I'm again in a period where I feel like I'm in between major missions. Duna was a roaring success and put my science total above 2400, which was sufficient to buy a lot of new toys. In particular, I closed out the two "aerospace tracks" that give you access to faster and more capable aircraft. To date, I haven't been all that impressed with KSP's aircraft: it's modeling of air movement is wonky at best and flat-out ridiculous at worst. It's quite simple, for instance, to flip a KSP aircraft end over end through 360 degrees or more of pitch and end up in stable level flight on the other side.
I assure you that if that were possible in real life, the Thunderbirds and Blue Angels would routinely make it part of their air shows. ;-)
While this can from time to time be amusing, it doesn't make for very satisfactory game play, particularly the way I play KSP. I tend to try to take this game at least somewhat seriously and I haven't yet built a lot of the wonkier vehicles that other KSP players are known for. I play the game like I'm... you know... simulating a space program.
I know, I know...
Anyway, there's a spaceplane included in one of the scenarios that comes pre-installed with KSP and I was curious to play around with it... even though my last attempts with aircraft were a disaster. But my next major mission is going to be to Jool and I haven't decided how I want to get there yet. So in the meantime, I figured I'd play some more in near-Kerbin orbit and do a few easier things. At this point, I was only 1950 science away from completing all parts of the KSP tech tree.
So, first step was to play around with the KSP scenario space plane. It's included in the "Space Station One" scenario and is docked to the station. The space plane itself is called the Aeris. Playing with it was my first attempt to control a KSP spacecraft using action groups instead of staging commands. So I got into the scenario, un-docked the Aeris, flew it around in orbit for a bit, took some screen shots, and then attempted to bring it in for a landing at the KSC (you start the scenario in orbit).
And I was pleasantly surprised at my own success! I managed to get the thing landed successfully on my first try, though on landing the center rear engine (an LV-T30) fell off. Heh, whoopsie! I felt like trying again, so I backed out of the scenario, went back in... and the Aeris was missing from the space station. Apparently when you make a change to the in-game scenarios, unlike the tutorials, they don't reset back to where you started. Double whoops! And without the center engine (to say nothing of the fuel I'd burned getting out of orbit), there was no way the plane was getting far after take-off.
But hey, I had access to all the parts in career mode and good screen shots. Could I rebuild it?
It turns out I could. But dear Heaven was the thing twitchy! Hard to get off the ground, hard to control, hard to get into a stable climb, hard to maneuver. And as I gained experience with it, I discovered that the scenario version of the Aeris hid a lot of flaws in the design. Fully fueled with all the mass spread out nicely around the center of lift, the design wasn't too bad. But as it burned fuel and lightened, all of its stability leaked away with its fuel. I dubbed my version of the craft "Fearless" and attempted a boost into orbit... and had to abort the attempts a few times until I got the knack of it.
I eventually settled on a flight profile that went something like this:
- Take off, 45 degree climb up to 10000m or so.
- Lower the ascent angle to about 20 degrees and pick up some speed until 20000m.
- Then put the ascent angle back up to about 35 to 40 degrees, aiming for a speed of 1000m/s at 30000m.
- Use an action group to close all the air intakes and shut down the turbojets.
- Use a second action group to light the center engine booster.
- Push the ascent angle back up to 45 degrees and hope I had enough fuel to make a stable orbit.
Needless to say, some upgrades were needed.
For my first set of upgrades, I went with simple things: more air intakes, moving the mass of the fuel around, using better canards, adjusting the center of lift some. Then I headed for orbit again and was pleased enough with the amount of oxidizer left when I reached a 100km orbit to try for Liberty's 250km one. And thanks to some judicious use of fuel and using a lot of the experience I've built up with dozens of rendezvous and docking maneuvers over the last few months, I managed a solid docking...
The entertaining bit is that the docking has to be run almost entirely with the Mark I Eyeball. You can set the target docking port all you like but KSP has no idea how to set alignments for the inline docking module used for space planes. The placement of the RCS thrusters also introduced all sorts of odd behavior due to the mass imbalance between the top and bottom halves of the space craft. If I'd not built up a ton of experience docking in all sorts of other regimens, I doubt I would have managed it.
My experiences with that version led me to use better canards, a better tail assembly, to spring for the Aerospike Engine, and to rearrange the RCS quads since the final docking was a bit more difficult than I really wanted. I also threw on a few solar panels because the thing just eats battery power. KSP really needs a "fuel cell" mod other than the little nuclear power source it includes for space probes. I also moved the landing gear and lower intakes around. I ended up with something I was pretty happy with:
Tinkering with a working vehicle really is my favorite part of this game sometimes!
That said, each time I tinkered, I was less interested in increasing capability and more interested in increasing ease of flying and performance of the one mission Fearless seemed capable of: delivering a single pilot to a 250km orbit and bringing him home. In short, my tinkering was about making the ship easier to fly. The basic capabilities of the craft improved not at all. It certainly wasn't going to be anything I could use to bring even a single Junior Science module into orbit. Even after four or five series of upgrades, I still arrived at Liberty desperately in need of a refuel in order to get home safely. It wasn't even a good crew return vehicle because (a) it could only carry one person, and (b) just chucking some parachutes at that problem was far easier.
All in all, I made seven or eight flights in versions of my Fearless class, four of which docked at Liberty. I managed to bring all of them home safely but only three of the landings were on the KSC strip. More often, any attempt at real maneuvering for a KSC landing would send the craft into a pitch or yaw tumble. While these were recoverable, it made fine maneuvering of the ship with an empty fuel load impossible. Landing with a full fuel load was much easier, but I certainly wasn't interested in a craft that was going to be taking fuel from Liberty and bringing it to the ground!
I reluctantly concluded that with this version of KSP, space planes are fun but ultimately fruitless and unproductive. Don't get me wrong! It was definitely a nice challenge: orbit a "single stage to orbit" space plane, dock it, bring it home safely. And I accomplished it on every flight, not losing any of my pilots in the process. But it's not something I'm too excited to repeat.
Still, I'm glad I did it! It's definitely a KSP "achievement." And playing with action groups gave me some experience for my next space mission, which also involved playing with new toys purchased with my Duna science haul... More on that next time.