The K Prize - 100% reusable spaceplane to orbit and back

[boolybooly]

Thanks Spartwo, welcome back to the K-Prize. Thanks very much for your mission report of a flight to the Mün (if I read the screenies correctly) and return (by a fine margin) to a landing on Kerbin. For which you have earned the coveted Astrokerbal Distinction. PS Its nearly impossible to see your first Sabre 3 screeny sorry, its so dark on my screen, is that just me (and I need to tweak my colour) or is everyone seeing it like that?

NikkyD congratulations on completing the challenge successfully with an Advanced Pilot Precision Award for landing on KSC runway. Welcome to the K-Prize roll of honour aka guest list for the K-Prize party.

falconek do you want to be linked as a gatecrasher or do you want to submit a completed challenge report later?

[Spartwo]

I decided to keep the name 'don't have a name'.I think the darkness might be a thing with screen brightness,try turning it all the way down.

[Naten]

I think it's time for a new thread.

DISCLAIMER: I AM IN NO WAY TRYING TO MICROMANAGE OR "BACKSEAT MODERATE." I AM ONLY TRYING TO POINT OUT THAT THE THREAD IS >100pages long. Please, don't ban me for this.

Anyways, here's (not really) an entry for ya.

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(Camald Kerman doesn't wanna go home yet. So, just don't count this in as a real entry. )

[British_Rover]

I realized I hadn't done this for .22 yet so here is my second to last mission before I upgrade to .23.

The mission is launch a weather/communication satellite, dock with my SSTO station and do a crew Swap. Jeb is ready to go home and there are no capsules up there for him to return in.

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[NikkyD]

Out of curiosity, is it "legit" for the challenges here to stack ram intakes into eachother as some do ? Ive seen some attached at the BACK or a tank but pointing forward etc. because maybe i could manage to drop one of my tanks ^^

[Markus Reese]

Out of curiosity, is it "legit" for the challenges here to stack ram intakes into eachother as some do ? Ive seen some attached at the BACK or a tank but pointing forward etc. because maybe i could manage to drop one of my tanks ^^

I have seen a fair few with an excess of intakes. Myself, I always say go by what you think is legit. I do mine without the stacked intakes. Also note that there is nacelles with intakes.

[falconek]

falconek do you want to be linked as a gatecrasher or do you want to submit a completed challenge report later?

I will post another attempt later when I find some free time, I developed a system for safe landings (aka parachutes) so I will show this off

[boolybooly]

If the stock game allows it then any amount of intake stacking is allowed, up to the player.

OK Naten let us know if you manage to complete the mission. Luckily most browsers don't load all the thread in one go (OK none of them do) so thread length is immaterial and it is in no way better to have several short threads than one long thread spanning all versions. In fact its a bit neater for mods to have one thread and is an interesting historical archive. The whole point of indexing the OP is to allow navigation of much of the thread at a glance. So I am not starting a new thread, but if anyone wants a shorter K-Prize thread they are welcome to start a new one and use the same scheme, providing Waffles Too agrees to use of his badges, but to be clear they will have to run it because I am not going to do it.

Congratulations to British_Rover for completing the K-Prize in v0.22 with an orbital docking and satellite delivery and a runway landing earning the highly regarded Utilitarial Commendation as well as the prestigious Advanced Pilot Precision Award 1st Class with R&R Launcher.

[Overfloater]

Mind if I barge in...? xP

Space Plane Mk-I

Has 1 Atomic engine, 4 Turbo jets and 10 Ram intakes. (regular intake in front for looks xD)

Gets to Minmus and back. Can also reach duna and stay there.

I went to Minmus because my original intention was to land on the flat surfaces in an aeroplane fashion, but didn't take the chance and did a full stop 1 inch above ground and flipped the wheels downwards.

Here's that beast of a plane :

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[barrenwaste]

I love how chubby and stubby that thing is, Overfloater. It almost looks like a chibi anime version of a plane.

