Pecan

There's no need to apologise for anything but you weren't being clear so we couldn't help. I'm glad you launched the thing but you really did do it the hard and expensive way. I understand that you didn't want the tanker to land again, the point of the design I showed you was a) it works, it turns, c) it is very low part-count, d) you can recover the LAUNCH VEHICLE (not the payload) so get nearly all the launch-cost back (>=98% if you can land at KSC, which is what it's designed for). It's that last that makes it more cost-effective than throwing-away all those boosters. While it's possible to get them to work for fairly large payloads they stop paying for themselves very quickly beyond mid-teens tonnes unless they are just used for a very short thrust-boost at launch. Trying to use them beyond a few kilometers, at most, just isn't worth it for a 100t payload.

"Canned air" is just that. You can, very briefly, run jets on the air that is contained within the closed intakes (shutdown jets and close intakes before leaving atmosphere, reactivate jets once at apoapsis, or wherever). Another trick would be to use the force of a decoupler to give your ship that final orbital push.

Yes - that was a description of your payload, not of the launch vehicle that wouldn't turn! All you said about that was 'boosters', which could be anything but the pictures you've since posted make it all clear. So why the 4km/s deltaV you've since mentioned? LV-Ns will always give the best figures 'eventually' because that's just down to fuel vs Isp. It's unlikely you'll ever be burning them long enough just within Kerbin's system to get through all that fuel though, that's why I suggested lighter engines such as 48-7Ss. Let's get you working at all first though ;-0 If you click on the picture of the launch-vehicle I posted you can see it in more detail, with a bit of description, on imgur. It is 741t itself but only 52 parts and launches an additional payload* of 100t - so should work for you. Although it costs ~321,000 it is a fully-recoverable, vertical landing, SSTO so each launch you only have to pay for the fuel it uses plus whatever percentage you lose from not landing exactly on the launch-pad or runway at KSC. (*The yellow and white pointy thing on top of the rocket is an NRAP test-weight, put the real payload there instead) SRBs are high-thrust and cheap but they are only really useful for a bit of extra thrust at launch on big builds, if you need it. It's easier to use a conventional design with less staging and, if you can recover parts, more cost-effective too. (In my experience, anyway. I've only found SRBs cost-effective for much lighter payloads, since you generally have to throw them away each launch).

/me nods at 5thHorseman At worst, where I've had a space-only tanker that went one way wet and the other (almost) dry I set RCS thrusters in three rings:- one set around the dry CoM for docking before reloading, two sets balanced against the wet CoM. Apart from wet/dry configurations that meant I had more thrusters when there was more mass to shift. Can't say I've ever bothered again but for any engineering problem, there's usually an engineering solution. Mods are nice, but you shouldn't rely on them ^^. Information is always useful so information mods (eg; RCS build aid) are always good but you shouldn't NEED an operational mod like this or any other fuel balancer/mod; they're just a convenience or gameplay choice. KSP is what it is, have fun with it however you decide to play :-)

This is a 100t SSTO launch-vehicle, fully recoverable with drogue & powered landing. (That's 4 KR-2Ls) Without pictures or even a description of your vehicle it's rather impossible to say why it won't turn. My only real advice is to not lift what you can't lift; there's no real reason for such a large payload except "Hey, I can". ETA: Oh - and on short trips to Mun/Minmus the LV-Ns probably aren't worth their mass. 2 (x 0.1t) 48-7Ss will give the same thrust, if not the same economy. EETA: (Oops) it has exactly 1 large SAS unit and handles nicely.

Yeah - because almost every single one of us has made the same mistakes or only avoided them because someone asked just before we got it all wrong.

Design it better. Loss of weight (mass) does not imply the CoM has to move. Nor does it imply that you can't design for expected fuel-load at the time RCS is likely to be used. There's not much point arranging RCS around the CoM of a launch-vehicle, for instance, if you expect it to move. Tweak the fuel down in the VAB/SPH to approximate the load and CoM position it'll have by the time it needs to dock. Arrange tanks to burn in a balanced way. Hey! You could use Goodspeed Fuel Pump to help ^^

Design it properly.

8-0 Time to rest and prepare for the coming of 0.25, and all the new bugs fun that will entail ^^. Thank you for all your work.

