would change over time. If this is the case, I would guess you could calculate the Mun's longitude (over Kerbin) as a function of time, then find the appropriate longitudes to burn to send your satellites out to wherever you want them to wind up.

I don't know what this is but it's beautiful. Keep it up with Duna.

I named my original series of manned rockets (back in .13) after my fiancee's (then girlfriend's) pet name: Ladybug. So the Ladybug I was my first manned rocket, Ladybug II was a refinement that made it to orbit, yada yada yada, I think Ladybug VII was my first successful Mun landing. Then whatever version came out with the 2m parts, and I made the 2m series my "Longbow" (my longtime gamer tag) rockets. Longbow I took 3 kerbals to LKO, Longbow II made it to the Mun and back (yay learning from your mistakes!), Longbow III is currently slated for a Duna trip here just as soon as I get it checked out. I named my expendable launch vehicles after one of my buddies (his gamer tag, anyway). We played a lot of KSP together (same room, shouting achievements and disasters back and forth), but then he had to go away (don't worry, he's not dead, he just moved), so I dedicated my ELVs to his memory. The Bulldog III is the (mostly reusable!) workhorse of my space program. Individual manned missions, however, generally just get a serial number (Longbow II-1, II-2, II-3, etc.). I did start giving landers unique names. Longbow II-8's lander was named Pioneer, and it oversaw construction of my first munbase. Most of my unmanned satellites just have mission descriptive names: Kerbin/Mun/Duna Omni Surveyor for my ISA/Kethane mapping satellites, for example. Landers get slightly more creative names: Ice Skater for my Minmus rover, Kuriosity for my Duna rover. I can't even say I made a real effort for my bases: Pioneer Base on the Mun, and Icecube base on Minmus.

0:15 Delta II GPS IIR-1, 1997. Crack in the booster solid motor triggers the rocket's onboard self-destruct, the whole thing blows, showers Cape Canaveral in flaming debris. I was an EOD (Explosive Ordnance Disposal) technician assigned to Patrick AFB, FL from 2004-2009. We're tasked with supporting every rocket and space shuttle launch from Cape Canaveral/Kennedy Space Center. We never had one go foom on my watch, but, at least at Delta II launches, somebody would bring up that explosion every time we sent one up. Similarly, I worked STS-114, the Shuttle Return to Flight, after the Columbia disaster in 2003. There was just such a weird, nervous vibe at the pre-launch briefings. I was only 5 when Challenger exploded, and I don't remember watching it at the time, but I do recall there being a sense at the time (of STS-114) that we might be witnessing history in the worst possible way, again.

I think the truth is somewhere between your two options. Launch, do a gravity turn, but don't stop at LEO, just keep burning until Earth escape velocity on whatever vector you want. As for gravity assists, I believe it's a matter of timing, waiting for them to be lined up just perfectly so that your slingshot maneuver saves you more fuel than you use getting into position for the slingshot. ETA: While many real spacecraft have used multiple gravity assists on their journeys, I wasn't able to find any that used a lunar slingshot. So maybe it isn't that feasible.

Here's the test rocket I built. Well, the best version. Should be stock, let me know if it's not and I'll fix it. https://www.dropbox.com/s/i8yqp6z7g00g6rp/Pendulum%20C.craft

For those who aren't familiar: http://en.wikipedia.org/wiki/Pendulum_rocket_fallacy I hadn't heard of this until yesterday, and when I did I immediately recognized I was guilty of the misconception it describes. Anyway, after finding out about it, I did some thought experiments and came to a startling conclusion that I wanted to test. The first thing I thought was that the standard Pendulum Rocket Fallacy (PRF from here out) described an unguided rocket, with the only stabilizing forces intended (but not actually provided) by the pendulum misconception. It didn't consider any actively guided rocket. I then thought about a "perfect" rocket, one where the center of mass and center of thrust are perfectly aligned. Any such rocket, pendulum (CoT above CoM) or conventional (CoM above CoT) would, if started pointing perfectly up, continue flying straight up, no guidance necessary. If started (or nudged) off-vertical, it would fly a gravity turn trajectory, in the absence of guidance. Next I added guidance to the mix, and I only considered guidance provided by gimbaled engines; no fins, no RCS, no reaction wheel torque. Let's say you want to fly straight up, but aren't pointed quite straight up right now. You turn your engine gimbals in such a way to provide a torque on your rocket to point it back to vertical. This means a component of your thrust vector is pointed perpendicular to your rocket heading. The simplest analogy I came up with is driving a car, with steering the wheels equivalent to gimbaling the engines of a rocket. Imagine driving backwards, so that the steered wheels are at the back of the car (relative to travel direction). Relative to the direction of travel, if you want to turn RIGHT, you have to point the steered wheels to the LEFT. This is analogous to a conventional rocket: to steer RIGHT, point your thrust vector LEFT. It's the opposite for a car driving forward (steered wheels in front): to steer RIGHT, point the wheels RIGHT. This is analogous to a pendulum rocket. What surprised me at this point was the realization that in a gimbal-steered pendulum rocket, that meant that your thrust vector should always point at your intended direction of travel, whereas for a conventional rocket, you actually have to point your thrust AWAY FROM your travel direction to keep yourself pointed there. Once I had that theory in hand, I went into KSP to build myself a pendulum rocket to test it out. Long, explodey story short, I found out that engine gimbals aren't "smart" like other control surfaces. Movable fins and RCS are both automatically configured to provide the correct forces to rotate your craft however you command it. Gimbaled engines, it turned out, are only configured to correctly rotate a conventional rocket. Build a pendulum rocket, and suddenly it handles backward. I'll upload the pendulum rocket I built so you can test it out if you want. I set up a mirrored set of controls on my numpad (8 pitch up; 5 pitch down; 4 yaw right; 6 yaw left) and it handled pretty well, but standard controls flip it quickly into the ground. Note that I used a low-torque probe core. I suspect that a high-torque manned pod would adversely react with the "backward" control scheme of a pendulum rocket, though I haven't tested that yet. Last, that "startling conclusion" I mentioned. I theorize that a "smart" set of gimbals on a pendulum rocket would be slightly more efficient than a conventional design for any sort of maneuvers or course correction, but at present it's only based on my thought experiment. Can't test it in KSP yet because I think the current gimbals are "dumb." Anybody care to share their thoughts?

