1.0.5, harder to make spaceplanes?

[panzer1b]

Well, im not gonna claim it has necessarily, but there is something very wrong with many older SSTO designs i have. For one, they seem to fry at much lower speeds making it near impossible to break 1400m/s before switching to rocket mode and having to pull up or risk just burning up, a thenomenon that was NOT that case in 1.0.4 (you still had to be careful but id often get up to 1600m/s at ~17-18km before engaging rockets).

It also feels (now when i say feels, it means i have no hard evidence of this as of now) that the drag has been increased. Before, drag would drop off to fairly low levels above 30km and you would still slow down quickly if you pitched up/down, but flying straights didnt exert much drag on a vessel.

These 2 things combines have exponentially decreased the usefulness of SSTOs, to the point that my dV after getting to LKO drops from above 7000 to below 6000 if you consider that i need more oxy, cant seem to get as much use out rapiers anymore (yes i can go faster but there seems to be some excessive heating preventing me from being able to reach speeds above 1500m/s), and there seems to be alot higher drag in the are between 20 and 40 km high (thats where i notice much higher speed loss when engines are out).

Now i havent and probably never will give up on SSTO designs, but im wondering if the increased drag and heating is just me, or whether it is actually the case that 1.0.5 increased both heating and drag to the point that many previous SSTO and or spaceplane builds are suffering?

When i get more time ill defenetely take a lok at the .cfgs and maybee compare the new one to the old one, but something is defenetely wrong with my old spacecraft at least when it comes to escaping kerbin.

[GoSlash27]

panzer1b,

Spaceplanes are actually easier than they were before. The intakes have been completely changed and now we need a lot less of them to keep an engine lit.

If you want to keep your old designs as they are, try doing your speed runs higher up.

Best,

-Slashy

[panzer1b]

panzer1b,

Spaceplanes are actually easier than they were before. The intakes have been completely changed and now we need a lot less of them to keep an engine lit.

If you want to keep your old designs as they are, try doing your speed runs higher up.

Best,

-Slashy

Im not trying to use 0.90 or older builds in 1.0.5 lol. Ive become very much accustomed to 1.0.4 spaceplanes/SSTOs, and heck, ive even pulled off a 40t 8K dV craft pushed by a single rapier and a single nuke combo. I now do speed runs above 20km, and its still impossible to break ~1500m/s before i either burn up or the drag just overpowers the engine. Im not saying i cant still make orbit, but i need to engage rockets much earlier, and run them for longer before i get up to a decent velocity, and im just suffering major energy losses due to drag and the fact that the heating vaporizes everything now (back then i could go in excess of 1800m/s at 20km with just some heat bars at best).

Im gonna give it a week and see if all i need is to alter my profile (17km speed run was optimal back in 1.0.4), but it really does seem that nomatter what i try i either run out of rapier thrust before i get high enough to escape on just the nuke, or i explode due to overheat well before i get near the speeds i need to be at.

Might be time to ducktape radiators to the plane . No idea if they fixed that obvious exploit (radiators shouldnt instantly let you fly at 2km/s near the deck realistically), but i gotta take a look to see if radiators still help alot in atmospheric flight.

[Starhawk]

I've definitely found that my more aggressive ascent profiles are no longer safety-certified.

I've had to adjust by starting my speed runs higher up.

Happy landings!

[panzer1b]

I've definitely found that my more aggressive ascent profiles are no longer safety-certified.

I've had to adjust by starting my speed runs higher up.

Happy landings!

May i ask what altitude and speeds you normally reach before switching to rockets? Im asusming its a rapier since the other engines are just useless above 1400m/s at high altitudes.

[Signo]

Around 24000 for rapiers. Using ramjets it depends on the "rocket engine" I am going to use. Usually I let them to flame out by themselves.

[TheDog]

...ive even pulled off a 40t 8K dV craft pushed by a single rapier and a single nuke combo.

[...]

Might be time to ducktape radiators to the plane . No idea if they fixed that obvious exploit (radiators shouldnt instantly let you fly at 2km/s near the deck realistically), but i gotta take a look to see if radiators still help alot in atmospheric flight.

