No more SSTO's

[arq]

In ye olden days (ie last week) I built SSTOs without airhogging. In both beta and in FAR aerodynamics. I almost never made a SSTO that could make over 1500m/s on jets (except for one time I built a pure jet that I made specifically to make 2000m/s at 40km, and that was 5 intakes for one turbojet), so now only making 1300m/s is not so bad (I can carry some thrust through 1200m/s just fine). Yes it requires another 1000m/s to get to LKO and yes jets suck more fuel than they used to (or at least the turbojet and rapier do), but I would hardly call my 200m/s lost to be gamebreaking. I repeatedly made orbit with two rapiers and some fuel, and had some to spare at the end.

Honestly right now my struggle is with getting them *back* from orbit. Until the thermal model gets retuned it seems impossible without exploiting silly things like re-entry parachutes, airbrakes (which are IMO too effective at hypersonic speeds), or extra nosecones (like throwing cubic octagonal struts on the front). The Mk2 cockpit seems doomed to explode using any of the common re-entry trajectories I've tried (though actually the back of my fuselage explodes shortly before, and my engines aren't even back there. I suspect there is an issue with how I mounted the part backwards to taper to a point and/or that it's behind a cargo hold.).

The key feature of an SSTO is that they are re-usable, not that they save fuel (they use more dV, though the jet ISP offsets some of this) or are more efficient at getting things to orbit. Yes they are harder in 1.0, but certainly not impossible.

[duckofthemoon]

@"Roflcopterkklol"

Just because you can't make an SSTO that doesn't mean it's impossible.

Other people have...

Complaining about the game's balance is also a moot point. If you don't like it, do something for yourself and don't complain, or just don't complain at all.

Edited April 29, 2015 by duckofthemoon
words

[rodion_herrera]

Until the thermal model gets retuned it seems impossible without exploiting silly things like re-entry parachutes, airbrakes (which are IMO too effective at hypersonic speeds), or extra nosecones (like throwing cubic octagonal struts on the front). The Mk2 cockpit seems doomed to explode using any of the common re-entry trajectories I've tried (though actually the back of my fuselage explodes shortly before, and my engines aren't even back there.

What I'd propose is a simple "tile" ablative system for cockpits and payload bays, and also for spaceplane-specific fuel tanks. These will just appear as "texture swaps" (i.e. showing tile textures on the lower surface of spaceplanes and or wing sections) if you select them as your part in a spaceplane you're constructing. By choosing this variant of that part, your spaceplane will have more overall weight, yet the part will be more robust on re-entry, provided that you correctly orient your craft. If this gets implemented, I'll be a happy man, and won't rely much on "airbrake cheating" anymore.

[RedDwarfIV]

I would be fine with this new system if it wasn't springing a new complication at me at every turn. Some things I can overcome with a little engineering, others just make it impossible.

Want to get to orbit with a turbojet/NERVA spaceplane? Suddenly all the jets cut out at 20KM up. Oh. Well, what if I try a shallower ascen... I just exploded. Maybe a steep ascent getting as close as possible to overheat without actually getting there? Oh good, I've got a 60KM apoapsis. Now, if I fire my nuke engine, I should be able to get to orbit quite easil... the engines exploded from overheating. They never did that before. Maybe if I run them at a lower throttle. Nope, still explode. Oooh, Squad says use solar panels as radiators... No, they do nothing. Someone else says use wings. Nope, that just slows me down on ascent and makes it harder to get to space in the first place. Maybe if I fit the nukes to a different part, it'll take more of the heat? Nope.

Nope.

Nope.

Nope

have I made my point yet

frigging 'nope'. Seriously, Squad added an air pre-cooler part so that things don't overheat in atmosphere. why is there not a dedicated radiator part for space? This really frustrates me.

[magnemoe]

Who builds a non plane SSTO?

The only ones i ever see are lifting rockets and they were air hoggers which used turbo jets to get up to orbital velocity before going above 40km which will not work anymore...

As far as rapiers go...

Sue me for not wanting to be stuck with a single type of enigine when building space planes, i like the ability to make a useful plane out of a combination of jet/rocket engines.

