Jump to content

Ion Plane Development Challenge

Recommended Posts

Backstory (please read at least once, but it will get cluttery after a while):


A long time ago, before version 1.0, ion engines produced full thrust at sea level. Even then, they were seen as difficult contraptions to master, and the Ion Glider Collier Trophy was started, which ultimately culminated in an Ion only SSTO!

Then came 1.0, and with it, the new aero model. Ion engines produced next to no thrust at sea level, and drag now made sense. It became a topic of wide interest - would anyone be able to build an ion plane in the new atmosphere? This started the Ion Plane Research Challenge:

Long story short - an ion plane that could take off from the runway was never built. People came close. However, (not to brag) I managed to take off and sustain flight by first building up speed with rover wheels and launching from Kerbin's tallest mountain. I incrementally improved my design, and after over two dozen designs, I came up with the Ion Plane 9P, which flew to just over 18 kilometers, carried a Kerbal, and splashed down in the ocean mostly intact, jettisoning only the launch cart, and breaking only the wing extensions.


The current altitude record for an ion driven plane is @EvermoreAlpaca, also known as Bradley Whistance, at 19193 meters. While being multistage and unmanned, it managed to take off at a lower altitude, and managed to be solar powered - something that I never got to work!


So that brings us to today. The research has been done, it is possible to build ion driven craft. Now, for the development...



Welcome to the Ion Plane Development Challenge! This thread will be a place to work towards many diverse ion plane related goals using a variety of different methods. As such, it's not a challenge with one set goal, it's a collection of challenges with loose guidelines, and hopefully an encouraging atmosphere, as opposed to Kerbin's atmosphere... Development towards challenges not listed here is encouraged. This thread is about branching out now that we know Ion planes are possible.

General rules:

  1. Ion engines are the only form of propulsion allowed. No propellers, no K-drives, no rockets, jets, RCS, ladder-drive, on purpose decoupler propulsion, etc. Only ions.
  2. The electrical power for the ions can come from anywhere, be it solar panels, RTG's, fuel cells, jets pointed in opposite directions to make use of alternators...
  3. Stock parts, stock performance. Do not use any modded parts on your crafts (they can be installed but not used), and do not use any mods that modify physics.
  4. Visual and informational mods are fine. Autopilots are also okay, as this challenge is mostly about design, but it will be noted on your submission. Launching from a mountain is allowed, but it will be noted in your submission. Be sure to mark down how high you took off from!
  5. Except in categories that forbid it, you can use a launch cart with rover wheels, or a catapult, or similar mechanism to launch your craft. However, this will be marked in your submission.
  6. Any method of getting to the launch site is fine. Use of HyperEdit and VesselMover are encouraged in this case.
  7. Manned or unmanned is fine, but it will be marked in your submission.
  8. For some categories, air launching is okay, most notably the low altitude category.
  9. Any KSP version from 1.0 onward is allowed, mostly to facilitate those who haven't updated to 1.5 yet, like me. However a recent version is encouraged.
  10. Part clipping is allowed, but it will be noted in your submission.
  11. Generally be sensible, don't cheat. Have fun!


Main Challenge Categories

In some categories, the current known first and second place record holders are shown for comparison purposes. These challenges have been chosen to push development on all fronts, you may suggest a category if you feel that one is missing.

Ion Plane Altitude Record - Absolute altitude record, using any tricks.

  1. @Ultimate Steve, 194453m in the Ion Plane 13C (Single Stage, Reusable, Fuel Cell, Manned, Part Clipping, Mountain)
  2. @EvermoreAlpaca, 19193m, not sure about the name (not from this thread, multistage, solar, launch cart, unmanned, Launch from the mountain west of KSC)
  3. @Ultimate Steve, 18048m in the Ion Plane 9P (not from this thread, launch cart, fuel cell, manned, part clipping, Launch from the highest mountain on Kerbin)
  4. @Ultimate Steve,  11822m in the Ion  Plane 12D (Single Stage, Reusable, Fuel Cell, Manned, Part Clipping, launch from the highest mountain on Kerbin)

Ion Plane Speed Record - Must be attained while in level flight, and not after a dive.

