Maiden flight of the Eagleray Carrier (To duna and back on a single tank)

[Rodyle]

Hello there everyone. My psychologist told me a while ago that I should take more pride in what I have achieved. He was talking about my scholarly presentations, but I thought: what the hell. Might as well make a post about the new carrier SSTO I made. It should be able to carry something in the neighbourhood of 6 tonnes to Dunar orbit and return to Kerbin without any refueling.

Of course, these things are all nice and well to say without testing, but I had a good reason for wanting to do so. A few days ago, I tested out a new long-range SSTO-VTOL, which, according to my calculations, should've been able to get to the Dunar surface and back to Kerbin on a single tank. But you know theory: it never really works out. In this case because I ballsed up my calculations by forgettign that Duna has an atmosphere, plus some slightly too aggressive flying by Minnard Kerman. So the test run went tits up and Minnard got stuk in a low Dunar orbit with about 300 m/s shy of a return to Kerbin. So obviously, he had to be rescued.

I hand-picked Jeb for this mission, since he has lots of experience flying earlier versions of carrier plane and sent Rodford with him for company. They were to fly to Duna, pick up Minnard and, since they were there, the boffins at the science building asked them to leave two brand-new research probes in Dunar Orbit. They were also given a few pieces of paper and were asked down to write down what they thought of the space plane and the auxiliary equipment, since none of it had ever been tested before. Scientist were especially concerned about the Minnard Recovery Vehicle, nicknamed MIRV by the boffins. Jeb was ecstatic when he saw the thing and called it Scooter.

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So, mission success!

Post-mission brieving:

So, in short, the mission was a success. The probes were deployed and Minnard was home in time to see his kid's baseball game. There were a few issues with the spacecraft, however. The first was that, as you may be able to read in some of the images, the Eagleray is well over 350 parts, which caused a slowdown of around 2:1. It took me almost a real-life hour to get this monstrosity into orbit. It did so quite fine, however. It was a bit nose-heavy between 10 and 20 KM, but nothing serious enough to warrant an abort. Furthermore: it got into orbit with 3.1 Km/s. Since the mass of the objects I was carrying equalled something like the large 1 meter fuel tank, I did some calculations, and I think this thing should be able to reach Laythe, if it carries an auxiliary fuel tank, which is quite cool.

The interplanetary burn showed me a slight defect in the craft: the centre of thrust of the nuclear engine is slightly off, making the craft somewhat squirrelly at full throttle and downright uncontrollable at 4X time acceleration. It should be fixable, but testing it will be a nightmare. And, since I'm using a single nuclear engine, the plane has a horrible T/M ratio of only slightly higher than 1. It may be worth considering sticking on a couple of LV-909ers for those times where you need that extra thrust.

The burn back was horrible. The craft was now around 30 tonnes lighter, making the off-centre thrust much more noticable. Furthermore: I overshot by quite a lot while time accelerating the planets into the proper position, making my use at least 500 m/s too much, possibly as much as as 1km/s.

Landing went exceptionally well, for something this weight and size (landing weight was still around 30+ tonnes). I was initially planning to land it at KSC, but I accidentally got myself in a clockwise orbit around Kerbin with too little fuel to correct it, and since I was already five, maybe six-ish hours into the mission and it was 4 AM, I decided not to do a few attempts at figuring out how landing at a specific point from a clockwise orbit works and just to land on the nearest piece of earth I could find.

Additionally: some lighting in the cargo bay would be nice for docking/undocking, I think. And perhaps I should try to make the crew entrance a bit more acceptable. It took me nearly the entire RCs tank of that poor Minnard to squeeze him in there without the Kraken showing it's ugly head. This could also be fixed, however, if I was allowed to rotate a kerbal in all three axes.

As for the scooter: it is the worst thing I have made and used on a mission. I did not balance the thing at all, making the CoT way out of line with the centre of mass. I was constantly fiddling around with the thrust limiters so it wouldn't go completely off-vector. Further design issues were forgetting to put on some batteries, making it uncontrollable for about a fourth of each orbit, and putting the thrusters slightly wider than the width of the cargo bay, making me do some annoying turning to avoid scratching the carrier while docking. Some lights would've helped as well. Furthermore: all these problems were exacerbated by the ridiculously low orbit Minnard was in (50 KM), making the entire process take too long, since I couldn't get past 10X time acceleration.

The ion probes performed admirably. Due to their exceptionally low weight (600 kilos) they had only a slightly lower acceleration than the Eagleray and I did balance these properly. The only issue was that I put the probe body on the wrong way around, which will make it somewhat annoying when I'm going to do some actual manoeuvres with them in the future.

So, yeah. I don't have much more to say, I think. Thanks for reading this!

Edited February 15, 2014 by Rodyle
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[Scotius]

Dang it And i can't even build a spaceplane capable of reaching orbit - not to mention travelling to another planet.

[Rodyle]

Dang it And i can't even build a spaceplane capable of reaching orbit - not to mention travelling to another planet.

Thanks. It took me a long, long time to get to this point (read: I've been playing this game since April last year and basically have been trying to get SSTOs to work since the beginning). Best advice I can give is: start small; single jet-engine spaceplanes still are the easiest, since flame-outs are not really an issue.

[MarvinKitFox]

ok. wow.

just

wow

[Rodyle]

ok. wow.

just

wow

Haha! I had the same reaction to your Octo-2 flock. ^^

[Geschosskopf]

Very impressive beast there. To me, the greatest problem with making big (and therefore useful) spaceplanes is the lack of big wing parts in stock KSP. This forces you to use scads of small wing bits which need a fair amount of strutting, resulting in a massive part count. Plus of course some real difficulty in opening the thing back up to put in a part you forgot, or moving things around for balance. Looks like you did well overcoming these problems.

[Rodyle]

Very impressive beast there. To me, the greatest problem with making big (and therefore useful) spaceplanes is the lack of big wing parts in stock KSP. This forces you to use scads of small wing bits which need a fair amount of strutting, resulting in a massive part count. Plus of course some real difficulty in opening the thing back up to put in a part you forgot, or moving things around for balance. Looks like you did well overcoming these problems.

Thanks, and I agree. Although I really like the flexibility of smaller wing bits (allows for more roundish shapes), it really adds up in the parts. The moving stuff was for this plane not a real issue, since it was built by design to be very open, but I see where you're coming from. I think it would help if it was possible to make 'meta-parts' out of, for example, wings put together, or multiple stacked fuel tanks. This would make it easier for the physics calculations, while allowing us the same degree of freedom (if not more so, since you can now build larger spaceships) in the building phase.

[LethalDose]

Good Job! Did you use any mods, like FAR?

[Rodyle]

Good Job! Did you use any mods, like FAR?

Nope. This one is completely stock. I only started using mods very recently, and I still think that stock KSP is the most fun to play, but I wanted to play with some stuff which isn't available in stock, but should be (fairings, openable cargo bays).