WOW!

I am somewhat struggeling with spaceplanes since 0.90, but I CAN get something into orbit.

However - 40t and 8k dv with one rapier sounds impossible to me, do you have that craft on KerbalX or in here, I'd love to take a look at it (just curious for learning)...

Regarding radiators - is (was?) there an exploit I am unaware of?

[Starhawk]

May i ask what altitude and speeds you normally reach before switching to rockets? Im asusming its a rapier since the other engines are just useless above 1400m/s at high altitudes.

It depends quite a bit on the craft, but I used to like to switch over at about 1.5-1.6 km/s usually around 25 km.

I used to start my speed run at 11 km with certain spaceplanes. That is just too low now and results in cockpit overheating explodyness.

Still trying to find the sweet spot.

Happy landings!

[Captain H@dock]

In 1.0.4 I was doing all my rapier runs at a constant altitude somewhere between 15.2 and 15.8 km. Anything lower and I was overheating when reaching 1100m/s.

Upon reaching 1450-1520 m/s, I was starting a constant speed pitch up, aiming for a 10-12 degrees climb (prograde marker) at 19 km.

Speed was usually starting to decay between 22 and 24 km, where I would usually switch.

I haven't had the opportunity to play 1.0.5 yet, but I should be able to 6 hours or so.

[panzer1b]

WOW!

I am somewhat struggeling with spaceplanes since 0.90, but I CAN get something into orbit.

However - 40t and 8k dv with one rapier sounds impossible to me, do you have that craft on KerbalX or in here, I'd love to take a look at it (just curious for learning)...

Regarding radiators - is (was?) there an exploit I am unaware of?

The craft that had 8K dV (in actuallity it was around 7.9K, i just rounded up cause 8K sounded better and i never spent enbough time with it to 100% optimize the ascent so 8K might have been doable with enough time) was the HK-201R6.

All in all, it was a proof of concept at best. What i used is a HK-201 (the base model is uploaded to my company page, click my signature, go to craft repository, go to AKS craft folder, and look for something called HK-201). I essentially stripped it of everything that wasnt absoluteley needed to get off teh ground, RCS system, docking ability, weapons, weapon hardpoints, monoprop, heck, i even replaced the RTG with a extendable solar panel and a small battery, and i crammed it with enough fuel to get it to ~40t. In 1.0.4 that thing pulled off above 7.9K dV after reaching LKO (assuming math is correct). I just rounded uit up to 8K since i believe it could achieve that with the right ascent. I honestly didnt play with it much, no utility and well, so bloody painful to reach orbit, couldnt use time compression or itd break, and took ages to get past speed of sound, although once past it it wasnt that bad since the rapier gave out over 300kN thrust.

If you ant to try and recreate what i did, just take the basic HK-201 i have on company page, remove everything that isnt wings, landing gear, engines, fuel tanks (and dump the monoprop), then add fuel tansk to the internal stack until you reach ~40t. At ~35t you get 7.3K dV, at 40t you get almost 8K (with the right profile and enough patience to try multiple times i bet it can be done. You also might need to tweak the wing layout a little bit (the uploaded version isnt optimized for anything above 37t and i think i added an extra pair of wet wing strakes as well but i dont remember and dont have the HK-201R6 model particular craft file anywhere to check).

For radiators, ive created a few terribly designed builds that never overheated cauise of radiators. Must try that in 1.0.5 though as ive yet to do it (they do add drag too).

As for the higher up profile, i still have heating issues, but you gusy are right that you need to accelerate at much higher up then in the past to be effective. It takes much longer to get to speed and i still cant break 1600m/s on pure jet mode, but its way better then burning up trying to go 1500m/s at 17km before i start to angle up.

Edited November 10, 2015 by panzer1b

[SpaceplaneAddict]

I dunno, spaceplanes are really fun now. That Panther jet, well, it can be an SSTO engine. Honestly, the atmo feels like FAR now. Different atmo pressures? Never noticed.

