Long-term Laythe Mission (pic heavy) - ^_^ With Part 45 ^_^

[architeuthis]

As always entertaining and inspiring.

[-RanZ-]

This.... is..... awesome!

[Specialist290]

Impressive work as always

[Oggula]

Pretty nice hardware you landed there. I've never really been one for bases myself because at the moment we have nothing but hitchhiker containers to set down. Once resources come out though I expect I'll send a hotel to Laythe with rover, spaceplane, mining equipment and fuel dump. Then things get interesting

[Brotoro]

Long-term Laythe Mission - Part 5

TL;DR version: Brotoro drives rovers all over Laythe some more.

Up in Laythe orbit, I did some juggling of the Nuclear Tugs in preparation for sending most of them back to Kerbin when the next launch window opens. Any of the tugs that weren't already docked rear-end-first to the station were flipped around so that their rear tanks were docked to the station. These tanks will be left behind to hold any excess fuel that the tugs won't need to return to Kerbin. Hopefully the tanks will be used in the future to hold fuel that is mined from Laythe or Vall...but the KSC boys in Division 0.19 say they won't be able to deliver the mining and processing equipment as soon as they originally expected. In the case of the tug that brought the refueler payload (which is in the lower right), there was a game bug that prevented me from just separating the payload from the tug and leaving it attached to the station... I had to undock the refueler along with the Tug, then separate them, then re-dock the refueler, and then move the tug to the next port over. Annoying. (Happily, the program WILL allow me to disconnect the rear tanks and leave them on the station... I checked... apparently it has to do with whether the parts were connected in the VAB or during an earlier orbital docking.) I also brought Tug #2 to the station (it had previously just been alone in Laythe orbit after dropping off the Base/Rover payload) so any excess fuel from it could be had as well.

Rovers Redux

Back to the rovers! Today was the start of Aldner's Big Mission: take the BirdDog rover/plane over to Fredoly Island and prove that it has the right stuff to explore other islands on Laythe. Mission planers also will allow him to explore other islands beyond Fredoly as long as he heads back to Laythe Base when his fuel level reaches 150/300 units. Despite what some people have said in the past (and was maybe even listed in parts info), the fuel can't be measured in liters... otherwise you get weird densities and mostly empty tanks, if you do the math. Anyway, below we see Aldner in the BirdDog after having left Fido Bay and reached his cruising altitude of 8000+ meters where he gets good fuel efficiency.

After an uneventful flight over the ocean, Aldner reaches the northern part of Fredoly Island (named for the second kerbal to land on Laythe, if you recall), and starts scouting out a possible landing location.

Here's an important lesson: Aldner left Fido Bay early in the morning (he's always excited to get flying), but because he was heading west and because the plane flies faster than the rotation speed of Laythe, he ended up arriving at Fredoly Island while Kerbol was quite low in the sky, so the lighting conditions were not great (although this does accentuate the ruggedness of the terrain and makes everywhere look uninviting).

After passing up all the so-so landing areas further east, Aldner decides that the peninsula on the far northwest corner of the island looks pretty good. He circles the BirdDog around and comes in for a landing roughly parallel to the wrinkles in the landscape (ignoring the dune-line texture).

The landing is no problem, and he's safely on Fredoly Island at the place shown by the capsule icon on the map below. Dansen Island with Laythe Base is off the the far right.

First order of business on Fredoly? Take a nap. Aldner is a kerbal who appreciates a good nap...and there's not much point in getting to work while the sun is so low. Once the daylight is in full force, Aldner raises the nose gear to put the rover wheels on the ground and drives to the seashore. Below is an overview of the area for anybody pondering nice landing sites on Laythe. It's a moderately flat area, located about 6.4 degrees south of the equator. The lack of a lot of east-west extent would make landing from orbit tricky to target.

Aldner: "Yo, Thombles, my Main Man! You reading me?"

Thompbles: "Laythe Base here. Reading you 5 by 5 through the station link."

Aldner: "I've started my drive. Some fine seashore property here. I'd like to name this peninsula Jenfir Point, if you would please log that."