  1. @Ultimate Steve, 250.5m/s in the Ion Plane 13C (Single Stage, Reusable, Fuel Cell, Manned, Part Clipping, Mountain)
  2. @Ultimate Steve, 222m/s in the Ion Plane 9P (not from this thread, launch cart, fuel cell, manned, part clipping, Launch from the highest mountain on Kerbin)
  3. @EvermoreAlpaca, 114.7m/s, not sure about the name (not from this thread, multistage, solar, launch cart, unmanned, Launch from the mountain West of KSC)

Ion Plane Range Record - Self explanatory. Leave a marker at your starting place and measure distance. If you manage more than 100 kilometers, then use the F3 display, although if you quicksave/quickload during your flight it will reset, so be careful!

  1. No recorded attempts.

Ion Plane Low Altitude Record - Isp decreases as the altitude decreases. This is for the lowest altitude where you can demonstrate acceleration while maintaining or gaining altitude. 

  1. @Draconiator, 3480m, name unknown (not from this thread, unmanned, solar, launch unknown)

Ion Plane Cargo Challenge - Measured by tons of ore carried. Must fly at least 10 kilometers from the starting point without falling below the altitude at which you start gaining altitude. You must also start gaining altitude very soon after the starting point.

  1.  No recorded attempts.

Ion Plane Airliner Challenge - Measured by number of Kerbals carried. Score is distance traveled in kilometers multiplied by the number of passengers. Must carry a minimum of three Kerbals and travel a minimum of 10 kilometers to qualify. The moment you fall below your launch altitude, the challenge is over, as otherwise you could just launch really high and glide really far. The craft must be single staged and fully reusable.

  1. No recorded attempts.

Other Cool Stuff - Experimental planes that may break the rules, but are impressive nonetheless.


Additional Challenges

World firsts, as far as I know, that may or may not be possible, but would be interesting to try. Also some minor leaderboards.

Runway Challenge - The holy grail. Make an ion plane that can take off from the KSC runway under its own power and maintain altitude and velocity.

Laythe Challenge - Make an ion plane that can take off and fly around under its own power from within 100 meters of sea level on Laythe. If this is done it will turn into an altitude scoreboard.

Duna Challenge - Make an ion plane that can fly on Duna.

  • @Xurkitree with his Surya 3, relying on mostly battery power! The design is capable of reaching above 10 kilometers and is recovered with chutes. It's also fully reusable and manned.

Space Challenge - Get into space, starting on Kerbin, only under ion power.

Battery Challenge - Fly the highest, farthest, or fastest without any power generation devices. Will be a leaderboard if enough interest is gathered.


Tips and Tricks

  • Ion engine thrust is not occluded by anything. You can stack them one in front of the other, and put them inside cargo bays. They will still function as normal.
  • Kerbin's tallest mountain is near 61.6N 46.4E.
  • An angle of incidence helps here.
  • Make sure to properly autostrut long strings of ion engines, and long wings!







My new attempt, for this challenge specifically:


Rather than focus on any specific challenge, in order to reawaken my ion plane skills, I tried to build something that was alright at everything while being manned, reusable, and controllable. It would also not require the use of a launch cart. This means, that while carrying loads of fuel and being really heavy, it didn't perform too terribly well, but that may be because the draggy bits are in a fuselage, not a cargo bay. Next time I'm going to replace that part with a fairing, I think.

After initial failure with the solar powered Ion Plane XI series, I went back to my old, inefficient but simpler way of fuel cell ion planes, with the Ion Plane XII series. After several revisions, I ended up with the Ion Plane XII D.


It's powered by 64 ion engines if I remember right, and 32 fuel cells, all stuffed in those two structural fuselages. So, yes, part clipping was definitely used. The takeoff altitude was around 6500m, I'm taking off from a flat-ish part near Kerbin's tallest mountain. Takeoff is done under the plane's own power. It has 5 landing gears.



After several minutes of flight it ran out of liquid fuel, oxidizer, and xenon and attained a final altitude of 11822 meters, and went as fast as about 80 meters per second, although I won't put that on the board because it's unconfirmed.


After that, we gently dive down and splash in the ocean. I have not tried a land landing, as the ocean does a pretty good job of cushioning the blow.


After landing, Valentina emerges, victorious after her flight! While it didn't set any records, it helped prove and disprove several experimental technologies. For example, a cargo bay or fairing will be used to properly shield the engines and fuel cells. Also, I might take another look into solar ion planes, after a while that fuel gets heavy to carry around.

Submitting Altitude - 11822 meters.



