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

[Spartwo]

This should be orbit capable right?6:1 intake ratio and stable takeoff/flight.

[boolybooly]

Only one way to find out Spartwo chocs awaaaay!

Interesting little vehicle zekes, linked, congratulations on creating another successful K-Prize winning design, the new v21 small inline rocket motors are quite handy. Multiple launches are an optional factor which are mentioned on the roll of honour when specified by a prize winner because it may be of interest to spectators or other craft designers perusing the list for inspiration. Choice is yours.

I think it might be worth adding a science related accolade for v22 though.

[pinolallo]

I forgot to specify:

lightSSTO made 2 orbit run (100km 141km) and a docking maneuver without refuel like the 3kPrize and the analog addict ssto .

[RogueMason]

Yeah, umm, I'm back again, but this will probably be my last one for a little while. This mission just blew my other SSTO missions out of the water.

The Cosmic Flyer:

The main difference is that this is the first time I've got a spaceplane with a nuclear engine to fly, which opened up all sorts of possibilities.

This orbit? Easy. Plus, I have a lot of fuel left over with that efficient engine strapped to the back. I wonder...

Yep, I'm about to perform the most daring manoeuvre of my entire career in KSP

I'm landing this thing. Horizontally. Backwards. No VTOL systems whatsoever. I'm a madman.

I think this is the single best take-off from anywhere that I've ever witnessed. It's so beautiful *sniff*

On the way back, another Mun flyby

This part was very tricky. The plane had a horrible tendency to just lose all control. I'm going to try and fix this problem but it will be a while before I commit to another SSTO flight.

The only reason I'm not at the KSC is because my orbit was inclined in a way that meant I just couldn't go there. Oh well, we're safely on the ground.

Like I say, the most complex SSTO mission I've flown. Sure, I flew an SSTO to Duna with aerospikes as the only engines, but that wouldn't count in this challenge (it needed refuelling a lot). The Cosmic Soarer never once refuelled on this entire trip.

[Moar Boosters]

Here is my design. I'm sure it's elegable for all sorts of interplanetary awards. It's 100% stock and can reach quite a few destinations without refueling.

So far I've used it for return missions to the Mun, Duna and Gilly. Minmus and Ike are also well within it's range, I've just not done the missions yet.

It carries 3 kerbals. It gets to orbit with around 3500 liquid fuel and 4200 oxidizer, so I guess that could be classified as cargo.

The last couple of pictures are of a spaceshuttle version which gets Laythe and back, but the regular SSTO version takes off from a runway. It has VTOLs for landing on non-atmospheric bodies, but they're not powerful enough to lift it when it's fully fueled on kerbin.

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[Cap'tain Kerk]

The plane: Sophia III, 20 intakes, nuclear engine

edit triing to put an albun instead of all the pics

edit2 if someone could tell me how to do it would be nice

the whole set of pics here:

http://imgur.com/a/y8Qle#0

the 3 'proof' pics

Edited September 12, 2013 by Cap'tain Kerk

[boolybooly]

So did you land safely Cap'tain Kerk? Your word is good enough its just that the K Prize mission is only complete on making a safe landing, which is often the trickiest part of a mission! Reloading from F9 is perfectly proper in case of mishap FYI.

Moar Boosters, an impressive craft by any standards though I have linked it as a gate crasher with a suitable jokey description, hope you are OK with that, because the craft launches vertically and has a lift stage which it decouples from which means it isn't technically a single stage to orbit! But thanks for the contribution and I am sure people will be interested to see what you did and how you did it.

Thanks for the Cosmic Flyer report Rogue Mason with picturesque screenshots, evidently a very capable ship and worthy winner of the highly regarded Astrokerbal Distinction which supercedes and includes the Kosmokerbal Commendation for a Mün flyby which I nevertheless mentioned in the link summary. Well flown!

Edited September 12, 2013 by boolybooly

[Moar Boosters]

So did you land safely Cap'tain Kerk? Your word is good enough its just that the K Prize mission is only complete on making a safe landing, which is often the trickiest part of a mission! Reloading from F9 is perfectly proper in case of mishap FYI.