Thompbles: "After that waitress who works at the Launch Pad Tavern? Aldner, we've been through this before..."

Aldner: "No, sir! I'm naming this after Jenfir Kerman, a very famous author from the 4th century."

Thompbles: "Ah. Who just happens to have the same name as the waitress from the Launch Pad Tavern."

Aldner: "Well, yes... now that you mention it, that's true. Very literary parents, Jenfir has."

Thompbles: "OK, Aldner. I can see that access to the Koogle search engine can be a dangerous thing in the wrong hands."

Aldner headed southeast, and pretty soon he came up against ridge lines that were too steep to take head-on. The best way to handle these is to drive along at a sideways angle that allows you to keep going at around 10 m/s. The BirdDog can generally keep rising at a vertical speed of around 1 meter/second while doing this...and eventually you'll either top the rise or end up driving in a spiral around the hill.

When you do cross a ridge line, be sure to take it more or less head-on. Early experiments driving around on the launch pad at the KSC showed that trying to drive ALONG a ridge line is dangerous because the wide spacing of the rear landing gear (which keeps the BirdDog nice a stable driving sideways along a slope) can result in bottoming out the center of the rover and damaging the jet engine. One of the reasons the BirdDog uses a standard jet engine instead of a turbojet engine is because the turbojet is longer and more easily damaged. Also note that the rear landing gear are not mounted directly on the underside of the wing, but are connected to small cubic struts that are attached to the wing to give the rear of the plane a little extra ground clearance.

After driving up over ridges that exceeded 1 km in height, Aldner drove down to check out an interesting low-lying area at the end of a inlet (there is a map at the end of the report). I'm always loath to give up my hard-won elevation because it takes a long time to drive back up slope... but one of the main points of this exploration trip is to check out possible base locations and landing sites. The area you see Aldner driving down into below has a fairly steep beach, but there is a moderate-sized flat area behind the berm that separates the beach from the flat area. And for anybody who worries that Laythe is obviously volcanically active and therefore subject to occasional tsunamis, having the berm as a seawall might be a comfort.

Aldner: "Yo, Mr. T! Do you copy?"

Thompbles: "I hear you Aldner. What's up?"

Aldner: "I'm at a nice little site on the end of a long inlet. I'd like to name it Klaudiya Cove if you'd be so kind as to log that."

Thompbles: "That would be named after Klaudiya Kerman, the famous historian from the 3rd century Ephebian Empire?"

Aldner: "... Why, yes. I didn't know you were the historical type, Thompbles old boy."

Thompbles: "I'm not. But I know how to use Koogle, too, you know. And I'm pretty familiar with your favorite waitresses."

Aldner: "I see why you get paid the big bucks, Cappy!"

Thompbles: "That's right. And remember to say hi to Klaudiya from me the next time you're at the Booster Bay Bar. Base out."

Aldner finds his first rock at an elevation of 1.4 km, so he stops for some samples. Note that we don't have the darn resource sensing equipment yet, so Aldner is regularly taking soil samples in sealed containers that can be tested later after the appropriate equipment eventually arrives.

Below we see the BirdDog at 2335 meters elevation, topping his highest ridge yet. Notice that the sand dune terrain has given way to a darker terrain that shows what are possibly very eroded impact features. I suppose this (and higher rocky areas) are what gets eroded into all that sand we see at lower elevations. I'd really like some radioactive dating equipment to test the local geology.

The thing about going way up in elevation...is that you have to come back down. And driving downhill can be some of the most dangerous parts of roving. But Aldner hasn't been having any problems with the BirdDog going downhill, so he's been letting it go a little faster coming down each ridge, even catching a little "air" from time to time as he passes over a ridge bump on the way down a big slope. But the BirdDog is an airplane...so getting airborne shouldn't be a problem, right? Below, the BirdDog goes over a sudden drop on a downslope and lands hard, blowing both rover wheels. Happily, the plane still handles well with the blown tires (no careening and crashing). The BirdDog was only going at a speed of 29 m/s when the wheels blew here...but the weight of the plane and the drop distance were enough to blow the wheels.

