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Unnamed tiny SSTO

Can reach 90k LKO with Nuke + Turbo Jet

You mean it has a probe core in addition to MK1 cockpit? where is the nuke?

Low complexity cargo SSTO :

E2FAA0F5BDF8832EE356FF9E4121525F78B0FCCE

20 part counts

less than 18t full

~$ 17 000

tech level <= 5 except fuselage (basic jets)

hands off take off : the first 80 seconds can be flown w/o input (user or asas)

1.7t in lko (playload ratio is 10 %).

Edited by Kesa
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You mean it has a probe core in addition to MK1 cockpit?

You may have misread "unnamed" as "unmanned". He's saying it has no name yet, not that it flies without a pilot.

For that small of a craft, wouldn't a nuke have less dV than 48-7S?

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The second functional SSTO I've built, and the largest, the Jupiter:

Albatross_1.png

Capable of reaching a 90 km orbit, possibly a tad bit higher.

Mandatory orbit picture:

Albatross_2.png

Edit: Mandatory reentry photo:

Jupiter_3.png

I discovered that it is very unstable due to fuel consumption a bit too late, and had to bail (no kerbals were harmed). It is the first of its kind.

Edited by Brownhair2
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D'oh, I just did one too and called it the Albatross... More specifically, the "Star Albatross" ^_^

10615370_10152861988901815_9145062612319623222_n.jpg?oh=fce51121d9131ff55dd4f9bd5b0e7f07&oe=54F9B15B&__gda__=1426047821_b84a0f9ce70ebadd6d1592a35c6df6fa

10885345_10152861988421815_5666656190773488342_n.jpg?oh=4607295881ae49c168cf67e991c7f613&oe=54FB59CF

Small Payload Satellite comes standard.

10848064_10152861988521815_7557373158209367632_n.jpg?oh=7418234af4878108a54569c21991c298&oe=55464C86&__gda__=1430568299_7fc98126c70c00fecd75aa5e6a27d7cd

Whoops, overshot my re-entry. Good thing that this can immelmann turn, LIKE A BAWSS!!

10891717_10152861989166815_7249818222357960697_n.jpg?oh=af0d106fe7c9db179fdaa90c8eb37f2a&oe=5505DD83&__gda__=1426470805_64094bb312ef48e2bfd43e2363d3f327

In the words of Obi-Wan Kenobi, "Another happy landing."

MERRY CHRISTMAS!!

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D'oh, I just did one too and called it the Albatross... More specifically, the "Star Albatross" ^_^

Heh, actually renamed it to the Jupiter, after my theme of naming my spaceplanes off of celestial objects

Edited by Brownhair2
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I need help on a payload SSTO.

This is the Skyranger F:

Ln2f00L.png

I've shown it in the thread once and it was certified up to 11.7 tons to orbit. This was with the use of Stock Drag Fix, which changes the drag calculation to only use dry mass as an approximation for cross-sectional area instead of total mass.

I'm trying to re-certify it under stock aero but it just isnt happening. The massively increased drag is preventing the aircraft from reaching the necessary speeds to perform. Its currently barely flying, having to maintain a 20* AoA above prograde and cant accelerate to near what it needs to for an efficient orbital ascent. Without payload, its suffering a severe instability on control actuation during the late stages of the initial ascent (about 12-18km up and 600-1000m/s). Any control actuation I make causes the SAS to momentarily disengage (per usual KSP behavior) and then the aircraft wants to pitch up strongly and it takes RCS to fight the nose back down. I checked that the CoM is not shifting in front of the CoL and it isnt. Is that just how bad the stock aero can be on a plane not designed for it or what?

And does anyone have any advice for making this thing fly to orbit again?

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I need help on a payload SSTO.

Not that I'm an expert on SSTOs, but I'll see what I can do. You're only experiencing instability issues without a payload? Is your center of mass inside the cargo bay? Maybe you should try shifting it there, and then adjusting your center of lift accordingly. As for the drag, you could add more wings to make up for it.

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I need help on a payload SSTO.

