Jump to content

SSTOs! Post your pictures here~


Recommended Posts

A friend asked me how soon can you make an easy to fly ssto. So today's blind attempt - as soon as you have panthers and terriers.

UbNL50R.png

"The whole gallery" at https://imgur.com/a/K1ZAD

The gimbal is disabled on the panthers since the plane needs no help turning. Wet mode from launch, engaging terriers at around 14km when the panthers start to bleed speed instead of adding, maintained 20 degree ascent up to 32km , then gradually brought the nose down. Nose gets a little heavy once you are up in space, pump all the fuel to the rearmost tanks when deorbiting.

Link to comment
Share on other sites

Initially I thought having a rotating VTOL engine for my SSTO space plane would offer an improvement in efficiency over my fixed VTOL craft.  Unfortunately this resulted in a craft that's twice as big and heavy while carrying the same payload.  The only advantage it has is the cool factor of engines that can go from vertical to horizontal mode.

8AFD0B3DF80C102DD85936F7BAEDBDD5E5C20958

ImgUr album

 

Edited by evader
Link to comment
Share on other sites

Like that a lot, mine is a little more versatile in terms of being multi role, and able to carry extra stuff,  but i'd say yours looks far more "pure". I've been trying to build a Galactica myself, but even a half scale one at 700m long is a bit too hard to get up in the air and keep in one piece. I'm still working on that though and i think i have most of the other BSG craft down pat. (as you can see here)  (Viper Mk2 and Mk7, Cylon Classic Raider, and Mk2 Raider, Raptor, Heavy Raider, and of course the Blackbird.)

 

 

Link to comment
Share on other sites

Guest Space Cowboy

Magnificent Basterd. I got 3 orange tanks to 300,000m and got it back on the ground.
 

screenshot599

 

screenshot678

screenshot741

 

Edited by Space Cowboy
Link to comment
Share on other sites

So another BSG themed ship.

This time the StealthStar. It will do SSTO and is quite simple and easy to fly.

https://imgur.com/4xhioJY.jpg

https://imgur.com/6Nt7O9l

https://imgur.com/Lx0PyH4

https://imgur.com/AuVLqfY

https://imgur.com/qt1DqqE

Easy enough to get to orbit, climb to 12km, drop the nose, accellerate past 400m/sec and climb out to Orbit.

F1 toggles Rapiers, F2 toggles Puff engines for more boost.

 

Hosted on KerbalX here.

https://kerbalx.com/atassiedevil/StealthStar

 

Enjoy and comments are welcome!

Edited by atassiedevil
Adding IMGUR album
Link to comment
Share on other sites

4 hours ago, Scarecrow said:

I had something similar to this in a previous version of KSP.  It worked quite well so I thought I would re-build it for the current version.

An elegant spacecraft... from a more civilized time.  I like it

I may have Star Wars on the brain from the post above yours

Link to comment
Share on other sites

Doing the nth enlargment of my venerable LackLuster, I figured out one I'm quite happy with, looks-wise.

9r6Plxh.png

Good-looking for a rocket, right? Not the most efficient, because I used a lot of tankage with awful fuel fractions, but 2.5mT to LKO, like the original, with a bit more margin, a nicer-looking tail, and no finagling with the control surfaces to rotate it during reentry. In fact, it is 100% Vernor-powered, with no reaction wheels on the design, so quite realistic too. The flaps double as high-speed airbrakes, but they are disabled otherwise, so you don't have to reverse their controls once you flip it. And yes, it is stable in both configurations (tough it will dance a bit around retrograde until you hit the chutes), and can switch between 'feet first' and 'nose first' with vernors completely under autopilot, as well as also being stable in a weird ~90º attack angle, for some reason that I suspect is an off-center body lift on the payload bay, but that can come in handy to brake in a hurry. But I digress. Solar power and medium range comms allow self-ferry on interplanetary trajectories, and the >4km/s in the tanks when full means pretty much anywhere is a fuel depot or two away. You guys like?

PKZZjij.png

 

Rune. Took me quite a while to find one I liked as much as the old one.

