Xeldrak

What did you do in KSP today?

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This was a large experiment I *won't* be repeating, as it killed performance entirely.  (2 second pauses every 2 seconds the craft was in scene...), but it worked in the end.

Trying out the new robotics parts for deploying an automated science rover to the Mun:

download

download

Yes, every one of those robotic parts moved during the deployment, and the rover was rotated 180 between storage and release.

The robotics parts on their own didn't kill performance - but they didn't hold the rover inside the cargo bay either.  To fix the latter I used Quantum Struts from the bay to the sides of the rover (you can see one in it's deactivated state as that small dot on the inside of the cargo bay), but that was what caused the performance to drop.

 

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12 minutes ago, DStaal said:

The robotics parts on their own didn't kill performance - but they didn't hold the rover inside the cargo bay either.  To fix the latter I used Quantum Struts from the bay to the sides of the rover (you can see one in it's deactivated state as that small dot on the inside of the cargo bay), but that was what caused the performance to drop.

Could try using struts on zero-force decouplers so they break when you stage to release the robotics, but I think they're adding same-vessel collisions back in to solve some of these problems in other ways.

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26 minutes ago, Loskene said:

Could try using struts on zero-force decouplers so they break when you stage to release the robotics,

From my understanding, that would be essentially the same as how I used Quantum Struts.  I just didn't need a decoupler, and I did need EC.  But the actual strut connection should be the same I believe.  I didn't watch to closely where they were connecting, so it's possible they were anchoring on a surface-attached part however.  (Which is warned against.)

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Posted (edited)
3 hours ago, DStaal said:

This was a large experiment I *won't* be repeating, as it killed performance entirely.  (2 second pauses every 2 seconds the craft was in scene...), but it worked in the end.

Trying out the new robotics parts for deploying an automated science rover to the Mun:

download

download

Yes, every one of those robotic parts moved during the deployment, and the rover was rotated 180 between storage and release.

The robotics parts on their own didn't kill performance - but they didn't hold the rover inside the cargo bay either.  To fix the latter I used Quantum Struts from the bay to the sides of the rover (you can see one in it's deactivated state as that small dot on the inside of the cargo bay), but that was what caused the performance to drop.

 

XD, nice work. 

(A simple ramp would have been one robotic part >_<)

((but not as cool!))

Edited by Dale Christopher

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I could have belly-landed it and used zero robotic parts.  ;)  The main goal was to play with the robotics system, as much as anything else.  Hmm.  A vertical ramp could have worked, but it would have still taken several robotic parts, and been harder to get the rover off of.  (Side note: *all* of the fuel tanks on this are mounted at the top - there was a secondary mission requiring KIS storage bundled into this trip, and the lower round tank therefore needs to be within Kerbal height of the ground for access.)

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57 minutes ago, The Doodling Astronaut said:

Came back after successful surgery :P. Going to have a lot of downtime so let's find some surface features 

Welcome back & good hunting!

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I kept working on my ornithopter. I think I’m getting close to generating meaningful thrust. Maybe I need to push down as well as backwards? Maybe I’ll just go with a dolphin/chinese dragon kinda thing where just the tail flaps?

My main issue is floppy robotics. Even with turning off damping and fiddling with autostruts, I just can’t get them to stop flopping!

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14 minutes ago, The Doodling Astronaut said:

JUST NOW GILLY LANDER ONLINE FOR LANDING GET READY FOLKS IT'S HAPPENING NOW :)

PICS OR IT DIDNT HAPPAN!!!

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i deleted the universe then managed to go 100 times the speed of light

screenshot89.png

screenshot78.png

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Today for me can only be described as SSTO Follies...hehe.

I've always wanted to build things like spaceplanes but have been hesitant due to my relative inexperience. But, you know, sometimes, you have to push past it and just dive in and start slapping parts together in addition to reading guides and FAQs. I have an SSTO project in progress that shows promise (and I've actually gotten it to fly) but a few niggling problems connected to CoM still plague me but I persevere in between some of the most spectacular crashes I've ever set up. I know I'm closing in on a solution and the trial and error is really fun.

Wallace

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Attempted to build an autogyro. failed many times. At last, I slapped coaxial rotors and it manage to fly. But still require constant attention due to shifting COL.

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Two failures in one

image-15.png?w=768

Antares 2.0! Falcorn Heavy tipping tower falls down

close.png?w=835&h=

Gilly landing failure. It didn't crash (that's impossible with Gilly) but instead due to engine gimbal failure, Maneuver failure, Electric failure, and a lot of other things, the lander failed to finish it's mission making the first landing failure since Mohome, the first attempted moho lander from my agency.

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26 minutes ago, The Doodling Astronaut said:

Antares 2.0!

not really, it had almost no fuel in it

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3 minutes ago, Coolinee Kerman said:

not really, it had almost no fuel in it

True but antares is a lot smaller. So a little bit same explosion size

image-16.png?w=768

WHO HOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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2 minutes ago, The Doodling Astronaut said:

True but antares is a lot smaller.

Antares 120 was about as tall as the first stage, also this one was in the water, if it was as powerful it would've blown the barge away a bit. doesn't really matter though

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1 minute ago, Coolinee Kerman said:

Antares 120 was about as tall as the first stage, also this one was in the water, if it was as powerful it would've blown the barge away a bit. doesn't really matter though

Meh It's still a joke

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I'm still tooling around with the BAK-9900 Seraph and variants.

