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Longer runway?


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Hello, 

Would it be possible that the runway not only gets broader and less bumpy by upgrading it, but also gets longer? :D

 

Sadly, the minimum required number of engines (EDIT: and lifting area) on all of my spaceplanes is defined by the number of engines required to reach takeoff speed until the end of the runway, while the number of engines needed to get to orbit would alwaysbe lower.

 

That means we could build much more efficient planes, if the runway was longer.

 

So please think about a longer runway, at least at the highest upgrade level. 

Edited by Kergarin
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3 hours ago, Kergarin said:

Would it be possible that the runway not only gets broader and less bumpy by upgrading it, but also gets longer?

It does, just not by much.

3 hours ago, Kergarin said:

Sadly, the minimum required number of engines on all of my spaceplanes is defined by the number of engines required to reach takeoff speed until the end of the runway, while the number of engines needed to get to orbit would alwaysbe lower.

RATO for takeoff, drag 'chutes for landing. At least that's what I do.

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4 hours ago, Kergarin said:

Sadly, the minimum required number of engines on all of my spaceplanes is defined by the number of engines required to reach takeoff speed until the end of the runway, while the number of engines needed to get to orbit would alwaysbe lower.

 

That means we could build much more efficient planes, if the runway was longer.

Hey Kergarin. I may be very wrong but shouldn't an efficient plane be one that needs less runway to take off? Your spaceplanes may be in serious need of canards or more general lift surface if they need to blaze the runway in order to nose up.

1 hour ago, Nothalogh said:

The runway needs to be 1.5 to 2 times its current length, for hypersonic optimized aircraft

Care to expand on this? I'm curious. I build hypersonic planes.

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Actually it would be very nice to have a second runway, which crosses the first one at an angle. It would serve the game well from several perspectives: polar returns flights, ability to leave one aircraft on the runway and lauch a second one at the same time, roleplay etc.

I heard an expression of such wish from several KSP streamers, including EJ_SA, Scott Manley and DasValdez.

Edited by Enceos
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6 hours ago, Nothalogh said:

The runway needs to be 1.5 to 2 times its current length, for hypersonic optimized aircraft

That would be fine :)

 

5 hours ago, steve_v said:

It does, just not by much.

RATO for takeoff, drag 'chutes for landing. At least that's what I do.

RATO is an option, but the Spaceplane the would not count as an SSTO, what i always like to build and fully recover.

Landing never is a Problem, i use chutes too. :wink:  half the runway would be enough for that.

 

4 hours ago, JadeOfMaar said:

Hey Kergarin. I may be very wrong but shouldn't an efficient plane be one that needs less runway to take off? Your spaceplanes may be in serious need of canards or more general lift surface if they need to blaze the runway in order to nose up.

Care to expand on this? I'm curious. I build hypersonic planes.

Hey JadeOfMaar,

That depends on how far out want to take your Spaceplane. In the upper atmosphere or at least once you are in space, every lifting surface and every additional engine is dead weight which you need to take with you all the way.

 

 

5 hours ago, Gaarst said:

The runway is fine. If you can't manage to take off with KSP's super-OP jet engines, the problem is you.

This sadly sounds a little offending to me. :/

 

It seems, like you are saying, the person who:
created the first ever EVE SSTO that can also land on its own
managed as first ever to SSTO at first vessel launch in career to space high
planted a flag everywhere including EVE based on a single SSTO launch
build a reusable 48ton Duna transfer SSTO
pushed a fully assembled station to LKO at the back of an SSTO
made the stock stearwing an SSTO without any external parts
build an SSTO that can get to orbit and land 4 times without refuelling
.......
Does not know how to build efficient spacecrafts? :)

 

So please explain, why am I the reason for the fact, that the TWR thats needed to go from sealevel to LKO is lower than the TWR thats needed to reach takoff speed until the end of the runway? (aiming for 180m/s on efficient designs)
I just do not like to carry a bunch of engines and wings throug the entire solar system, which would have been obsolete by a longer runway.

Sorry if this sounds any offending too. It's not meant like this. I just had the feeling, i need to justify myself.

Edited by Kergarin
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This discussion pops up at least once or twice a year. And every time it ends with the well established fact the runway is already unrealistically long.
If your plane can not take off before the end of the runway it is lacking in some way or another. Usually one of the following three:

  1. Not enough lift or in the wrong place.
  2. Not enough control surfaces or in the wrong place.
  3. Incorrect landing gear placement.
Edited by Tex_NL
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5 minutes ago, Kergarin said:

RATO is an option, but the Spaceplane the would not count as an SSTO, what i always like to build and fully recover.