Aldner sets the brake, lowers the nose gear to jack up the front of the plane, and then gets out to fix the wheels. A kerbal is such a handy thing to have along on a rover. Below, the rover wheels still need fixing.

Here's another animated GIF of the speeding BirdDog topping a ridge...but this time the suspension absorbs enough of the shock that the tires don't blow. Note that I always have the Avionics package on when flying or roving the BirdDog for extra stability enhancement. After zooming over another downhill ridge line at over 35 m/s, the BirdDog blew another wheel (only one this time) and it still handled well during the braking to a stop. Good stability.

After several ups and downs over ridges in the 2000-2300 meter elevation range and depressions in the 1200-1500 meter elevation range, Aldner comes into view of a big basin area that bottoms out at just under 1000 meters. If you are looking to set up a big inland base area and don't care about easy sea access, this would be a nice area. Especially if you like scenic mountains off in the distance.

The view below shows the Big Basin area and the general route that the BirdDog took to reach it. The outgoing arrow shows where Aldner is heading next.

Fredoly Island doesn't have a lot to offer in the way of inland lakes. The little depression below (reached from the Big Basin after driving over a kilometer+ tall ridge) is as close as you get in this area with a elevation of just 150 meters.

As Aldner started driving up out of the low depression, Kerbol was getting low in the sky and the rover started draining the batteries faster than the solar cells could recharge them, so Aldner stopped by a big rock to collect more samples and make camp for the night.

Below, Aldner sits by the ol' campfire (just imagine a campfire there) and does a little star and moon gazing.

The next day, Aldner drove further south and decided to see what that lighter-colored material is that makes up the tops of the mountains. This required careful driving at a shallow angle along some steep slopes (see below) as he wound his way up and around a small mountain. The very wide spacing of the rear landing gear of the BirdDog lets it handle slopes like this, but you need to constantly be jogging the right-turn key with quick presses about once a second to keep the nose from wandering downhill. And each time you tap the key, the right landing gear wheel almost lifts up off the ground. Exciting.

Partway up the mountain ridge, Aldner came to a flat area where he could park, rest a bit, and collect some more samples, and he noticed that the the upper limb of Jool could be seen peeking above the atmospheric haze. I didn't think you could see Jool from Fredoly Island, but I was wrong.

Finally Aldner made it to the top of the mountain ridge. It wasn't the highest point, since there was a higher mountain peak if he'd kept driving north, but this was as high as he wanted to go (3481 meters). The lighter-colored terrain looked similar to the darker-colored terrain lower down (I was afraid it would be slippery ice).

After the rather harrowing drive up the mountain, and because he wanted to get some nighttime pictures from the peak, Aldner set up camp for the night.

Thompbles: "Laythe Base to BirdDog. Space Station's coming overhead...do you copy?"

Aldner: "Indeed I do, Commander Thompbles Sir! I've set up camp at 3480 meters. The view is great."

Thompbles: "What does the experimental radiation meter read?"

Aldner: "Let me check. Hmm. Hmm. *banging noises* Still reading zero, Cap."

Thompbles: "Huh. Same here. I guess Vanallen Kerman needs to do some more work on these things."

Kurt and Nelemy's Excellent Adventure

I'm sure all you Kurt and Nelemy fans are wondering what our dynamic duo are up to in the Folding Fido back on Dansen Island. No? I'll tell you anyway. Because of the wobbly Damned Robotics hinges, driving that rover isn't nearly as much fun as driving the BirdDog (it has to be kept at a slower speed), but the boys have been driving slowly north from Gusten Bay, sticking close to the coastline. They found a nice beach at 13.6 degrees north latitude, which Nelemy named Corfrey Beach after a fellow kerbalnaut who was with him on the Pol & Bop mission (and a stint at Minmus Moonbase).

Then they headed inland to go see a couple small lakes. After driving the BirdDog, I had to keep reminding myself to take it slower with this rover, especially going downhill. As our heros top the rise into the little lake valley:

Nelemy: "Dude, look! Two lakes...your turn to name them. Whoa!"

