Spaceplane speed challenge: shortest elapsed time from runway to orbit.

[Wanderfound]

Just as the title says: how quick can you get a spaceplane to a 70 x 70km orbit?

Rules:

* Post a screenshot of your plane in orbit, with both the orbital details and elapsed time visible.

* Ferram Aerospace Research must be in operation, with default settings; stock aero is a whole different game. Keep aerodynamic failures on.

* Must take off horizontally from the runway and be recognisably a plane; no fair just sticking fins and landing gear on your favourite rocket. We're looking for spaceplanes, not winged missiles. Lift with your wings rather than your engines. Climbing vertically is fine to get out of the low-altitude soup, but you should be levelling off and building speed spaceplane style once you get into the stratosphere.

* No abusive airhogging; no intakes within intakes and go easy on the tricouplers. Kudos substantially increased if you can do it with something that actually looks like it might work in the real world.

* Must hit orbit with sufficient fuel remaining to get back down again. Gliding in to KSC is okay if you've got the plane for it, though.

* Spaceplane Plus and B7 (edit: B9, of course) parts allowed; other spaceplane packs will be considered on application. Apart from that, all stock parts. No non-stock engines.

* Do it airbreathing SSTO if you can, but if you want to strap some solid boosters onto your plane, give it a shot. Separate prizes for SSTOs vs planes that drop parts during ascent.

EDIT: do it however you'd like. However, the intention is to see who can get an SSTO spaceplane to orbit the fastest. Separate leaderboards will be maintained for stock aero vs FAR/NEAR, SSTO vs dropped boosters, genuine spaceplanes vs winged missiles, practical vehicles vs specialist speedsters, etc.

Post your craft file with your entry. If you think you can beat someone else's piloting, feel free to have a go with their designs.

EDIT 2: If you'd rather treat this as a pure piloting challenge, see http://forum.kerbalspaceprogram.com/threads/90747-Kerbodyne-SSTO-Division-Omnibus-Thread?p=1357777&viewfull=1#post1357777 for the benchmark plane to use.

All stock, no mods required.

--

To get the ball rolling, my most recent experiment with Spaceplane Plus:

Runway to orbit in 5 minutes 58 seconds (about 2 minutes of which was coasting to apoapsis), using a 30° pitch until the air ran out and 45° while the oxidiser burnt. Craft file available at http://forum.kerbalspaceprogram.com/threads/90344-Kerbodyne-Velociraptor-light-cargo-express-SSTO-for-Spaceplane-Plus-and-FAR

--

Current Leaderboard:

Stock Aero SSTO:

O-Doc: 4 min 40 sec

FAR with dropped boosters:

Renegrade, 4 min 1 sec

FAR SSTO Speedster:

Wanderfound: 3 min 32 sec

FAR SSTO Practical Cargo Lifter:

Wanderfound: 5 min 58 sec

FAR Kerbodyne Benchmark (control plane):

Wanderfound: 4 min 5 sec

Edited September 5, 2014 by Wanderfound

[gchristopher]

Suggestion: Turn this into a piloting challenge instead of a building challenge.

Since there's a lot of subjective rules, (what is "recognisably a plane", what altitude is "low-altitude soup", where exactly to draw the line on "abusive airhogging"), winning this challenge will mostly be about who can bend the rules enough and still pass your interpretation. Sounds like a headache for all involved.

How about, if you want a good challenge, make everyone fly the exact same plane and see who can get to orbit the fastest, as a test of piloting skill?

If you want a build component, maybe have people suggest/build craft for the challenge, then after picking a plane, start the timed challenge with everyone flying the chosen plane.

[Wanderfound]

Suggestion: Turn this into a piloting challenge instead of a building challenge.

Since there's a lot of subjective rules, (what is "recognisably a plane", what altitude is "low-altitude soup", where exactly to draw the line on "abusive airhogging"), winning this challenge will mostly be about who can bend the rules enough and still pass your interpretation. Sounds like a headache for all involved.

How about, if you want a good challenge, make everyone fly the exact same plane and see who can get to orbit the fastest, as a test of piloting skill?

If you want a build component, maybe have people suggest/build craft for the challenge, then after picking a plane, start the timed challenge with everyone flying the chosen plane.

