Flieger, grüß' mir die Sonne, grüß' mir die Sterne und grüß' mir den Mond. Dein Leben, das ist ein Schweben, durch die Ferne, die keiner bewohnt! - Hans Albers, F.P.1 antwortet nicht (Adaptation in the 80s: Extrabreit)

Monday, 29 February 2016

Crash boom bang

I don´t know why, but constructing spaceplanes gets me riled up and keeps me challenged at the same time. Two full sessions pass, without any other progress in the game.

Some versions do not make it even off the runway. We are talking about a 80 ton heavy spaceplane, due to all the fuel intended as a payload. Somehow, the flimsy wing parts do not seem made for this weight. Sigh. Add struts everywhere.

Strutted galore, some versions indeed make it off the runway, but cannot climb anymore. Too much drag meets a too weak engine power.

Trying to prevent having to strut every wing part, I open another tech node for the biggest wings available in one part. However, the lift rate is lower and I have to half the payload. I don´t care, it it would just work out this time!

It did not. So, add more engines, and more wings for more lift power. Looks much better. However, I don´t like the design, and it still has only half the payload (1440 units of fuel), difficult to access, on top because it is totally hidden under the wing parts.

Back to the previous design, then. The right amount of struts and some canards, and I finally have something up. I still do not know whether it will make re-entry, though...

First things first. Docking. The spaceplane the "Fuel Dragon", turns like a slug, despite an extra heavy reaction wheel. I wonder why that is. Looks a bit weird that the supplying spaceplane is much bigger than the already big Spacewreck Terminal. But soon, the station will be complemented with the habitat module.

This game session has to end with a cliffhanger. Will my spaceplane make it safely down? I hope this time, I payed attention to the center of mass being way enough in front of the center of lift when empty of fuel. Not as here in the picture from one of my many tries, where CoL (blue) and CoM (yellow) are dead wrong.

Sunday, 28 February 2016

Change of plans

There are three missions which require a huge spacecraft, aka spacestation in Kerbin orbit, aka surface outpost on Minmus, aka spacestation in solar orbit. The game´s mission check is such that I can fulfill all missions in with one single ship, provided that I build it after I have accepted these contracts.

However, to proceed like this seems like cheating. Since I am almost at the end of the tech tree and have enough cash anyway, I decide to play it a bit more realistic.
First task, a habitat module for Kerbin orbit, to be docked to the Spacewreck Terminal for the first mission contract. I built it as a ring structure in order to simulate artifical gravity by rotation. And plenty of docking points of each size, because it will extent the orbit capacity as a transfer terminal.
Launch. It takes some tries, aka reloads. First, I have to add a lot of struts to make the whole structure stable enough to withstand the drag. Then I have to figure out the path to orbit. A standard gravity turn is not possible due to excessive drag of a monstrous structure like this, so I need about 20% more deltaV to launch it straight up for a long time, until the atmosphere is so thin that the drag is no hindrance anymore to turn it in orbital direction.

After a while, the Transit Terminal has made it. The launch stage was constructed as an SSTO (single-stage-to-orbit), minus the usual booster stages for the first 100m/s. However, now that it is up, instead of guiding the launch stage back down, it could rather double as a huge fuel depot. This could totally replace the improvised Spacewreck Terminal as a whole, after I fulfilled the mission contract and docked both together.

In the meanwhile, the Spacefish launches from Spacewreck Terminal for its second itinerary, a Minmus flyby for four tourists.

Now to my favourite, spaceplane construction. Unfortunately, the construction is hindered by some weird inconsistencies. When I attach wing parts together, why do they not form a whole and behave like this? Totally annoying and only fixable by adding unwieldy struts everywhere, thus amplifying drag, which in turn is very damaging for a spaceplane´s performance.
Jeb, is chief test pilot, because he grins and laughs even when everything totally goes wrong...

... like here. After spending many hours trying to finally get a version up into space, rendez-vous and dock it to Spacewreck Terminal for a transfer of 2880 units of fuel (a proud figure!), re-entry gets screwed. I guess I did not look properly for where the plane´s center of mass (CoM) was located when devoid of the heavy payload/fuel!

I needed two flights up to Spacewreck terminal, because the mission contract requires that the spacestation has a fuel depot with 5211 units of fuel. However, this version of a spaceplane supply will not make a second run. Just barely I am able to stabilize the fall at about 8km altitude...

However, when the center of mass is behind the center of lift, it is almost impossible to keep the plane stable. At 5km altitude, it therefore suddenly sharply veers off, and the drag forces do their job and tear the plane apart. Thankfully, there are enough wings left to guide the remaining parts remotly safely downwards.

I even manage to produce a landing, making a sacrifical touchdown with the backpart hitting first and again shearing it apart. Priority was to save the crew, and thus I still count this as a successful mission, in Kerbal terms. However, economically this was a total loss of about 110,000 Credits.

Back to something easier. The Atomic Kitten has in the meanwhile left Minmus SOI and needs about eight days to return to a 70km periapsis at Kerbin.

