Foil. SSTM Crew Trainer.

[AeroGav]

2 minutes ago, ibanix said:

I wouldn't mind SSTOs with less tech investment, since with CTT you have to be pretty far along to get all the best plane parts (including the RAPIER, which is at the very end of a tree).

Could give Kerbal construction timer a go, rewards you for re-using stuff (shorter construction times if your ship can re-use parts that you brought home). Although with default settings , the research time kills me once you start getting to tier 6.

I've also started using NoMoreGrindRedux (an auto download on CKAN), a teeny mod that reduces (by default) building upgrade costs by 90%.

To offset that I've gone in  and created custom rules for my save that means i have to purchase each item separately once i've unlocked the node.

I've also started using Engineer Tech Tree, which reorganises the tech tree to put airplane stuff etc. on a completely different branch to rocketry.

Finally, I've just started downloaded the Life Support and USI Colonisation mods.  I figure if my goal is not just to visit planets and fill the tech tree, i'll have an incentive to build out my infrastructure and put some ISRU, spaceplanes and space tugs about the place.

 

[ibanix]

4 minutes ago, AeroGav said:

To offset that I've gone in  and created custom rules for my save that means i have to purchase each item separately once i've unlocked the node.

 

I'm pretty sure that's a stock game option?

[AeroGav]

46 minutes ago, ibanix said:

I'm pretty sure that's a stock game option?

yeah that bit of it is.  it's done to balance difficulty since my building upgrades are so much cheaper, thanks to the mod

[ibanix]

Trying to get the Foil through the atmosphere without exploding - on landing - is a major pain. The cockpit invariably overheats and explodes.

[AeroGav]

Re-entry heating is ramped up again, there was a bump from 1.04 to 1.05 and lots of people complained, but they obviously turned it up some more in 1.1.2.

As a minmial modification to the Foil, how about replacing the mk2 cockpit with an inline one, then put a type 2 to 1 adapter on in front of that (might want to leave it empty if you're not comfortable building planes since fuel here will mess with the centre of gravity), then put a 1.25m heat shield on , with a little bit of ablator (does not need to be full).  Finally attach an aerodynamic nose cone at the front of all that.    In a normal re-entry, the nose cone covers the heat shield, and it has no effect.  If things go wrong, the nose cone explodes, and the heat shield is now at the front - it will then protect the rest of your fuselage, at the price of higher drag and burning off a bit of ablator.  If your wings melt ofc you're done.

 

[Rune]

44 minutes ago, ibanix said:

Trying to get the Foil through the atmosphere without exploding - on landing - is a major pain. The cockpit invariably overheats and explodes.

It's a tricky bird to fly, yes, but considering the huge lift/mass ratio that it has, the problem lies only with the reentry path. Put all that wing to work for you (high AoA reentry, move fuel backwards if necessary to gain enough control authority), and you can shed all your speed incredibly high... experiencing peak temperatures way lower than that cockpits absurdly high temp. rating. I know from experience that it flies well enough on ridiculously thin atmosphere that you can almost circumnavigate kerbin flying level at 50kms just with the reentry energy that you have from as Minmus return... because I once reentered right over KSC, and still managed the runway landing, only the long way around.

 

Rune. Now, if you dive towards the ground prograde, OTOH, it has very little drag. Meaning you will reach denser atmosphere very, very fast. And crispy.

Edited May 23, 2016 by Rune

[ibanix]

I've been hitting Kerbin with a 45 degree AoA and a perapsis of 65km... and I gradually heat up until 50km, and then rapidly heat up, and then explode.

[AeroGav]

https://www.youtube.com/watch?v=Bf3qqAStsFU&list=PLF64Jfn9iJDGPpBfLk01SZDmFCeaA0DB_&index=9

this seem familiar?    the save scumming that appears partway into video is because on my previous re-entry, i increased pitch more steadily and later in the descent, and ended up overshooting KSC  so much i didn't have the fuel to get back.    Pitching up like that was done to slow down, but if anything made heating on the crew sections worse.  Notice how the cockpit glows red, the first passenger cabin is yellow (about to blow!) but the one behind isn't glowing at all.

