Flying Duna, Ineptly (Pic Heavy)

[andyfaewatford]

Prologue

Happier times. In this photo, you can see the crew of the Duna Hummingbird, shortly after landing at (unsurprisingly) Duna. Look at the excitement on their little faces!

The crew's mission was to explore Duna, paying particular attention to some anomalies that had been picked up by the network of scanning satellites that had been deployed previously. From left to right (possibly), we have:

Billy-Boblorf Kerman: Cowardly pilot

Jebediah Kerman: Courageous yet surly pilot

Bob Kerman: Mission controller

Enald Kerman: Xenoarchaeologist ('cos, y'know, that's a thing)

Albart Kerman: Driver

The Hummingbird was so called because of its ability to feed whilst flying. Essentially a large lander with a Kethane drilling rig and refinery included, it could hop around the planet investigating anomalies and filling up its fuel tanks on all that delicious Kethane that's scattered around the place.

Well, in theory.

In practise, Duna is a lumpy hell of a planet where it's near enough impossible to land a skyscraper-sized lander without killing everyone on board. Even Jebediah, after the first near-fatal landing of the craft, was having second thoughts about the mission profile.

Still, there was always Plan B:

The Hummingdog X2A! Similar designs had been trialled with great success on Minmus and the Mun. As you can see, the Hummingdog features a Kethane drill, converter, four tiny rocket engines, and a mess of pipes, enabling the Hummingdog to hop from place to place and land where the Hummingbird couldn't, thanks to its many rugged wheels.

Well, in theory.

In practise, Duna's got a far higher gravity than the Mun, and this rover was the heaviest design of its type that the inept designers back at KSP had yet come up with.

Still, the rocket engines did come in handy...

In the above photo, you can see a typical driving scene. Albart, bored out of his mind at the tedium of negotiating a hostile environment in an 8-wheeled death-trap, has managed to flip the Hummingdog, thus sending himself and his mission controller careening off a cliff. Fortunately, Mechjeb is at hand to save the day. Albart hits the big red button on his dashboard [read: I hastily change the control point of the rover to the docking port on top, and hit 'land anywhere' on one the landing guidance window]...

...and the autopilot drops us safely down on to terra firma (Duna firma?). Unfortunately, a manoeuvre such as this uses up pretty much all of the rover's Kethane stores. Until Albart can drive (slowly, carefully) to another Kethane deposit, the big red button is kind of a one-shot deal.

Basically, the mission planners have blown it big time, and the crew are going out of their tiny minds.

[Geschosskopf]

PrologueBasically, the mission planners have blown it big time, and the crew are going out of their tiny minds.

Well, nobody's died quite yet . But seriously, rovers are boring. For getting around on Duna, there's nothing like an airplane. Sure, the atmosphere is almost too thin to count and most of the ground on Duna is the equivalent of about 16-18km on Kerbin, but you can still fly a plane in it and maybe even land safely in the lumpy dune fields that cover most of the planet, if you give it a chance. You just need the proper tools for the job. Check this thread out.

[andyfaewatford]

Part 1

Some kind of plane was required. The boffins got to work. First of all, a proof of concept:

The Dunabomber was tested extensively in... err... computer simulations. Whilst it worked fine in the air it could barely land. It was also, frankly, ridiculous-looking. However, some important ideas were proved; namely, that Firespitter's electric propellers worked on Duna. And due to the thin atmosphere, they work pretty much indefinitely too.

The KSP engineers eventually came up with a more worthy craft, called the Dunahopper- a kind of cross between a microlight and a dune buggy. Initial attempts to get it off of the surface of Kerbin were not successful:

Eventually, it was decided to attach the Dunahopper into an unreasonably large space plane in order to get it into orbit:

(Yeah, it aint pretty...)

The plane didn't take off until it was going over 100m/s- which was rather more than the rover wheels were built to withstand.

To get the plane out of the atmosphere, a single RAPIER engine was used. Surprisingly, considering that the wings were made out of wood and canvas, they withstood speeds of about a mile a second.

(Still not using any oxidiser at this altitude, although that would change shortly)

And voila! We're in orbit.