[Korizan]

Well

in 1.0.4 you could expect to see your nose cool down above 15 km so make sure you do not exceed 1,200 m/s below 15 Km.

In 1.0.5 you do NOT receive the cool down, I just blew up my MK2 Cockpit @ 21,215 KM doing ~ 1,435 m/s.

Not sure where the atmosphere thins enough to cool you down now if at all.

[Red Iron Crown]

All in all, it was a proof of concept at best. What i used is a HK-201 (the base model is uploaded to my company page, click my signature, go to craft repository, go to AKS craft folder, and look for something called HK-201). I essentially stripped it of everything that wasnt absoluteley needed to get off teh ground, RCS system, docking ability, weapons, weapon hardpoints, monoprop, heck, i even replaced the RTG with a extendable solar panel and a small battery, and i crammed it with enough fuel to get it to ~40t. In 1.0.4 that thing pulled off above 7.9K dV after reaching LKO (assuming math is correct). I just rounded uit up to 8K since i believe it could achieve that with the right ascent. I honestly didnt play with it much, no utility and well, so bloody painful to reach orbit, couldnt use time compression or itd break, and took ages to get past speed of sound, although once past it it wasnt that bad since the rapier gave out over 300kN thrust.

Did you use some engine other than the Rapier? A Rapier in rocket mode in vacuum has an upper limit of a bit under 6600m/s of dV in a single stage (and the practical limit is much lower).

[ment18]

He had a Nerv as well

[herbal space program]

I spent some time playing around with my SST014 last night (2 RAPIER, 1 nuke, ~46.5t wet, 3 shock cone intakes), and it seems like things have definitely changed in a fairly complex way. It seemed considerably easier for me to break the sound barrier at a lower altitude, making getting to the transonic realm a fair bit cheaper, but ten I also lost power at a considerably lower altitude. My lift seems like it’s less for some reason too, with the ship wanting to nose down significantly more than before, especially up high. Monitoring the engine’s performance, it seems like I need more air intakes up high now and not less to maintain the same thrust. I was only able to get close to the RAPIER nominal maximum thrust below 10km. In the past, I was accelerating steadily to around 1400m/s at 20km, then engaging the nuke and getting up to maybe 1500 in the 21-15km range, nosing up a bit, and dropping back down to maybe 1470 at a 29.5km switchover. I was able to make orbit with ~6km/sec dV fairly easily this way. Now I seem to lose all my thrust significantly lower down, and I think it’s more because of the intakes than the engines. When I slapped on a couple of inline intakes, performance definitely seemed to improve. I will try with even more tonight…

[Red Iron Crown]

He had a Nerv as well

Still pretty impressive, an LV-N needs the vessel to be almost 64% fuel by mass to deliver 8000m/s of dV. I'm going to have to take a closer look at the craft when I get to my KSP computer.

[GoSlash27]

Im not trying to use 0.90 or older builds in 1.0.5 lol.

panzer1b,

I didn't figure you were. I'm talking about 1.04 designs when I say "old".

A 1.05 design needs a lot less intake. You can redesign to use a cleaner nose and less intake or you can run the "old" designs by doing your speed runs at a higher altitude.

Best,

-Slashy

[KerikBalm]

http://forum.kerbalspaceprogram.com/content/358-KSP-1-0-5-is-live!

* Drag coefficient changes based on the same factors as turbulent convection (a Pseudo-Reynolds number). This means higher drag high up in the atmosphere, and slightly lower drag when going very fast very low.

So... yes, it seems you aren't just imagining higher drag between 20-40km (probably even at 60km, but the drag is so low there that it may not be noticeable).

[panzer1b]

Still pretty impressive, an LV-N needs the vessel to be almost 64% fuel by mass to deliver 8000m/s of dV. I'm going to have to take a closer look at the craft when I get to my KSP computer.

