Zaxton Space Program: Heinlein II: The Jeb-Squared Law

Rebels without a Clue

When last we left our intrepid crew of Bertred, Dunmore, and Huddrin Kerman on the surface of the Mun, their Heinlein I landing vehicle had toppled over under the force of a gratuitously fast landing combined with an impractically top-heavy landing stage design. Stranded on the Mun with no help of repairing their broken, battered spacecraft, there can be no other help for these heroes than for the brave astronauts that follow them to be their saviours - even when they themselves failed the task!

Heinlein II on the Launch Pad

I did some quick playing with the Heinlein design, with no other purpose than to correct a few problems I had with the original, and to considerably overhaul the lander - adding a physically smaller engine, solar arrays, RCS for attitude control, and extra crew capacity - I replaced the "Luna" satellite module with the Mk1 crew-capsule from which our pilot, accidentally Jeb, will fly the whole craft all on his lonesome.

Circulation burn.

The plan is relatively simple - make exactly the same flight as last time, but land properly and bring everyone home. Due to an oversight on my part, Jebediah Kerbin will be assisting MechJeb in piloting the darn thing.

The circularization burn for LKO was designed purposefully to use slightly more than the last booster stage, with the intent being that the stage would drag back into atmo and be destroyed. KSP doesn't actually model this unless the stage has a probe core for you to watch crash and burn, but I thought it would be a good detail to grab.

Orbital Math for Dummies. White ring is ASARTES.

I started using MechJeb because, frankly, the control of these craft is beyond me on a keyboard. I can do the math on the orbit transfers just fine, but I needed a basic autopilot to hit my nodes with the right timing and keep things straight in atmo. I'm not saying you have to use an autopilot mod, or that doing so necessarily detracts from your ability, but I simultaneously really admire the people who do this manually, and can't be arsed to do it myself.

Sitting in Kerbin orbit, just staying cool.

So, we sit in orbit for about 2/3s a rotation and then burn to Hohmann transfer orbit for a Mun encounter. Why Hohmann transfer instead of a faster burn? It didn't add that much time to my trip (about a half an hour), but it did save me fuel and I was trying to fly light for once in my miserable life - dealing with Delta-V budgets is going to be a common theme here.

Fins in, Legs Out

I've never really been sure what you would do in this situation if you were Jebidiah. You're alone on a ship built for four, flying rather roughshod all on your lonesome, with nobody but Mission Control to help you or keep you company. Obviously mission control aren't playful types, so you... what? Read? Play Klondike Solitaire with magnetic-film cards?

This understates the situation.

I don't really know, but either way we capture at the Mun safely, circularize down to 15 km, and then I quicksave so I don't have to do it again, while I manage the landing manually - apparently I haven't learned my lesson from last time.

Unfortunately, I don't get that nice, perfect, perpendicular landing I was hoping for, and the entire landing stage, which is actually slightly TALLER than the original (because I'm dumb or something) is leaning over at about 80%. It's not much of a tilt, but it looks severe and I get queezy about bumping astronauts into the damn thing, for fear of knocking it over. For that reason, I elect to keep the solar fins stowed, and let one of the rescues do the flag-planting, instead of Jeb.

When you only walk at half-normal, 4.5 km is actually far.

Fortunately, someone had the foresight to equip every single astronaut with an PMU-type jetpack, which is exceedingly helpful in situations like this, because the crew transfer takes a tediously long time even using the packs. One at a time, the intrepid astronauts load up their consumables, climb out onto the munar regolith, lock their sights on the Heinlein II, and fire up their EVA packs to get over there.

Going at what I estimate to be 100 m/s. Whoops.

This seems simple enough, but flying in the relative vacuum near the Munar surface is different than flying in atmosphere, and on the first pass, Dunmore had some interesting accidents, like flipping himself over, then landing on his head and bouncing end over end for almost a kilometer past the target before finally coming to rest on his stomach. Fortunately, this somehow didn't injure him at all, and he was able to get back up, fly halfway to Heinlein II, and still have enough EVA fuel to float up to the Rescue Return Capsule.

Self-Burial on Impact.

Next up was Bustred, who I thought to take a different arc on, going higher but horizontally slower, and then burning the whole way back down to slow the impact. Unfortunately, I'm the sort of inattentive person who intuitively thinks that burning in the down direction will slow your descent, and poor Bustred hit the ground so hard he seemed to become one with it, becoming the sad first casualty of the Zaxtonian Space Program.

Interesting Flight Plan, Dunmore

Still, this was better than losing the full crew of the Heinlein I, so we pressed on, moving Huddrin over in a relatively calm way.

Memorial Plaque

Once I had everyone into the new crew capsule, and had Huddrin take a moment to plant a flag in Bustred's honour, I had a strange decision to make. With enough crew capacity in the second crew module, and extra fuel in the landing stage (because MechJeb maps more efficient paths than I can), I had the decision between moving Jeb down to the Rescue Return Module and jettison his command module, or trust in the extra fuel and the fact that the return stage was designed to have enough fuel to return both, thereby skipping the tedium of shifting the crew around.

Blastoff Burn

In the end, I opted for the latter, burned up to a 25 KM orbit to stay out of the munar satellite network's way. By this time I'm actually getting pretty tired in reality, it being rather late at night and my own having conducted a sattelite launch earlier in the day which we would talk about later. Because of all that, I went ahead and let mech-jeb place the return node. It was practically a free return, using something like a quarter of the whole fuel budget I came up with, taking full advantage of the aerobreaking that Kerbin naturally provides.

So in we come. The modules seperate, the too-full fuel tanks crash hard into the ocean, and everyone goes home happy and alive that night.