Yeah, the challenge of spaceship construction, space flight and landing on planets is still luring me into the Kerbhal Space Programme. I have spend about four game sessions since my last blog entry in order to prepare my next steps. My "Warthog" spacecraft is still orbiting Mun and I used its last fuel reserves to re-dock to the Mun lander, them being now effectively a space station around Mun. However, I need my three Kerbals safely back at some point, and I still want to tackle those last two landing missions on Mun. A second mission is in order. Just sending up and out another Warthog of similar design would cause redundancy and repeat the same problem of probably being too fuel starved, so I should better invent something new and better.
The transfer between planetary orbits is going to be a frequent thing, and from the forums I see that specializing your spacecrafts is the most efficient way to go. Launching new spacecrafts is done by launcher-configurations, fuel and crew can be brought into orbit via spaceplanes, landing on other planets is done by landers which are specialized according to the gravity and atmospheric requirements, transfer of orbit between planets is done via a "transfer stage".
Which means, I should better design a proper transfer stage. This one will travel to Mun, bring new fuel to enable the lander to reach the last two mission points and then bring back my Kerbals. The space station will remain there for probable later missions again on the Mun.
And, I figured, since spacecrafts kind of stick around like old furniture, and my Warthog designs seem to be very, well, plain, I might as well invest some thought into a nice design as well. Behold the result after almost two game sessions, the Swan Yacht.
- pride of my fleet, Swan Yacht, docked at U-limb station
The Swan Yacht is a sleek design, inspired by of what few nicely designed stock elements are actually available, without having to resort to clipping-tricks, and some 60s sci-fi art and Star Trek. I use the stock parts for planes, which are not cylindidrical but a bit oval and flattened out. A sweeping wing structure does carry two engine nacelles which are equally made from plane-parts. As enginges, I choose the nuclear engines, a decision which incurred me some headache because of the prevalent real-life culture of condemning everything which alleges to nuclear power as being too dangerous. However, since that craft will never again touch Kerbal ground, and nuclear engines are much more efficient than your standard liquid fuel engine, they basically are a must for a spacecraft which is going to work as a proper transfer stage.
Overall six nuclear engines applying 60 tons of trust each on a hull of a mass of overall about 33 tons. This is a rather low thrust-to-weight ratio (TWR) of 1.1something, but a transfer stage does rather need efficiency and not power, and already TWR of 0.5 would be sufficient in "open space" (which means I can still attach additional mass to my transfer stage, which is the concept indeed). A delta-V of about 5000m/s should be more than enough to reach most planets in the solar system. Plenty of docking ports make sure that I can attach whatever I need to bring along, and also have in mind a configuration by which two Swan Yachts could dock to and serve as engines for a larger mother ship structure. To be efficient, I try to build things to stay around. So, I now have a beautiful white working horse which will probably be the base fleet for all my further ventures into the Solar system.
Launching the Swan Yacht is done under its own engine power, but due to its low TWR supported by two large solid fuel boosters for the first 10km. I have to reload my first attempt because I realize too late that I forgot to actually attach some monopropellant for the maneuvering engines. The clou about the Swan Yacht is that it does not have a cockpit, but a passenger unit which accomodates four Kerbals; the piloting is done by a computer. Yes, we are modern, who needs pilots these days anymore?
A second attempt at launch results in a crash because I loose control at around 15km. I assume that this was due to the fact that the plane parts do have a lift rating each, which pulls the ship "up" and thus is a bit off-vector when you do a vertical rocket launch. With some care, the third launch finally arrives in orbit, some 200 units of fuel remaining. Magnificent! Now to bring up a refuel and my transfer stage will be actually ready to work as a sleek beautiful spaceship and not some simple stage-construct.
Unfortunately, my following attempts to bring up a spaceplane tanker fail repeatedly. I had already constructed a tanker spaceplane, but had deleted it accidentally because of me confusing version numbers. Trying to re-conceptualize this plane failed, to the point where I wondered how the hell I was able to get that first tanker up in orbit at all!?!
- this plane didn´t make it all the way up
Finally, after two more game sessions, a newly designed spaceplane tanker is ready and goes into orbit, docks with the Swan Yacht and transfers about 1000 units of fuel. Not enough for a complete refill, so I want to apply another delivery. Unfortunately, I did not pay enough attention to the Center-of-Mass / Center-of-Lift position on my spaceplane tanker when it is empty, and it happens as it must; the plane becomes uncontrollable during descent and crashes. Damn, two full game sessions and about 60,000 credits gone for what should have been a simple refuel maneuver!
- this plane finally went up, but came back down a little too hard...
- ... aaand again a failed attempt
A bit frustrated, I decide to stop any further attempt with spaceplanes until the final version of the game is out, which is going to sport a new atmospheric physics model, anyways. Instead, I look at a few pictures for a rocket-based SSTO tanker and give it a go. Half a game session later, I have an almost full "orange tank" (Rockomax "Jumbo-64", about 2000 units of fuel left) up in space, attached to a launcher stage consisting of 16 jet engines and the enormous LFB KR-1x2 engine (fueled by a X200-32 tank). As this is now for sure way too much fuel for the Swan Yacht, both the latter and the tanker get rerouted to my "U-limp" orbital space station. Being a remainder from a past mission, it was good that I did not scap it; it can now serve as a refueling depot and ready-room for crew members.
As usual with playing an engaging good computer game, time just flies by and thus my fifth game session since my last blog entry has to end.
News today are that the final version of the game is going to come out on April 27th. This will mean a reset of my career campaign and some new game mechanics. Good! This game has me hooked so very much right now and I do not mind to restart with an already slight knowledge advantage from having come this far during the beta phase.