1.0.2 - Any hope left for SSTOs?

[diegzumillo]

What's the best strategy for ascension?

[Radam]

What's the best strategy for ascension?

Put yourself in a lotus position, meditate deeply, gather your energy into a single point and break the reality barrier?

More seriously, ascent should be as fast as possible, top at highest speed with good apoapsis and low enough not to explode from heat. Some just stick to 19 degrees (with good twr), some go up to 11km and drop down to break the sonic barrier and back up again.

[Redshift OTF]

Surely this isn't realistic. I can fly a 285 ton spaceplane into orbit, deliver an orange tank and land on Kerbin again with barely any wings on the plane.

Hope fully this isn't considered spamming by the mods but I think it is relevant to this thread. And it is a new piccy.

[Radam]

Surely this isn't realistic. I can fly a 285 ton spaceplane into orbit, deliver an orange tank and land on Kerbin again with barely any wings on the plane.

I just think the cargo fraction is low. 36/285 is like 12.6%. Look at what rocket sstos are doing. 20% cargo fractions for a mammoth engine, ok surely it will take some of it to return it down to kerbin.

[Cailean_556]

Give a brick enough thrust and it will fly, aerodynamics and physics be damned!... Is that all stock? I don't use mods or try to clip parts so I dunno... Also, I'm not that far into either of my new games to SSTOs are still a ways off for me. The wing configuration is different however it does bear some resemblence to the Skylon... Maybe that helps? How does it go during re-entry? I've yet to see a successful SSTO landing on Youtube - though I only really watch Scott Manley and some EnterElysium. It's kinda put me off any large-scale craft until I get the gist of re-entry. I've only just made it to the Mun and planning a Minmus mission as we speak.

[Wanderfound]

Surely this isn't realistic. I can fly a 285 ton spaceplane into orbit, deliver an orange tank and land on Kerbin again with barely any wings on the plane.

http://i.imgur.com/sp7dGvB.jpg

Hope fully this isn't considered spamming by the mods but I think it is relevant to this thread. And it is a new piccy.

As previously, if you want realism, go FAR. Stock aero is less fanciful than it was before, but it's still a long way from the real thing.

Incidentally, though: see Skylon and the assorted other real-world spaceplane proposals. Big wings are about carrying heavy loads or making high-G turns at low speed; if you want to go fast, the wings need to shrink or disappear entirely. Hence the prevalence of lifting bodies and stub wings.

With enough power, even a brick will fly.

[cybersol]

Surely this isn't realistic. I can fly a 285 ton spaceplane into orbit, deliver an orange tank and land on Kerbin again with barely any wings on the plane.

With 32 engines (one/8.9t) that isn't really a plane, its a rocket that takes off and "lands" horizontally.

[KerikBalm]

With enough thrust, anything will fly, even in real life....

Lots of part clipping there... I can't tell if you're using any part mods.

Looks like ram air intakes clipped onto the front of the engine nacelles, lots of engines clipped on the back... but what part are they attached to?

what is the TWR?

The V^2 relationship of lift means that it doesn't take a lot of wing area to lift something, if its going fast enough... what speed does it take off at?

How slow can you get it without any power?

[Levelord]

As previously, if you want realism, go FAR. Stock aero is less fanciful than it was before, but it's still a long way from the real thing.

Incidentally, though: see Skylon and the assorted other real-world spaceplane proposals. Big wings are about carrying heavy loads or making high-G turns at low speed; if you want to go fast, the wings need to shrink or disappear entirely. Hence the prevalence of lifting bodies and stub wings.

With enough power, even a brick will fly.

Incidentally, KSP's aerodynamics can't distinguish wings placed together into a lifting body shape. The only thing it recognizes as a lifting bodies are MK2 (and to a lesser extent MK3) parts. It pretty much reduces all craft to flying sausages and disregards any lifting bodies marginally larger than the MK2.

[Redshift OTF]

I just think the cargo fraction is low. 36/285 is like 12.6%. Look at what rocket sstos are doing. 20% cargo fractions for a mammoth engine, ok surely it will take some of it to return it down to kerbin.

I think that is more of a 1.0 argument, that jets don't perform as well in the upper atmosphere as they did in 0.90. I agree but then I think the real Skylon only has a payload fraction of 5% so it is debatable for some. The main issue is the utter lack of wings that comes with the 1.02 package. The tail sections I used in this ship don't even have lift according to the Aero read outs.

[Radam]

I think that is more of a 1.0 argument, that jets don't perform as well in the upper atmosphere as they did in 0.90. I agree but then I think the real Skylon only has a payload fraction of 5% so it is debatable for some. The main issue is the utter lack of wings that comes with the 1.02 package. The tail sections I used in this ship don't even have lift according to the Aero read outs.