 

Edited by Rune
Link to comment
Share on other sites

43 minutes ago, eloquentJane said:

Looks great @Rune! And I'm glad to see you're still making SSTOs, yours have always been some of my favourites.

Thanks! It's not that I stopped, it's that I can't get them to be any better. :blush:

I'm still flying variations of my stuff from ages ago, basically. If it's cargo and it goes to LKO, it goes inside a Claymore. If I need to drop stuff somewhere, it's an Orca. And of course the main point of my save is putting a Base Pack or two on every rock. I may use slightly modified files, maybe (I should update to 1.3.1 one of these days and then I'll upload new files to KerbalX), but they are still the same initial design. Almost all of the new ones just don't do anything better, so they don't get to the finish line.

 

Rune. You guys only get to see the polished stuff, and the more I play, the higher I set myself the bar.

Edited by Rune
Link to comment
Share on other sites

8 minutes ago, Rune said:

It's not that I stopped, it's that I can't get them to be any better.

If you want something new to do, you could always scale up the stock system (3.2x is quite a nice scale factor) and start designing SSTOs for that. Or planet packs are an option. Although I know you like to keep everything stock.

Link to comment
Share on other sites

On 01/09/2017 at 10:41 AM, MustaKotka said:

Well, I assume there's a million of these, but who cares. It takes a full large Kerbodyne tank up.

The above comment is an example of:

a) honesty.

b) a KSP player commenting on a craft thread without advertising some discreet name for his craft, putting mk___ in front of said name to show just how much we worked on it, or pushing some weird "company" he imagines himself in.

+1 like.

Link to comment
Share on other sites

18 hours ago, eloquentJane said:

If you want something new to do, you could always scale up the stock system (3.2x is quite a nice scale factor) and start designing SSTOs for that. Or planet packs are an option. Although I know you like to keep everything stock.

Jane pointed me in the direction of the Kopernicus and Sigma Dimensions mods, which allowed me to rescale the Kerbol system while keeping everything else stock.   As suggested,  I rescaled by a factor of 3.2 and increased atmosphere height by 1.4.     Hopefully that's close to the conditions she's playing her career save under.

With these changes,  orbital velocity is a bit over 4200 m/s compared with a bit over 2200 m/s at normal scale.   The top of Kerbin's atmosphere is now about 98km instead of 70km.

With stock parts, this adds a lot of extra difficulty.      A normal SSTO can get 1600 m/s air breathing.   Theoretically,  just 600 m/s delta V in closed cycle mode gets you into orbit, which is why so many people are able to do it despite the poor ISP of RAPIER engines and high dry mass of most space planes (compared with your typical rocket upper stage).      With the rescale,  you now need 2600 dV rocket mode delta V - more than four times as much.

To be honest,  I doubt this is possible unless you are using NERV engines,   and since they have poor TWR, you need wings that can support the craft against gravity all the while it slowly builds momentum,  and low drag since it doesn't take much drag to overcome the weak thrust of the nukes.   

My first attempt was with my MK1 Griffon crew SSTO.    Stock, this goes to orbit with over 3000 delta V left over.   

HmAX3P5.png
But in the rescaled system , it fell about 100 m/s short and didn't have enough fuel to circularise its orbit.  Not only are the delta V requirements larger,  in stock Kerbin, you're up to a substantial portion of orbital velocity soon after lighting nukes.   This means gravitational freefall starts supporting most of your weight, which means at a constant lift/drag ratio, less drag is needed to get sufficient lift to stay airborne.   Or, another way to look at it, the reduction in apparent weight means your lift takes you up higher into the atmosphere, where drag is less.

On rescaled Kerbin,  this effect takes much longer to kick in, leaving you with higher drag losses for longer.  More seriously,  the much more protracted nuke engine burn caused the NERVs to overheat the crew cabins attached in front of them.    

Spoiler

 

Y85Wwjc.png

The mountains look more spectacular on rescaled Kerbin - no graphical mods installed ! 

 

 

 

As a "minimal changes" mod,  I simply deleted these crew cabins outside of the main stack, reducing the seating capacity from 11 to 7, and the mass from 39 to 37 tons.  The truncated vessel made it to orbit first try, albeit not with huge margins 

gx2ilKQ.png

QA6Ct4s.png

52km up at mach 10, still making lift.     Lift/drag ratio is 3.3 to 1,  TWR is 0.55 to 1  and we have 22kn drag against 119kn thrust.