[NikkyD]

Does any one know the exact formula of Ram Air Intakes ? I just figured out that it makes no sense to accelerate to more than 2000 m/s because thats were the thrust critically drops. I want to calculate my maximum altitude but i cant find the formula for the intakes. During the flight it says "Units" of air and sometimes my engines still can breath with 0.00 intake air resource

[barrenwaste]

NikkyD, I don't know the formula, but I can give you my observations. First, the different intakes produces differing amounts of air for the jets so, what works for one may not work for another. Second, there is no max altitude as you can leave atmo with just two intakes per engine, and likely do it with only one ram air intake. Third, the only reason to cram excess intakes on a plane, correctly piloted with attention payed to the throttle, is to achieve max altitude and speed in the minimum of time. If you are looking for a plane that can run full throttle at 35,000 meters then you are going to have to cram insane amounts of intakes on the frame. If you simply want a platform that can cruise at around 40,000 meters at 1/4 throttle, then you can get away with just two ram air intakes.

The biggest factor in how your jet performs at altitude isn't the amount of intakes, but how you pilot the craft. The keys are to constantly lower your throttle while making only minute changes to direction and altitude. Changes in direction and altitude lower the amount of air the intakes gather. Chart your course before you reach your desired altitude and drop somewhat below to maneuver. If you do that while constantly lowering your throttle you'll be able to reach speeds and altitudes you hadn't thought your plane could achieve. I find it amazing how little throttle is needed at heights above 25k meters.

[boolybooly]

Overfloater, interesting design there for Space Plane Mk1, an atomic biplane, with extra steampunkily crossed struts, which somehow seems to suit the Kerbal Space Program. Thanks for your mission report and congratulations on completing the K-Prize with flying colours, including a lainding on Minmus and a return to the KSC runway for which you earned the prestigious Astrokerbal Distinction as well as the highly regarded Advanced Pilot Precision Award.

PS Merry Christmas everyone

[PatchouliKnowledge]

Hey there!

For my first post on the forums I thought I'd try this challenge. Here's my entry:

KirisameAerospace CrowTengu

Yes, my spacecrafts' names are often Touhou themed. This one uses R.A.P.I.E.R engines. The only modded parts are Kerbal Engineer Redux, and the flag decals that are purely cosmetic (though they generate a little bit of drag and weight a bit).

Had barely the amount of fuel/oxidizer to reach orbit.

I also overshot my deorbiting so I made use of the remaining fuel in atmospheric mode to reach the KSP runway. This plane glides incredibly well. Landing it was really no challenge at all.

Here are some screenshots.

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EDIT: I figured how to embed, never mind !

Edited December 24, 2013 by PatchouliKnowledge

[boolybooly]

Hi PatchouliKnowledge, thanks for giving us a mission report with your first post. I am guessing that the frescos of His Noodliness did not add to the lift characteristics in any way, on which basis your FSM themed craft Crow Tengu earned an Advanced Pilot Precision Award for a precise landing on the KSC runway fair and square. Congratulations and welcome to the K-Prize party guest list aka the roll of honour.

[NikkyD]

So...

i got to a point where the game is limiting me.

I replaced my rapier for a turbojet and put 2 48-7S aside it. I removed 2 of the swept wings and reduced the fuel to about 40 Units liquid and 20 Oxi.

With the turbojet alone (with 3 intakes) i can fly up 90° like a rocket, turn 5° at about 20km and accelerate to 2100 m/s surface (reached at somewhere 25 to 30 km), which at this point would be 2300 m/s orbit.

With mechjeb managing the intakes and throttle i can thrust to about 40 km but its merely 5 kN thrust or less, but thats enough to fight any drag that still exists at that height. My projected AP is about 100 km with a PE of -20 km. Thats pure Turbojet at this point. At the AP i need just a 5 sec burn or so with the 2 rockos to achieve a rock solid 100 km orbit. Decending requires about 60 m/s retroburn and the rest is aerobrake and glide.

If i could, i would drop so many more parts to make the thing lighter... but its impossible to attach the still necessary parts to the ones that remain. Thank god the cockpit is so huge, that gives me plenty of mountpoints for the wheels and wings. The lightest mount for intakes unfortunately is a small fuelcan, even if that can is only filled to about 30%. Which means the 1/9th of container weight turns into 1/4 th. So i would need the next flattest version of a fuel can.

Because the engine makes about 40% of the total weight, my center mass is at the very rear, which makes it difficult to place the gearbays and wings so far back that it allows for stable flight and more importantly LANDING.