Moar Boosters, an impressive craft by any standards though I have linked it as a gate crasher with a suitable jokey description, hope you are OK with that, because the craft launches vertically and has a lift stage which it decouples from which means it isn't technically a single stage to orbit! But thanks for the contribution and I am sure people will be interested to see what you did and how you did it.

Didn't you read my post? It's a SSTO for the missions to Duna, the Mun and Gilly. Ignore the pictures of the version on top of the heavy lifter, that is a separate craft designed to go to Laythe and back.

The regular version show in all but the last 3 pictures doesn't have the launch section, it's a standard SSTO that takes off from horizontally on Kerbin and Duna, and vertically on the mun, minmus and gilly.

Here's the craft file if you want to a play around with it. If anyone actually wants to fly it let me know and I'll post the flight plan/action groups. It's actually very easy to fly to Duna and back... I'm a crap pilot so I have to make everything idiotproof.

https://mega.co.nz/#!TEUXhaBD!G0Ad1gzboPhe6SCR2cgEOXDYnc92h7JvVILsLNMY91c

Edited September 12, 2013 by Moar Boosters

[boolybooly]

Oh sorry, my mistake, the lack of horizontal lift off screenies and the extra vertical take off screenies confused me before I read the post. So I have moved your entry to the Roll of Honour and recorded that you earned an Expeditionary Astrokerbal Distinction for the Duna landing and return which supercedes and includes the other landings for purposes of the listing. Technically you also earned an Exploratory Astrokerbal Distinction for Gilly and an Astrokerbal Distinction for Mün. FYI

Edited September 13, 2013 by boolybooly

[HueHue]

I still can't make a working SSTO for the life of me, is it because I feel bad about intake spamming and refuse to use nuke engines in-atmo? Any design tips?

[Stochasty]

Any design tips?

Build one that doesn't use any jet engines at all. It's not as hard as you might think.

A problem that I've found plagues a lot of people trying to build spaceplanes is that they think spaceplanes are mostly about the "plane" with a few parts added for the "space." This is wrong. Spaceplanes are primarily about the "space," with only as much "plane" added as needed to get off the ground.

[glacierre]

Build one that doesn't use any jet engines at all. It's not as hard as you might think.

A problem that I've found plagues a lot of people trying to build spaceplanes is that they think spaceplanes are mostly about the "plane" with a few parts added for the "space." This is wrong. Spaceplanes are primarily about the "space," with only as much "plane" added as needed to get off the ground.

I have to disagree on that one, I find quite easy to make jet based SSTO with veery weak rocket engines and little oxidizer (or just ions!), just enough to give you the last push. With no jets and disregarding the plane side the thing degrades way too quickly into a rocket with wheels.

My path is: single jet, small plane. And no, I don't spam intakes, 2:1 or 3:1. A tiny rocket tank, a couple of 909 or the new little rockomax (way too easy, those) are more than enough to make 100x100 orbit and back.

I did build a few 1:1 back in the day when somebody claimed it was not possible.

[Hejnfelt]

Any design tips?

Consider your center of mass and your lift. Make sure your lift goes straight through your center of mass.

Make sure you have a control torque part like the inline reaction wheels for improved SAS. At high speeds this is crucial. I like to place it right behind the cockpit so it comes far in front of the center of mass.

Make sure you have at least 2 action groups. One for your jet engines and one for your rocket engine and turn your engines on and off before you hit the "stage" button (spacebar) at launch. Then use the jet engine action group to turn on your jet engines. When it's time to shift, use your action groups to turn engines on/off without touching your throttle.

I suggest using the LV-T30 Rocket engine as it is light, powerful and has good isp in vacuum.

Use 2 jet engines, 1 LV-T30 and make sure to use fuel lines to funnel fuel between tanks. Yes, oxidizer can run through liquid fuel tanks as long as parts are connected with fuel lines.

Hope it helps.

[Moar Boosters]

I still can't make a working SSTO for the life of me, is it because I feel bad about intake spamming and refuse to use nuke engines in-atmo? Any design tips?

If you don't want to ugly up your craft by spamming air-intakes all over it, then do what I did with the plane I just posted and make a blended wing body, and then hide all the air-intakes inside. That thing has a maximum of 207 air, and apart from the line at the wing edges, no visible intakes in unrealistic positions.