Edited by Ultimate Steve
Link to post
Share on other sites

This is an interesting challenge! Drawing from my non-existent experience in building ion planes, I've decided to go against what seems to be the trend and towards minimalism.

I don't have a properly working plane just yet but I am working on the iKarus6000: twin-engined and weighing just over 3.2t, it can takeoff on its own on a slope at 6,000 m (I'm using a lower mountain that has nice slopes to launch from), is somewhat controllable and generates enough electricity if you launch it at noon, but cannot sustain level flight just yet: best I have done is maintaining airspeed with a -0.6 m/s vertical velocity. I've made a three-engine version that can get in a small climb but then the solar panels are not enough and I would have to add more, maybe it's the way to go?

For specific entries I might end up using a launch cart to get rid of landing gears or make it unmanned, to reduce both mass and drag.


Edited by Gaarst
Link to post
Share on other sites

I believe I have broken the altitude and speed records!

This is the Ion Plane XIII C, or 13C. The main changes from the 12D is the switch from structural fuselages to a fairing, the inclusion of two vertical stabilizers, an increase of angle of incidence from 5 to 10 degrees, and 25% more fuel (on the same amount of engines).


Interestingly enough, one of the hardest parts of the mission is taking off without clipping the wings. The landing gear really like to bounce in a positive feedback loop. For this mission, I drove off the mountain and fell for a bit, before pulling up.


This is the moment I knew I was actually in the air instead of bouncing.



My strategy for flying this thing was to keep the plane accelerating at the lowest possible angle where I was still climbing at a decent rate. If my velocity started dropping, I'd nose down. This allowed me to gain a significant amount of velocity down low, which translated into, at one point, a 25m/s constant vertical climb while still maintaining horizontal velocity.


After 8km it gets vastly more forgiving to fly. I continued the pitch down method for a while until the air became thin enough. Then I had to start pitching upwards.

On previous high altitude craft, the limitation was how far I could pitch. I'd have fuel left and not be able to go higher because I couldn't pull up.


This is the highest speed I have proof of, 250.5m/s. At this point I think I had adjusted all of the authority limiters to 150 and was gradually increasing the pitch trim. Unfortunately, at this point I should have nosed down a bit to pick up speed while maintaining altitude so I could effectively climb. I think. But looking at fuel levels, I decided that would have taken too much time and pulled up all the way at just over 18 kilometers.


And it worked! I still had a little fuel left, but not much. Altitude record is now 19453m.

The limiter for this craft is now the speed it can reach at high altitudes. More fuel could allow more time to pick up speed. Unfortunately, take-off mass is already approaching a limit. I could get away with a bit more, though. I think the next step is optimizing drag and dry mass a bit more.

I think I'll make one more attempt with the fully reusable manned version with a goal of 20-21km and then move on to using other tricks to push the record.


"Now, where are the recovery crews?" -Valentina

Link to post
Share on other sites

Cool job! Yesterday I just did a proof of concept Duna Ion Plane, and its actually pretty easy. It took off, flew around, destablized and crashed. I had Unbreakable cheats on so that I don't crash on take off, but then, this was just a test. I'm planning to improve the Surya 1.

Link to post
Share on other sites
11 hours ago, Xurkitree said:

Today, I improved upon the Surya 1, to create this.


Congratulations, you are the first person, to my knowledge, at least, to demonstrate ion powered flight on Duna!

And I think you might be on to something with those batteries... I did the math, and if I did it right, if you only need to power the ion engines for five minutes or less, then batteries are actually lighter than the solar panels, while most likely being lower drag. Plus, you can jettison those batteries as they get empty. I'll mess around with this in my newer designs.

Link to post
Share on other sites

hey hey @Ultimate Steve

I think I did a thing.

Using totally hacked and absurd OP parts I made a runway takeoff capable ion plane.



Seriously though, don't count this. I edited the file for some absurd numbers. The cockpit has capacity for something like 5*10^18 units of electric charge and the xenon tank has something like 315,000 units of xenon in there.


I should give this an honest shot sometime, but uhhh.... I felt like doing this just for fun.

Serious non-hacked entry maybe coming soon(tm).

Link to post
Share on other sites
  • 4 months later...
  • 2 weeks later...

This is continuing to accelerate after the Panther has died. Not sure if that really counts but as long as it starts at high speed and altitude from the Panther's help, this will go very fast and high in one stage.


Link to post
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...