Friday, 26 February 2016

Flooded by Science

My science expeditions come to a closure.

Work is done, every biome on Minmus has been landed at and all science from the science equipment has been recorded. Time for a break to admire sunset on Minmus. Or is it high noon, here at the polar region?

One last hop back to the equatorial area, because I want a launch into an equatorial orbit. It is a luxury to have plenty of deltaV, thanks to the nuclear engine!

Perfect touchdown with 1m/s, after all that practise. I then launch into equatorial orbit. A resuce mission is waiting there, a new scientist Kerbonaut joins us. After that, the Atomic Kitten immediately departs for Kerbin. I thought about dropping off some science points for the Science Lab in polar orbit. However, it is still stuffed with plenty, so no there need to waste time and deltaV.

In the meanwhile, the Spacefish returns from Mün via five or six rounds of aerobraking. Boring, but aerobraking saves over 900 m/s of deltaV and is indispensable for efficient spaceflight.

The tourist passengers are a good mood. Next itinerary for them: A Minmus flyby (and maybe again a try with a Mün flyby for that one bugged tourist).

Welcome back at Spacewreck Terminal! Docking is a bit difficult because the RCS thrusters of the Mini Lander are not aligned with those of the Spacefish.

The Mini Lander gets undocked and goes back to Kerbin; I have no more use for it, since my new nuclear powered vessel surpass a simple lander vessel in every aspect.

That´s more science points than I expected from a mere four Mün biomes plus low orbit readings from the gravioli detector! Wow! I cannot help but immediately play around with these points. And I find that I have science points for more tech nodes and parts as I can actually pay for to unlock them for use!

The Atomic Kitten with an even higher load of science points is still on its return trip, but I can already unlock all spaceplane related tech nodes and play around with this nice high tech design here. It costs 63,000 Credits, powered by the high tech Rapier and Aerospike engines, and recycles at 100% minus fuel für 60,000 Credits. Which means, simple orbital launches of a satelite and/or up to five passengers will only cost me 3,000 Credits with this high tech spaceplane! For comparision: My old Orbiter launches for 34,000 Credits and recycles only for 20,000 Credits.

Wednesday, 24 February 2016

Science Reaping

I needed to jolt out of my construction reverie. A good design idea from the Kerbal forums, small and quick to realize, finally got me back into action. Target activities: To squeeze out both Minmus and Mün of the last of their scientific potential.

This is a borrowed design idea from the Kerbal forums. While I always thought that nuclear engines are best for huge payloads, this very slim design also profits very much, with an available deltaV of  >6000. More than enough to reach Minmus and land on every biome, thereby using every science toy from my insofar fully unlocked tech tree.

The Spacefish together with the Mini Lander arrive a Mün. First task, a mission contract to measure temperature at five locations, all conveniently above 10km altitude. This takes some time, time-warping forward. The orbit is low and fast enough that I cannot miss any of those navigation points while they pass by under the spaceship.

Finally, I am ready to let the Mini Lander do its job.

First touchdown, "polar lowlands". It´s dark on Mün´s south pole, and mountain ridges block the low raising sun. This particular location is very close to "pole" biome, but I do not have enough practise and waste too much deltaV, and thereby not dare anymore an even little hop accross the hill. It dawns on me that the old Concept Lander with about 1000dV more would probably have been a better choice.

Going back into orbit, refueling at the Spacefish, then down again to the next location, the biome "Southwest Crater".  Again, other biomes are very close, but practically out of reach. Also, due to being on the night side, electricty runs low and I have to switch off and conserve the meager battery supply. Which in turn leads to a bug; after returning vom EVA and switching battery back on, the SAS is defunct. I thus crash two reloads worth of launches, and a third launch produces a totally screwed orbit, thus stranding the Mini Lander too far away from its re-fuel supply, the Spacefish.

A fourth or fifth reload in a new game session finally solves the bug; SAS gets screwed when you return from EVA while batteries are switched off. Switch them back on, go again on EVA and return, and all is fine again. Up we go, re-fuel, and down again at the biome "Twin-Crater". I am now trying to save as much fuel as possible, and produce a very hard landing. Oops. But lucky I am; somehow, the biome "Northwest Crater" has been smuggled in!

The deltaV saved from the last touchdown at 12m/s indeed does enable me to do afford a little hop onwards, to the orignially planned location, the biome "Twin-Crater". I even get to catch the biome "Midland", too (though it has already been measured by most science toys from a previous expedition of the Mun Lander).

The Spacefish´s fuel reserves are finally depleted, and I make way back to Kerbin orbit. One little bug bugs me again, though. One tourist had opted for both a Mün flyby, as well as a Mün orbit. Well, just the orbit got checked, but not the flyby. I fear that a whole expensive tourist contract is going to be screwed because of this.

My Mün expedition took over six Kerbal days, enough time for my new nuclear driven vessel to arrive at Minmus. BTW, its female pilot baptised the vessel in the meanwhile; "Atomic Kitten".

First touchdown; biome "Great Flats". Well, after a reload because of a touch- and "litterally" topple-down on the neighbouring "Slopes"...