CRAFT: Ladybug XI-4 MISSION: Munar rover, investigate loss of contact with Ladybug XI-1 CREW: CMD Camsby Kerman, PLT Munler 'Good Luck Charm' Kerman, ENG Mersel Kerman LAUNCH DTG: 11:39 22 Jun 2012 (EDT) FLIGHT LOG: (Abridged) 00:00:00 Ignition. Liftoff! 00:07:27 MECO2, 100km orbit nailed 00:15:30 TMI burn 04:50:00 Mun encounter 06:20:00 Deorbit burn 06:32:15 Munar touchdown at 0 9 57N 125 18 47W 06:36:00 Beginning search for evidence of Ladybug XI-1 06:57:00 Rover tracks found at 0 42 37N 127 39 45W. Tread pattern indicated NW direction of travel. 07:16:00 End of rover tracks found at 0 53 7N 129 44 57W 2961m at sharp dropoff of terrain down 15 deg. 07:19:00 Glancing impact trench discovered south of end of tracks. Possible bounce off terrain? Terrain grows steeper to south, turning E->S->W to investigate valley floor. 07:40:00 Crater and spacecraft debris field discovered at 0 3 58N 129 42 51W 1784m. Debris fragments consistent with Ladybug XI-1 rover. 09:22:00 Investigation complete, preparing to launch 09:25:00 Liftoff. Gear up at t+5s 09:26:54 MECO at 10km munar orbit 10:36:45 TKI burn NOTES: Mission Background: Ladybug XI-1 Munar rover mission to Great Rift Valley on Mun\'s far side. Contact was not reestablished as expected. Ladybug XI-1 presumed damaged/disabled/lost. Ladybug XI-4 launched to investigate/render aid if possible. MechJeb flew a beautiful ascent; e=0.00008 after circularization at 100km Highest ascent efficiency yet with XI series, total DeltaV = 4361 m/s Necessity of Mun encounter tweak burns indicates earlier TMI for future flights MISSION DURATION: 10:40:00 AND COUNTING MISSION OUTCOME: IN PROGRESS (SUCCESSFUL) Ladybug XI-1 confirmed LOST Analysis of relayed investigational data suggests Ladybug XI-1 crew attempted proscribed 'Ramp to Orbit' launch [first attempted (sucessfully) by Jebediah Kerman, et al.(See J. Kerman disciplinary records for details)] at valley edge (0 53 7N 129 44 57W 2961m). Evidence found indicates Ladybug XI-1 left the ground horizontally at velocity approx 80m/s (probable rocket assist), traveled about 100m before 'bouncing' off terrain, damaging/destroying one or both ascent engines. Vehicle then continued into uncontrollable descent into valley, impacting floor some 38 seconds after initial 'ramp' at a velocity of almost 90m/s (far above acceptable limits for crew survival). Crater at valley floor consistent with explosion of 2 partially filled FL-T500 fuel tanks, shattering and spreading vehicle debris over a wide area. Crew killed on impact. The Kerbal Space Agency extends its deepest condolences to the families of CMD Seanlock Kerman, PLT Wehrner Kerman, and ENG Billy-Bobnard Kerman, crew of Ladybug XI-1.

So I was thinking about Lagrangian points, and it occurred to me that we can already fake 3 of them with a fair degree of accuracy, and we could probably fake the other 2, for certain systems, with a (minor/major?) tweak to a bit of the game code. Here\'s what I\'m thinking: We can already fake the L3, L4, and L5 Lagrangian points of any 2-body system (Kerbin-Mun, Kerbin-Minmus, or Kerbol-Kerbin) in the game. Put your satellite at +180, +60, or -60 phase degrees, on the orbit of your smaller body. Easy. L3 wouldn\'t be slightly outside the orbit like it should, but it\'d be very close. Added bonus: these orbits are completely stable in the 2-body problem -> no station keeping! Now for the L1 and L2 points. It requires tweaking the game code a bit. This tweak would only work with tidally locked satellites, like Kerbin-Mun and MAYBE Kerbin-Minmus. Tidally locked satellites still rotate relative to the background of stars, and that means, absent a larger body nearby, you could put an artificial satellite in a synchronous orbit around them. Do you see where I\'m going? Synchronous orbit = spacecraft doesn\'t move relative to the surface. Tidally locked = parent planet doesn\'t move relative to the surface. Put a spacecraft in a synchronous orbit of the Mun, right at the surface point where Kerbin is ALSO directly overhead. From the Mun\'s view, the spacecraft and Kerbin are right in a line that never changes. Just like L1. Same deal on the other side of the Mun for L2. But there\'s a problem: according to the wiki the Mun\'s theoretical synchronous orbit is outside its SoI. So the tweak would be to extend the SoI to allow Mun synchronous orbits. The same tweak may or may not work with Minmus. It\'s less massive and rotates slower, so it\'s SoI may have to be MUCH larger for the tweak to work.

Now that the vote\'s up and working again, I cast my ballot for 5 continents. I agree with HOC, Continent 6 is tiny, and it\'s not clear to me that it\'s even a landmass. It could well be just a frozen ocean.