Indigo - Light Cargo SSTO (1.1.1/2 Only)

[Cupcake...]

CRAFT FILES:

https://goo.gl/o0G2X0

It's my great pleasure to present the Indigo; a light cargo spaceplane and the latest model in the newly revived SSTO fleet.

In addition to it's primary role of hauling Mindy dropships to orbit this versatile design can also be loaded with extra fuel and fly SSTO missions to Minmus (R Model). 

In addition there's a D or Docking model which takes advantage of the Indigo's near perfect 50/50 mass distribution for easy transport to Laythe.

With most of the lift coming from the advanced canards the Indigo is a lot to fun to fly, and can comfortably cruise back to KSC at a blistering Mach 5 after dropping off its payload.

The design comes with a dedicated support/crew truck able to tow the plane and re-fuel it, making for a completely re-usable design. You can even re-dock Mindy dropships once they've landed back on Kerbin!

 

CONTROLS:

1 - Toggle Mindy Engines

4 - Toggle Support Truck Fuel Production (Drill Must Be Activated Manually)

5 - Undock Mindy Top Port

6 - Toggle Rapier

7 - Switch Rapier Modes (Auto Switching Disabled By Default)

8 - Toggle Front Landing Gear (For Attaching To Support Truck)

9 - Toggle Main Cargo Bay/Toggle Support Truck Ladders

0 - Toggle Crew Cabin(s)

ABORT - Undock Indigo Payload/Mindy Cargo Port

 

FLIGHT MANUAL (M MODEL):

 

STAGE 1 - SETUP.

A joystick is highly recommended for this design.

Ensure the support truck is fully crewed and launch.

Apply the brakes and load your Kerbal(s) into all vacant command seats.

Stage once to separate the support truck and drive it off the runway if need-be.

Set control to the Indigo's cargo port and activate SAS.

Press 0 to close all cockpit doors and 9 to close the cargo bay.

 

STAGE 2 - ASCENT

Set full throttle, release the brakes and press 6 to activate the Rapier engine.

Align the plane on the runway as quickly as possible.

Once you leave the runway fold the gear and pitch up to 10*.

Make occasional, small corrections to keep your pitch at 10*.

Once you hit 1300m/s pitch down to 5* and try and try and squeeze as much speed from the Rapier as you can, you're aiming for at least 1600m/s.

Once you start losing speed hit 7 to switch to closed cycle mode and pitch back up to 10*.

Hold the nose at 10* until your apoapsis hits 40,000m then pitch down follow the prograde marker.

Keep the Rapier burning until it runs out of oxidiser and keep pointing prograde until you clear the atmosphere.

You should end up with a 500x15k orbit.

 

STAGE 3 - High Kerbin Orbit

Once safely out the atmosphere press 9 to open the cargo bay doors and provide light for the solar panels.

Press 5 to undock the Mindy, switch over to it and manoeuvrer it clear of the Indigo.

Switch control over to the top docking port and burn prograde at the apoapsis to bring the craft's periapsis safely out the atmosphere (at least 70,000m).

 

STAGE 4 - RE-ENTRY/LANDING

If you haven't already done so switch back to the Indigo and ensure the cockpit/cargo bay doors are closed before you hit the atmosphere.

Pitch the nose up to 20* above the horizon line and ensure your wings are level.

Press 7 to switch the Rapier back to open cycle mode and set the throttle to maximum.

As the craft hits the upper atmosphere pull back on the stick to keep your nose at 20* pitch.

At around 40,000m the wings will bite into the air and you rate of descent will level off, you'll still be going faster then orbital velocity so you can actually start climbing and save up some potential energy.

As you loose speed adjust you pitch so your descent speed stays around -5m/s and try to keep as much momentum as you can. With a bit of careful flying it's possible to make it all the way back to the KSC without burning a drop of LF!

This will probably be a good time to select the support truck as a target.

You'll be re-entering over the desert and should have around 150 units of LF left.

At approx 29k the Rapier will re-start and at 25k you'll have enough thrust to cruise along at Mach 5 (1500m/s).