Kurt: "Hells blazes! Don't drive so fast! Watch it!"

Nelemy: "Dude, I don't think they'll let you name them Hells and Blazes."

Kurt: "Watch the damn road! Or let me out and I'll walk down."

As it turns out, Helsblaze Kerman was the discoverer of both propellium and oxium. Very famous chemist. So they were able to name them Helsblaze's Lakes. Below, the Folding Fido stops for a rest and some samples by one of the lakes.

Then the intrepid explorers herded the Fido up over the dunes again and drove along the coast to the northern-most point of Dansen Island.

Nelemy: "Yo, Thompbles! We are speaking to you from the very top of the island! I want to name this Ludger Point after my fine bud Ludger Kerman. We had some great times on the Minmus Moobase mission. That makes him famous enough, right?"

Thompbles: "Sure, Nelemy. I'll radio it in."

Nelemy: "Thanks, Dude!"

Thompbles: "Kurt, how are you doing? Your blood pressure telemetry was rather high a while back."

Kurt: "I'm fine. I'm now standing at the farthest north point of Dansen Island. Very relaxing view."

Nelemy: *splash splash* "No, Dude... I'm farther north than you!"

Kurt: "Look, Thombles... can I go out with Aldner in the BirdDog next time?"

Thompbles: "The BirdDog only has one seat, Kurt."

Kurt: "That's OK... I'll hang onto the wing."

Aldner Again

After a night camping on the mountain top, Aldner pondered whether it would be better to attempt the steep drive down the mountainside, or whether he should just fly off the mountain. He decided to drive (the point was to test out the rover, after all). The drive down was surprisingly easy. It was steep, but there were no surprise bumps to cause problems.

At the bottom of the run, Aldner found a nice beach at about 25 degrees south latitude with a view across the way to the next island over. So he got out to stretch his legs and do a little sampling, then hopped back into the BirdDog and fired up the jet engine and said aloha to Fredoly Island.

The distance to the next island over was not too far, so he only climbed up to around 4500 meters before making an approach to a moderately flat area raised up a short distance above sea level. To the east was a berm separating the beach from the flat inland area, and to the west was a smooth-topped rolling ridge, and beyond that was a depression. Not too bad of a site.

Aldner: "BirdDog to Base. Aldner calling the Incredible Thompbles. Come in."

Thompbles: "Base here. How's it going, Aldner?"

Aldner: "Fine and dandy. I have landed on the next island, and I'm naming it Kelby Island."

Thompbles: "What bar does she work at?"

Aldner: "Ha, ha! You are such a card, sir. Named after Kelby Kerman, first kerbal on Duna."

Thompbles: "So noted."

Aldner: "And I'd like to name this location Dunsel Landing after the commander of that mission. Could be an acceptable site if somebody wants a base at 27.5 degrees south latitude."

Aldner drove up and over the rounded ridge (steeper than I expected) to check out the interior depression. By then he was kind of bored with roving, so he decided to do more flying. He took off from the depression, headed west up the hill (speed fast enough for takeoff...pull up...land is rising..pull up more...more...excellent) then turned northwest to fly over the interior mountains of Kelby Island.

Aldner scouted along the west coast of Kelby Island looking for potential base sites. There was a moderately nice beach area that rose to a higher-elevation, moderately bumpy area to the north. Possible base area...certainly would be an accessible area if it had good resources. Aldner named it Lambert Landing after the third kerbal on the historic Duna mission (the first kerbal to land on Ike). The landing was a bit of a surprise because he overshot the flatter area of the beach and ended up landing on a bit of an upslope...but part of this mission was learning to land in imperfect terrain, so that was fine.

After some quick sampling and surveying, Aldner took off again and headed north quite a ways to the next island (as yet unnamed). Much of that island is mountainous, but there was a likely looking lowland area jutting out from the west coast at about 6.5 degrees south latitude, so he took the BirdDog in to a little peninsula by a bay.