Next, a rocket was sent up carrying a bunch of spare fuel (although for some reason I don't have any screenshots of that), which successfully docked with the Dunahopper before returning home. Then, young cadet Kenfield Kerman was launched into orbit, so that he could repair the damaged rover wheels.

A while before Kenfield arrived at the rendezvous, though, mission control pulled out their party trick- and dumped the RAPIER engine:

This was done because Kenfield was carrying a rather special package with him- a nuclear engine to dock to the Dunahopper.

Here we see Kenfield repairing the damaged wheels:

Once he'd finished with that, he retired to a safe distance. The Dunahopper was ready to brave the inky depths of space! To coincide with this auspicious event, a solar eclipse occurred. That's got to be a good sign, right?

Excitement mounted at mission control. To their knowledge no-one had replaced just an engine on a spacecraft in space before. This would be a first. The ship was lined up for the burn to Duna. The countdown began. The countdown finished, and...

"OH FOR CRYING OUT LOUD!" (That was Werner, obviously. I said something much worse...)

The engine refused to work, no matter what buttons were pressed from mission control. Fuel crossfeeds were disabled and re-abled. Any button that could be pushed was pushed. Tears were shed.

Eventually, mission control came to the conclusion that possibly the reason they'd never heard of anyone replacing just an engine in space before was that it wasn't possible. You can see their confusion though, can't you? I mean, that RAPIER engine worked fine, getting fuel and oxidiser passed to it through two clamp-o-trons, so why wouldn't the same thing work once they'd replaced it with an LV-N? Now, I don't know if maybe KSP doesn't work that way, or if the docking wasn't right, or what, but it was an infuriating setback.

But there were options. A tug could be flown up to push the Dunahopper to its destination. Or another engine with a small fuel tank could be docked to the plane in place of the useless LV-N, and Kenfield could weld a fuel pipe from the main tanks to the little one to get it working. Maybe a replacement engine could be sent up with some RCS fuel so that it could try docking a few more times until it worked properly.

So let's pretend that I did one of those things, instead of what I'm ashamed to admit I actually did- which was just hyperedit the plane into a Duna orbit. I know, I know! I'm not proud of this. But, to be honest, I just didn't have the time for any of those other options. And considering that they were all perfectly feasible options, that I knew I would work, I rationalised to myself that I didn't actually need to do them.

Anyway, if you're still with me, let's pick up the story at Duna...

Here we see the Dunahopper being disconnected from its spaceplane 'cradle', after making a de-orbit burn. The burn wouldn't really drop the plane anywhere near the Hummingbird (I could have done this better, but saw a long boring flight as my penance for the whole hyperedit faux pas), but that would just give the crew some extra time to see how the thing flew, and give them the opportunity to iron out any kinks whilst it was under remote control, instead of when someone was sat in the pilot's chair.

Ideally, those huge wings would have been gotten rid of before the craft made the long trip out to Duna, but the engineers were more concerned with keeping it structurally sound on the way out of Kerbin's atmosphere than they were with a bit of extra weight on the voyage to the red planet (a voyage that didn't technically happen anyway...)

I don't think I thought about what would happen after the 'cradle' was decoupled, but what did happen was quite shocking. After the clamp-o-tron separated, all of the magical struts holding it together broke free too, meaning that the 'cradle' was now just two enormous wings barely tethered together. They flapped away wildly from the Dunahopper, which was quite entertaining for a while...

But then mission control had a sobering thought. The 'cradle' wasn't just a collection of wings and struts. It also carried a nuclear engine. Which was now hurtling toward the planet at several times the speed of sound. Back on Kerbin, an ashen faced Werner von Kerman turned to the assembled scientists and journalists crowded around mission control. "Ladies and gentlemen, due to our short-sightedness, we appear to be in the process of dropping a nuclear bomb on Duna." (I still feel a bit bad about this, to be honest...)

Fortunately, the Hummingbird was pretty much round the other side of the planet when the cradle exploded into the ground, so no-one was hurt. Oddly enough, the explosion didn't even leave a crater.

