Evolution of an Orbiter

[Corona688]

Since this has become a series of craft, figured I'd gather them together instead of making more posts in the big thread. It's weird to see how it's changed over time, as my piloting and modding skills have changed. So I'll post my thoughts here and reattach the ships the forum move ate.

Mark I

The Mark I was built when I felt I just had to use solids somewhere:

Neither pretty, nor efficient, nor all that flyable; look at how many SAS it has. But it orbited. If I'd thought about it at the time, I probably could have saved more than enough fuel to deorbit by NOT carrying a deorbiter! Observe the Y-shaped upper stage -- the upper stage does shrink and change but the basic arrangement stays the same, since there's a sweet-spot in thrust versus time for two-engine arrangements. Also observe the SAS on the upper stage. I wasn't too confident in my flying then. The middle and outer 'slices' of inline solids fired at different times to avoid overheat.

Mark II

Replacing the liquids with solids solids with liquids made it almost respectable-looking, and much easier to control. The upper stage is still way bigger than sensible -- everything but the three inside engines -- but if you wanted to learn how to orbit, you could do worse than the Mark II. Plenty of room for error. Also the SAS moves from the upper stage to the lower.

Mark III

Then I decided to add payload to the equation and it became a behemoth again. Though the top stage diminishes, if only to make room for the satellite... See the three SASes -- it needed manual input to stay stable too. And it had a tendency to reduce the satellite to ionized particles if you weren't careful when switching stages. But it orbited, and put payload in orbit, with plenty of delta-v to spare. If you wanted something that made putting a sat in orbit simple, you could do worse.

This is about the time I created the MTS tuned sas mod pack. So there's also a variant that substitutes the three stock SAS's for one 'big red' SAS. You had to add extra couplers on top of the left and right legs in place of SASes or else they'd flail like a dying bug until they flew apart.

Mark IV

Then I realized I could use the fork-shape to hold the satellite so you could drop the satellite without ditching the upper stage, and so not hit it by exhaust all the time. Otherwise the arrangement is unchanged.

Mark V

I had a lot of delta-V left over, so the deorbiter was redundant. Cutting it out saved a bit of weight, which let me shrink everything and replace one liquid engine with a solid, just so it can leave the pad. The SAS moves to the upper stage again, since I'm not used to flying the smaller arrangement.

Mark VI

The solid turned out to be unnecessary given all the reduced weight. Still, the extra delta-V it gave was nice, so I wondered if there was a way to squeeze out just a little more:

Mark VII

Which was accomplished by moving the SAS down to the first stage again so the second doesn't have to lift it into orbit. It's so light now that I can use my 'small' SAS.

It's not quite as nice as the Mark III in that if you miss the window, you're out of luck, and don't have the delta-V to recover, but it's a lot lighter, cheaper, prettier, and easier to manuever.