This time he experimented with landing the plane along the shallow slope parallel to the shoreline, with no problems (animated GIF below).

Aldner: "Yo, Skipper! You on the channel?"

Thompbles: "Yes, Aldner. Station LOS is in 2 minutes. What can I do for you?"

Aldner: "I have landed, and I'd like to name this fine island Jebediah Island, if you please."

Thompbles: "After your mentor. Very nice."

Aldner: "And he was also the first kerbal on Minmus and Tylo, Your Recordkeepership. I'd also like to name this pretty little bay Bob Bay."

Thompbles: "So noted. Are you heading back now, or camping for the night?"

Aldner: "I thought I'd try the central lake next. Still have over 150 fuel."

Thompbles: "Are you sure? The orbital imaging shows the shoreline is pretty steep in there. *static*"

Aldner: "Don't worry, T-man. Smoke me a kipper *static* I'll be *static*" (loss of signal).

Aldner lit the fires and headed up over the mountains. Indeed, the shoreline all around the interior lake was pretty steep. Aldner circled the lake looking for the best landing spot...

...and decided not to try it.

Just kidding!! *I* thought looked bad, but take a look at Aldner's face below. The guy is a maniac. The southeast shore looked the best, so Aldner took the plane on in. Actually, the little beach there doesn't look TOO bad once you get close to it, but it was going to be an up-slope landing...

...which he pulled off like a charm. I like my lil' ol' BirdDog.

Aldner very carefully drove the plane down to the narrow beach, located about 1 degree north of the equator, then got out for some samples and a little recreational wading. Once the comm link was back, he named it Bill Lake after Bill Kerman, famous kerbalnaut. Also, since the BirdDog was down to 152 units of fuel, this was going to be Aldner's last stop before heading home.

Getting back out from Bill Lake was a bit tricky. Do a downhill run and hope to pull up quick enough to avoid splashdown? No thanks. Sideways run along the steep slope? Doesn't appeal either. So Aldner drove the BirdDog up the slope at an angle to reach a somewhat more level area higher up. This turned out to be a difficult drive...he got stuck in one place where the slope was getting too steep to drive and he had to do a backwards turnaround at the expense of some hard-won elevation to head back the other direction. Anyway, he got to the flatter area (which wasn't as flat as it looked), then fired up the jet engine and headed south. The ground almost immediately dropped away as the plane bumped over a little ridge, but it stayed in the air... heading straight toward the mountain slope to the south. Pull up. Pull up. But not too much! The BirdDog is more skittish in pitch as it uses up its fuel...so don't pull up too much. The BirdDog skirted the mountain slope while Aldner laughed maniacally.

Aldner headed southeast so that he could overfly the site where Fredoly Kerman originally made the second landing on Laythe. It's an arc of relatively low-lying dunes between 2 and 3 degrees south latitude. A good landing site because it's close to the equator and has good east-west extent for targeting errors, but it does leave you on the smaller arc of land and not on the main bulk of Fredoly Island. But maybe we'll be lucky and this is where some useful resources will be located.

Out over open ocean, watching the fuel level drop... it sure was nice to see Dansen Island finally rear up over the horizon. Sure, I knew there was plenty of fuel...but I'm happier when land is in sight. Finding the way back home was easy since I used the Haystack mod to select Laythe Base as the target, then pointed using the pink marker on the navball.

Below, coming in for a landing at Fido Bay...by far the nicest landing area I know of on Laythe.

Aldner landed with 89.75 units of fuel left (out of 300 units at the start), so he had used 210.25 units of fuel on this mission. He drove on over to the GasStation and refueled the BirdDog. Afterwards, there were 574 units of fuel left in the GasStation, so BirdDog could easily do four more big missions like this one.

Below is the mission map. I think I've seen all the sand dunes I need for quite a while now.

Meanwhile, the KSC engineers and mission planners are deciding what to send out to our brave Laythe Base explorers when the first Jool launch window since they landed opens up. A sturdier rover to replace the Folding Fido, certainly. And a single-kerbal SSTO that could be used to rescue kerbals from other islands (or to explore even more distant islands), almost certainly as well. Another BirdDog? Or just more gas? A high-orbit comsat is needed. Building rockets sounds like a lot more fun than driving rovers right now.