Jeb, from the Hummingbird, managed to guide the 'hopper via remote control, and pretty soon worked out its limits. Maximum attainable height was about 6,000 meters, and the max speed wasn't much to write home about either. Still, he would get to be the first Kerbal ever to fly a plane on a different planet.

That 6,000m flight ceiling got the crew thinking though. Bob pulled up a map from the scanning satellite, showing the Hummingbird's location at 'Flat Landing' (about the only flat spot Jeb managed to find to land on), and the current location of the Dunahopper...

"OH FOR CRYING OUT LOUD!" (That was Bob. I said something much worse...)

[andyfaewatford]

Well, nobody's died quite yet . But seriously, rovers are boring. For getting around on Duna, there's nothing like an airplane. Sure, the atmosphere is almost too thin to count and most of the ground on Duna is the equivalent of about 16-18km on Kerbin, but you can still fly a plane in it and maybe even land safely in the lumpy dune fields that cover most of the planet, if you give it a chance. You just need the proper tools for the job. Check this thread out.

Oh yes! I should have mentioned in the main text that this whole idea was pretty much inspired by your 'Kethane Travelling Circus' thread on the topic- so thank you. I actually did this mission a while ago, but am only really finding the time to write it up now. For the reasons outlined in Part 1 though, I'm afraid I don't meet the requirements for the 'Flying Duna' challenge (definitely failed on rule 5, possibly failed on rule 4 too)

[andyfaewatford]

Part 2

Bob frowned at the scansat images for a long time. "Err... Jeb"

"Yup"

"Take a look at this please"

"OH FOR-"

"Yeah, I've done that already"

The Hummingbird was essentially stuck in a hole, ringed by mountains of a height somewhere between six and seven kilometres.

"Can you see a way round that Bob?"

"Maybe to the south of where you've got the Hopper at the minute, but I think you should land it immediately whilst we think about a plan B."

So Jeb landed the Dunahopper by remote control, and the crew pored over the maps. There appeared to be no safe way round the terrain. Still, on the plus side, the plane would have access to all the anomalies that the crew were supposed to be investigating. Both Jeb and Enald were adamant that they weren't going to sit in a hole and explore the planet by remote control though. After conferring with mission control, it was decided that if the Hopper couldn't come to them, the crew would have to go to the Hopper.

The maps were consulted again, and a suitable-looking Kethane field identified, almost at sea-level, in the so-called Wu Crater just over the wall that surrounded the Hummingbird (If you squint a bit at the Scansat picture and tilt your head to the side a bit, does it not kind of look like the Wu-Tang Clan logo?).

Jeb used the Hopper to scout out the flattest landing site he could find. The plan was for the Hummingbird to get into orbit around Duna (which would be a good test for when the mission eventually returned home anyway), and then aim for the Hopper on the ground.

Billy-Boblorf was elected to fly the Hummingbird from the Cuppola module, as he was a cowardly pilot and therefore less likely to get everyone killed upon landing. The rest of the crew buckled in for the trip.

It was all smiles before lift-off, but landing was a different story.

Billy-Boblorf: "Oh Kod, we're all going to die!"

Jeb: "HAHAHA! Billy-Bob, you suck you cowardly pilot!"

Enald: "I think I'm going to be sick..."

All six of the Hummingbird's engines and her eight parachutes were used in landing. Fortunately, the fuel supply held out just long enough for the ship to land safely.

And here's the monstrosity in all its dubious glory, a mere 1.5 km from the Hoppper. (Frankly, there are many things wrong with this ship, but the two worst have to be the layout of the landing legs, and the impossible height of the thing. The height, from what I recall, what a result of the fact that I hadn't worked out how to use fuel lines to link the Kethane tank/converter with the fuel tanks (turns out you have to use them backwards), and also because I wanted lots of room for the crew to hang out in- they were, after all, going to be cooped up for looong time. The landing legs... there's no real excuse for. Suffice to say the ship was prone to tipping over.)

Happy to still be alive, the crew posed for a photo next to the world's first extra-terrestrial ('extra-Kerbestrial'?) aeroplane:

Now it was time to go and explore those anomalies!

Enald: "I think I'm going to be sick again!"

