Spaceplane Speed Challenge 2: Fastest time from orbit to runway

[Wanderfound]

Howdy.

This is a pure piloting challenge. As the title says: how fast can you get from a 70x70 orbit to stationary on the KSC runway. All pilots should use the Kerbodyne Benchmark to keep the aircraft factor even. No adding, moving or removing parts allowed (apart from Mechjeb and Engineer flight instrumentation bits), but it is permitted to alter the tweakables on the control surfaces to your personal taste. Deliberately raising and lowering your orbit or using TAC Fuel Balancer to dump fuel is allowed.

http://forum.kerbalspaceprogram.com/threads/90747-Kerbodyne-SSTO-Division-Omnibus-Thread?p=1357777&viewfull=1#post1357777

Separate leaderboards for FAR, NEAR and stock, as well as Deadly Reentry or not. Let us know what flight data mods you used, if any. Feel free to explain how you did it and why you did it that way. Losing parts on landing disqualifies the attempt, but if you manage to lose things during descent but still land, more power to you.

Post screenshots of yourself in orbit with apoapsis, periapsis and elapsed time visible, then another on the runway at 0m/s. Highlights of flaming spin recoveries and explosive landings during attempts encouraged.

Leaderboard:

Stock Aero

Kasuha 2 minutes 22 seconds

FAR

Wanderfound 6 minutes 27 seconds

Wingblaze 29 minutes 42 seconds

FAR/DRE

Wanderfound 6 minutes 27 seconds

Edited September 23, 2014 by Wanderfound

[Wanderfound]

An early attempt to get it started.

The Adventures of Sherwig Kerman, official Kerbodyne test pilot

A dawn launch:

Sherwig Kerman, calm and focused:

Away we go:

Up into the minimum drag zone:

Before flattening out a bit:

That'll do for now:

And we're in orbit:

Hit the brakes over the target:

And smoothly descend to the runway:

Who's next?

Edited August 23, 2014 by Wanderfound

[Kasuha]

In what way do you mean it is easy to fly? This thing can't even glide!

Edited August 23, 2014 by Kasuha

[Wanderfound]

Aerodynamic markers with FAR:

It was designed in FAR, and that's what its aerodynamics are tuned for. But I took it to orbit in stock aero last night to make sure that it flew okay. It does: I didn't touch the yaw or roll controls once between takeoff and final landing approach. Stock air is thick and chunky enough that it can tolerate quite a bit of active instability before it becomes a problem.

Keep the SAS on (an actively unstable plane like a modern fighter needs fly-by-wire assisted avionics to be controllable; that's what the SAS is representing in this design), don't let the nose get too far from prograde, flatten out to build speed between 20,000 and 30,000m, shut off the RAPIERs when they switch modes and turn them back on when the turbojet chokes. Reentry was similarly uncomplicated.

Have you taken it for a spin yet, or just looked in the SPH? Try flying it according to what I said above, and report back on how it goes.

Edited August 24, 2014 by Wanderfound

[Wanderfound]

Stock-aero aerobatic demonstration photos coming soon.

Edited August 24, 2014 by Wanderfound

[Kasuha]

Have you taken it for a spin yet, or just looked in the SPH? Try flying it according to what I said above, and report back on how it goes.

I tried it first, noticed its behavior, then took it for inspection into SPH, then did some more testing. I'm definitely not the best pilot around here but in my opinion this thing is almost unflyable under stock aerodynamics. Yes it should be possible to get it to orbit. Getting it down and doing so fast is another story, I had some hard moments with way more stable planes.

If you say it is for FAR then okay but you should probably declare that in your promo post and perhaps make the challenge FAR/NEAR only.

Edited August 23, 2014 by Kasuha

[Wanderfound]

Sharp turns:

Steep climbs:

Can tolerate an aggressive landing approach:

Downward glide on edge of stall speed, give it a touch of throttle just before landing.

Recovers easily from deliberately-induced spins:

Back on deck:

You need to lead the plane, don't try and force it. Every time you move the nose away from prograde, do it by 10° or so, then give the prograde marker a chance to catch up with your new heading; it should only take a second or two to get back to an angle of attack of 5° or so, then you can do it again. If you need to turn a lot, you just need to keep leading it.

If the nose starts moving without you telling it to, it means that you're either on the edge of losing control or have lost control. Once you get the hang of it you can ride the edge, but for now you should reduce your angle of attack as soon as the nose starts wandering. How much angle you can get away with varies depending on speed and altitude, but as you see above it's a lot more than 10° down around KSC. If you do spin out, throttle up all three engines and get the nose pointed prograde. Stabilise there for a second, then start leading prograde back to where you want it again.

I will say that it does benefit from the gimballing on the engines, though. You need the power on if you want to pull out of a dive or a spin.

Edited August 24, 2014 by Wanderfound

[Wanderfound]

However, the challenge is for fun and I don't fly stock unless I need to do something like above.

Vote from the potential competitors: do you want a rules change to let the stock aero flyers shuffle the winglets back a smidge for stability?

[Kasuha]

Vote from the potential competitors: do you want a rules change to let the stock aero flyers shuffle the winglets back a smidge for stability?

I'd suggest about this form, trying to keep it as intact as possible and the same parts.

I'd also suggest adding action key 1 as turbojet on/off

But in my opinion to declare it "easy to fly" in stock it needs another pair of wings to be able to glide, and wider landing gear.

