GoSlash27

The point of spaceplanes is to provide a cheap, safe, and reliable "delivery van" between KSC and a station in low Kerbin orbit and back. They are unbeatable for the mundane logistical jobs that form the backbone of a space program, like rotating crews and delivering fuel to orbit. These are payloads that fit inside a fixed shape, transfer through a docking port, and would create major problems for your program if they couldn't be delivered with maximum economy, safety and reliability. They're not as useful outside of those jobs, but a lot of people make them simply because they are more challenging (and hence fun) than the usual vertical lifters. They take a lot more time, expense, expertise, and piloting skill to develop than vertical boosters. They are definitely not for everyone and honestly aren't worth the hassle in most situations. But where they *are* worth it... they are an incredibly powerful tool. Best, -Slashy - - - Updated - - - Celem, Spaceplanes are actually *way* superior to vertical lifters in terms of payload fraction and can deliver huge payload masses for cheaper than anything else.... *if* they're done properly. It's the "done properly" part that's difficult. Best, -Slashy

The retrograde launch is simply a matter of launching west instead of east. It'll cost you an additional 350 m/sec DV because you're overcoming Kerbin's rotational speed instead of using it to your advantage. For inclined orbits, you launch into the plane of the orbit. KSC is directly under the desired orbit plane twice daily. It will cost you somewhere between 0-350 m/sec depending on the inclination. Keep in mind that you are carrying 175 m/sec velocity to the east when you launch due to Kerbin's rotation and you'll have to steer a few degrees to compensate for that. Best, -Slashy

Things it should've warned us about but didn't: The internet Hipsters Political correctness Things we had to look forward to that it didn't mention: The internet Smart phones Genetic sequencing Nanotechnology 3D printing Things it promised that we didn't get: Flying cars "Mr. Fusion" Self- tying shoelaces The Cubs winning the World Series Rampant fax machines Antigrav hoverboards

paul23, I don't know how to edit the save file, but you have a couple options if that doesn't pan out: 1) Send a kerbal mechanic on EVA to repack the chutes 2) set the minimum pressure to .5 ATM. Option 2 won't repack the chute, but it should keep the pyros disabled long enough for safe deployment. Best, -Slashy

A lot of the early launch vehicles (and some current ones) have an automatic self- destruct system built into the launch vehicle because human reaction and communications are unreliable. The self- destruct is disarmed until a certain altitude is reached (protecting the launch complex), but once it is armed it will self- destruct under adverse conditions unless specifically commanded not to. The book is a little vague on exactly how the launcher explodes, but IRL if there's no fire or burn- through then the explosion is due to the auto self destruct, *not* structural failure. So my read is that you and your dad are *both* correct. The shifting load and structural failure caused the rocket to tumble, but the launcher's self- destruct system would have blown it up. Best, -Slashy

Two, An SSTO spaceplane is do-able the moment you unlock the Whiplash. Here's a small runabout design http://forum.kerbalspaceprogram.com/threads/129374-Pro-SSTO-builder-pilot-Challenge?p=2100291&viewfull=1#post2100291 Here's a larger utility version: http://forum.kerbalspaceprogram.com/threads/129175-Mainway-Adobe Both of these designs are made exclusively of parts that are available once the Whiplash is unlocked. Best, -Slashy

Norcalplanner, Not a problem. Thanks for starting the thread! Unfortunately, my back problems make it impossible for me to "fly" every day so development is slow. Here's the "Cheep31" (still tweaking): http://wikisend.com/download/177932/cheep31.craft Launch profile is simply "hit spacebar and hold D until the first stage is expended". For disposable 2 stage launchers, the key to being "cheap" is in using SRBs exclusively for the first stage. No LF tank and engine combo can match the SRB in terms of cost effectiveness. But having said that, it can impact the "cheerful" factor if not done right because SRBs don't throttle, thrust- vector or generate electricity. That is easily remedied with staggering the thrust, a couple tailfins, and a battery if needed. This results in a cheap booster stage that isn't any more difficult to get to the injection phase than a LF&O booster would be. And FWIW I agree with you about the SSTOs. Not only do they require recovery, they also carry a risk of failure because they cost so much more to build and there's a chance of destroying them. SSTOs are a whole lot cheaper, but also a whole lot less cheerful.

