Stock Payload Fraction Challenge: 1.0.5 Edition

[Val]

That was a bit harder than I expected, but here we go.

Craft: C-1 Payday Mk.7

GTOW: 318.67 t

Payload: 171 t (10 full large ore canisters + 10 pairs of struts)

Propulsion: 14 RAPIERs

LF/O: 11040/7040

Wing: 33.16 Lift Rating

Power Load: 22.76 t per RAPIER

Wing Load: 9.61 t per Lift Rating

Payload fraction: 53.66 %

The Payday is back. WOOHOO!

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Full launch, unedited video (11 mins)

UPDATE: The video now has annotations to explain stuff and make it less boring!

Edited October 25, 2015 by Val

[Red Iron Crown]

Added your entry to the board, Val, congrats on setting the new high water mark.

djmad, apologies for missing your revised entry on the previous page. I've added it to the board, great fraction and design.

[Bomaye]

Nice one Val!!

I can see that I need to dl MJ to get better flight profiles.

[Val]

Added your entry to the board, Val, congrats on setting the new high water mark.

Nice one Val!!

Thank you. Took me 2 whole days. One day of revising the old Payday design, and one day of improving ascent profiles.

I can see that I need to dl MJ to get better flight profiles.

MJ only removes the worry of steering the craft, like nose dropping and countering roll and yaw forces. You still have to figure out a flight profile for yourself.

I've added annotations to the video, to make it less boring, and to explain what I'm doing. Hope you like it.

[Nefrums]

Nice one Val, well done!

[Bomaye]

Thank you. Took me 2 whole days. One day of revising the old Payday design, and one day of improving ascent profiles.

MJ only removes the worry of steering the craft, like nose dropping and countering roll and yaw forces. You still have to figure out a flight profile for yourself.

I've added annotations to the video, to make it less boring, and to explain what I'm doing. Hope you like it.

I basically have same approach and engines to weight I also use in same ballpark depending task ahead (I build mine for use in career).

I think MJ helps a lot because its so easy while sit and "tap, tap, tap" to mess up But i never used it, I tried that flight mod you can see but it will flip the craft (or close too) when you go trans orbital. Hmmmmm

Edited October 25, 2015 by Red Iron Crown
Language, please.

[Nefrums]

Well we cant let the Danes beat us now can we?

Stingray Mk2: 53.75%

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I think this design has a bit more to give. I made orbit on the first attempt.

[Red Iron Crown]

Well done, Nefrums, a new high water mark (though not a single stage...). Added you to the top of the board.

[Val]

Well we cant let the Danes beat us now can we?

Stingray Mk2: 53.75%

http://imgur.com/a/INVzc

I think this design has a bit more to give. I made orbit on the first attempt.

Gratz Nefrums. Well done!

I guess, I'll have to start working on a new design.

[Nefrums]

I tried using mechjeb. Smart A.S.S. made things a lot easier!

I could get the same payload to orbit for significantly less fuel.

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56.30%

[Val]

I tried using mechjeb. Smart A.S.S. made things a lot easier!

I could get the same payload to orbit for significantly less fuel.

http://imgur.com/a/DGw2h

56.30%

That is crazy awesome, Nefrums! Not sure I can match that.

[Red Iron Crown]

Awesome, Nefrums, added to the board. Just when I think we're nearing the theoretical maximum someone edges it up further.

[Sanic]

Just a question for you people. What do you think the maximum payload fraction possible is? I personally think it's around 57%.

[Nefrums]

I'll try to do 60%

[Johould]

That is crazy awesome, Nefrums! Not sure I can match that.

Have you tried using a fairing instead of those heavy Mk3 cargo bays?

[Val]

Have you tried using a fairing instead of those heavy Mk3 cargo bays?

Not really. Mostly because I can't think of a way to do it without having to place struts outside the fairing.

And struts outside fairings/bays really hurts performance, too.

[Johould]

I've been trying to put a frame and struts inside the fairing, with lengthwise struts around the payload, building scaffolding as needed to reach. The only big trick I'm using is surface mounting stuff onto the part under the fairing base, so it sticks through and I can attach struts.

Unfortunately I'm using cubic octagonal struts for scaffolding, for the low weight, but my computer can't really handle the part count. I'm calling it a night after a computer crash, but saving about 4t off the Payday launch weight by switching to a fairing looks possible.

Edited November 4, 2015 by Johould

[Right]

Wow nice work Val and Nefrums! Would you stop raising the bar so I can get on the airbreathing leaderboard? LOL

So the best entries have a TWR of 0.43 on the runway right now, good to know.

Sounds pretty creative Johould, its too bad creativity and lag are proportional in this game haha

Edited November 5, 2015 by Right

[tewpie]

I think this is as far as I can push this design without dropping the FAT wings (they overheat way too easily). I really like the look

Scarab Mk4 (.craft)

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Payload fraction: 54.29%

Stay tuned for a clean sheet multistage design

[Red Iron Crown]

Ye gods, that's a high fraction, tewpie! Added to the top of the leaderboard, well done!

[tewpie]

...and here it is.

Drake (.craft)

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Payload fraction: 57.02%

It's become fairly obvious that using cockpits in the payload, and using payload as structure, are really "unfair" advantages in multistage designs. I humbly suggest either

- separating the categories, with practical, reusable single-piece SSTOs in one and exotic unrestricted multistage designs in the other.

or

- adding additional restrictions to all spaceplane designs (i.e. must be able to achieve orbit with the payload missing).

[Red Iron Crown]

Added another great entry of yours to the leaderboard, tewpie.

You raise an interesting point. Since we have an update imminent, now might be a good time to open the floor to possible revisions to the rules and scoreboards. So far I am thinking:

- Only the best entry per participant on each board.

- Four boards: Multistage rocket, Single stage rocket, Multistage airbreathing, Single stage airbreathing

I'm not sure about the changes you suggest, tewpie, as recoverability/reusability is not really considered for this challenge. I am open to the idea though if others feel strongly about it.

Does anyone have any feedback to offer about further rule changes or the leaderboard revisions suggested above?

[SpaceplaneAddict]

I would actually be interested in this if SSTOs had a board of their own. Also, I get that Cockpits are treatable like payload, but really, can we actually think of the Kerbals we have stranded for this? I mean, for singlestagers, it would make a bit of sense to get the Kerbs home.

-SPAddict

IMHO of course

[Val]

Dammit, tewpie. You're making me work really hard for the #1 single stage spot.

Great entries and gratz on taking multi stage, too.

[Johould]

Val, I got a fairing working: Fairing applied to Payday Mk.7.

Instead of a structural frame or clipping games, this just connects struts to the fairing, and keeps the vessel connected by adding a second docking port at the front of the payload.

Takeoff weight is 314.58t.

KER reports a terminal velocity of 485m/s at zero pitch on the runway, I think that's actually an improvement.

I haven't tried to reach orbit, but it works up through building speed at sealevel.

It jiggles a bit on load, but seems stable enough after physics settles down - and surviving takeoff requires pitching promptly up by about seven degrees after rolling off the end of the runway, so I think it's sturdy enough.

- - - Updated - - -

If it can reach orbit, that takeoff weight should be enough to beat the Mk.4 Scarab for SSTO fraction.

Edited November 6, 2015 by Johould