Why don't you want to use nuke engines in atmposphere? They're nice and efficient at higher altitudes, and the exhaust from NEVRA engines isn't radioactive, so you're not going to disperse a death cloud all over kerbin, despite what the contrail conspiracy theory kerbals say.

[HueHue]

If you don't want to ugly up your craft by spamming air-intakes all over it, then do what I did with the plane I just posted and make a blended wing body, and then hide all the air-intakes inside. That thing has a maximum of 207 air, and apart from the line at the wing edges, no visible intakes in unrealistic positions.

Why don't you want to use nuke engines in atmposphere? They're nice and efficient at higher altitudes, and the exhaust from NEVRA engines isn't radioactive, so you're not going to disperse a death cloud all over kerbin, despite what the contrail conspiracy theory kerbals say.

My SSTOs tend to crash or explode nearly as much as the Space Shuttle (huehuehue) so slapping a nuclear engine on it seems rather environmentally unsound. Thanks for the tips, all.

[boolybooly]

I still can't make a working SSTO for the life of me, is it because I feel bad about intake spamming and refuse to use nuke engines in-atmo? Any design tips?

Partly the air intake which limits altitude and therefore top speed on aero engines (atmospheric drag is on a log scale of some kind relative to altitude, you can go a lot faster higher up) but nukes are very hard to lift, a pair of the smaller engines like the LV-909s work much better around a single aeroengine SSTO. example This layout has the advantage that all air goes to one aero engine and if it flames out* it wont spin the craft like dual aero / single rocket layouts. You will find it easier if you can add at least a couple of radial air scoops in a suitably aesthetic location. If not then consider a pair of T30 rockets as you will have to make up more altitude and speed with the rockets. They have 2.5x the weight but 4.3x the maximum power of the 909 but you will need to lift more rocket fuel in the first place. Air intake is pretty critical and we don't have anything which approximates a supersonic ramjet yet so I use radials and hidden arrays, but that example has no hidden parts and works fine.

*One tip is to reduce throttle as air become insufficient as this reduces the demand for air and allows the aero engine to continue working at reduced power at higher altitudes. If you cut throttle 20% and then wait it will usually reignite.

When building the craft relative location of lift and mass centers is critical, lift behind mass. But then it flies like a paper plane with a lump of blue tack on the nose and just nose dives unless you have attitude control surfaces far enough back from the center of mass that it gives leverage to overcome attitude droop. The further apart the lift and mass centers the more downward torque mass creates. Its all about leverage. Same goes for the undercarriage, place the rearmost pair just behind the center of mass so the plane can tilt back using the leverage of the control surfaces, if the wheels are too far back the leverage of the mass to wheels distance overcomes the leverage of the control surface to wheel distance and the craft will not lift its nose.

So let us know how it goes.

[Stochasty]

I find quite easy to make jet based SSTO with veery weak rocket engines and little oxidizer (or just ions!), just enough to give you the last push.

Yes, but that's because you already know how to do it.

My point here is that I see a lot of people who try to start with a working plane design and then add a few rockets and some rocket fuel to get themselves into space. That's not a very good idea, and even if it works will tend to only work marginally, because the emphasis in spaceplane shouldn't be on the "plane." The starting point of your design should be "how am I going to get to space," not "how am I going to fly through the air." This is what I mean about emphasis.

Sure, if you already know how to do it it's trivial. However, for someone just learning, it's a heck of a lot easier to get to space starting with a rocket-with-wheels-and-wings design than a plane-with-rockets design.

[boolybooly]

This for example is one I built today to minimise intake spam. It has no hidden intakes and you see 3 inline ram intakes, one scoop beneath and a jet body intake on top.

It (Deuce) can just make a 70km orbit, though you really do have to get the climb just right there is plenty of air fuel for the job, only just enough rocket fuel/oxidiser though.

[ihtoit]

maybe a specification of "Must be crossrange capable and have the ability to perform an unpowered safe landing"?

That would imply "Must have lift/control surfaces".