Whatever the flyers are interested in is fine by me.

I was hoping to see a few other attempts at fast-but-realisticish spaceplanes, though. I don't see a non-subjective way to stop it from being dominated by things that either aren't really spaceplanes (e.g. runway-launched missiles) or rely on game exploits that shatter suspension of disbelief (e.g. extreme airhogging).

Anyone feel like seeing if they can beat my runway-to-orbit time in the Velociraptor?

[O-Doc]

I agree about this being more of a pilot challenge rather than a build challenge. Air hogging is not much of an issue, it might save you about 10sec in atmo so, it could scrape you over the line. Why not make some clear rules about intake to turbojet ratio?

Also, the rules should be HOTOL craft only and carry at least one turbo jet or rapier engine, used or not.

Anyway, I've got plenty of craft that will do equally well on this. My weapon of choice is the Robin because style.

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Time at screenshot is 4:40min. I only did a few runs but, could squeeze out more time in turbo peak and on reducing the unused rocket fuel in SPH for better TWR. So, I would say 4:20 is not out of the question. I may come back to this if there are any serious challenges who can beat 4:40min.

[Wanderfound]

Nice time; stock aero?

I'm gonna have to build myself a specialist speedster...

Second draft of qualifying rules, then.

* HOTOL

* Wings & control surfaces.

* At least one air-breathing engine.

[O-Doc]

Yeah, stock aero. I missed the FAR thing but, really you should have two leaderboards. I think stock aero would be slower than FAR anyway as it has more drag.

The engine rule would mean weight which is critical for your time, and rockets with HOTOL would under-perform a spaceplane. If you get big rocket entries and they would need to be disqualified with some sort of rule like part count or mass. Hard to say because my flight profile was basically like a rocket except the brief level-out to maximise energy into orbit during turbo peak 800-1200m/s. I don't see how HOTOL rockets are going to compete with the performance of turbos through atmo given their fuel consumption.

[Wanderfound]

Yeah, stock aero. I missed the FAR thing but, really you should have two leaderboards. I think stock aero would be slower than FAR anyway as it has more drag.

The engine rule would mean weight which is critical for your time, and rockets with HOTOL would under-perform a spaceplane. If you get big rocket entries and they would need to be disqualified with some sort of rule like part count or mass. Hard to say because my flight profile was basically like a rocket except the brief level-out to maximise energy into orbit during turbo peak 800-1200m/s. I don't see how HOTOL rockets are going to compete with the performance of turbos through atmo given their fuel consumption.

I'm happy to track stock/FAR/NEAR as separate categories; the more the merrier. The big limitation for FAR is aerodynamic failure; you can't pile on serious Mach numbers at low altitude without shattering the airframe.

As for HOTOL rockets...if someone wants to do that, go for it. But the intention is to see who can get a spaceplane to orbit the fastest.

I'm not going to disqualify anyone who wants to stretch the rules and build something creative, but I'm likely to make a separate category for "blatantly not really a spaceplane" if it comes up. Unfortunately, there really isn't an objective way to tightly define what is and isn't a spaceplane. It's one of those "know it when you see it" things.

[WafflesToo]

I've got a robotic spaceplane I might give this a shot with. It's got pretty high wingloading so it can get up and move, even at lower altitudes. I haven't tried an especially agressive approach yet but I'm willing to bet it has the chops to do it...

Well, when it isn't hauling a 3-ton payload anyway

[R0cketC0der]

I'm happy to track stock/FAR/NEAR as separate categories; the more the merrier. The big limitation for FAR is aerodynamic failure; you can't pile on serious Mach numbers at low altitude without shattering the airframe.

It's possible to get to serious speeds even at low altitudes with FAR. I've once hit Mach 3 below 5 kilometers. However you shouldn't try to steer when doing it.

Also, I can't seem to find a mod called B7. Did you mean B9?

[Wanderfound]

It's possible to get to serious speeds even at low altitudes with FAR. I've once hit Mach 3 below 5 kilometers. However you shouldn't try to steer when doing it.

Also, I can't seem to find a mod called B7. Did you mean B9?

Yup, whoops.

