Developing Duna - Part 8

Amelia Airborne Around Duna

After Hellou and Kurt left for their expedition to Mt. Idaho (and from there they took off to explore the SSTV Signal Pyramid), Emilynn Kerman continued exploring the Lesser Helium Basin in her DunaDog rover/plane, the Amelia. First she went eastward from the giant Face on Duna, then southwest toward the rim mountains, and then east to the southeast corner of the basin where it connects to Barsoom Canyon.

Below: The Amelia heading toward the southwest corner of Lesser Helium Basin, with the dome where the Face on Duna resides in the background.

Emilynn: "Emilynn Kerman calling Duna Base."
Thompbles: "Duna Base here. What can I do for you, Emilynn?"
Emlynn: "I've finished the survey or Lesser Helium that Hellou wanted done, and I'm ready to fly back to Barsoom Base."
Thompbles: "Roger. After refueling at Barsoom, you can continue the planned test mission of the Amelia. Be sure to check in along the way."

On her flight up to Lesser Helium, Emilynn had flown along Barsoom Canyon. For the return flight, she would fly over the highlands just south of the canyon so that the surface scanners mounted on the underside of the Amelia could gather data from new terrain.

Emilynn used the rear 48-7S to takeoff and gain altitude. She switched over to ion power at 6000 meters, and still coasted upward to 7800 meters before the DunaDog started dropping.

As the Emilia started dropping back down to the mid-6000s, the land ahead was rising even more...and things got a bit hairy, requiring a re-boost from the 48-7S that ended up lobbing the plane to over 8700 meters and 295 m/s, easily clearing the peaks.

For the rest of the trip, Emilynn was able to just let the Amilia slowly lose altitude. Once over the peaks, there was a dip in the highlands (with more peaks ahead to the right), so Emilynn banked left a little to follow the dip down into the widening Barsoom Valley.

Emilynn cut the ion engines 15 km from Barsoom Base, at about 5000 meters altitude (3800 AGL), but she still overflew the Base and had to bank back around to get in position to pop the chutes and land. She touched down 400 meters from Base.

The expedition up to Lesser Helium Basin to find the Face, and then the trip back to Barsoom Base, used 47% of the LFO and 46.2% of the Xenon onboard the plane.

Barsoom Base was now a lonely outpost with only the Fuel Station and Fuel Fido there. Emilynn handled the multiple dockings and refueling herself, of course, since everybody else from the Base was down at the southern ice cap pyramid. The refueling of the dozen tiny Xenon tanks was tedious as ever (it is sure going to be a lot more fun to do this when we have the larger Xenon tank in KSP 1.0).

Emilynn: "Hey, Thompbles, are you awake?"
Thompbles: "Yes, Emilynn. Refueling went OK?"
Emlynn: "Sure thing. I've decided I'm going to make the next leg of my test flight starting this afternoon."
Thompbles: "You don't want to wait until tomorrow when you're rested?"
Emilynn: "Nah, I feel fine...and Barsoom Base is pretty dull now. All the bars are closed."
Thompbles: "OK. But keep me informed during your flight. You're going to be covering the biggest empty stretch of land yet."

Emilynn's next refueling stop would be at Fido Canyon Base (where Aldner, Adly, and Kelby were stationed). That's about 147° of longitude west of Barsoom Base. Not only is this further than any DunaDog has yet attempted to fly, it's also further than a DunaDog CAN fly in one hop westward because of solar panel illumination considerations. The sun needs to be at least 30 degrees above the horizon for the solar cells of the DunaDog to provide sufficient energy to run the ion engines at full throttle...which limits a flight to something around 120° of longitude.

So Emilynn would need to attempt this journey in two hops, with a landing somewhere to wait for the sun to advance across the sky before the second hop could be made. So not only is this trip longer than ever attempted before, but it also must include two takeoffs and landings before the next refueling. Can she make it? As it happens, the first rover I ever landed on Duna (an ancient RCS-powered/landing-gear-wheels rover from the days before KSP even had proper rover wheels) is located at a convenient location for the mid-flight stopping point. So Emilynn will visit this old rover.