Edited March 11, 2014 by andyfaewatford

[Geschosskopf]

Good mission. Congrats on making a plane that flies on Duna, too. That's an undervalued achievement IMHO. Few seem to have attempted it, fewer have succeeded, as far as I can tell. And thanks for the props

[andyfaewatford]

Part 3

Spoiler Alert! Just in case anyone reading this doesn't know what/where Duna's easter eggs are, and doesn't want to know either, then probably best not to read this bit.

Our (debatably) intrepid duo headed off in search of anomalies and glory...

Enald: "Err... Jeb?"

Jeb: "Yup"

"I can't help noticing that this plane doesn't have a cabin"

"So?"

"Well, that kind of means we're going to be stuck in these suits for a while..."

"Haha! I wouldn't worry about that my man. Bill once spent near enough a year floating road Kerbol in one of these suits. We'll be fine."

"He WHAT!?"

"Yeah, damn fool drunk one too many Tekila Kerbolrises at an office party, got a head full of ego and decided it would be a grand idea to steal an experimental craft from the launchpad and head off to Minmus!"

"I don't believe you..."

"Except he was so drunk he fell asleep at the controls, overshot and escaped Kerbin's SOI, and used all his fuel in the process. Then he panicked and tried to use his jetpack to get home! HAHAHAAAA! So, I wouldn't worry about spending a couple of days in your suit; it'll be fine."

"Good grief! I never- how did he get back home?"

"Bob had to fly out and get him. Got awarded command of this mission for his troubles- that and a medal. Bill should have been thrown of the programme, except for the fact that he'd accumulated so much deep space time on his little jaunt that he'd become the most experienced astronaut we have! Ahhh, it's a mixed up world alright... Anyway, you wanna try a barrel-roll in this heap of junk?"

"NO! I mean, no thank you Jeb."

Actually, a barrel roll would be an exceptionally bad idea in this plane. In a straight line it flew fine. I would just put SAS on, point the nose up about 15 degrees, speed up time-warp to 4x, and wait. After about 5 minutes, the curvature of the planet would force the nose up to about 30 degrees. A wee tap of the 'F' key would disengage SAS for a second, bringing the nose back down again. Lather, rinse, repeat.

But when it came to going round corners, this thing had the turning circle of a supertanker. Or an American car. In fact on the first point of their journey, Jeb decided it would be a wise move to land first, and then adjust course.

Right enough they're in a pretty big valley here, but it didn't hurt to practise landing before it was really necessary to do so.

Anyway, before too long the chaps were pretty close where the map said the first anomaly should be...

Jeb: "Hmmm... you see anything?"

Enald: "Not yet"

"Any idea what we're looking for?"

"Jeb, didn't you read the mission book!?"

"No Enald, I didn't read the mission book. I did fly a 40-tonne rocket halfway across the known Kerbolar system though, if that counts for anything. Now, do you want to tell me what we're looking for or should I show you a barrel roll?"

"Well, one of the scanning satellites was looking for clues as to the mineral composition of Duna, and found a patch- really a very tiny patch- of something unexpected near the surface: metal."

"Metal, huh?"

"Well, metals really. The most likely explanation is some kind of meteorite. Although I'm hoping for something a bit more exciting; maybe an exposed seam of precious minerals or something. It almost certainly won't be another monolith like on the Mun or back home. We've found enough of those now that we can recognise their signature on the Scansat"

"Ha! Well, it's good thing you brought your pick-axe with you, maybe we can take us back home some gol- hey, what's that right ahead!?"

"I've no idea. It doesn't look like a meteorite."

"Don't look like no pot of gold either. Okay, stow away your table, I'm taking us down..."

Enald: "What the...? It looks like a camera!?"

Jeb: "Good Kod, so it does. It's not one of ours. I don't think it's working though. Reminds me of a rover or something. Well, get your shovel out and let's dig."

"What? No! Don't you know the first rule of archaeology?"

"'Don't talk about archaeology'?"

"No. The first rule of archaeology is that you only dig if you need to; and when you've learnt all your going to learn about what you'll destroy by digging"

"You mean: the dirt?"