SRBs are cheap, and often cheaper than the extra fuel to move more jets, or a second launch to split the payload. The whole point of SSTO is that it reduces cost per ton to orbit... But if a not-quite-SSTO works out cheaper, I'll go with that.
Or you culd just use the grass... it's longer than the runway and just as flat. :P

4 minutes ago, Tex_NL said:

If your plane can not take off before the end of the runway it is lacking in some way or another.

...Or you're running FAR and building ridiculously slippery things with silly high wing-loading. :)
Hence the RATO to get off the runway.

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9 minutes ago, steve_v said:

...Or you're running FAR and building ridiculously slippery things with silly high wing-loading. :)

That's what I said. Then there is something wrong with your craft.
You can not expect to have control without gripping the medium you're travelling through. A car without tracking will slide off the road. An airplane completely without drag will fall from the sky.

Edited by Tex_NL
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11 minutes ago, Tex_NL said:

This discussion pops up at least once or twice a year. And every time it ends with the well established fact the runway is already unrealistically long.
If your plane can not take off before the end of the runway it is lacking in some way or another. Usually one of the following three:

  1. Not enough lift or in the wrong place.
  2. Not enough control surfaces or in the wrong place.
  3. Incorrect landing gear placement.

Thanks for your suggestions. They are all true. But please have a look at the post above yours, I'm not a beginner i think :)

I do build my Spaceplanes for a takeoff speed around 180m/s cause this seems most efficient on the current runway.
If you want to go interplanetary, every wing and every engine that would not have been needed on a loner runway, is dead weight lowering the efficiency. And this is an indiscussable fact.

18 minutes ago, steve_v said:

SRBs are cheap, and often cheaper than the extra fuel to move more jets, or a second launch to split the payload. The whole point of SSTO is that it reduces cost per ton to orbit... But if a not-quite-SSTO works out cheaper, I'll go with that.
Or you culd just use the grass... it's longer than the runway and just as flat. :P

...Or you're running FAR and building ridiculously slippery things with silly high wing-loading. :)
Hence the RATO to get off the runway.

Thats true, RATO can be cheaper.
But if the plane works with RATO, thats just another evidence that it would work without it too, if the runway was longer. And this is an indiscussable fact too.

 

 

Anyway, i think this wont happen and if you say this pops up fequently, and does not get considered, we should close here.
I don't want to argue :)

Fly safe and happy landings to all :)

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23 minutes ago, Tex_NL said:

Then there is something wrong with your craft.

If you say so... Though I do have more than one craft (one of which was my workhorse for station assembly until superseded by something bigger) that require RATO to get off the runway at MDTOW. Fly fine, re-enter fine, land fine. I don't see a problem here. The limiting factor for minimum TWR & wing area is often the length of the runway. Not saying it's too short, but it is a limitation.

Edited by steve_v
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6 minutes ago, Frozen_Heart said:

You might have the landing gear too far back, as that makes it near impossible to pivot the nose up for takeoff. Move the rear landing gear to just behind the CoM and takeoff runs should be easy.

I watched some of the vids, and checked out some of the pics and yes indeed; the landing gear is way too far back on most of the planes to be able to rotate off the runway.

That said, obviously the guy builds a lot of SSTO's and has a lot of success with his designs. I'm not knocking his methods and I'm sure there is some reason he was forced to or decided to place his gear so far back.

If someone modded in an extra long runway, I'm sure there would be lots of people who'd make use of it. I doubt it'll happen in stock anytime soon though.

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33 minutes ago, Tex_NL said:

An airplane completely without drag will fall from the sky.

Where did I say no drag?
I said 'slippery' as in low drag. If supersonic drag is low enough, the length of the runway is the limiting factor, not high altitude acceleration, and certainly not control authority.

Edited by steve_v
Ahh, right, that list.
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49 minutes ago, steve_v said:

If you say so... Though I do have more than one craft (one of which was my workhorse for station assembly until superseded by something bigger) that require RATO to get off the runway at MDTOW. Fly fine, re-enter fine, land fine. I don't see a problem here. The limiting factor for minimum TWR & wing area is often the length of the runway. Not saying it's too short, but it is a limitation.