I did this a while back so i do not remember exact specs, all i know is that it did rely on EXCESSIVE part clipping to work. The fuselage is essentially a shock cone, then a mk1 to mk2 short adaptor, then a short mk2 bomb bay, then a 2nd mk1 to mk2 adaptor, then a mk1 inline pit, then a rapier, and then a nuke, and then a air intake facing backwards (depending on model that intake was different but used to cut down the drag of open node).

Now the only other equipment was 1 of the smallest solar panels that could extend and retract inside the bomb bay, a 0.6m inline batter in bomb bay, primarily big-S wing strakes filled with fuel for lift. 2 control surfaces in the nose, and then 2 small delta wings with 2 control surfaces on those, and ths usual smallest control surface alone for rudder. Then i ofc had to have landing gear, 2 were on wingtips, 1 was inside the bomb bay.

As for the only other components, i added basically clipped together FLT-100 fuel tanks inside the cargo bay until the weight was ~40t. These fuel tanks were only holding LF and had no oxy at all by using a mod i had that let me pick what fuel was placed in teh tanks (this could also have been done via .craft file edit too). More recent iterations of the HL-201 (now renamed the HK-101 as i decomissioned the old HK-101 and i the 201 kinda was the same basic role so i renamed it) feature a dfferent fuel setup, instead of FLT-100s that store 100 LF, i opted to use xenon fuel tanks with 660 LF in them to save on parts. Assuming my math is correct, the FLT-100 being a LFO tank stored 100 units of fuel, and has a dry mass of 0.0625. The xenon tank has a dry mass of 0.4125, which is exactly 6.6 times that of the FLT-100. SO using the same dry mass fraction, i gave xenon tank 660 LF capacity to keep it identical to the FLT-100 or any of that tank line, its just way more fuel in less parts (having a stack of 40 or so FLT-100s isnt fun for lag, and then will go outside of teh tank when u timewarp at all.

Now not everyone will consider this fair, but ive gotten to the point that i just nolonger care whatsoever about part clipping, and in my eyes, having 40 FLT-100s with 100 LF each in virtually the exact same spot (i dont quite clip them 100% into each other but not far off from that) is no different, you are violating volume logic either way, i just save on parst with the xenon tanks.

The actual reson behind even using such small tabnks and not clipping say FLT-400s or wha tnot is that the FLT-100 (and xenon tank as its same size) is the ONLY tank that can fit inside a mk2 bomb bay without interfering with the 2 missiles i placed beside em. Again, its a matter of preference, i enjoy compact builds, and external missiles are a big no-no when you are talking aerodynamics, so my only option left since i had no intention to make a large craft was to shove fuel between the 2 missiles, all in the bomb bay.

Anyways, here is a screenshot of the HK-201R2 model, which (assuming my math's right s i calculate dV manually using the log formula since i dont use any mods with dV readouts in em) gives me approximately 7.3K dV

My math (based purely on screenshot data of the fuel level and vehicle stats windows) gives the following:

*full mass 34.92t

*mass in LKO 27.01t

*empty mass 10.62t

Therefore:

*dV fully fueled: 9342

*dV in LKO: 7326

I do not have any pics of the HK-201R6 (that i can find currently, if i find one ill be sure to post the 40t monster in LKO with fuel/mass readouts), so i cant really prove that i got almost 8K dV, but since the 35 ton one got ~7300, its not like im making these numbers out of thin air, and it is within reason that if a 35t vessel gets 7.3K, a 40t one can get around 8K (and if i remember correctly it got ~7900K in LKO when i was messing with it).

panzer1b,

I didn't figure you were. I'm talking about 1.04 designs when I say "old".

A 1.05 design needs a lot less intake. You can redesign to use a cleaner nose and less intake or you can run the "old" designs by doing your speed runs at a higher altitude.

Best,

-Slashy

So you are saying EVEN less intakes? My craft (the HK-101A4 im working with) has 2 shock cones, one of which isnt even uses as an intake but to lower the drag the nuke engine has (since its end is exposed). So its basically one intake in the front, a fuselage, engines, and one intake to cap it off clipped far enough inside as to not block thrust (unless 1.0.5 made the whole capping the end nolonger as critical or important).

