The Avatar Challenge: Master All Four Elements

[foamyesque]

Awight people, rules are simple.

Build a rocket that can:

• 
  [li]Fly, level and under power, at a speed greater than 100m/s at an altitude below 2km, for at least one minute[/li]
  [li]Achieve an orbit at an altitude of at least 100km, with an eccentricity of no more than 0.05 (for an orbit of the specified altitude, this means a periapsis of 95km and an apoapsis of 105km)[/li]
  [li]Land on the KSC runway, from an altitude of at least 5km[/li]
  [li]Achieve a speed of 100m/s or greater while on water[/li]
  

Bronze medal: Rocket can complete all four, in seperate missions.

Silver medal: Rocket can complete all four in a single mission.

Gold medal: Rocket can complete all four in a single mission without the use of parachutes or staging.

Allowed part packs are Sunday Punch\'s Wobbly Rockets, C7\'s Flight Pack, FAKOOM ASASes, and Nova Silisko\'s SIDR.

Good luck.

[Zeroignite]

What counts as 'on water'? In your 230 m/s screenshot it looks like you\'re just dipping your landing gear in while flying, not really buoyant. Can I just run with a wingtip underneath? (It\'s still a good test of ship stability/maneuverability.)

[foamyesque]

What counts as 'on water'?

From a dead stop (<1m/s) flat on the water to the specified speed, without having the entire craft leave the water\'s surface (i.e there must be at least one part below water).

[Tim_Barrett]

What was your take on the challenge, how thy OP do?

[foamyesque]

What was your take on the challenge, how thy OP do?

I\'ve managed all the component pieces, in some cases to considerable excess. I haven\'t strung them all together myself; I goofed my re-entry on the attempt and wound up too far away from the KSC to perform the landing.

It is possible, including the gold medal portion.

[Zeroignite]

Water is by far the hardest part of this. Landing in the water is no problem, but I can\'t figure out how to go from 0 to flying in the vertical envelope of two meters. I keep either taking flying up or bouncing down into the water and exploding. I\'ve also tried making 'keels' of both wings and stacks of landing skids, and have had nothing even close to success. It\'s made especially problematic when parts tend to want to float.

Hints would be greatly appreciated.

[foamyesque]

Water is by far the hardest part of this. Landing in the water is no problem, but I can\'t figure out how to go from 0 to flying in the vertical envelope of two meters. I keep either taking flying up or bouncing down into the water and exploding. I\'ve also tried making 'keels' of both wings and stacks of landing skids, and have had nothing even close to success. It\'s made especially problematic when parts tend to want to float.

Hints would be greatly appreciated.

A tuned ASAS module will help a lot in holding you level to the water\'s surface while you go for the 100m/s. My designs have a strong (intentional!) tendancy to pitch up when under thrust in atmosphere and come to rest at an upward angle on both land and water, so I need pitch-down to avoid premature liftoff. A good ASAS module is better at the job than I am as a pilot.

[Zeroignite]

Ah.

I just downloaded your tuned ASAS modules today, haven\'t tried them yet. Hope so.

I have a bit of an irrational bias against ASAS. It\'s definitely irrational though until we get features like trim or control-range limiting.

[comradephil]

Eh, fly by wire is essential when flying a rocket plane more complicated than, say, an X-15

[rdfox]

Eh, fly by wire is essential when flying a rocket plane more complicated than, say, an X-15

Actually, even the X-15 used fly-by-wire, at least for the third (and final) vehicle and the exoatmospheric controls. Per Wikipedia:

The X-15 had multiple control systems for the pilot, including a traditional rudder and stick, but also another joystick on the left which gave commands to the reaction control system (RCS). There was yet another joystick on the right for use during high G maneuvers that augmented the center stick. The X-15 also had a 'Stability Augmentation System' (SAS) which gave extra inputs to the aerodynamic controls to help the pilot maintain control. The reaction control system could be operated in two modes: manual and automatic. The automatic mode used a feature called 'Reaction Augmentation System' (RAS) that helped stabilize the vehicle during high altitudes. The RAS was typically used for around three minutes of a X-15 flight before being automatically turned off. The X-15 actually had two different types of controls, one type was just discussed and was used on airframe 1 and 2, and another on airframe 3. Airframe 3 had the MH-96 flight control systems, allowing one joystick in place of three and allowing simpler pilot inputs over the course of a flight.

So the #3 vehicle had a full fly-by-wire system, while the RCS on the first two vehicles were FBW, too! 8)

[comradephil]

Bell X-1 then.

[SchildConstruct]

Bell X-1 then.

Well. 'Fly-by-wire' means that instead of mechanic or hydraulic input, you use electronics (electric signals are much quicker and lighter than aforementioned hydraulics or a pulley system ). That doesn\'t mean that the plane/rocket does automatic adjustments of/to its current flight state.

[comradephil]

Getting closer, created a plane which\'ll land on water survivably, now to get it to keep its wings on every time.

Seahorse I

Got a Seahorse II which survives every time, but I can\'t be arsed to take pics.

[foamyesque]

I have successfully completed the challenge, but I won\'t post my design or pictures for a while yet; I\'m interested in seeing what other people come up with.

[Zeroignite]

Still working on water. RCS is helping but I\'m still encountering floaty-keel problems.

[Iskierka]

That might be caused by keels being heavy (=> not buoyant), and wings being light (=> buoyant) ...

Just a suggestion.

[comradephil]

The problem is that wings are more fragile than keels. I started this challenge with a biplane with lowered wing for hydrofoil usage, but landing without a parachute is impossible with that, and your wings will just get ripped off at any speed anyway.

EDIT: I have achieved more than 100m/s on water, proof will follow in a second.

EDIT2: Can\'t be arsed right now, but I\'ll do a run for the gold challenge later, my ship only needs an RCS tank adding for that. The only staging involved is for takeoff, since I need pylons for that.

EDIT3: The first water speedrun pics are from a different flight apparently, I\'m an idiot who gets confused.

Then I went around for a landing, didn\'t go 5km up, because I forgot that, but rest assured that she can do it.

Then took off again, landed the other way around.

Another water run followed by my final landing which I botched slightly

[comradephil]

Orbit achieved

Apoapsis:126.223

Periapsis:121.364

My attempt for gold was sadly thwarted by my lack of skill as a pilot, not that the plane couldn\'t have done it, I messed up my reentry, causing me to have to fly an extremely long way to the KSP centre, I sadly ran out before I could enter the sea and then land on the runway.

After retroburn and reorientation.

But here\'s some other pics of me landing from 5km altitude and doing the boat speed run.

Dive bombing manoevre!

hitting full throttle to climb back out, it was getting a bit too hairy for me at that speed.

[foamyesque]

Nice work, Phil. That\'s a weird looking plane, though. Did you put your pod in the middle or something?

[comradephil]

Yeah, it makes sense if you screw up the water part. It\'s also really damn unbalanced, I had to add two of the C7 RCS tanks to get her spaceworthy to any extent.

[foamyesque]

I recorded my own attempt (badly IMO, I need to figure out a better way to do it!):

I messed up my own landing; floated too far down the runway and ran out of it before I could come to a stop.

[foamyesque]

http://awesome.redial.net/Avatar.rar

In case anyone wants the design.