If need be pull some high G turns to burn off speed and approach the runway at 70m/s with a small amount of throttle.

Deploy the landing gear and once over runway cut the engine and aim to touchdown at around 50 m/s.

 

Enjoy!

 

Cupcake...

 

Edited August 6, 2016 by Cupcake...

[Dafni]

Nice one! Time for some 1.1.2 action then. Thanks for sharing.

[Majorjim!]

A clean well thought out design, another Cupcake classic. Nice work mateo!

 

[Rune]

So... I've got to give the Indigo a try yet, but you can take out that silly 1.1.1/2 notice at least form here: this gorgeous spaceplane makes space without issues in 1.1.3.

I actually touched nothing (other than SAS) and was busy tinkering with the GUI to see if there was some anomalous source of drag, when I noticed that I was well above Mach two already under 2,000m. I pitched up a bit, let it go to see where it went, and I almost got roasted.

 

Rune. Remember, hug sea level to give the RAPIERs plenty of air to spool up.

[Majorjim!]

Just now, Rune said:

you can take out that silly 1.1.1/2 notice

Oh Cupcake.. Do more testing! Fly different ascents to hone in on the optimum. I do this for every launcher to find the sweet spots as read out will not tell you where that is unfortunately. Nice find Rune.

[Cupcake...]

4 hours ago, Rune said:

So... I've got to give the Indigo a try yet, but you can take out that silly 1.1.1/2 notice at least form here: this gorgeous spaceplane makes space without issues in 1.1.3.

I actually touched nothing (other than SAS) and was busy tinkering with the GUI to see if there was some anomalous source of drag, when I noticed that I was well above Mach two already under 2,000m. I pitched up a bit, let it go to see where it went, and I almost got roasted.

 

Rune. Remember, hug sea level to give the RAPIERs plenty of air to spool up.

 

4 hours ago, Majorjim said:

Oh Cupcake.. Do more testing! Fly different ascents to hone in on the optimum. I do this for every launcher to find the sweet spots as read out will not tell you where that is unfortunately. Nice find Rune.

Well that's embarrassing! I tried an earlier version of this craft in 1.1.3 and for whatever reason I couldn't get it past Mach 1. Clearly I wasn't trying hard enough. Thanks for taking it for a spin @Rune ,you got a really high AP too, far more than I've managed which is slightly annoying, I'm clearly gonna have to head back to flight school.  

 

Just to confuse things further I've decided to retire the Indigo and transfer its name to the Violet instead. Although the Indigo has a lot more power the Violet is a much better craft overall and really hits the sweet spot in terms of looks, handling, practicality and performance.

 

Cupcake...

[Cupcake...]

I did another test run in 1.1.3 and still couldn't get past Mach 1. The good news is, I think I've finally tracked down the culprit and ironically enough it's the one part you can't get drag readings for. After I replaced the crew with probe cores of equivalent mass (0.1t) the Violet worked perfectly.

I ran another test using the Siren, now normally this VTOL can cruise along at 200m/s however with a Kerbal at the controls I was only getting 150m/s.

Replace the Kerbal with a probe core and lo and behold, we're back to 200m/s.

So it seems to be that the Kerbals themselves aren't occluded properly and consequently causing a ton of drag. The question now is if this issue is only affecting my copy of the game or are other people experiencing the same thing? @Rune I assume when you did your test of the Violet the craft was unmanned? If so do you mind taking the craft up again, this time with a full crew? @Dafni, @Majorjim if you guys get a chance to run a quick test flight I'd really appreciate it. Ta.  

 

Cupcake...

Edited July 21, 2016 by Cupcake...

[Majorjim!]

Awesome! Perhaps @Rune can reveal if he had a Kerbal onboard or not. If not I owe @Cupcake... an apology..

[Dafni]

I'll jump to it as soon as I get the chance. I am at the job now, with a bit of luck I can fly it tonight.

So the version I downloaded yesterday is the current one? No update required? Will try the Siren too, probably.

