Spricigo

No mod required. The deltaV required to reach a certain orbit is the same regardless of the craft. Since you already have the stock deltaV readout, you just need to check if the craft, with the desired payload have the deltaV for the task. It can be done the other way around, as you suggest, but no one founf it to be useful enough to warrant designing a mod for it. (At least not that I'm aware).

Nice designs and good explanation of the reasoning for it too. My later example is quite the same, just don't have an instrument(adding thermometer&barometer would have negligible impact in performance) and uses fixed solar panels in 3x symmetry (never ended in the shadow with me, but I suppose it could happen). How much it costs with that included? Given the tolerance, and if you set decouple force to minimum, it may be good enough. However, there is little benefit in not keeping the engine with whatever fuel is left.

Well, you only have trouble until you find a reliable way to do. And science gathering parts will quickly pay for the investment if you can afford the uncial cost. Personally, I don't mind to wait a bit more for the lab, but tend to rush the science experiments for that reason.

Actually sticking with the FL-T100 would be enough for a satellite capable of completing the most basic contract of the type. Since it would also mean a smaller (and cheaper) launch vehicle the cost would be way down. However the extra deltaV is not a waste, since it allow for the completion of more contracts (either extra deployment contracts accepted before launch or repositioning contracts offered later). So, is trade off, higher initial cost for higher income per launch. In any case, the craft itself is not that important. The idea is to explain what I feel is important and the considerations I do while designing a craft. Mind you, it's not the while story, there is some details decided by personal preference and other nuances, but trying to explain that could cause more confusion than help new players trying to figure out what would work for them. Quite hard to believe, when my bare bones stellite, made with cheaper and lighter parts, cost more than this.

your game, your decision. But I think all that trouble with rendezvous made a strong case for getting Advanced Flight Control (RCS systems) as fast as possible. Propulsion System is good for satellites and micro-landers for Mun and Minmus. Heavy Rocketry (engines) and Fuel System (tanks) will be useful when you want to build something bigger. You probably don't need to rush it. Aerodynamics for planes, same deal. Landing is probably the least needed of the 90 nodes with Space exploration being close. Again: just my opinion. You may have different priorities.

Many thanks, @VoidSquidand @Daveroski

I think you almost got it. Not the drag but lift. Does it make sense?

Exactly what amuses me. I was expecting it to become aerodynamic unstable without the fins. So it was a nice surprise. However, the original craft (first link in the OP) fall nicely into a auto gravity turn without steering input and this craft don't do it. PS:I don't have KJR but the craft have plenty of autostrust to prevent wobbling

I designed a basic rocket and it performed quite well. It even got into the gravity turn without need of steering input. Then I decided to try to explore the limits o the design a bit and among other thing I wanted to look how it behaved without the basic fins. To my surprise, it don't flip but also don't get into the gravity turn by itself. Despite being launched with more tilt than the original craft it went up. And is not that it didn't turn at all, rather it osculated slightly west-east, as if there was some sort of self-righting mechanism. Just I have no idea of what it might be. There is the craft file if anyone is interested in trying it for himself: Strange and a picture

yes, I got it. The craft that brought the new kerbals there have an empty crew space? Otherwise you just have 2 craft with the same limitation.

OK, lets see what we can design with that. (the idea is to be cheap and cheerful ) For a basic satellite we start with what we need/want when deployed. The most essential (contracts ask for it) is probecore, antenna and power generator. We will take the OKTO (because of SAS), a communotron 16 and a pair of solar panels. Let's also and a thermometer (in case we get a 'do science in orbit' contract later) and, given the OKTO limitations, a Z-100 battery and a small reaction wheel. Finally, lets put that inside a fairing for the atmospheric part of the flight. That is our payload, 0.310t, cost 2800 Funds. A FL-T100 tank (smallest available) with a Terrier engine will provide 1.5 Km/s of deltaV with TWR4.4 (funny how our weakest engine is 'too powerful"). We will keep the terrier but swap the tank to the larget FL-T400 for 3.5km and TWR2. Our craft reaches 3t and 3700funds. Bellow the terrier we put a stack decoupler and build the launch vehicle. 4 FL-t400 and a Reliant will provide 2,3km/s with TWR1,5 at sea level. For good measure we will add some autostruts (grandparent)*, set fuel priority* from bottom to top and add 4 basic fin near the bottom of the craft. Finally, we give a small inclination towards east and hold it with a launch clamp. The craft cost 7300 funds, with 13.5t and 21 parts. You may download it Here or try to replicate from my description. But more important, try to understand the process described, how we started with the top(later use) and worked our way to the bottom (early use), how at each step we keep to the essential and not much else. If you have doubt, ask. *requires Advanced Tweakables enabled in the game settings.

What else can I say? It seems you are fully aware that your station cannot hold any extra kerbal.

then an extra seat is required

How do you expect him to get back in if Bob took his seat??! You are in the same situation: one kerbal without a seat dangling outside.

For your own good, please stop. There is a part, EAS-1_External_Command_Seat, and you may confuse people trying to help, making them assume this part may be present in the tube. Kerbals cannot grab to random things, are you sure he is not grabbing the ladder in the command pod? In any case, Bob Kerman cannot get inside since all the seats are filled. Either someone get out first, or Bob go back to where it came from. There is really no way around it. If the kerbal dangling outside came with a different craft than the contract is already complete. Now its a matter to get him back to the craft he came from.

For all game purposes the kerbal in the tube is not on board. Every time you warptime and every time this craft get outside the physics range (when you are at KSC, tracking station or a distant craft) the kerbal will just drift away. Look at the tube, between a crew cabin hatch and the bottom of the ship. Beat me if it don't appear to be the perfect spot to hold a kerbal in EVA without the risk of drifting away. Unfortunately it is not.

It is not a glitch, it is a game limitation. When you switch away from the station or warp time the game stop calculating the physics. Which includes Bob colliding with the structural tube. The only way to prevent it from happening is to let him inside a crew cabin/pod or to strap him in a EAS-1_External_Command_Seat

You will notice that many, many things in KSP are blatantly obvious in hindsight. Yet figuring it out seemed impossible at the time.

Well, I just mentioned it as an option, you don't need to use it if you don't like the idea. However, it is kind of a general consensus that it is only really cheating on your game if you decide so.

I'm forced to agree. Because of Krakatoa, among other things.

How about some mission automation mod like Routine Mission Manager, KSTS or Davin Fuel Supply? I mean, given that you are playing in sandbox, you may even use [set orbit] from the debug menu and call it an automatically deployed craft.

As @Daveroski mention,the structural tube is not a proper crew holding part. You need either of a crew cabin, command pod or external seat. Well, it seems you already get close and now you want to transfer the crew. First, get closer to the target, while also reducing the relative velocity between both crafts ( I will ask you to o take a look at the guides offered .If you still don't get it we may try to break it, but with the guide's images is usually easier than with just words) When you have both craft within a few meter of each other and their relative velocity as close to zero as possible then you do the EVA transfer. That is pretty much like the docking part of the guide, you just are going for the crew hatch instead of the docking port. You will need to press F to grab the ladder (and B to board) when you get close enough for it.

Want to. That is all the reason someone needs to take an option over another.

You already increased the apoapsis and have a higher Specific_orbital_energy at the time you burn to raise de periapsis

The Fund reward for rescue mission are not bad either.