This is the Skyranger F:

http://i.imgur.com/Ln2f00L.png

I've shown it in the thread once and it was certified up to 11.7 tons to orbit. This was with the use of Stock Drag Fix, which changes the drag calculation to only use dry mass as an approximation for cross-sectional area instead of total mass.

I'm trying to re-certify it under stock aero but it just isnt happening. The massively increased drag is preventing the aircraft from reaching the necessary speeds to perform. Its currently barely flying, having to maintain a 20* AoA above prograde and cant accelerate to near what it needs to for an efficient orbital ascent. Without payload, its suffering a severe instability on control actuation during the late stages of the initial ascent (about 12-18km up and 600-1000m/s). Any control actuation I make causes the SAS to momentarily disengage (per usual KSP behavior) and then the aircraft wants to pitch up strongly and it takes RCS to fight the nose back down. I checked that the CoM is not shifting in front of the CoL and it isnt. Is that just how bad the stock aero can be on a plane not designed for it or what?

And does anyone have any advice for making this thing fly to orbit again?

Suggestions:

1. You probably do not have either enough thrust or enough lift or both. A good rule of thumb is 15t per jet engine, 13t for RAPIER. and go to slightly more loading (17-15) when you get this working.

2. It could be hard for a large plane, but try to calculate the total lift rating of the parts and make sure it is around 0.8-1 lift rating per t.

3. Make sure the center of lift is slightly behind the center of mass (the spheres should touch or nearly touch), and the thrust vector is pointing towards the center of mass.

4. Install more control surfaces: canards near the nose of the plane, elevons near the rear. Make sure the canards are facing the right way or they wont work.

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Suggestions:

1. You probably do not have either enough thrust or enough lift or both. A good rule of thumb is 15t per jet engine, 13t for RAPIER. and go to slightly more loading (17-15) when you get this working.

2. It could be hard for a large plane, but try to calculate the total lift rating of the parts and make sure it is around 0.8-1 lift rating per t.

3. Make sure the center of lift is slightly behind the center of mass (the spheres should touch or nearly touch), and the thrust vector is pointing towards the center of mass.

4. Install more control surfaces: canards near the nose of the plane, elevons near the rear. Make sure the canards are facing the right way or they wont work.

I'm definitely putting more than that per engine, and thats also one of its biggest issues right now (not enough thrust to fight increased drag).

Lift is something I don't *think* is a huge issue. If I can get more speed than I can currently, then lift will take care of itself.

The CoL is a bit more distanced behind the CoM than almost touching, partly due to how much it shifts as the fuel drains. As this isnt a small craft in the slightest, the larger separation doesn't create any problematic behavior which i can notice. The CoM remains inside the cargo bay fully but is not centered. Adding payload does shift it forward some but not a huge amount.

Aero control seems pretty decent. It has the control authority it needs, I just don't understand what could make it pitch up hard. I believe its a quirk with the SAS overcorrecting when I lower my climb angle.

Theres not really anything I can do to improve the engine layout on this bird, so starting from scratch, possibly with a smaller payload bay (and only around 6 ton capacity) is definitely being considered. Real shame because I love that bird.

As a sidenote, it cannot fly under FAR either unless I manually undo FAR's nerf to jet engines. Otherwise I lose my turbojets way too early in the ascent and I cant maintain sufficient acceleration.

Lurker here. Just wanted to comment that I finally made my first SSTO. 120x120 orbit and back home for a touch down at Kerbal space center. I know it's nothing big but it felt huge to me.

For some people SSTO building comes naturally. For others its a persistent struggle. Single Stage To Orbit is nothing to sneeze at. Gratz man.

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Lurker here. Just wanted to comment that I finally made my first SSTO. 120x120 orbit and back home for a touch down at Kerbal space center. I know it's nothing big but it felt huge to me.

Congrats. I know the feeling :P

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I'm definitely putting more than that per engine, and thats also one of its biggest issues right now (not enough thrust to fight increased drag).

Lift is something I don't *think* is a huge issue. If I can get more speed than I can currently, then lift will take care of itself.

The CoL is a bit more distanced behind the CoM than almost touching, partly due to how much it shifts as the fuel drains. As this isnt a small craft in the slightest, the larger separation doesn't create any problematic behavior which i can notice. The CoM remains inside the cargo bay fully but is not centered. Adding payload does shift it forward some but not a huge amount.