Brotoro's KSP Mission Web Pages

Edited August 2, 2016 by Brotoro

[FlandersNed]

That post is amazing! This whole mission is great and it really really makes me want to go to Laythe.

Unfortunately, Jool is at the wrong phase angle right now so I will have to wait.

Keep it up!

[Logan.Darklighter]

Amazing work sir! Love it! Inspiration for future missions of my own to be sure!

[Elven_sword]

Ephebian Empire

Pratchett, right?

[Brotoro]

Pratchett, right?

Yes. I needed a weird name for an empire, and that's what popped up in my brain. Sir Terry is one of my favorite authors.

[Lortto]

Excellent story. I have to see if I can subscribe to this.

[Scotius]

What? Aldner ran out of waitresses to name various landmarks after? Incredible...I'm kinda sad you are not using Kethane mod in this mission. Setting up refinery would add both more things to do, and more freedom operating your ships with fuel source on site. Anyways, very nice and interesting chapter of this incredible voyage.

[Brotoro]

Well, I kept expecting stock resources to be released any week now... And I didn't want to start doing it some way that would be superceded.

And regarding waitresses... test pilots push the boundaries, but a good test pilot knows to never push it too far.

Edited May 15, 2013 by Brotoro

[Henri von Braun]

Hello, I just want to say that I find your Laythe colony incredible!

Keep the good work up!

Henri von Braun

[Caelib]

Nice work! How many hours did you invest in this project? My guess is no less than 200!

[playec1992]

once again a epic journey :-D

[Torch]

totally flipping awesome!! Read all your stuff on the mindspring pages. Don't suppose you post craft files anywhere, do you? Anywho, look forward to reading more about your kerbalnauts missions!!

[Fourjays]

This is great. Been reading through all of your others on your website as well. Keeping me entertained for ages and inspiring me to try all sorts of new ideas in KSP.

[Brotoro]

totally flipping awesome!! Read all your stuff on the mindspring pages. Don't suppose you post craft files anywhere, do you? Anywho, look forward to reading more about your kerbalnauts missions!!

Only when people request something. Some of my threads on the KSP forum have craft files posted that people have asked for.

[Brotoro]

Nice work! How many hours did you invest in this project? My guess is no less than 200!

Some of the rover driving takes up a lot of time, but I listen to audiobooks while driving, so I don't get bored. I was listening to the third book in Larry Niven's Ringworld series while I was driving all over Fredoly Island.

[Greywind]

This is an amazing story, really a good read. Personally I really like the way you refueled your birddog, clever.

[Kromey]

I love reading your mission reports! They both inspire me to get crackin' on my own epic missions, and daunt me with how much work and time you've obviously spent on the whole thing!!

I'm loving your BirdDog, I'm going to have to build a rover/jet hybrid of my own based upon your design here. Have you experimented at all with extra (maybe even detachable) fuel tanks to extend its range? I was thinking I might be able to put a pair under the wings to avoid messing up CoG/CoL too much, primarily for giving it a longer range to explore more of Kerbin.

I'd also be curious on your thoughts on replacing the jet with a turbojet? Your mission reports mention that you went with the jet because it's less likely to hit the ground while roving and is more resilient if it does, but outside of those considerations what are your thoughts on that?

[Kromey]

Oh, by the way, on your mysterious disappearing solar panels: I've seen it with the smaller folding panels that sometimes clipping through objects makes them shatter, although most of the time they behave as if the obstruction isn't there. I bring this up because I noticed that your solar panel is clipping through something between it and the girder it's counter-balancing, perhaps that's why it disappeared on you?

I always take great care to design my craft so the solar panels don't clip with anything at all, ever, not because of this risk of them breaking (only seen it happen twice, both times though I was in vacuum and under no acceleration so there was absolutely no reason for them to break) but because I don't like seeing clipped parts.