[Rune]

1 hour ago, Cupcake... said:

I did another test run in 1.1.3 and still couldn't get past Mach 1. The good news is, I think I've finally tracked down the culprit and ironically enough it's the one part you can't get drag readings for. After I replaced the crew with probe cores of equivalent mass (0.1t) the Violet worked perfectly.

I ran another test using the Siren, now normally this VTOL can cruise along at 200m/s however with a Kerbal at the controls I was only getting 150m/s.

Replace the Kerbal with a probe core and lo and behold, we're back to 200m/s.

So it seems to be that the Kerbals themselves aren't occluded properly and consequently causing a ton of drag. The question now is if this issue is only affecting my copy of the game or are other people experiencing the same thing? @Rune I assume when you did your test of the Violet the craft was unmanned? If so do you mind taking the craft up again, this time with a full crew? @Dafni, @Majorjim if you guys get a chance to run a quick test flight I'd really appreciate it. Ta.  

 

Cupcake...

Yup, that has to be it. I slapped a probe core for expediency, and it would explain everything. Including how the bug came to be at the same time as the occlusion bug! Kerbals were also messed with on EVA to fix the issues with wheels and landing gear, I think. I'll still take it for a spin with a pilot, tough, to confirm just in case (I didn't have any handy in my main save when I tried it, just lots of engineers).

 

Rune. Well, at least this is generating info to fix things for 1.2. Will update my bug in the tracker when we finish with this!

Edited July 21, 2016 by Rune

[Majorjim!]

6 minutes ago, Rune said:

Yup, that has to be it.

Sorry I doubted you @Cupcake...

 

[Dafni]

5 hours ago, Cupcake... said:

So it seems to be that the Kerbals themselves aren't occluded properly and consequently causing a ton of drag. The question now is if this issue is only affecting my copy of the game or are other people experiencing the same thing? @Rune I assume when you did your test of the Violet the craft was unmanned? If so do you mind taking the craft up again, this time with a full crew? @Dafni, @Majorjim if you guys get a chance to run a quick test flight I'd really appreciate it. Ta.  

 

Cupcake...

I can confirm I get the same results. All the craft I tried (with Kerbals in external seats in cargo bays) were noticeably faster when I replaced the kerbal with a 0.1t probe core.

Edited July 21, 2016 by Dafni

[Cupcake...]

18 hours ago, Rune said:

Yup, that has to be it. I slapped a probe core for expediency, and it would explain everything. Including how the bug came to be at the same time as the occlusion bug! Kerbals were also messed with on EVA to fix the issues with wheels and landing gear, I think. I'll still take it for a spin with a pilot, tough, to confirm just in case (I didn't have any handy in my main save when I tried it, just lots of engineers).

 

Rune. Well, at least this is generating info to fix things for 1.2. Will update my bug in the tracker when we finish with this!

If you could inform the powers that be that'll be great!

17 hours ago, Majorjim said:

Sorry I doubted you @Cupcake...

 

It's all good, I was starting to doubt myself to be honest. I'm just glad we've hopefully got to the bottom of this at last!

14 hours ago, Dafni said:

I can confirm I get the same results. All the craft I tried (with Kerbals in external seats in cargo bays) were noticeably faster when I replaced the kerbal with a 0.1t probe core.

Thanks for that mate, really appreciate it.

Cupcake...

[Rune]

1 hour ago, Cupcake... said:

If you could inform the powers that be that'll be great!

 

Ok, I think this is the last word on the subject. Everything is confirmed. The Violet can make orbit manned... if you fry a poor kerbal in the process!

It is even more clear in this pic, taken a few seconds before:

Yup, Val burned up. Rest easy, this was a 'simulation' in my testing save. And I was able to break the sound barrier only because I skimmed the surface like, close.

Note in this pic I had already accrued 12m/s of vertical speed due to the increase in speed, imagine the height when I leveled... Yeah, the extra drag is surely there. But it can be done nevertheless. I'd be willing to bet I can even do it without burning the kerbal, I was just trying to prove a point there.

 

Rune. Experience flying SSTOs is a thing. You really learn to milk them with practice.