Below, Emilynn sits in the Amelia and waits for the sun to drop to around 30° above the western horizon.

The map below (part of Duna's biome map) shows Emilynn's flight plan. Her first concern is going to be the highlands immediately west of Barsoom Base. This is also the part of the flight where the solar cells have the poorest illumination, so it's not possible to keep the ion engines at full throttle, and therefore not possible to maintain high altitude flight on just ion power. Once clear of the highlands, the Amelia needs to cross the vast stretch of midlands and lowlands that Emilynn will name the Pacific Planitia.

Emilynn: "OK, Thompbles. The sun is low enough, so I'm going to make my takeoff run. Lighing up the 48!"
Thompbles: "Good luck, Emi. Give me reports as often as you can."
Emlynn: "Wheels up at just under 40 meters per second. Climbing."
Thompbles: "Your telemetry signal is breaking up a little."
Emilynn: "Copy. 4800 meters. Rocket engine off, ion engines on."

Emilynn: "Can't hold altitude on the ions...they're draining the batteries too fast. Mountain ridge ahead."
Thompbles: "Roger."
Emlynn: "Rocket engine on. Whoa! Settle down girl."
Thompbles: "Problem?"
Emilynn: "I got some yaw from asymmetrical flameout of the ions. They're off now. Climbing on rocket only...but getting a good close view of the ridge line."
Thompbles: "Your data telemetry is still breaking up."
Emilynn: "The data recorders are running. OK...cleared that ridge. Leveling off at six thousand. Rocket engine off and ions on. Hm. Still drinking too fast. Decreasing throttle to 70% on the ions. Yeh. I can keep the batteries from running dry at that level, but I'm losing altitude again."

Emilynn: "If I pitch down a little, I can pick up battery charge...but then I lose a little altitude. Pitch back up to gain some altitude...and the batteries drop."
Thompbles: "Hopefully the new fuel cell planes Elon's engineers are working on will eliminate the need for all of this sun angle vigilance."
Emlynn: "That would surely be welcome. Another ridge ahead...I'll use some more rocket boost."
Thompbles: "What's your fuel level?"
Emilynn: "LFO just over 70%. But we knew this would be the tricky part. And burning off LFO now will make Amelia lighter so the ions will perform better."

Behind the Amelia, Ike sets below the highlands.

Emilynn: "All right! The sun angle has improved. Even with the ions at full throttle, the batteries are getting fully charged. Altitude holding at over five thousand. And since the terrain is dropping ahead, I think Amelia and I are past the hairy part."
Thompbles: "Good to hear."
Emilynn: "Should be peaceful flying ahead. I'd like to name these wide open spaces the Pacific Planitia, please."
Thompbles: "I've logged the name. Happy flying."

The map view below shows the position of the Amelia flying over the Pacific. Xenon gas level is 58.2%.

With the Xenon down to 38.4%, the markers for the Fido Pup probe and its lander showed up (the Fido Pup's marker showed up first, since it had traveled about 45 km from its lander). The Fido Pup rover is located in large crater at moderate elevation, higher than the DunaDog normally lands. (This used to be a well defined crater with steep walls back in version 0.18 of KSP when the Fido Pup landed on Duna -- but with the later reworking of Duna, it's a pretty poorly defined crater now.)

Emilynn cut the ion engines 23 km out from the target, at an altitude of 5.5 km (1.9 km AGL). The Amelia overflew the Fido Pup at 335 meters, then pulled up sharply to lose speed, and then she popped the chutes. There were strange lighting effects going on -- the terrain square the Fido Pup was on was lit up brighter than the surrounding terrain.

Emilynn used the belly engine to slow the horizontal speed and then to cushion the landing.