"Yes, the dirt. If I'd known what we were going to find I wouldn't even have let you park the Hopper this close. We're not digging here Jeb. Our mission is just to see what we can see and report back. I'm as excited as you are by this, but we're not digging."

"Fine. Here, hold this camera... TA-DAAA!"

[andyfaewatford]

Good mission. Congrats on making a plane that flies on Duna, too. That's an undervalued achievement IMHO. Few seem to have attempted it, fewer have succeeded, as far as I can tell. And thanks for the props

Well, thank you for the props. It was actually quite fun getting a plane to work on another planet. I also tried it out on Eve and it worked there too (but very slowly, I seem to recall). I just hyper-edited it there though; not sure how I'd get it there for 'real'. I'm thinking about trying something on/above Jool too- if I could make a plane that could fly indefinitely (as this one could on Duna) then it wouldn't matter about landing it...

[andyfaewatford]

Part 4

Spoiler Alert! Again, if you don't want to see the Duna easter eggs then probably best not to read this bit...

We'll leave the boys flying to their next location and discussing the origins of the camera they found in that valley. Is it a remnant of the ancient space-going race who left all those monoliths scattered on the Mun? Was it a secret Krussian probe? And what is it about KSP that makes me want to add the letter 'K' to the start of every word?

So, let's talk about the (inept) design of the Dunahopper.

First of all, the wings. There's loooads of them, 4 pairs in all. These just about allow the Hopper to reach 6,000 meters on Duna. Having many shorter wings (rather than two long ones) and having them perched on top of an i-beam means that they are unlikely to strike the ground in the (inevitable) rough landings that you get on Duna.

The rover wheels were chosen over the more robust aeroplane landing gear to allow a bit of roving where the plane couldn't fly. The tyres tend to burst when the plane approaches 100m/s on the ground, but as I didn't plan on landing that fast (the thing barely flies faster than that) it wasn't a problem. When it was in its spaceplane 'cradle' leaving Kerbin it didn't take off until it was going over 100 m/s, which is why Kenfield needed to be sent up to fix them.

We've got two electric engines, mounted in-line to each other. I'm not sure if that would be a help or a hindrance in the real world (I imagine that a propeller causes lot of 'dirty' air behind it) but KSP's aerodynamics engine doesn't seem to have a problem with this as far as I can tell. These are powered by 10 solar panels, and also 2 RTGs (I think- unless I've hidden any more somewhere). Due to Duna's thin atmosphere, these are sufficient to power the engines indefinitely, which was a nice surprise. (Actually, at a high enough altitude on Kerbin the plane can fly indefinitely too, but it's a bit tricky to get up to that altitude in the first place...)

Rounding it off, we have air brakes that barely do anything in Duna's atmosphere (switching the engines to run backwards using action groups is a far more effective method of slowing down), and a pair of lights that (before I noticed that Scansat will tell you how far above ground level you are) can be used to indicate when the plane is close to the ground. If you see two pools of light on the ground, then that means you're about to crash.

Top speed is about 110m/s, and it handles like a pig.

Anyway, back to our intrepid astronauts. Studying the map, Jeb reasoned that the next anomaly, whilst being at a fairly low altitude, was on a bit of a hill, so he landed the plane early and decided to drive the rest of the way. Here we see their first sight of something off in the distance:

Jeb: "Looks like we found our anomaly. Whatever it is it looks pretty big. What are we supposed to find here anyway?"

Enald:"Well, aerial photographs from the scanning satellite are pretty low resolution, but the shots from this area got some over-imaginative people pretty excited. In the photos it looks like a... well, it looks like a giant face has been carved out of rock."

"What, like the face of that weird creature carved on the Mun monoliths? One of those tiny-eyed monsters?"

"No Jeb, a normal face, like one of ours. Like I say though, the photo resolution's pretty bad. It's more likely to be a big rock with the light hitting it at the right angle that makes it look like- oh my..."

Enald: "This is amazing! Wait here, I'm going to use my jet-pack to get a closer look"

Enald: "Woohoo! This is incredible! It is a face! The ramifications of this are immense! Imagine: ancient space-faring Kerbals could have made this!"