[zekes]

Intake spam? Just do what i do... make really long "super-compressor" intakes. 100% plausible, they are like a hyper ram intake because they are so long...

see the bottom of my "Pip"? that is a hyper-compressed intake. one long one made from about six. Looks good, works awesome, and is with in realistic bounds.

[British_Rover]

I have made a couple of SSTOs but never got to posting one in this thread.

This my new modular SSTO based off an older design from a couple of versions ago.

It is ridicliously overpowered from a jet engine standpoint but I originally modified it to compete in that blackbird challenge.

I kill the four inner turbojets once I hit about 25,000 meters.

The docking port on the back lets me swap rocket engines in orbit.

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Landed on KSC runway for a Advanced pilot precision award.

This plane is part of my Blackbird series of SSTOs and high speed aircraft. It does look vaguely like a SR-71. Sort of.

This particular one is Blackbird_MOD for the modular nature of its rocket propulsion.

Edited September 16, 2013 by British_Rover

[glacierre]

This for example is one I built today to minimise intake spam. It has no hidden intakes and you see 3 inline ram intakes, one scoop beneath and a jet body intake on top.

It (Deuce) can just make a 70km orbit, though you really do have to get the climb just right there is plenty of air fuel for the job, only just enough rocket fuel/oxidiser though.

If you replace the fuel tank and the nacelle for two of the "conical" jet fuel tanks (flip one for visuals) you get a similar length (a bit shorter), more fuel and less weight. Ditch the radial intake (which is only useful at heights were you can climb vertically with this plane), and you should find yourself much more comfortable with the oxidizer.

[pa1983]

My latest SSTO. Falcon XIV Kosmos.

Some people have requested that I make a medium size SSTO so this was the result. Its LKO only and is basically a shuttle equivalent.

I got here up to about 425km orbit and delivered a 9 ton test payload. Then I reentered and glided all the way and landed at KSC.

Very nice preforming craft. First test flight failed due to a broken fuel line but other then that no modification was needed.

Fitting here with a docking port in the nose cone and she could dock Im sure off.

So she would work well for building small space stations, transporting crew, deploying satellites and probes.

Flight instructions and craft file is available in the description of the video in my youtube channel and the video shows pretty much how one would fly it. Didn't edit much out.

And yes she is all stock so should be valid for the K-prize.

http://youtu.be/ayHBGs9Ztrw

[boolybooly]

Good advice glacierre, I did it the hard way because it is hard in this instance and it can easily be improved by dropping the nacelle and adding a double radial scoop instead of single. I think the received wisdom on radial scoops may need rewriting btw because they have dropped in weight and have a high intake value.

British_Rover thanks for your mission report. I am assuming you did not use modular propulsion during the K Prize mission and am adding you to the guest list with an Advanced Pilot Precision Award. Congratulations and welcome to the K Prize.

pa1983 thanks very much for your instructive mission video of Falcon XIV Kosmos, as usual a beautifully finished craft and another K Prize winner.

This is a K-Prize mission with "Milligan Jet K-Prize" a stripped own Milligan jet which went to 4x lift off, full orbit and safe landing with the same craft without refuelling. It all relies on a lot of internal air intakes and four radial scoops which you can see in the screenies.

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[tavert]

I think the received wisdom on radial scoops may need rewriting btw because they have dropped in weight and have a high intake value.

They're the same mass as the circular and ram intakes now, but with more intake air "storage" capacity. The intake area is 0.004 for the radial, 0.008 for the circular, and 0.01 for the ram. Since storage capacity for intake air isn't too useful (unless you're using the disabling trick to save some intake air for jet use in space), the ram is still the way to go on an intake area per unit mass basis. It can be a bit trickier to find places to mount the inline ram intake though, so if you can mount 2.5 radials for the same number of parts as 1 ram, then radials can be worth using to save on part count.

The drag coefficient is also lower for the radial at 0.2 vs 0.3 for the circular and ram, but as far as I can tell (should probably do some more detailed experiments on this) the increase in drag coefficient at higher speeds when the intakes are open are comparable. So I think this only influences closed intakes, or makes a difference at low enough speeds that the open-intake drag coefficient is not yet saturated at its max value.

Edited September 17, 2013 by tavert