No, because someone posted a 20% cargo fraction spaceplane just a few posts earlier...

[Redshift OTF]

Give a brick enough thrust and it will fly, aerodynamics and physics be damned!... Is that all stock? I don't use mods or try to clip parts so I dunno... Also, I'm not that far into either of my new games to SSTOs are still a ways off for me. The wing configuration is different however it does bear some resemblence to the Skylon... Maybe that helps? How does it go during re-entry? I've yet to see a successful SSTO landing on Youtube - though I only really watch Scott Manley and some EnterElysium. It's kinda put me off any large-scale craft until I get the gist of re-entry. I've only just made it to the Mun and planning a Minmus mission as we speak.

Yes, this is all stock. It handles fine during re-entry and there are no heat issues whatsoever especially if you use air-brakes at 30km

- - - Updated - - -

With enough power, even a brick will fly.

With 32 engines (one/8.9t) that isn't really a plane, its a rocket that takes off and "lands" horizontally.

With enough thrust, anything will fly, even in real life....

Seriously, those tail sections don't even give any lift according to the Aero readouts. It's 285 taking off from a runway and landing horizontally at 118 tons. This is beyond un-realistic, it's broken. The "power gets anything into the air" mantra only applies if you can significantly angle the craft upwards, which you can't normally do taking off from a runway and only applies to landings if you land tail down.

This may not apply to those who I quoted just now but it amuses me when people say that high altitude jets and adding wing pieces for aesthetic reasons are wrong and shouldn't be in the game because they are un-realistic but then completely accept that a plane built like the one above can fly without any wings at all. Consider my mind boggled.

- - - Updated - - -

Lots of part clipping there... I can't tell if you're using any part mods.

Looks like ram air intakes clipped onto the front of the engine nacelles, lots of engines clipped on the back... but what part are they attached to?

what is the TWR?

The V^2 relationship of lift means that it doesn't take a lot of wing area to lift something, if its going fast enough... what speed does it take off at?

How slow can you get it without any power?

The ram intakes and Rapiers are attached to cubic octagonal struts and offset slightly into the fuel tank that serves as an engine pod. I just wanted to make a cool looking engine as Rapiers are the only real choice to getting SSTO's into orbit with big payloads. The TWR is completely dependant on how fast you are going and how high you are. Peak TWR at 20km is only 2.19 and then you are limited by drag and heat factors. You need this many engines to make it useful!

It does need about 200m/s to take off but it will glide at about 90m/s for landing when it is lighter.

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No, because someone posted a 20% cargo fraction spaceplane just a few posts earlier...

I meant that the arguments about high altitude jets came about when 1.0 came out and before 1.02. The issues regarding wings are a 1.02 issue.

[Bomaye]

This is also un-realistic:

Kerbal jungle word: "In thrust we trust" ;-)

http://theaviationist.com/2014/09/15/f-15-lands-with-one-wing/

[KerikBalm]

It does need about 200m/s to take off but it will glide at about 90m/s for landing when it is lighter.

200 m/s is 720 kph.... which will generate 4x the lift of a 100 m/s takeoff speed.. which is still very fast.

This thing landed at 200 mph:

200 mph -> 320 kph -> 88.9 m/s

Due to the V^2 relationship of airspeed to lift... that thing would be generating over 5x the lift at 200 m/s

The speeds these craft are going in KSP.... yea... they should be lifting off if they have even small lifting surfaces.

Have you never seen an F-104?

Touchdown speed, as best as I was able to find: 150 kts -> 172 mph -> 276 kph -> 76.7 m/s

200 m/s is really realy really fast to still be on the ground

[Wanderfound]

The Silbervogel would've been king of the crazy takeoff run if they'd ever built it.

To quote Wiki: "The aircraft was to have begun its mission propelled along a 3 km (2 mi) long rail track by a large rocket-powered sled to about 800 km/h (500 mph)."

http://en.wikipedia.org/wiki/Silbervogel

[Bomaye]

Awwwww you guys ruined my point ;-)

Boosters to the people! :-D

[GoSlash27]

This one is scaled up from my usual Mk.II approach. It delivered payload to orbit at a 22% payload fraction, but I scaled it back to 19% to give it a couple hundred m/sec DV on orbit.

The trick to it is using the wet wings to hold almost all of the fuel. They reduce overall mass and bulk, and as a bonus they can be used to shield the rest of the aircraft from reentry heat. Since most of the mass is contained within the wings themselves, there is minimal CoM shift during the mission.