True

 

59 minutes ago, Frozen_Heart said:

You might have the landing gear too far back, as that makes it near impossible to pivot the nose up for takeoff. Move the rear landing gear to just behind the CoM and takeoff runs should be easy.

49 minutes ago, Rocket In My Pocket said:

I watched some of the vids, and checked out some of the pics and yes indeed; the landing gear is way too far back on most of the planes to be able to rotate off the runway.

That said, obviously the guy builds a lot of SSTO's and has a lot of success with his designs. I'm not knocking his methods and I'm sure there is some reason he was forced to or decided to place his gear so far back.

If someone modded in an extra long runway, I'm sure there would be lots of people who'd make use of it. I doubt it'll happen in stock anytime soon though.

Thanks for these objectively posts :)
You are right, the landing gear would be way to far back, if i would consider pulling up while I am on the runway.

But since i allways use the entire runway to build up speed, i do never have to do so.
I do pull up in the moment when the plane gets airborne by "falling" from the end of runway, so it doesn't matter where the wheels are, because they do not touch anything.
I do build all my SSTOs so that they need the entire runway to reach takeoff speed, because - like i said in first post - the runway length dictates the minimum numer of engines and lifting area, and i want to keep both as low as  possible.

Edited by Kergarin
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6 hours ago, Gaarst said:

The runway is fine. If you can't manage to take off with KSP's super-OP jet engines, the problem is you.

This is way too dismissive. OK, you shouldn't need a longer runway for most reasonably sized designs (tens of tonnes), but runway length for larger designs is an issue, and the suggestion of a longer runway is a perfectly reasonable one.

I'm no stranger to designing large airframes, and I regularly encounter the following problems:

- Lack of large (long) landing gear, making tail-strike a real challenge on long, sleek airframes. This is not an issue of landing gear placement in relation to CoM. I can get my aircraft to rotate, it just can't reach sufficient incidence to become airborne without a ridiculously high TWR.

- FAR, although it is an awesome mod, does not simulate ground effect.

JleRk8G.png

1 hour ago, Tex_NL said:

And every time it ends with the well established fact the runway is already unrealistically long.

No, it's not. It is about 2,5 kms long, which is regional airport size. Major international airports are 3-3,5 km or more, and some of the major test flight facilities (Istres in France) have 5 km.

I'd be interested if anyone could name one real life large delta design (>100 tonnes) that can take off in less than 2,5 km at max weight..?

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 I have found the opposite to be true; low power/ low drag spaceplanes don't have a problem taking off from the KSP runway, they have a problem landing on it. They simply lack the drag to properly scrub off speed and can float the length of the runway unless measures are taken to help.

Best,
-Slashy

45 minutes ago, Kergarin said:

I do build all my SSTOs so that they need the entire runway to reach takeoff speed, because - like i said in first post - the runway length dictates the minimum numer of engines and lifting area, and i want to keep both as low as  possible.

 You don't actually have to limit the wing area. Wings impose a very low drag and mass penalty. Also, there is a point where going too low on thrust results in a loss of efficiency. The mass savings of the engine are overshadowed by the increased fuel mass consumed.

 HTHs,
-Slashy

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13 minutes ago, UnusualAttitude said:

I'd be interested if anyone could name one real life large delta design (>100 tonnes) that can take off in less than 2,5 km at max weight..?

That's like asking for VTOL fighter jets other that the Harrier. There are others within those specs but only a few.

Too short landing gear is a poor excuse. If your gear is not tall enough you use bigger gear. And when there aren't any bigger available you MAKE them bigger. Put them on pylons, use TweakScale. Be creative and think outside the box.
And if all else fails, loose the wings completely and launch vertical.

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I have honestly never had a problem with the runway being too short. IF any space plane of mine cannot take off before the end of the runway, that probably means it does not have enough lift anyway. Occasionally, I will have a plane that will get to the end of the runway, and then will jump off the small drop-off at the end, and then be fine. Mods such as Kerbin Side add longer runways as well.

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1 hour ago, Tex_NL said:

That's like asking for VTOL fighter jets other that the Harrier. There are others within those specs but only a few.

My point is simply that the runway is too short for certain real/proposed hi-performance designs that many players, myself included, like to attempt to replicate. 

And sure, there are workarounds. But it would be nice to not have to resort to ugly gear on pylons or fairings, RATO, or yet-another-mod.

Sheesh, just another 1,000 metres and I would be happy. And I fail to see how this would spoil anyone else's fun.

Edited by UnusualAttitude
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