Being warned of the treacherous slopes, I try to let the Atomic Kitten gently hop over there. Both Slopes and Midlands get checked off like this. Unfortunately, there is no way to keep this vessel upright on slopes, less even to get it up again! In my need, I just use the whole slope as a starting ramp. Thanks to the low gravity, this works without damaging the vessel. Next touchdown location; "Lowlands". Like the former two, it has already been measured from the Minmus Lander, but the Atomic Kitten has additional science equipment, so I might as well go and measure again all biomes. This vessel has more than enough deltaV to do so, anyways.

Monday, 22 February 2016

Contemplative Construction

As more and more science points unlock more and more tech nodes, I get hit by the curse of lots of choices. Should I build this? Or better that? Or, how about this?

I had already undocked and prepared a maneuver node to send the Spacefish with the Mün Lander to, well, Mün. Then I thought otherwise and re-docked it. Instead, I first focused on the Minmus Lander and brought it through its aerobraking exercise back to Kerbin.

The Minmus Lander brings back about 2100 science points, and I figured that I should use those before building the next batch of rockets for new missions. I don´t just dock it in orbit and re-use it, because the first thing I am doing with those science points is unlocking the last batch of science equipment.

The new and last batch of science equipment, here driving to the fully upgraded research center.

A new lander, especially small and little deltaV, just enough to undock from the Spacefish and land and come back to it in Mün orbit. This saves a lot of fuel and thus allows for more landings from the Spacefish´s fuel reserves.

Off we go to Mün!

This is where the curse hits and I am off distributing science points on tech nodes and construction new stuff. Finally, some nuclear engines! This design hails from the "Candlekeep"-class from my last career game. Coincidentally, there are three mission contracts requiring me to bring a "space station" into Kerbin orbit, place an "outpost" on Minmus, and bring a "space station" into solar orbit. This thing could do it all in one, netting overall one million credits.

... or maybe, this thing?

Or this thing, being more of a thug concept with high TWR?

Or, how about the good old Navitas-design from my last career game with Poodle engines? It is still most flexible concerning sharing fuel with smaller non-nuclear driven landers, and total deltaV is not so important because it can re-fuel itself at the destination.

And, while I am at it, how about a rover?

... it could fit down there! Ooops. Squashed wheels.

In the end, I have kind of non-progressed through three more game sessions. Hey, it was fun!

Friday, 19 February 2016

Kerbal: Docking Synergies

After last sessions´ failures, I play my game much more cautiously. It is always the same, as is in real life: routine and repetitiveness incoming, attention slips, mistakes happen. My next few sessions in-between do indeed fare better, but are largely about finishing up the existing bundle of missions and thus resemble a project and scedule management. Fun nevertheless, as tedious as doing a dozen missions in parallel is, the synergies are considerable. And I am a sucker for synergies!

I make the best of the now defunct Big Spacglider in orbit, by repurposing it as a refueling point. I wouldn´t have thought that my first real space station in Kerbin orbit would look like this! I call it lovingly "Spacewreck".

Never miss to reap additional science points by using your new science toys at each building of the Kerbal Space Center! Because cars have not been invented yet, Kerbals use jet-driven rovers.

A new Lander gets sent into orbit. Two capsules to collect copies of each science experiment and report, and parachutes, because this version will have to be replaced once I have unlocked the last science toys. Besides, there can be accidents and I don´t want to have to burn it in the atmosphere like the last one!

Stuff in another tourist, send the Lander to Mün and back. Routine. Except for, the extra capsule and parachutes take their toll on the deltaV budget. Back in Kerbin orbit, about 50km before reaching the Spacewreck for a refuel, the Lander is, well, out of fuel. And that despite my nice effort to do a point-exact pure aerobraking return into a 70x72 orbit!

In comes the Spacefish, which finally has done its aerobraking return into a low Kerbin orbit. This spaceship still has plenty of fuel reserves and will nicely do to rescue the Lander from its predicament. And all without extra costs for extra launches. Never underestimate redundancy in orbit.

So, this is how my Apollo mission would look in this career game. Wait... not a bad idea, right? I think I will send them together to Mün, where the Lander can profit sur place from the Spacefish´s fuel reserves and then do multiple landings before returning to Kerbin. A fitting coincidence that the next tourist contract requires a Mün orbit for four tourist (in additon to a Minmus flyby).
But first, I have to bring the current tourist passengers from the Spacefish back to Kerbin. I do this via my new refuel and transit terminal, the Spacewreck (tm).
Up goes an Orbiter, with a new batch of tourists for Mün and Minmus flybys, and to fetch the returning tourists at the Spacewreck.

Takes some practise in docking. Looks and feels like an intricate game of Tetris.

All goes well and the Orbiter returns down to the surface. Just a slight miscalculation of the re-entry point, so that it lands a bit far off in the sea, but that´s a minor detail. Once big tourist contract is finally fulfilled (~300,000 Credits), plus I receive about 400 science points from the last two Mün landings with tourists!