[Cupcake...]

20 minutes ago, Rune said:

Ok, I think this is the last word on the subject. Everything is confirmed. The Violet can make orbit manned... if you fry a poor kerbal in the process!

It is even more clear in this pic, taken a few seconds before:

Yup, Val burned up. Rest easy, this was a 'simulation' in my testing save. And I was able to break the sound barrier only because I skimmed the surface like, close.

Note in this pic I had already accrued 12m/s of vertical speed due to the increase in speed, imagine the height when I leveled... Yeah, the extra drag is surely there. But it can be done nevertheless. I'd be willing to bet I can even do it without burning the kerbal, I was just trying to prove a point there.

 

Rune. Experience flying SSTOs is a thing. You really learn to milk them with practice.

So the Kerbal's aren't shielded from drag or heat? The news doesn't get much better does it.

 

Cupcake...

[Rune]

3 minutes ago, Cupcake... said:

So the Kerbal's aren't shielded from drag or heat? The news doesn't get much better does it.

 

Cupcake...

One kind of implies the other. They definitely aren't getting the 'occluded' flag applied to them, as parts. And that means your kind of cockpits are very dangerous places to be in during high-speed atmospheric flight.

 

Rune. What do wheels, legs, and kerbals have in common?

[Cupcake...]

4 minutes ago, Rune said:

One kind of implies the other. They definitely aren't getting the 'occluded' flag applied to them, as parts. And that means your kind of cockpits are very dangerous places to be in during high-speed atmospheric flight.

 

Rune. What do wheels, legs, and kerbals have in common?

Let me know how the bug reporting goes. Shame really, if it wasn't for this glitch I'd be all over 1.1.3, oh well, here's hoping they come up with a fix soon.

 

Cupcake...

[Dafni]

Great, we are getting to the bottom of this. Interesting. Definitely something to keep in mind and hope for a fix.

@Rune, on another note, on your last picture of the post with the exploded kerbal, you can see this green line in the ocean. I get that too sometimes. Any idea what is causing this?

[Rune]

On 22/7/2016 at 11:43 AM, Cupcake... said:

Let me know how the bug reporting goes. Shame really, if it wasn't for this glitch I'd be all over 1.1.3, oh well, here's hoping they come up with a fix soon.

 

Cupcake...

Done. I also took the liberty of throwing your name, in case that got anybody's attention and made them look into it. Can't hurt, right?

On 22/7/2016 at 1:46 PM, Dafni said:

Great, we are getting to the bottom of this. Interesting. Definitely something to keep in mind and hope for a fix.

@Rune, on another note, on your last picture of the post with the exploded kerbal, you can see this green line in the ocean. I get that too sometimes. Any idea what is causing this?

Yeah, I only noticed now that you brought it up. No idea where that came from, honestly!

 

Rune. Old graphic card here.

[Cupcake...]

8 hours ago, Rune said:

Done. I also took the liberty of throwing your name, in case that got anybody's attention and made them look into it. Can't hurt, right?

Yeah, I only noticed now that you brought it up. No idea where that came from, honestly!

 

Rune. Old graphic card here.

Cheers Rune.

 

Cupcake...

[zdkroot]

On 7/22/2016 at 5:36 AM, Rune said:

One kind of implies the other. They definitely aren't getting the 'occluded' flag applied to them, as parts. And that means your kind of cockpits are very dangerous places to be in during high-speed atmospheric flight.

 

Rune. What do wheels, legs, and kerbals have in common?

It's not just those things. It doesn't seem like cargo bays prevent drag at all. Yesterday I was trying a tiny mk2 SSTO with seats in a cargo bay and sure enough jeb and his buddy burned up. Also a few weeks ago I was having an incredibly hard time getting a mining SSTO past mach1 with 0.8 TWR - I replaced the IRSU/drills in the cargo bay with a fuel tank and it can climb at 15 degrees and still make mach1 in about 1:30.

[Cupcake...]

