AVK Spaceworks - [r4] [12/19/11] [NEW: Cyclone 1.1]

[venku122]

Your fuel tanks are awesome

[aevionknight]

The Cyclone model is 99% done, just a few small touch-ups and I\'m ready to do the KSP import (need to fix some smoothing on the CMG and give the flaps some actuator arms).

Assembled view:

Exploded view:

Sadly I think the only two things that will be useful in other builds are the heat shield and CMG (1m and .43m respectively), everything else is custom to the Cyclone. I think that\'s okay for this pack - I wanted to squeeze a fully-functional orbiter into a tiny package, which is difficult to do with stock stuff.

I intend for almost all of my future stuff to be more interchangeable.

[Spoot Knight]

Beautiful. I love your idea of adding the RCS panels seperately but merging into the pod.

[aevionknight]

Cyclone rocking a coat of Range Safety Orange in the VAB. All parts are functional, now I\'m going to actually tune the thing and then texture it.

[Spoot Knight]

Ooh. Do the flaps move according to the control type being applied?

[aevionknight]

Yep! The flaps move, the thrusters work. The main engines have 'gimbal' (they don\'t move, they do differential throttling).

[Lunniy Korabl]

This is looking very exciting! Keep up the good work.

[venku122]

This will probably be the best command pod ever. All self contained

[aevionknight]

Okay, I have the orbital handling down pretty well now. It\'s going to take a few days of tweaking and tuning to get the re-entry flight dynamics correct. I will probably have to split the RCS tank into two pieces and make one of them a lifting body to actually get some cross-range out of it.

I was hoping for a completely unpowered pressure vessel w/ RCS and the gyro, but no dice. The thrusters don\'t seem to fire at 100% when doing rotation, so I have to jack up the thrust to get decent control, but then they become essentially another main propulsion source all by themselves and can send you to the Mun (literally - I did this). I decided to give the pressure vessel a small torque and scale the RCS way back - it is useful for orbital touch-ups and linear motion, but not so much rotation anymore.

[aevionknight]

Friends! I return from an expedition deep into the heart of the KSP aerodynamic model armed with nothing but spreadsheets and a vague guess about how it all works.

I think I\'ve finally got something flyable. Re-entry is downright fun in this thing - it has just enough of a lift-to-drag ratio to give you some really nice maneuverability and cruising range.

I balanced the center of lift and center of drag such that the lifting body stalls out at about 200 m/s - this is a good thing! Once you\'ve decelerated to about this speed you\'re at maybe 3000 meters altitude, so you can fire up the engines, mash the pitch controls and do the pitch-over, then settle in for a nice propulsive landing.

I\'m going to do a few more flights tomorrow to really dial in these values, then go into texturing. Also I\'m going to whip up a nice aerodynamic decoupler that goes from the 1.5m square base back to a 1m rocket stack.

[Spoot Knight]

Yeeesssss.

Sounds good.

[MC3craze]

Friends! I return from an expedition deep into the heart of the KSP aerodynamic model armed with nothing but spreadsheets and a vague guess about how it all works.

I think I\'ve finally got something flyable. Re-entry is downright fun in this thing - it has just enough of a lift-to-drag ratio to give you some really nice maneuverability and cruising range.

I balanced the center of lift and center of drag such that the lifting body stalls out at about 200 m/s - this is a good thing! Once you\'ve decelerated to about this speed you\'re at maybe 3000 meters altitude, so you can fire up the engines, mash the pitch controls and do the pitch-over, then settle in for a nice propulsive landing

I\'m going to do a few more flights tomorrow to really dial in these values, then go into texturing. Also I\'m going to whip up a nice aerodynamic decoupler that goes from the 1.5m square base back to a 1m rocket stack.

I need this...

[aevionknight]

I really hit the sweet spot tonight.

1. The RV has just the the right amount of control authority. By grabbing the flaps hard-over, you can hold a 15-20 degree angle of attack throughout the whole entry, but you can\'t cause it to tumble. This seems like a reasonable amount of authority for the size of the flaps.

2. The RV doesn\'t stall until just over 45 m/s (!). This gives you a nice smooth deceleration with good control almost the entire way in.

3. When it finally stalls, the RV actually does the pitch over all by itself! It\'s almost too easy to light the engines and gain stability for the landing. This will be offset by the fact that you probably won\'t have a lot of fuel left by this point, so this is a really neat behavior.

4. Lift-to-drag is a bit higher than I\'d like but not absurd. I tried to cut this down but it ended up messing with the wonderful performance I had, so I\'m going to leave it.

I\'m baselining this configuration for the first release. Stuff left to do before then:

1. Texturing

2. Decoupler

3. Finalize propellant budget (I\'ve been flying on nearly-infinite fuel to tune the aerodynamics, need to ensure the orbital delta-v feels right).