Emilynn: "Yo, Thompbles! Amelia has landed safely. LFO is at 66 percent, and the Xenon is at 37.4 percent. I'm going out to repack the parachutes."
Thompbles: "Roger. Good work, Emilynn. How far are you from the Fido Pup?"
Emilynn: "Less than a kilometer. But I'm a might tired, so I'm going to get some shut-eye before I drive over to it."

Below: Emilyn arrives at the Fido Pup rover probe. The drive was a little uphill, which is tedious in the DunaDog. The old probe used aircraft landing gear for wheels, and used RCS thrusters for propulsion and steering (the landing gear did not have a steering option at the time). Life is so much nicer with proper rover wheels. The lights on the Fido Pup are still going strong, of course, because the amount of Plutonium 238 in the RTGs is still at 83% of its original value after the 23.5 years since this probe was launched. Or, it would be, if KSP calculated such things.

Having come all this way, Emilynn stuck around for a couple days to gather samples from the area, lest Hellou never forgive her.

The next leg of the Amelia's journey was to fly to Fido Canyon Base, located about 51° west and 6° north of the Fido Pup site. Because this would be a shorter hop, Emilynn could wait until a little past local noon to takeoff, so there would be no problem with the illumination angle of the solar panels. Referring to the earlier map (repeated below), we can see that the biggest problems Emilynn faced on this leg of the trip were the large area of highlands immediately to the west of the takeoff site, and the question of whether she still had enough fuel left to cover the distance.

Below: The Amelia takes off for its flight to Fido Canyon, illuminated by the Fido Pup's lights.

Emilynn: "Climbing well on rocket power. I have more than enough LFO, so I'm going to use a lot of that for this climb out."
Thompbles: "Roger. Be sure to keep enough for dodging mountains. And landing, of course."
Emilynn: "Of course. Forty-nine hundred meters...adding the ion engines to the push. Looks good. Full throttle and the batteries aren't draining. Good sun pays to sleep in until afternoon."
Thompbles: "That always seems to be Aldner's opinion."
Emilynn: "Approaching six thousand meters...leveling off. Rocket engine off. Now at sixty-three hundred, cruising along at two-thirty-four meters per second on full throttle ions. Looking good."

With the full-power ion engines, Emilynn could easily maintain 6400 meters, which was enough altitude to overfly the highlands with almost a kilometer to spare. The icon off in the distance in the picture below is the Fido Pup's lander stage to the south of the Amelia. Note that one of the ships at the Fido Canyon Base was selected as the target so that its target indicator on the navball could be used to guide the flight.

Once beyond the highlands, the flight over the midlands biome was uneventful. The markers for the Fido Canyon ships started showing up about 90 km out from Fido Canyon Base.

Flying straight toward Fido Canyon Base would have involved climbing to fly over some quite high mountains on the southern rim of the canyon (and then having to very rapidly drop down to the Base). So, instead, Emilynn banked to the right so that she could fly down into the canyon where the midlands met the canyon.

Emilyn lost altitude and skimmed a few hundred meters over the rim of the canyon before the terrain dropped away below her.

Once safely in the canyon, Emilynn turned off the ion engines and flew using the rocket engine at quarter-throttle. Xenon is more precious that LFO on Duna...especially if the ISRU engineers finally deliver on their promise of equipment for making fuel and oxidizer (to be sent out in the next launch window).

Emilynn: "Amelia calling Fido Canyon Base."
Aldner: "Hey there, Hawk. Welcome to our neck of the woods."
Emilynn: "Thankie, Buzz. I'm coming in low and slow. Landing in a couple minutes."
Aldner: "Roger, Hawk. I'll set out the party snacks."
Emilynn: "Chutes open! Belly engine on."

Again there were strage lighting effects on the terrain. Apparently having a ship with lights on sitting on the surface can cause its square of terrain to light up (at least when a ship with lights on is overhead). The landing was smooth, touching down between the Lander Hab (730 meters away) and the Fuel Station (370 meters away).

After landing, Emilynn repacked the Amelia's chutes, raised the nose gear, and rovered on over to the Lander Hab.