I made two full trials yesterday with a different rotor power solution -- four powered rotors instead of six contra-rotating, freewheeled pairs --, a heavier orbiter, and more fuel on the lifter. I'm going to have to try again with the contra-rotators because something counterintuitive happened: I got the one with more power but less rotor up to 30k pretty easily, with a much lower blade pitch than the classic freewheel-powered one. However it climbed much more slowly through the thicker air. Basically, optimal climb was < 10 m/s at a pitch of around 5 degrees (rather than 7), and when I dropped it to around 2 degrees at high altitude it maintained a climb of about 5 m/s up to 30 km and beyond. After that, the increasingly fast rotors summoned the Rotor Kraken and the craft started accelerating its climb in a most worrying fashion, so I stopped it and flew to orbit. 

It was considerably more difficult than with the original however. It clearly struggles with my 6-ton orbiter where a 3-ton one went up easily. But clearly there is room for scaling up the payload, a 2-kerbal craft would certainly be possible.

I'm now focusing on the orbiter module, which I slapped together rather hastily. The main issue with the current version is re-entry, getting it through the thermal shock without burning retrograde is iffier than I would like. I also thought it might be possible to make it more efficient. I tried a whole bunch of different designs including one rather wonderful one where a kerbal was sitting exposed on a row of Oscar-Bs and a wing; unfortunately kerbals are really draggy so the aerodynamics did not work because it was delightfully stupid. Ultimately I did end up with a design that should be slipperier going up, draggier coming down, has less dry mass, a better TWR, and more dV -- so, better in all ways that matter. The only downside is a tiny bit of thrust torque which I wasn't able to completely eliminate, still there's not so much of it that it's seriously bothersome. 

So today's program will be sending that up with the original BAK-9900, with the freewheeling rotors, and I will see if I can get it to climb higher by considerably decreasing the pitch near the ceiling.

This project is slow because it takes about an hour real-time to get to orbit, and almost as long to get back to the surface.

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Posted (edited)

Today I'm sploring some Mun craters ^_^

Still a lot of fuel in the sky crane! ...it just become my permanent roof racks XD

rhedxreg.png

Edited by Dale Christopher

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Posted (edited)

All right, I made the experiment. Interesting stuff. I believe I now have a genuinely usable recoverable Eve launch system, even if operating it will take a lot of infrastructure and effort. I still have to prove the final design in a full experiment, but I'm pretty confident it will work -- I had to tweak my orbiter's aerodynamics in a separate partial experiment because the one I used in the full one failed to re-enter safely; however I'm fairly certain that didn't affect any other parts of the mission. In particular it didn't add or remove any parts so mass is unchanged.

Discoveries:

(1) More motors + fewer rotors -> higher ceiling but slower ascent. 

The BAK-9901X with four powered motors each running a single pair of two-blade rotors will crack 30 km on Eve, and will then summon the Rotor Kraken. The BAK-9900 with three powered rotors on freewheels running two pairs of two-blade rotors each has a practical ceiling of ca 27 km, but it will get there a lot faster, and consume significantly less fuel in the fuel cells to do so. On balance I prefer that solution. With the new orbiter she has enough dV and TWR to easily get an Ap over 70 km in a nice low arc, giving me plenty of time to send the orbiter to orbit.

(2) I now have a rather neat-looking orbiter/return module which can reliably re-enter the Eve atmosphere. Burn down to 90 km Ap, set Pe to 24 km, and hold a tail-first attitude of about 60-70 degrees from surface, and it will stay within its thermal limits... barely. Because it has wings it's also somewhat controllable in the final part of the descent -- you can fly it like a glider where you want. However the CoM and CoL are perfectly aligned so expect it to handle like a maple leaf. The orbiter also has somewhat excessive dV -- it was reading 298 m/s after my somewhat sloppy insertion (sloppy because I needed to hurry to get back to the lifter). I haven't been able to build a better-tuned orbiter that still has the aerodynamics to survive re-entry so I think I'll leave it as it is. There's not much point not carrying the fuel as the craft has sufficient TWR also.

(3) The BAK-9900 lifter has no need of parachutes when returning. It's quite easy to bring down safely on autorotation only. So I'm going to ditch them. Instead I'm going to see if I can add some KAL-1000s for preset blade positions, now that I've discovered the optimal ones for both ascent, descent, and touchdown.

(4) The hardest part of the trip is lift-off, and it's especially hard if the craft is leaning more than just a little. You have to finesse torque and blade pitch to keep the blades from buckling, you have to lift off fairly briskly to stop the landing legs from dragging and tipping the craft over, and there is a risk of getting into an unrecoverable pendulum motion. I'm not quite sure what to do about this, but I am thinking about it. The main problem is that running a full up-and-down trip is so time-consuming that iteration is difficult -- and if I fix the behaviour on lift-off, I risk screwing it up on orbit or ascent.

A few pictures from the latest experiment, craft will be re-published when ready:

dAxxJhM.png

VZOkPdI.png

3r7CAq0.png

Edit: All right, I did the final experiment. The (simulated) mission was 100% successful, and required no quickloading. I've updated the craft on KerbalX

The pictures are very similar to the above so here's just two from the bit that failed the previous time:

tfxkt5B.png

GdlHvid.png

Man oh man what a project this was. I think I'm done tinkering with it. Maybe I'll eventually make the infrastructure for it -- it needs a service craft to refuel it from an ISRU, with a crane that can pick up and lift the orbiter back where it belongs. That ought to be fun and not so time-consuming.

By the way, if you fly it carefully, that little orbiter is an SSTO in its own right... on Kerbin.

Edited by Brikoleur

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