Even saying that the rapiers are still useless because you need to carry 1000m/s of delta v to escape the atmosphere, never mind any maneuvers in space or orbit, rendering SSTO's useless.

Whats the point of the large cargo bays? they cant be used.

Or do i build a 100 ton SSTO to deliver something in a small mk2 cargo bay to a 70km orbit and act like im enjoying myself when i know it could be better lol?

The devs dun goofed.

Back in 0.25 I made lots of rocket SSTO, in 0.90 they was not cost effective, my main launchers was SSTO planes for light cargo and crew, SRB with returnable core for larger stuff.

Now the only issue with returning is accurate enough landing, braking parachutes and air brakes should take care of the rest.

[Roflcopterkklol]

In ye olden days (ie last week) I built SSTOs without airhogging. In both beta and in FAR aerodynamics. I almost never made a SSTO that could make over 1500m/s on jets (except for one time I built a pure jet that I made specifically to make 2000m/s at 40km, and that was 5 intakes for one turbojet), so now only making 1300m/s is not so bad (I can carry some thrust through 1200m/s just fine). Yes it requires another 1000m/s to get to LKO and yes jets suck more fuel than they used to (or at least the turbojet and rapier do), but I would hardly call my 200m/s lost to be gamebreaking. I repeatedly made orbit with two rapiers and some fuel, and had some to spare at the end.

Honestly right now my struggle is with getting them *back* from orbit. Until the thermal model gets retuned it seems impossible without exploiting silly things like re-entry parachutes, airbrakes (which are IMO too effective at hypersonic speeds), or extra nosecones (like throwing cubic octagonal struts on the front). The Mk2 cockpit seems doomed to explode using any of the common re-entry trajectories I've tried (though actually the back of my fuselage explodes shortly before, and my engines aren't even back there. I suspect there is an issue with how I mounted the part backwards to taper to a point and/or that it's behind a cargo hold.).

The key feature of an SSTO is that they are re-usable, not that they save fuel (they use more dV, though the jet ISP offsets some of this) or are more efficient at getting things to orbit. Yes they are harder in 1.0, but certainly not impossible.

To get them back just put air brakes all over them, i have 16 on my plane and it slows to 1200ms by 30km with them open from a 90km drop at 2200m/s.

Maybe its just i don't like change...

I could just make all my craft 2 stage to orbit but the idea of it irritates me.

[rrkss]

The way I've been able to get back from a 150km x 150km orbit with a space plane is set the periapsis to 48km and re-enter the atmosphere with the nose pitched up at 40 degrees.

[rodion_herrera]

...with the nose pitched up at 40 degrees.

Just like the Shuttle does. Unfortunately, with the current heating system, nothing will protect some parts of your craft from blowing up, even if your craft re-enters in this realistic orientation, unless you activate air brakes. I still lobby for that tile system...a tile system and 40-degree pitch up (and without having to rely on the current air brakes) is gonna looks sweet AND realistic.

Edited April 29, 2015 by rodion_herrera

[arq]

Alright so the Mk2 cockpit wasn't behaving (kept exploding on re-entry) so I decided to try minimal: I strung together a ram intake, Mk1 inline, 2 FL-T800 fuel tanks (minus a little oxidizer), and a RAPIER. I bolted on two delta wings and a pair of elevons, a delta deluxe winglet as a rudder, an RTG, and a landing gear. It only made around 1000-1100m/s on the jet but still had 1200m/s of dV left in the tank once it made orbit. It would have had a little more if I'd guessed the LF consumption better to balance with the O.

A ship big enough to utilize an LV-N could probably make a moon landing and return if it wanted, extrapolating from here. Maybe I'll aim to do that tomorrow.

The ship is a little low on lift and has poor elevator authority (a horizontal stabilizer with a proper elevator would fix that), but it flies alright. It re-entered without incident with just maybe 10deg of nose-up during descent. No stalls, airbrakes, or parachutes to kill speed. There's a lot of thermal inconsistency with parts, it seems.