Aero control seems pretty decent. It has the control authority it needs, I just don't understand what could make it pitch up hard. I believe its a quirk with the SAS overcorrecting when I lower my climb angle.

There is also a sort of "center of drag" that isn't shown in the VAB and SPH. Perhaps it's too far in front of your center of mass, and is forcing your nose up. This would also be aided by the huge difference between the angle of your nose and your direction of movement. More thrust could help with this, if it is the case.

Edited by Brownhair2
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For some strange reason my mind expunged all knowledge of the new Root Part tool.

As such, I'm currently trying to get a rover to orbit on top of a spaceplane, when I don't even have Mk 3 spaceplane parts yet.

OgZAZ9k.png

I had to build an embarkment vehicle just to get the rover on top.

EDIT:

Wooooo! Got it to orbit! Funnily enough, it wouldn't have made it if I hadn't fitted monopropellant engines to the MunBug. The spaceplane might work with a nuclear engine if it had no cargo, but as is I thought I was going to lose it. Pretty happy with this though. Now to get it to the Mun.

ro2F8ec.png

NEaDHEh.png

EDIT 2:

Got the MunBug to the Mun with a nuclear tug. The monopropellant engines proved just how useful they are - the MunBug was able to descend and land all by itself. And it's 6 tons.

elhCNrL.png

Edited by RedDwarfIV
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There is also a sort of "center of drag" that isn't shown in the VAB and SPH. Perhaps it's too far in front of your center of mass, and is forcing your nose up. This would also be aided by the huge difference between the angle of your nose and your direction of movement. More thrust could help with this, if it is the case.

KSP uses mass to approximate cross sectional area, so your CoD is generally the same or at least very close to your CoM because the former effectively draws off the other for its derivation. Now, I know intakes generate more drag when open than just normal part drag. The big intakes up forward are significantly ahead of the CoM. In that picture, you cant see about 24 structural intakes lined up under the wings near the trailing edge. I'm guesstimating all that drag counteracts the extra drag up front, but I'd have to actually look at the parts with non-standard drag coefficients and do some approximation math.

Either way, thanks for that. I know the issue has to do with drag. Now, if I empty all the tanks (or otherwise get no drag from resource mass), the plane flys perfectly! Unfortunately I kinda need fuel or else I gotta use hax.

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KSP uses mass to approximate cross sectional area, so your CoD is generally the same or at least very close to your CoM because the former effectively draws off the other for its derivation. Now, I know intakes generate more drag when open than just normal part drag. The big intakes up forward are significantly ahead of the CoM. In that picture, you cant see about 24 structural intakes lined up under the wings near the trailing edge. I'm guesstimating all that drag counteracts the extra drag up front, but I'd have to actually look at the parts with non-standard drag coefficients and do some approximation math.

Either way, thanks for that. I know the issue has to do with drag. Now, if I empty all the tanks (or otherwise get no drag from resource mass), the plane flys perfectly! Unfortunately I kinda need fuel or else I gotta use hax.

Surely you don't need all the fuel. Also, I only see rocket fuel fuselages. If you haven't already, you could get rid of a little oxidizer to make up for the liquid fuel your jet engines will be burning. It probably won't be enough to get your plane working, but it could help

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Surely you don't need all the fuel. Also, I only see rocket fuel fuselages. If you haven't already, you could get rid of a little oxidizer to make up for the liquid fuel your jet engines will be burning. It probably won't be enough to get your plane working, but it could help

I'm working on a scratch redesign. The problem seems to exist in all my larger SSTOs, being that I'm not bringing enough thrust and air intakes. There's no way to add intakes without stupidly excessive clipping, and I can only rectify the thrust issue with more engines, which again is difficult. Far as fuel goes, I need about 80% of it on a decent ascent. If I cut the weight (as in payload capacity) down, I can reduce my fuel needs. I'm working on an increased intake/engine build thats actually larger, but significantly stronger in the thrust department. Its also hauling the extra fuel internally rather than in a bay (true tanker over cargo hauler). I'll keep people posted.

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