Jeb: "You think?"

"Well, who else?"

"I dunno man; I've seen cave paintings of buffalo and deer and rabbits, and they weren't painted by nothing with paws..."

"That's a pretty dark thing to be thinking Jeb. Anyway, I'm going in for a closer look"

Enald: "Err..."

Enald: "Errrrrr..."

[Right. I'm not even going to try and explain KSP's dodgy collision detection here. Let's just pretend that this didn't happen]

[andyfaewatford]

Part 5

Spoilers!

The chaps spent the rest of the day examining the anomaly,and trying to decide on what to call it. Jeb wanted to call it 'Enald's Big Head', but Enald felt that would somewhat lower his stock in the academic community. They also spent the night there, camped out under the stars.

The next morning, after taking breakfast through a straw (they couldn't open their space helmets, after all) they set off pretty much due south for the penultimate leg of their journey. This would be the furthest south they had gone yet. No-one had bothered [read: I hadn't bothered] comparing the latitude of the last anomaly with the latitude of the southern ice cap, so Jeb had no idea if a snow-based landing was on the cards. It wasn't long before he discovered that it was:

Enald: "Wow! After months of seeing only red, this ice makes a real change for the eyes. Can we land and take a sample?

Jeb: "Nope. You see the bottom right corner of the map screen there?"

"Uh-huh"

"Well, that tells me that we've got less than two and half kilometres between us and the ground. Which means that the ground is over three kilometres high. And we're not even above the snow-line yet, or whatever you want to call it. I don't want to try and land us on this ice unless I absolutely have to. In fact, I'm not sure we'll even be able to land near the next anomaly."

Enald: "Are we there yet?"

Jeb: "Very funny. We're nearby according to the GPS. What seemingly-innocuous-but-ultimately-amazing thing are we looking for now?"

"I've really no idea. Something... bright"

"What, bright like that?"

Enald: "Gosh. Yes. Let's land!"

Jeb: "No chance. The ground's too high and I don't trust this ice; it's nowhere near flat enough. We'll have to fly on and see if there's anywhere better to touch down. If there is we'll drive back"

[Read: I lost count of the number of times Jeb and Enald died trying to land near the anomaly. Good old F9 button!]

Eventually the boys managed to land in a crater to the west of the anomaly- and that was difficult enough. The drive back was as tedious as anything ever attempted in the Hummingdog- and without even the safety of mechjeb's self-righting mechanism. Here we see that the team have climbed out of the crater, but still have so very, very far to go:

Finally, they reached the anomaly:

Enald: "It's kind of pyramid shaped. But it's so bright! Where's the light coming from though?"

Jeb: "Well, Kerbol's to the west, and that's the bright side of the... structure? Maybe the ice is just really reflective?"

"I'm going for a closer look"

After examining the pyramid, Enald decided that whatever was under the ice was almost certainly manufactured. He still found no answer at all as to what made it glow though. The team took various measurements, and then decided to head back to base so they could finally take their spacesuits off.

As they were flying east, they flew into the night, but decided to just keep going. They started off pointing directly east (as it's a quicker journey going east near the poles than it would be near the equator), but the curvature of the planet kept pushing them north- which at least kept Jeb alert through the long hours of flying. When they were almost directly south of Wu Base, they turned north again, and were soon home. After the horrors of the south pole, it was a relief to have a simple flat landing.

And that's pretty much it. The team stayed on Duna for months after this, spending their time (I would imagine) documenting the anomalies and trying to find the source of that strange glowing light (it does reflect Kerbal by the way, as the light moves as the day progresses). At the end of their mission [read: when I remembered they were still there] the crew set off for home. The Hummingbird had plenty of fuel left when it got back to Kerbin orbit- which just goes to show how much fuel I burnt up making the hop from one landing site to another.

Anyway, thanks for reading, and I hope it wasn't too painful! I think it took almost as long to write all this up than it did to actually do it in the first place.

Cheers.

[Geschosskopf]

Great story and, again, congrats on the successful Duna plane. I bet you can make a better one next time

[Th_]

Yeah, flying on Duna is definitely nothing to scoff at. Well done