[Enorats]

I've given up on spaceplanes. Just done. They used to be all I used, even going so far as to build 300+ ton planes pushed into orbit by turbojets and B9 SABER M's (basically large RAPIER's) to use as orbital fuel stations (they could make orbit with 80% of their 25k or so LFO still left.. enough to go anywhere with a few LV-N's they carry for space).. but now I can't get anything up. Airbreathers flame out too low, and they burn up at any altitude they can operate at.

[Duke23]

So far I haven't had much luck with SSTOs so I'm a little discouraged... I just assumed I could drag out my pre-1.0 ones, do a couple modifications, and keep on rolling. Not quite. Good news is they all fly fine in atmo with minor tweaks (at least, at reasonable speeds and altitudes below 20km), bad news is not one will get me an apo above 65km as of right now. I'm getting close with a scaled down version of one that used to be very successful. Funny part about that is the larger one used to be my "masterpiece" that outperformed any SSTO or atmospheric plane for that matter that I had built, in every way. Now it's a deathtrap the instant I switch to closed cycle and nose up. The smaller version I've been tweaking, which used to be slow as molasses and barely able to take a payload up, is now insanely fast and surprisingly stable compared to everything else I've dusted off so far. Still no orbit though.

Butthurt aside (I spent a lot of time on these), I think it's going to be fun once I get the hang of it again.

[Wanderfound]

Stock SSTOs are still trivially simple. The first thing I threw together in NuStock:

Javascript is disabled. View full album

[Laie]

ironically it gets easier with larger and larger spaceplanes.

Not totally unreasonable: for any given shape, drag increases with the 2nd power of the size, while mass increases with the third power. If you get large enough, drag becomes neglegible. Overall.

In real life, you need to reinforce the vessel so the more outlying bits won't be blown off... those reinforcements add weight that wasn't there in the smaller version, and often increase the surface area as well. But in KSP, scaling up is easier to do.

[KerikBalm]

If you can cram it into the mk3 bay, my SSTOs can lift it.

First design, turbo-ramjet/rapier hybrid:

2nd design... I haven't even optimized my ascent profile yet.

Tonight when I get back, I'll be working on my 100 ton to orbit design that will keep everything in an aeroshell with aa 3.75m base.

That one should be quite useful.

[Torham234]

*picture of a crazy contraption*

SSTO'd that and I wasn't even trying to. Even managed to kick it out to the Mun and hit it.

Oh boy, here we go again!

[The Destroyer]

I was able to make one, but the cockpit exploded. Second try, heatshield+fairing, was working well, some stuff uncovered exploding, nothing major, then suddenly massive spin and it exploded. Somehow the airplane body+fairing created a lifting body and saved the crew, awesome!

[Roflcopterkklol]

I was able to make one, but the cockpit exploded. Second try, heatshield+fairing, was working well, some stuff uncovered exploding, nothing major, then suddenly massive spin and it exploded. Somehow the airplane body+fairing created a lifting body and saved the crew, awesome!

I have managed to get mine into LKO, I am hearing it has a lot to do with the pilot, i think i might just be flying my plane like a chump

[Gravaar]

I have managed to get mine into LKO, I am hearing it has a lot to do with the pilot, i think i might just be flying my plane like a chump

NO. Like everyone else you just need to work out the new "best" flight path

"MOAR BOOSTERS :)"

[KerikBalm]

To get them back just put air brakes all over them, i have 16 on my plane and it slows to 1200ms by 30km with them open from a 90km drop at 2200m/s.

Maybe its just i don't like change...

I could just make all my craft 2 stage to orbit but the idea of it irritates me.

My first design that worked had... 2...

My 2nd design... 4

I could reenter without them, just a matter of pitching up enough to generate a good amount of lift and drag, such that you don't drop too low while still going too fast.

I'd love to be able to just follow prograde the whole way in until I'm ready to land.... right now I'm having a hard time judging when to deorbit to come in back at KSC.