Best,

-Slashy

[Redshift OTF]

200 m/s is 720 kph.... which will generate 4x the lift of a 100 m/s takeoff speed.. which is still very fast.

This thing landed at 200 mph:

http://upload.wikimedia.org/wikipedia/commons/thumb/6/61/X24.jpg/300px-X24.jpg

200 mph -> 320 kph -> 88.9 m/s

Due to the V^2 relationship of airspeed to lift... that thing would be generating over 5x the lift at 200 m/s

The speeds these craft are going in KSP.... yea... they should be lifting off if they have even small lifting surfaces.

Have you never seen an F-104?

http://upload.wikimedia.org/wikipedia/commons/thumb/0/01/Lockheed_F-104C_Starfighter.svg/300px-Lockheed_F-104C_Starfighter.svg.png

Touchdown speed, as best as I was able to find: 150 kts -> 172 mph -> 276 kph -> 76.7 m/s

200 m/s is really realy really fast to still be on the ground

I appreciate the comparisons there. Interesting stuff. However, and if you want to check this that's cool, because it is late, my craft is 10 times as dense as X-24a you've shown there, (my crafts length is 38.8m and it actually weighs 291.5 tons, (mechjeb was reading it wrong)).

- - - Updated - - -

http://i52.photobucket.com/albums/g13/GoSlash27/HOT1_zpssvn7hp7z.jpg

This one is scaled up from my usual Mk.II approach. It delivered payload to orbit at a 22% payload fraction, but I scaled it back to 19% to give it a couple hundred m/sec DV on orbit.

The trick to it is using the wet wings to hold almost all of the fuel. They reduce overall mass and bulk, and as a bonus they can be used to shield the rest of the aircraft from reentry heat. Since most of the mass is contained within the wings themselves, there is minimal CoM shift during the mission.

Best,

-Slashy

Very nice. I am kind of wondering what the performance would be like without the wings though.

[GoSlash27]

Very nice. I am kind of wondering what the performance would be like without the wings though.

Well...

Since the wings are holding the fuel, I'd imagine it's performance would suffer a bit

Best,

-Slashy

[RobotsAndSpaceships]

Yes, you just need to git gud.

[RocketBlam]

"things like laythe roundtrips are as good as dead"

I don't see how a round trip to Laythe in an SSTO can be remotely considered realistic. It's absurd in fact.

If your game model allows you to build an SSTO that can do that, why would you ever build a regular rocket?

I'm glad you can't build an SSTO that goes all the way to Laythe. Any SSTO that can go to Laythe is almost certainly using methods I would consider cheating (infiniglide, intake spam).

[Sattorin]

Hey guys! I don't forum much (mostly Reddit), but with the massive changes to SSTOs I found this thread and eagerly read through the discussion!

For me, SSTO's are not dead. They just don't have jet engines anymore.

Of course, you have to completely disregard cost and efficiency, but it works!

[Temeter]

Lol, Nice. I don't think that plane get survive a reentry, though.

[Roflcopterkklol]

My new SSTO, has 1000m/s of delta V left in orbit and that is without putting extra fuel in the cargo bay.

The Nuclear Comet mk1

120kmx120km orbit remaining resources

Description:

Cost: 216,566

Part count: 243

Weight: 126.2T

Quite maneuverable in the atmosphere and capable of 1,000,000km+ orbits (More if you add more fuel in the cargo bay, less if you put a load in the craft other than spare fuel) the Nuclear Comet is about as good as it can get when it comes to single stage to orbit, With a choice of Nuclear or Rapier engines depending on how far out you need to go, once refueled this craft is an interplanetary explorer.

As an added bonus there are emergency parachutes for easy landing.

Flight instructions:

On launch it is easiest to just let it fly off the end of the run way before touching the controls, once in the air pitch up to 40 degrees until 12km.

At 12km bring the pitch down to 5 degree and gain speed until 1200m/s, at 1200m/s pitch up to 30 degree until orbit, at 22km engage nuclear engines, at 24km switch rapier engine mode. once apoaps is at 100km you can kill the Rapier engines and use the nukes to orbit.

If returning to kerbin after orbiting without refueling you will need to move fuel into the forward most fuel tanks for stability.

Action groups:

1- Toggle Rapiers

2- Toggle Rapier mode

3- Toggle turbo jets

4- Toggle Nuclear engines

5- Toggle solar panels

Download link:

http://www./download/9q7m4i8s3ymdit5/Nuclear+Comet+mk1.craft

[Sattorin]

Lol, Nice. I don't think that plane get survive a reentry, though.

It does, but only because air brakes are OP, lol.