I'm calling this variant the "Griffon SP" (Special Performance), like the Boeing 747 with shortened fuselage was called the "special performance" variant.

@eloquentJane  I'd be delighted if you give it a spin,  you could make a challenge/craft request thread for partially reusable rockets and spaceplanes/tsto for your career save.

Flight Manual

Spoiler

 

Action Group 1 - Sets nose up trim (raises nose a couple of degrees above prograde)

Action Group 2 - Neutral Trim 

Action Group 3 - Nose Down Trim (lowers nose a couple of degrees)

Action Group 4 - Toggle Nukes

Action Group 6 - Atmo cruise mode (turns off RAPIER and sets Panther engine to Dry mode for economical cruising at low speed/alt)

 

Lift/Drag ratio is absolutely crucial on the rocket mode part of the flight,  this means angle of attack needs to be accurately controlled for long periods in order to make orbit.  For this reason I've set the aircraft up to fly with SAS set to Prograde Hold.      Manual control inputs are only needed to correct heading - on flight to orbit, pitch is to be controlled solely by triggering action groups 1-3.

Preflight

Note - We've had some reports of a quality control problem on the wiring of the trim flaps.    For this reason,  we recommend doing a manual control check before engine start on every flight.     Verify that when Action group 1 is pressed,  the outboard (Advanced) Canard at the front of the aircraft twists to that the leading edge goes up  and the trailing edge goes down.  When Action Group 3 is pressed, the leading edge should go up, and the trailing edge go down, on the elevator that connects the airplane's tailbooms.  Should any of the surfaces move in the wrong direction, return to the SPH and change the "deploy direction" of the relevant surface in tweakables.

Takeoff 

Turn SAS on before engine start.    As soon as the aircraft is rolling, set Prograde Hold mode, and ensure the Navball remains in "Surface" mode any time the aircraft is flying in the atmosphere.      Select action group 1 for nose up trim.       After takeoff, leave trim set for nose up until the climb angle becomes such that the airplane is no longer accelerating.    At this point, use action group 2 (neutral trim) or 3 (nose down) to stop the nose rising further.   Maintain a steady climb angle with these action groups.

Transition to Supersonic

Above 8km you will probably have to use action group 1 to maintain the climb angle.   At 10-11km the plane will start to level off despite this, and start accelerating into the transonic region.    At 250 m/s go to neutral trim to minimise drag.       Note, you can use action group 4 to get  a burst from the nukes between 260 m/s and 440 m/s.

Above 440 m/s the nose will start to rise, use nose down trim as appropriate to stop it climbing too steep (about 7 degrees is fine)

Speedrun

With a 1.4 scaled atmosphere the speedrun is best conducted about 28km.  Toggle between action groups 2 and 3 to keep altitude to around this level.         At about 1400 m/s, acceleration will begin to die away.      Activate nukes, but select action group 3 for nose down trim , this holds the altitude low enough for the RAPIER to continue to produce power till about 1600 m/s.     At this point,   the RAPIER is becoming ineffective,   so set action group 2 (neutral trim) for optimal lift drag ratio and enjoy the ride to orbit.

 

 

 

Craft file is here -

https://www.dropbox.com/s/xiwg7m7c47u1oyp/Griffon SP.craft?dl=0

 

Next project - I want to try making a partially re-usable spaceplane with Whiplash engines on drop pods.      This may offer better margins or payload fraction, whilst still being relatively cheap compared to the sort of disposable rocket needed to complete the same task

Edited by AeroGav
Link to comment
Share on other sites

@AeroGav You're a better spaceplane engineer than me to get an SSTO working in 3.2x scale. I can do shuttles (I can probably do a shuttle on most practical rescales just as long as I can make an orbiter that works) but an SSTO for 3.2x scale still eludes me. I'd been planning on trying it with liquid hydrogen engines, but those are obviously not stock. I'll test out your plane some time, perhaps at the weekend. I'm not sure you're using quite the same rescale settings as me but they're probably close enough.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...