[Wanderfound]

I'd suggest about this form, trying to keep it as intact as possible and the same parts.

I'd also suggest adding action key 1 as turbojet on/off

But in my opinion to declare it "easy to fly" in stock it needs another pair of wings to be able to glide, and wider landing gear.

http://i.imgur.com/NSsBZqc.jpg

You'd probably be better off leaving the canards where they were and removing the winglets entirely. It's not short of pitch authority. After you've taken it to orbit, stability will increase further; all the fast-burning oxidiser is up the back.

It's always a matter of subjective opinion of course, but to me "easy to fly" doesn't mean "impossible to crash". I tested the landing gear by taking it for a 50m/s grounded spin around the paddock, turned in a circle and popped over the berm onto the runway at 25m/s. Not a wobble.

Action key 1 does toggle the turbojet on my version. Is there something scrambled with the download?

Edited August 23, 2014 by Wanderfound

[Kasuha]

The extra lifting surfaces are good as the plane has lack of of them. It's not about pitch authority, it's about lift. Even if I remove winglets, the canards in the front move center of lift too forwards so they'd need to be moved anyway.

Anyway, using the plane I posted above, my time is 2:22 (38:30 - 40:52). It does break the rule "No adding, moving or removing parts allowed" as I moved its front control surfaces backwards so I leave it up to your decision if it counts or not. I'm not willing to run the challenge with original plane as it's IMO more matter of luck than piloting skills. Or I'm just too crappy pilot to be willing to handle such plane on reentry and fast descent - pick your favorite excuse

Edit: oh, here's the craft file.

Javascript is disabled. View full album

Edited August 23, 2014 by Kasuha

[Wanderfound]

I think there might have been something wrong with the file; when I downloaded, I couldn't access any craft in the SPH until I removed it from my save. I've replaced the download link with a new version that is definitely fine, and definitely has the turbojet assigned to action group 1.

I've also put together a version of the Benchmark retuned for stock aero the way I would do it.

https://www.dropbox.com/s/lbnz9s8k9h7gwgb/Kerbodyne%20Benchmark%20StockAir.craft?dl=0

[Wanderfound]

Thanks for having a go, BTW. I'll leave the call on the rules for the majority vote of the stock-aero flyers after a few more of you show up. It may not be too much of a problem if you guys are using slightly modified versions, so long as it doesn't turn into everybody rebuilding the plane until it becomes something entirely different. If there's an obviously superior version from amongst the three stock aero options so far presented, the best flyers should rapidly converge on it.

FAR and NEAR pilots, however: original rules still stand. Don't fiddle with the plane apart from tuning the control surfaces to taste. We want this to be a piloting challenge, not engineering.

[Wanderfound]

Again?

Coming in less steep than last time.

Still a bit steep, though.

Possible a little too steep, even.

But no biggie; she still flies pretty well. More streamlined now, too.

Got her flattened out...

Just need to lift the nose a whisker to get over the mountains. Bit harder than usual without the canards.

Oops...

It still flies! I wonder if we can get over the mountains?

Maybe...

Nope.

[Wanderfound]

Okay; killing time before the .26 drop, so I figured I'd finally make a serious attempt at this.

Launched, flew to orbit, computer crash, reload, Kerbpaint glitch. Oh well. 35:15 start time.

Hit the brakes.

Down we come.

Smidgeon toasty, but nothing serious.

A few S turns to wash off speed.

Still too quick, and running out of time. Give it a loop.

Bugger trying to brake on the runway, land on the paddock and then taxi up the berm.

41:42 at stop, so that makes it 6 minutes and 27 seconds. Fairly conservative; there's probably plenty of time to be shaved if you really try. Apart from a second's worth of taxiing thrust when I misjudged my braking and stopped on the runway edge berm, it was dead stick the whole way.

Anyone else?

Edited September 20, 2014 by Wanderfound

[Wingblaze]

Didn't expect to see me here did ya?

With FAR: I think it's 29 minutes, 42 seconds. I know, not tops. Not even close. I'll be honest - I was thrilled to do it. At all. I had to reload on approach a couple times - I didn't see rules on that but again, to me this was a personal challenge. And if it matters, I ended up landing just *before* the runway and taxing up the 30 feet to get on the tarmac.

In orbit:

Landed:

[Wanderfound]

Didn't expect to see me here did ya?

With FAR: I think it's 29 minutes, 42 seconds. I know, not tops. Not even close. I'll be honest - I was thrilled to do it. At all. I had to reload on approach a couple times - I didn't see rules on that but again, to me this was a personal challenge. And if it matters, I ended up landing just *before* the runway and taxing up the 30 feet to get on the tarmac.

In orbit:

http://i.imgur.com/IBYhCai.png

Landed:

http://i.imgur.com/2YeArT2.jpg

Cool.

Did you tune the control surfaces at all before you went? If so, what settings?

[Wingblaze]

No tuning. I slapped a Mechjeb module on it and flew it as is.

I think I "lost" some time because I took the screenshot before I was at my re-entry position. But I didn't care.

[Wanderfound]

Maybe practice screenshot timing at the Minmus ice races.

http://forum.kerbalspaceprogram.com/threads/91644-Spaceplane-Speed-Challenge-III-Ice-Skating-on-Minmus

[Wingblaze]

You're like a crack dealer, aren't you....