A_name, This is why I recommend *not* having active control surfaces as rudders. You should have a vertical empennage to weathervane the fuselage into the wind, but active rudders only confuse the SAS. When you bank, the active rudder wants to resist changing heading when it's supposed to allow the turn. It dials in more and more cross- control trying to hold heading until you're side slipping and something like this happens. You don't need active rudders in KSP. Just stick a passive wing in that position or if you want to use a control surface, disable it. Give that a shot and I suspect it'll fly a lot better. Best, -Slashy

Norcalplanner, I'm putting together a series of cheap disposable lifters and have a couple points to add on SRBs: 1) If you're building a 2 stage rocket, the first stage will be thrown away during launch with no recovery value (assuming you're playing without mods). Therefore your first stage should always be SRBs. 2) surface attached clusters of SRBs are very useful. You can adjust the throttle in opposing pairs of boosters to regulate the thrust throughout the launch. My best disposable launcher at the moment can orbit 31t of payload and costs $35,000 (less if the payload controls the launch vehicle). 3) If you're going for ultimate cheapness, then the entire LV should be recoverable. Thus no staging and thus no SRBs. Best, -Slashy

^ Val is *definitely* correct. You should always get your lift from wings, not fuselage parts. Wings create the necessary lift with a lot less drag and minimizing drag is the secret to efficient spaceplanes. I personally prefer to use more wing area and less incidence because it makes the spaceplane more stable during launch and more forgiving during landing. This approach carries a mass penalty, but it's relatively miniscule since wing mass is such a tiny fraction of the total. *BUT*... If given the choice between less wing area or more wing area with struts, I recommend going with less wing area. Struts are the devil for spaceplanes. Best, -Slashy

Looking strictly at PTR is good for the lower half of a stage (it should always be SRBs), but the upper half really needs to focus on payload fraction in order to minimize the workload of the booster stage. The booster is the most expensive part of the launch to orbit. Best, -Slashy

Alshain, Almost always 2 stages. It's very rare that I've found a situation where 3 stages improves my bottom line. Best, -Slashy Of course... SSTO spaceplanes are still the king of "orbit for cheap"....

ltajax, Not a problem. Glad it all worked out! Looks like you're all set to kick some serious booty now. Good luck, -Slashy

If you have the AV-T1, use it. It should provide plenty of control authority. If that does it, I'm gonna call this one "resolved". Best, -Slashy

Okay. Try this: Enable the offset tool in the SPH and drag the wings as far back as they'll go. Let me know what happens. Best, -Slashy

Okay, it looks like you're using a HECS, which does have a weak reaction wheel and SAS. Do you have the Delta Deluxe winglet?

Okay. Now we're cookin' with gas Do you have access to any kind of reaction wheel, or is that not unlocked yet?

Okay... but what is your airspeed when it happens? What's your acceleration in gs?

This is all correct and the drag cube file predicts it. If you really want a dramatic reduction in drag, try using the tail connecter A instead. Best, -Slashy

Itajax, I can't tell by your pic what point in the atmosphere you're talking about. What's the altitude and airspeed? What's the acceleration in gs? Where are you pointed relative to prograde? Best, -Slashy *edit* Oh wait... you mean about 7,500 m altitude? Yeah... try getting a pic just before the rocket flips. That'll help pin it down.

Dances With Squirrels, Back in .90 I had a vertical lift SSTO as well... http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/Lifter-Ception/Flight It could orbit more than it's entire fueled mass on the pad. As good as that was, it was still nothing compared to what could be achieved with spaceplanes. http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/DoubleDipper This little bugger could make the round trip to LKO with passengers 3 times without refueling and didn't even need airhogging. Those were the days... Best, -Slashy

Requia, Clearly I don't, because the entire concept of "dv optimization" is an exercise in futility IMO. But if you put together a write-up about it, I'll be sure to give it a once-over. I don't optimize for minimal DV expenditure. I optimize for minimal stage mass in upper stages and minimal cost in lower stages. Best, -Slashy

Psychotic_Blaze, If the after-action report says "Collision with launchpad" (or other facilities at KSC), it's a known bug. If not, I have no ideas. Best, -Slashy

Yeah, same here (although I haven't conducted a rigorous study like the one you've presented here). I've found my upper stages to be most mass- efficient when designed to have a minimum t/w around 0.7. For lower stages it's in the neighborhood of 1.3-1.6 depending on the engine, but in most cases right at 1.4. Of course... since my booster stage is considered disposable and it's weight doesn't cascade down the stack, I almost always use solid fuels for the first stage because they're so much cheaper. Best, -Slashy

DancesWithSquirrels, No worries, and again... my tirade wasn't directed at you personally. Best, -Slashy