The amount of fuel required for a given deltaV can be found from a familiar equation: Fuel Mass = EXP(dV_Required / (Isp * Gravity)) Since you know how much fuel your engine burns per second it's easy to work out how long it'll take to get through that much :-) The 'Fuel Mass' here is a percentage of the total rocket mass. The equation comes from NASA:- http://exploration.grc.nasa.gov/education/rocket/rktpow.html

Nice work :-) Planning and designing are features I enjoy too, rather than just winging it. In case you didn't know you can post your mission reports on the forum in the section called, er, Mission Reports

Stop teasing! WHEN? There's rep waiting for you, you know ... ;-)

Nosecones are not useless as long as they are placed ahead of the CoM. Their lower drag coefficient than other parts will tend to keep the ship facing the right way.

Right! Who do we know that belongs to the International Astronomical Union?

BTSM would be Better Than Starting Manned, Diazo.

An 'ideal' launch TWR is generally considered to be 1.6 - 2. As fuel is burnt during the launch stage this will increase, aiming for an average TWR of just over 2 during the burn-time. The point of this is to reach terminal velocity as soon as possible without exceeding it and losing too much energy to drag. As people become more experienced they tend to reduce this launch TWR for two reasons, i) loading extra fuel will increase mass and deltaV, ii) more realistic aerodynamics models (FAR being the standard mod for this) punish excess thrust and favour a more realistic launch TWR of ~1.2. Most importantly, a very high TWR - over 3 or so - can tear your vehicles apart, which as an engineer you'll recognise as "a bad thing". Incidentally, the tutorial in my signature contains 10 or so launch vehicles for various payload masses if you wish to try them.

The thread How do I calculate payload mass to orbit? is hidden in the tutorials section of the forum instead of gameplay questions. TL;DR - Launch capactity (tonnes) = ((Launch_Ratio * Mass_Dry) - Mass_Wet) / (1 - Launch_Ratio) Where :- Launch_Ratio = EXP(4,500 / (Isp * Gravity))

My entry, post #34, updated with "SP 40 B" replacing the original (larger cockpit, smaller rockets, lighter and cheaper) and "Bantam" light spaceplane added.

Practice on Minmus first, it's easier.

The first major problem with this challenge is attempting EVA during high-acceleration atmospheric manoeuvres. 'Pure', untethered, EVA is probably a non-starter but you may be able to do it by climbing up and down ladders. I suspect that you will need to climb quite slowly in order to stop the Kerbal being torn-off the ladders by atmospheric drag. The other major problem is the requirement for a video of the launch. I for one don't have the broadband capacity or personal patience to watch those. Of course, a crew-transfer mod that allows movement of crew between positions without EVA makes this pretty trivial

Read more ;-) Read the wiki, read the keybinding list on the wiki, think "I have no idea what those keys mean, there must be more to the game than I've found so far". Then read tutorials - the drawing board stickied at the top of the tutorial section is a great place to see what they're about. Watch videos if there's a particular thing you can't picture or need to see demonstrated. The thing is, if you want to explore it all yourself then you won't know what is and isn't available - how could someone explain manoeuvre nodes without explaining that you can go to other places, rendezvous and dock with other vehicles, etc. It is perhaps best to read and look for specific things, then ask in gameplay questions when there is something you especially miss. More than 80% of players in a (fairly) recent forum poll wanted to see deltaV and TWR information in the VAB/SPH, for instance, but just as you have found, Squad do not think that's appropriate for their view of KSP so you will need to work it out by hand or install a mod. My first question was so basic it's incredible that I still haven't found any tutorial that mentions it - "what's a flag?" However you find out, finding out is fun :-)

And in Chapter 5 of the tutorial in my signature are two single-Kerbal designs for return Minmus (easier) and Mun (harder) landings and returns. Chapter 6 has a three-Kerbal Apollo-style vehicle if you want to do it the hard way.

Right-click the core tank - there are green 'flow' symbols to the right of the fuel and oxidiser guages. Click those to change them to red/stop, click again when you want to use it. There's no way to reverse the flow but you can at least keep the fuel in the core until you need it.

The amount I use. Seriously; I've got a version of Claw's "Intake Stick" as a sub-assembly and tend to stick copies on everything. I over-did it when I made it so I have about 11 intakes per engine (see Sirene's comment) but I think it looks OK. With 5 I think you're safe anyway :-)

I don't suppose so, no - although I (personally) would expect a 'space'plane to be able to make orbit. On the other hand the jets can probably get it into space on a sub-orbital trajectory so it could still deliver a load to space I suppose. If you're not sure there is a 'non-space aeroplane' category - might as well enter it for both.