It's possible to blow up a plane in FAR even while flying dead straight, although you need to get fairly extreme to do it. Keep the flight indicator at "high dynamic pressure" for long enough and you've got a good chance of a rapid unplanned disassembly. With the Velociraptor used in the first post, it's a choice of climb steeply or back off the throttle; if you keep it at full juice while flying level at low altitude, it only takes a minute or two to make the whole thing explode.

[zarakon]

The keys to flying extremely fast with FAR while avoiding disassembly seem to be:

1. Don't use SAS

2. Use a joystick of some kind and be gentle on the controls. Using the keyboard is no good

[O-Doc]

Nice time; stock aero?

I'm gonna have to build myself a specialist speedster...

I have to admit I did too. 3:36 is the current best time flying it.

I wanna tweak it a bit before screenies.

[Wanderfound]

Okay: a new entry, this time designed as a specialist speedster rather than a cargo plane that just happens to be quick. It does still have a cargo bay, but that was because I wanted somewhere to hide the unaerodynamic bits.

Craft file at https://www.dropbox.com/s/evi0sary5oijw9s/Kerbospeed.craft

Requires Spaceplane Plus, Mechjeb and FAR/NEAR. I'd normally pull Mechjeb off for the shared version, but I couldn't find where I'd hidden the MJ unit, so it would need to be rebuilt. Shouldn't take long, though; it's a very simple plane.

Runway to orbit in 3:32, and that was at a first attempt; there's probably 30 seconds to be shaved off with an optimal ascent. About one and a half minutes were spent coasting to apoapsis; the reason for the seriously elliptical orbit is because I couldn't shut down the engines fast enough during the circularisation burn.

Although it's certainly a spaceplane, it is stretching the spirit a bit. If you stood this thing on its tail on the launchpad it could easily get to orbit as a vertical rocket. There were quite a lot of "reentry" flames on the way up.

The nose Vernors were there because I thought it might be a bit of a handful, but it turns out that I didn't need them; they stayed off the whole way. It flies beautifully.

And, yet another demonstration of the pointlessness of airhogging: this has exactly one intake per engine.

Edited August 16, 2014 by Wanderfound

[Renegrade]

I was wondering how fast this could be done... here's something I scribbled up when I saw the bit about 'separate prizes for planes that drop parts':

Craft File C-8250 IIA

There's one little caveat: it uses a quartet of parts from Procedural Fairings (two fairing rings and two procedural fuselages to hide a pair of batteries and an RTG behind the cockpit which replaced an inline clamp-o-tron).

Flight procedure is this:

1. LIGHTLY TAP trim for a slight pulling up (about a pixel. no, not a notch, a pixel.. with 'medium' GUI. Actually, more like a half pixel...)

2. Ignite solid rocket boosters

3. OH DEAR GOD THEY HAVE ALMOST NO FUEL AND ARE SET TO 100% I'M GOING TO --Oh, I'm flying.

4. Drop boosters and stage to rapiers.

5. Using TRIM ONLY, slowly pitch up to 40-or-so degrees to clear what now feels like a souposphere of high Q death

6. Pitch back down to like 20-ish degrees past 12k or so

7. Once air intake falls below 100%, pitch back up and press '4' to toggle to oxidizer.

8. At desired orbit, circularize

I have DRE installed for this, so catching on fire was a definite possibility. Some parts were 950C or thereabouts

I noted that you have to fly just right to get a fast time, it has no margin for error and only leaves a little fuel for de-orbitting after some very expensive/inefficient orbital adjustments. Flying a more sane, 5-8 minute launch leaves like.. half of the fuel or more.

It's an expensive, un-ideal plane. My usual 'rescue' ones are much smaller and lighter and lower tech and cost like half as much~

[Wanderfound]

For those who'd rather treat this as a pure piloting challenge, I've made a simple spaceplane to use as a benchmark. See http://forum.kerbalspaceprogram.com/threads/90747-Kerbodyne-SSTO-Division-Omnibus-Thread?p=1357777&viewfull=1#post1357777

All stock, no mods required.

I'll let some other folks have a go before I post a time.

Edited August 18, 2014 by Wanderfound

[Wanderfound]

Decided to have a go with the Benchmark just to get a time on the board for it.

4 minutes, 5 seconds.

There's definitely still time to be shaved off that. Think you can do it?