My first deisgn, I got back at the west end of the KSC continent, and then re-lit jets to fly to KSC... but went too fast too low in the atmosphere (I was accelerating and climbing, the Reentry was successful), and lost my canards... I shifted all fuel to the back, and was able to keep flying... then I'm not sure what I did, but the enxt problem was a structural failure between one of the fusalage fuel tanks and the cargo bay... the front section with the 4 rapiers came off... the canards had already come off....but it stabilized pointing retrograde... and still had some fuel in it... perfect... rapiers were functional and could be used as retrorocket/jets... rapiers on... but I didn't judge the throttle and timing right... but thankfully the mk3 cockpit has a good impact tolerance... the crew survived.

Thats why design #2 uses a canard with a higher heat tolerance... I'm thinking of adding struts to reenforce the cargobay-fusalagefuel tank joints.

[djnattyd]

Basically what I've gotten from this is people are trying to build SSTOs that are suited to the old souposphere.

[Jaeleth]

Welcome to reality! And we're talking about a lilliputian system, try that on the solar system.

That's the way things are in the real world, and that's the way they should be in Kerbal. This is no ordinary game, this is rocket science! Now you'll give more credit to those guys working hard at places like NASA, ESA and SpaceX uh?

Next step? Add remote tech and life support mods, for another taste of the "real"

[wired2thenet]

In a recent post (pre-1.0) I managed to get this baby into orbit with little or no problem: http://forum.kerbalspaceprogram.com/threads/107567-SSTO-Jet-Engine-RCS-only?p=1675000#post1675000

It isn't realistic at all, and something I noted immediately when it happened, because it was a total accident. NASA doesn't even have one right now, and never did even though concepts are on the table. It's a dream that can probably be done (and someone will eventually in KSP if they haven't done it already), but ... like Rocket Science ...

... it's extremely hard.

[katateochi]

So far I've not had any luck with SSTO spaceplanes, but seeing what some of you have managed gives me hope.

Stock SSTOs are still trivially simple. The first thing I threw together in NuStock:

http://imgur.com/a/iVVwB

If you can cram it into the mk3 bay, my SSTOs can lift it.

First design, turbo-ramjet/rapier hybrid:

https://scontent-fra.xx.fbcdn.net/hphotos-xpf1/v/t1.0-9/10986175_10103548407260233_3056408651622725291_n.jpg?oh=9fb75b1210df356aa49b62f443497f09&oe=55C6C245

https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/11205152_10103548408288173_5405657931943816741_n.jpg?oh=7bff57b1435c0c04bae949e0be3e5dd7&oe=55DE75B6&__gda__=1439780323_f5fa0ddde63b7ef1e9deccd23d576d6d

2nd design... I haven't even optimized my ascent profile yet.

Tonight when I get back, I'll be working on my 100 ton to orbit design that will keep everything in an aeroshell with aa 3.75m base.

That one should be quite useful.

These two show that both small and large SSTO's are possible, I've just not had the ah-ha moment with the new aero. Could you guys take a moment out from building awesome aircraft and explain what your flight profile is like now.

Update:

Just made a copy of Wanderfound's small SSTO and realised he'd put his flight profile in the imgur album description. Followed that and presto, I reached orbit!! (and returned safely). Thanks Wanderfound!!

Edited April 29, 2015 by katateochi

[DaMichel]

I turned the heating difficulty slider to 120%. It was a mistake ...

Quite a big step up in difficulty compared to previous FAR+DRE. Stuff just explodes at mach 2 already. I managed to make an SSTO plane though. It just has lost its canards and therefore won't be able to return

[Teutooni]

Spaceplanes are definitely possible still. Coming from FAR+DRE+AJE I'd say current stock is easier. Did a 130-ton spaceplane and lifted 20-tons of cargo in a mk3 bay to 100km circular orbit with plenty of fuel left. If I used the payload as fuel the plane could probably land on minmus, drill and refine to full fuel again and go pretty much anywhere. Possibly. And it was a horribly wobbly design. One thing I noticed is control surfaces create enormous amounts of drag, so any small oscillations your plane does reduces efficiency a lot. On that note, I found just by using control surfaces to airbrake the new actual airbrake parts were unnecessary.