[Rune]

1 hour ago, ibanix said:

I've been hitting Kerbin with a 45 degree AoA and a perapsis of 65km... and I gradually heat up until 50km, and then rapidly heat up, and then explode.

You might be slowing down too fast, too soon, and then dropping too steeply? Or touched the difficulty settings? Or trying a reentry at very high (interplanetary) speeds? I say this because that crew cabin has a very high temperature rating, and if it's going fast enough, the Foil can level its flight at >50kms without issues, shedding speed up there until you are in a standard ~2km/s reentry. Watch the vertical speed indicator maybe? You have me a bit confused here, frankly.

1 hour ago, AeroGav said:

https://www.youtube.com/watch?v=Bf3qqAStsFU&list=PLF64Jfn9iJDGPpBfLk01SZDmFCeaA0DB_&index=9

this seem familiar?    the save scumming that appears partway into video is because on my previous re-entry, i increased pitch more steadily and later in the descent, and ended up overshooting KSC  so much i didn't have the fuel to get back.    Pitching up like that was done to slow down, but if anything made heating on the crew sections worse.  Notice how the cockpit glows red, the first passenger cabin is yellow (about to blow!) but the one behind isn't glowing at all.

Yup, something like that (though I skipped a lot) except that the main fuselage of a Foil has a temp. rating about 500º higher than your bird... lots of low temperature "rockety" parts in there.

 

Rune. If anything, it should be the engine nacelles that blow up on the Foil.

Edited May 23, 2016 by Rune

[ibanix]

I've been doing returns from Minmus, and my max entry speed at atmosphere (70km) is 2.4km/s. 

I've tried both rapid descent and very gradual descent, and both have eventually given me excess heat, and always in the cockpit. It many cases the cockpit explodes, leaving the rest of the vessel intact but uncontrollable. My heat was set to 100%. I finally got fed up and set it to 30% just to land my craft; heating on the cockpit still reached 70% of critical. 

[AeroGav]

20 minutes ago, Rune said:

 

Yup, something like that (though I skipped a lot) except that the main fuselage of a Foil has a temp. rating about 500º higher than your bird... lots of low temperature "rockety" parts in there.

 

Rune. If anything, it should be the engine nacelles that blow up on the Foil.

From now on I'm building with shuttle wings again,  if I can keep AoA lower the inline cockpit gets less heat and even if it does have a problem then the old trick of putting a heatshield behind a a nosecone on a decoupler should do the trick.

I can use two pairs of shuttle wings in a  double delta and get the same quantity of fuel storage and lift rating, but i would need twice as many fuel ducts which are very draggy.    The entire design concept of that ship was something that could fly to orbit without requiring the pilot to do any fuel management at all, and without the CG changing, nor require any mods.  It was very easy to use but re-entry issues could threaten that status.  I could try a heatshield behind its nose cone..

[Rune]

17 hours ago, ibanix said:

I've been doing returns from Minmus, and my max entry speed at atmosphere (70km) is 2.4km/s. 

I've tried both rapid descent and very gradual descent, and both have eventually given me excess heat, and always in the cockpit. It many cases the cockpit explodes, leaving the rest of the vessel intact but uncontrollable. My heat was set to 100%. I finally got fed up and set it to 30% just to land my craft; heating on the cockpit still reached 70% of critical. 

Well, if you are coming back from Minmus, you should have the fuel to lower that entry speed considerably... Minus returns are indeed on the edge of what any spaceplane with a pointy nose can handle. Besides, if you keep the fuel on the tanks, your lift/mass ratio will be lower...

In any case, during my most daring reentries, I usually set a 50kms Pe, bounce back up with a high AoA (meaning I move my Pe towards me and go over it), then invert the plane and pull downwards, shedding speed on the very high atmosphere until I manage to get level with a small AoA. Then I stop panicking and let it fall as I lose speed back to ~50m/s vertical speed watching the temperature, arrest my vertical motion when it starts climbing again, rinse and repeat until I'm slow enough.