[oggylt]

Great story read them all, it is clear that you read and listen to books, since your stories are rich of content even in plain dunes of sand But how do you track your travels so nice on a map?

[Brotoro]

I love reading your mission reports! They both inspire me to get crackin' on my own epic missions, and daunt me with how much work and time you've obviously spent on the whole thing!!

I'm loving your BirdDog, I'm going to have to build a rover/jet hybrid of my own based upon your design here. Have you experimented at all with extra (maybe even detachable) fuel tanks to extend its range? I was thinking I might be able to put a pair under the wings to avoid messing up CoG/CoL too much, primarily for giving it a longer range to explore more of Kerbin.

I'd also be curious on your thoughts on replacing the jet with a turbojet? Your mission reports mention that you went with the jet because it's less likely to hit the ground while roving and is more resilient if it does, but outside of those considerations what are your thoughts on that?

When I first built and tested the BirdDog with Laythe in mind, I started a thread to get input from players with more experience flying planes because I had only used rockets until then...BirdDog was the first serious plane I built in the SPH. There were some who recommended the turbojet (which I tried in my first version of the plane) and others who recommended the standard jet engine. I got the impression that the guys recommending the turbojet did so because they spend a lot of time zipping along high in Kerbin's atmosphere building up speed to get an SSTO spaceplane into orbit, or traveling long distances, and that's where the turbojet is clearly King. It also may have an edge on Laythe in that the atmosphere on Laythe is thinner, so its equivalent to flying around Kerbin at a higher altitude. But for shorter hops between close islands or loitering at low altitudes (things the BirdDog also needs to do), the regular jet engine has the advantage. I suspect that my intended flight profiles on Laythe called for tradeoffs that would make either engine acceptable...but when the needs of the BirdDog also being a ROVER are figured into the mix, the standard jet engine gets the edge because it is more compact and less likely to get knocked off by hitting obstructions on the surface. If you want to build a version mainly for flying long distances at high altitudes on Kerbin, the turbojet may be the better choice.

Regarding extra fuel tanks: When I was testing the BirdDog, I tried adding two more fuel tanks behind the ram air intakes. But that made the plane (with a nearly-full fuel load, anyway) fly like a cow, and I would always crash it when I tried to land. I think it doesn't have enough wing area for all that extra weight (of maybe it just needed more landing gear to support that weight on landing). I'm not sure...but whereas I (a newbie to the SPH) have been able to get the BirdDog in and out of sites with limited area, I could not get the fat version to land safely. If you were just going to add drop tanks and never tried to land the plane with those drop tanks still on, I think the plane would get you to anyplace in Kerbin and back. I did not pursue the drop-tanks idea because I would have no easy way to reattach drop tanks on Laythe.

My only warning about flying the BirdDog is to be careful about not pitching up too much, which you can easily do if the avionics package is turned off (I guess this is the price you pay for a plane that that lift off in short distances). But I have been amazed by the ability of the plane (when it did pitch up out of control on me in Kerbin test flights) to just keep doing tight loops at low altitudes when I was sure it would smash into the ground. I got out of that situation by rolling over at the top of the loop, and that got me back to horizontal flight.

[Brotoro]

Oh, by the way, on your mysterious disappearing solar panels: I've seen it with the smaller folding panels that sometimes clipping through objects makes them shatter, although most of the time they behave as if the obstruction isn't there. I bring this up because I noticed that your solar panel is clipping through something between it and the girder it's counter-balancing, perhaps that's why it disappeared on you?

I always take great care to design my craft so the solar panels don't clip with anything at all, ever, not because of this risk of them breaking (only seen it happen twice, both times though I was in vacuum and under no acceleration so there was absolutely no reason for them to break) but because I don't like seeing clipped parts.

Thanks for the tip. I didn't try to figure out the problem because that solar panel was only added to that place as a counterweight, so its disappearance did not affect the mission. Also, a friend of mine had the mysteriously-disappearing-solar-panels happen to him on his Eve base, so I though maybe the big solar arrays just do not play well on bases located in planetary atmospheres.