Emilynn: "Howdy, Buzz! Long time, no see. Gimme a hug!"
Aldner: "It's nice to see you, too, Hawk."
Emilynn: "Where are Adly and Kelby?"
Aldner: "They are out in the Fido rover, surveying the highlands to the south of here. If we got good data from your scanners, they'll probably head back a ways along your flight path to gather surface data to correlate with your scans. So it's just you and me for the welcome party. Come on in to the Lander Hab."
Emilynn: "Sounds fine, Buzz. But how about you scurry on up to the command module so that I can have a shower first...I've been living out of the Amelia's cockpit for a while now."

The next day, Aldner drove the Fuel Fido over to the Fuel Station with Emilynn following in the Amelia. Then came the usual surface docking maneuvers to get all three ships linked to make the refueling easier (come on, Squad...a refueling hose...please!). There was a lot of Xenon to be transferred from small tanks to small tanks, so this was again tedious. And after the refueling...the undocking.

Aldner: "Hey, Hawk...I want to leave the Fuel Fido here by the Fuel's a real pain to drive. So how about letting me hitch a ride on the side of your DunaDog?"
Emilynn: "No problem, Buzz. Hop on."

I wasn't sure how well giving Aldner a ride on the side of the cockpit was going to work...I expected he would fall off partway to the Lander. But as the Amelia drove back to the Lander, Aldner slid up the ladder and eventually came loose from the top...and tumbled back along the top of the plane until he got snagged in the parachute mast...where he was stable for the rest of the drive. I was worried he might be all rag-doll-unresponsive after that, but when the Amelia braked to a stop at the Lander, Aldner slid forward and popped up onto his feet like he meant to do it that way all along. Why bother hanging onto a ladder when you can recline leisurely on top of the wing?

After a short stay at Fido Canon Base, Emilynn was ready for the final leg of the Amelia's test flight...the return to Duna Base. This would be another long flight, but it's one that Aldner had already made in the opposite direction (which is actually the more difficult direction, since as Emilynn flies west she will have the sun moving with her, giving better illumination on the solar cells). So, again, it was a matter of sleeping in late and getting ready to take off when the sun was down to around 30° above the western horizon.

For the climb out of Fido Canyon, Emilynn was profligate in her use of LFO, running the Amelia up to 7200 meters before turning on the ion engines and then cutting the rocket engine. She was able to run the ions at over 83% throttle...but was still losing altitude. An additional rocket boost was needed to get the plane beyond the highest terrain west of Fido Canyon...but then the sun angle improved and she could up the ions to 100% to cruise along.

Although there is a long stretch of highlands west of Fido Canyon, they aren't particularly HIGH highlands, so the Amelia was able to cruise above them. The only significant obstacle along the path was the mountain range that makes up the western rim of a crater. Using just the ion engines, Emilynn was able to gradually increase the Amelia's altitude to over 7000 meters, which was sufficient to fly above the western rim mountains without need of a rocket boost.

Beyond the crater it was smooth sailing. Ike rose above the western horizon (due to Emilynn's westward motion) and the Amelia passed out of the highlands into the airspace above Adly Planitia. Happily for me, the plane handles well enough that the cruise phases can be flown at 2x or even 3x physical time warp.

Emilynn cut the ion engines 24.5 km from Duna Base and glided the rest of the way. She overflew the base at 600 meters, making sure to land a couple kilometers to the WEST of her starting point, just to be sure that the Amelia had made a complete circumnavigation of Duna by air.

Emilynn drove the Amelia back east to Duna Base. This last leg of the around-Duna trip used about 50% of the plane's Liquid Fuel and Oxidizer, and about 65.5% of its Xenon.

Emilynn was quite happy to get back to the spacious Duna Base ship...and was even happier when Thompbles presented her with the Flying Duna patch in recognition of her flying-around-Duna expedition, awarded by the Geschosskopf Aeronautical Association back on Kerbin. A prestigious honor indeed.



That wraps up what I needed to finish in version 0.90... So, next time, the version 1.0 hammer hits the universe.