Is the shock cone still the best nose cone part in terms of drag, or has that now changed so that other intakes have perhaps better performance? Ohh, and what about radial intakes, are those any good now, or are they still a bad idea since before those radials had alot of drag and not so much area. Ohh, and what about the cool looking inline intake with some fuel inside, is that good at all, or worse then a shock cone (which im guessing still has to be in the front either way, unless regular nose cones are superior now to the ram in terms of raw drag values).

Ohh, and the main reason i started this thread is that my recent project, the HK-101C series is failing hard (and the old HK-101A series from near the end of 1.0.4 as well) has major trouble getting up to speed on the rapier alone. In general, the HK-101 line is kinda heavy and i just CANT kick in rockets until ~1550m/s velocity as the nuke doesnt quite have the thrust, and i need the speed to give myself enough lift to accelerate to ~2000 orbital before i get above 35km. Such a profile (regardless of whether its realistic or not, or more fun or not), just does not work anymore, and im finding i actually need to drag alot of oxy to get above a minimum of 1700m/s before 30km or ill just drop out of the sky (and the nuke does not have the thrust to save me once i stop gfaining altitude, and rapier oxy is so inefficient i mnight as well forget low weight.

the project is suposed to have ~3000 dV in LKO, have 4 tons of payload capacity, all in something that uses the same or similar shape (i like compact sci-fi style vessels even if they arent very realistic) and is ~20t maximum. Can this even be done? the reason for teh highish payload is that i want 2 missiles, and a full IRSU system onboard. With 3000 dV (and preferably around 4K full fuel), i can finally have my infinite range SSTO to anywhere (you could do any planet with that, provided that spots like eeloo you refuel elsewhere beforehand.

Edited November 10, 2015 by panzer1b

[luizopiloto]

No one noticed, but body lift is not working on KSP 1.0.5...

w/o body lift, crafts need a higher AoA to maintain vertical speed, increasing drag...

This makes rockets more easy to launch... but makes SSTOs way more inefficient...

Edited November 10, 2015 by luizopiloto

[Red Iron Crown]

No one noticed, but body lift is not working on KSP 1.0.5...

w/o body lift, crafts need a higher AoA to maintain vertical speed, increasing drag...

I never rely on body lift, it is always better to have 0 AoA and have an angle of incidence on the wings.

[panzer1b]

No one noticed, but body lift is not working on KSP 1.0.5...

w/o body lift, crafts need a higher AoA to maintain vertical speed, increasing drag...

This makes rockets more easy to launch... but makes SSTOs way more inefficient...

Im not liking this. If they lower the drag across the board then fine, but without either ISP buffs or drag reductions to compensate, the loss of body lift is just a major slap in the face to spaceplane builders.

But like above, i dont really rely on it much (only at certain speeds is body lift useful).

[Red Iron Crown]

The Mk2 profile stuff still lifts, it's only non-lifting body lift that seems to be affected.

[iospace]

At first I thought this was a FAR issue, but I guess not.

I've found that lowering the throttle on ascent helps with the heat. It does take longer to get to orbit, but my old ascent paths are still possible.

That being said, re-entry is now next to impossible with Mk1 parts (I have yet to do it), and I've only done it with Mk2 parts and four airbrakes. At 53 km up my nose on a Mk2 based plane is already glowing.

What makes it really weird to me is that the shielded clamp-o-tron, which has the same skin heat tolerance of the Mk1 Cockpit, shows absolutely no sign of any excessive heating when flying at a similar speed and altitude.

Edit: double checked the tolerances, they're different. It doesn't explain why the Mk1 cockpit heated up like it did and the clamp-o-tron didn't.

Edited November 10, 2015 by iospace

[herbal space program]

The Mk2 profile stuff still lifts, it's only non-lifting body lift that seems to be affected.

I guess that would explain why my 3Xmk1 plane seems to have less lift than it did before. I thought those fuselages had no lift before, but I guess they did!

Edited November 10, 2015 by herbal space program