17 hours ago, AeroGav said:

From now on I'm building with shuttle wings again,  if I can keep AoA lower the inline cockpit gets less heat and even if it does have a problem then the old trick of putting a heatshield behind a a nosecone on a decoupler should do the trick.

I can use two pairs of shuttle wings in a  double delta and get the same quantity of fuel storage and lift rating, but i would need twice as many fuel ducts which are very draggy.    The entire design concept of that ship was something that could fly to orbit without requiring the pilot to do any fuel management at all, and without the CG changing, nor require any mods.  It was very easy to use but re-entry issues could threaten that status.  I could try a heatshield behind its nose cone..

The problem with heatshields is that they serve no other function, and are blunt as boop. But if you don't mind the drag of a blunt nose, there is an alternative. The humble shielded docking port not only has a ridiculously high heat rating, its bluntness means you get a detached shock wave (yup, the game models such things, albeit in a crude manner), which transfers way less heat to the leading part.

In other words, I toyed a bit with a 1.1.2 replacement for the Foil... simpler (40 parts) and tougher, with a bit extra dV, and I think a bit better balanced, CoM barely moves form full to empty.

 

Rune. Had to lose the sexy tail, though.

[AeroGav]

5 hours ago, Rune said:

 

The problem with heatshields is that they serve no other function, and are blunt as boop. But if you don't mind the drag of a blunt nose, there is an alternative. The humble shielded docking port not only has a ridiculously high heat rating, its bluntness means you get a detached shock wave (yup, the game models such things, albeit in a crude manner), which transfers way less heat to the leading part.

 

No , the heat shield is not going to create extra drag on the ascent because there will be a nose cone in front of it.   Only if the nose cone explodes from re-entry heat will the heat shield be exposed. You'll have the drag penalty but as the mission is over it's no big deal.  I've used this heatshield behind nosecone trick before on rockets,  just before the nose cone goes boom, the mk1 sections behind it are also glowing red, but after it goes boom temperature bars on stuff mounted further back on the stack disappear almost immediately.   This is only true if i stay close to prograde however, and i doubt a spaceplane's wings get much protection.

 

[ibanix]

8 hours ago, Rune said:

Well, if you are coming back from Minmus, you should have the fuel to lower that entry speed considerably... Minus returns are indeed on the edge of what any spaceplane with a pointy nose can handle. Besides, if you keep the fuel on the tanks, your lift/mass ratio will be lower...

In any case, during my most daring reentries, I usually set a 50kms Pe, bounce back up with a high AoA (meaning I move my Pe towards me and go over it), then invert the plane and pull downwards, shedding speed on the very high atmosphere until I manage to get level with a small AoA. Then I stop panicking and let it fall as I lose speed back to ~50m/s vertical speed watching the temperature, arrest my vertical motion when it starts climbing again, rinse and repeat until I'm slow enough.

The problem with heatshields is that they serve no other function, and are blunt as boop. But if you don't mind the drag of a blunt nose, there is an alternative. The humble shielded docking port not only has a ridiculously high heat rating, its bluntness means you get a detached shock wave (yup, the game models such things, albeit in a crude manner), which transfers way less heat to the leading part.

In other words, I toyed a bit with a 1.1.2 replacement for the Foil... simpler (40 parts) and tougher, with a bit extra dV, and I think a bit better balanced, CoM barely moves form full to empty.

 

Rune. Had to lose the sexy tail, though.

I like simple tails. Is that thing ready for release?

[Rune]

On 24/5/2016 at 0:48 AM, ibanix said:

I like simple tails. Is that thing ready for release?

Not yet. I'm still making small tweaks here and there, and flying a test mission... I want to be able to state with confidence that it can survive a high-speed reentry!

 

Rune. The new tweakables in control surfaces are all kinds of awesome, BTW.