Re-entry at max Q (5.4 G), holding 20 degree angle of attack w/ full flap extention.

[Spoot Knight]

That\'s great, this will be fun to fly while I wait for the release of other crewed vehicles.

What do you plan on doing for the textures?

[MC3craze]

This will be the perfect orbital platform, I\'ve always liked things like this.

[Herpderpsslerps]

I really hit the sweet spot tonight.

1. The RV has just the the right amount of control authority. By grabbing the flaps hard-over, you can hold a 15-20 degree angle of attack throughout the whole entry, but you can\'t cause it to tumble. This seems like a reasonable amount of authority for the size of the flaps.

2. The RV doesn\'t stall until just over 45 m/s (!). This gives you a nice smooth deceleration with good control almost the entire way in.

3. When it finally stalls, the RV actually does the pitch over all by itself! It\'s almost too easy to light the engines and gain stability for the landing. This will be offset by the fact that you probably won\'t have a lot of fuel left by this point, so this is a really neat behavior.

4. Lift-to-drag is a bit higher than I\'d like but not absurd. I tried to cut this down but it ended up messing with the wonderful performance I had, so I\'m going to leave it.

I\'m baselining this configuration for the first release. Stuff left to do before then:

1. Texturing

2. Decoupler

3. Finalize propellant budget (I\'ve been flying on nearly-infinite fuel to tune the aerodynamics, need to ensure the orbital delta-v feels right).

Re-entry at max Q (5.4 G), holding 20 degree angle of attack w/ full flap extention.

Dude, that thing is like the Traffic cone of death, I\'d take it as it is!

[Spoot Knight]

Dude, that thing is like the Traffic cone of death, I\'d take it as it is!

[me=SpootKnight]looks at the Bob\'s Backyard Science Kit thread, then looks at this quoted post again.[/me]

Traffic cone nosecones?

[Herpderpsslerps]

[me=SpootKnight]looks at the Bob\'s Backyard Science Kit thread, then looks at this quoted post again.[/me]

Traffic cone nosecones?

Sounds kerbal to me!

[Warringer]

I would like to humbly request a version of the lander tanks with the center filled so that they can be attached to another set of those lander tanks.

[aevionknight]

I would like to humbly request a version of the lander tanks with the center filled so that they can be attached to another set of those lander tanks.

Isn\'t that just a cylinder? I think there are a few cylindrical tanks floating around the mod forums. : )

[CardBoardBoxProcessor]

@_@ nice. reminds me of something i seen somewhere

buy hey. it is neat not so much a fan of cone engines. have you concidered aero spike engines ? like the fin kind?

quick question. how did you get the RCS blocks to attach? stack (blue orbs) or node_attach? if blue orbs how do you rotate them like that?

[aevionknight]

I readily admit to stealing the shape of the EXPERT RV, I love the look of it.

By 'fin kind', do you mean a linear aerospike engine, like the one that was developed for the X-33? In that case, I did look, but I decided against it:

1. I wanted a docking hatch in the center of the baseplate, so couldn\'t put part of an engine there.

2. The engines are used 90% in space, with a short burst for landing. An aerospike engine requires a gas generator and other complexity, when you really just want a lightweight pressure-fed engine. The altitude compensation was also unnecessary.

All parts are stacked. The RCS blocks just have an attachment node in the +z axis, rotation isn\'t required.

[CardBoardBoxProcessor]

can you assist me? i couldn\'t get my RCS to rotate off stack nodes but i would much prefer stack nodes. how might one do this?

for example. what si the rotations of the stack they attach to and the rcs block itself?

this is the problem. i need it solved i cannto figure it out for the life of me.

[aevionknight]

I\'m not sure I quite understand your problem. Here\'s what I did:

[list type=decimal]

[li]Gave my capsule body four nodes called [tt]node_stack_rcs1[/tt] through [tt]node_stack_rcs4[/tt].[/li]

[li]Gave my capsule body [tt]stackSymmetry = 3[/tt][/li]

[li]Gave my RCS thrusters a node called [tt]node_stack_top[/tt].[/li]

[tt]stackSymmmetry[/tt] is vital, and your nodes need to start with [tt]node_stack_[/tt]. I believe it\'s also important to number your symmetrical nodes 1 - N with the same base name.

Best of luck.

[CardBoardBoxProcessor]

ah. let me go test this. these are things I have yet to try due to lack of such knowledge of them existing. I thank you kindly!

also, my i inquire as to what the reetry flaps are? are thy like fins but the axis is changed so they stand up?

ah gosh there we go thank you sir. you have saved the durgun capsule.