I wish that all parts would come in "tiny" size as well. With reasonably weighted engine housings (300 kg for a thing that does NOTHING is a joke)...

tl;dr;

With only vanilla parts at hand and no glitching/cheating i cant improve my vehicle any more and its almost perfection and i doubt that anyone can do any better so the game sets the limit for this challenge which makes it less of a challenge :/

[sploden]

Name: Minisistilikio 3

Weight: 1.136 tons

Parts: 13

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It seems that something changed between .22 and .23. It's quite a bit harder to achieve orbit with the Minisistilikio in .23 than it was in .22 (hence the MechJeb).

Edited December 28, 2013 by sploden

[sploden]

tl;dr;

With only vanilla parts at hand and no glitching/cheating i cant improve my vehicle any more and its almost perfection and i doubt that anyone can do any better so the game sets the limit for this challenge which makes it less of a challenge :/

NikkyD, perhaps these will inspire you...

The Chair

Hummingbird

MinLKO 6d

The Bumblebee

MinLKO 8b

MinK 1a

Minisistilikio

As you can tell from tavert's MinLKO 8b, it's possible to achieve orbit with a turbojet onboard with just 2 oscar B's worth of fuel, with a craft weighing 1.51 tons (and I think this can be decreased slightly :-).

[Redshift OTF]

I would like to submit my entry for the K Prize with the Cormorant XI. She's not the smallest plane in the world but as small as I could get it while keeping it looking as much like a plane as possible and retaining excellent flight characteristics. She has enough fuel to get into a 100 Km orbit with fuel to spare and land. (Sorry about the Mechjeb!)

http://imgur.com/a/lzHLi#0

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Sorry if the pics don't fit the page. I couldn't get imgur to resize them. Click link instead.

Edited December 28, 2013 by Redshift OTF

[NikkyD]

NikkyD, perhaps these will inspire you...

The Chair

Hummingbird

MinLKO 6d

The Bumblebee

MinLKO 8b

MinK 1a

Minisistilikio

As you can tell from tavert's MinLKO 8b, it's possible to achieve orbit with a turbojet onboard with just 2 oscar B's worth of fuel, with a craft weighing 1.51 tons (and I think this can be decreased slightly :-).

Those tiny crafts are unmanned! And as i wrote, i dont want to use glitches or part-placements what can only be achieved by using tricks.

[Redshift OTF]

Those tiny crafts are unmanned! And as i wrote, i dont want to use glitches or part-placements what can only be achieved by using tricks.

No part clipping? If not, the ram intakes will attach to the tiny octagonal struts and you can attach them to the wings quite easily. You only need 4 rams per jet engine in 0.23. Also you only need 1 pair of wings for a craft of your size. To aid stability you want control surfaces behind the centre of mass as that stops the craft flipping. It naturally wants to correct itself.

[British_Rover]

Those tiny crafts are unmanned! And as i wrote, i dont want to use glitches or part-placements what can only be achieved by using tricks.

Use the Mk 1 landing can instead of the MK2 cockpit and cubic octagonal struts have no mass once the craft loads.

[NikkyD]

Use the Mk 1 landing can instead of the MK2 cockpit and cubic octagonal struts have no mass once the craft loads.

Why would u suggest that ? have u done the math ? its worse with the landing can because of its drag coeff

600 kg * 0.2 = 120

1000 kg * 0.08 = 80

edit:

didnt mean to be rude, but what u are suggesting is worse than what i have

Edited December 28, 2013 by NikkyD

[numerobis]

NikkyD, you're giving up too early!

Instead of two 48-7S you could use one LV-1R and save 170 kg. Use only one; you'll be thrusting off-axis, but it'll be so little that your capsule's reaction wheels can compensate.

You can use much lighter wings. First off, the delta-deluxe has better lift per mass than the swept wings. At low angle of attack, it's 10% better lift per mass, at high angle of attack the improvement is higher. Even better: use the small control surface, and lock all the controls so it's just a wing. Half the mass of a delta-deluxe, same lift. Finally, you certainly don't need all that wing surface; I'm confident that two of the smallest wings is sufficient. Instead of 200 kg of swept wings, you would have 20kg of small control surfaces.

So that's 350 kg you could save.

Finally, I agree with using a lander can for an SSTO. The drag coefficient of the lander can is higher, but gravity still matters even if you've got a plane. Once you get up high, inertia is what matters, and the drag coefficient is irrelevant. In the atmosphere, gravity is a bigger influence until you start flying above the speed of terminal velocity.

[kepicness]

I'm happy to see that this challenge still exists . I might just start playing ksp again with my obsession with ssto space planes.