2 hours ago, zdkroot said:

It's not just those things. It doesn't seem like cargo bays prevent drag at all. Yesterday I was trying a tiny mk2 SSTO with seats in a cargo bay and sure enough jeb and his buddy burned up. Also a few weeks ago I was having an incredibly hard time getting a mining SSTO past mach1 with 0.8 TWR - I replaced the IRSU/drills in the cargo bay with a fuel tank and it can climb at 15 degrees and still make mach1 in about 1:30.

Here's hoping 1.2 is the answer to our prayers. Or better yet 1.1.4.

 

Cupcake...

[zdkroot]

On 8/1/2016 at 2:24 AM, Cupcake... said:

Here's hoping 1.2 is the answer to our prayers. Or better yet 1.1.4.

 

Cupcake...

After more testing it appears I am wrong - cargo bays do in fact eliminate drag on at least most parts. Kerbals definitely appear to be an exception at least in the mk2 bays. 

Drag is weird. I'm still unsure how a lot of things are calculated. Surface mounted parts seem to always cause drag regardless how far offset they are. A rapier attached directly to a rear fuel tank node will have approximately the same drag as the part it is connected to - add any part in between the rapier and fuel tank (Dawn engine in my tests) and the drag on the rapier will be 2-4x higher. A 1.25m fairing - no effect. Offsetting the rapier to be flush with the fuel tank - no effect. Putting the dawn engine on the bottom of a 1.25m service bay and attaching the rapier to that - drag solved.

It seems my SSTO failures were a combination of too many draggy parts (struts, fuel lines, solar panels) and poor piloting. Hugging sea level really helps with low TWR. The AeroGUI and tooltip info were both very helpful in troubleshooting my planes. Putting all the batteries/misc components inside service/cargo bays has made my planes feel like I just unlocked a more powerful engine.

Is there a drag sticky somewhere I haven't found? I've see scattered threads/videos but nothing comprehensive.

It just occurred to me that node size might play some role? The dawn engine has a smaller attachment node than the rapier, perhaps adding adapters would fix it. Will do some more testing later.

Edited August 3, 2016 by zdkroot
words

[Rune]

17 hours ago, zdkroot said:

After more testing it appears I am wrong - cargo bays do in fact eliminate drag on at least most parts. Kerbals definitely appear to be an exception at least in the mk2 bays. 

Drag is weird. I'm still unsure how a lot of things are calculated. Surface mounted parts seem to always cause drag regardless how far offset they are. A rapier attached directly to a rear fuel tank node will have approximately the same drag as the part it is connected to - add any part in between the rapier and fuel tank (Dawn engine in my tests) and the drag on the rapier will be 2-4x higher. A 1.25m fairing - no effect. Offsetting the rapier to be flush with the fuel tank - no effect. Putting the dawn engine on the bottom of a 1.25m service bay and attaching the rapier to that - drag solved.

It seems my SSTO failures were a combination of too many draggy parts (struts, fuel lines, solar panels) and poor piloting. Hugging sea level really helps with low TWR. The AeroGUI and tooltip info were both very helpful in troubleshooting my planes. Putting all the batteries/misc components inside service/cargo bays has made my planes feel like I just unlocked a more powerful engine.

Is there a drag sticky somewhere I haven't found? I've see scattered threads/videos but nothing comprehensive.

It just occurred to me that node size might play some role? The dawn engine has a smaller attachment node than the rapier, perhaps adding adapters would fix it. Will do some more testing later.

Good to see you are discovering the wonderful world of drag. Yes, it's weird, and yes, it's poorly explained. The best way of learning it is with the debug options, especially the right-click info. It helps to know what things to look for and yes, open nodes are always the first worst thing. Ditto for unmatched nodes (a 1.25 node connecting to a 2.5m one, for example). Also, note that the shielded volumes of the cargo bays are modeled as ovoids, so you will likely have problems if you place stuff in the corners.

The drag bug (so far) is confirmed to affect all kinds of landing gear and legs, and kerbals sitting on chairs BTW. But only those kinds of parts, as far as I know. And I've studied it quite a bit...

 

Rune. Keep on sciencing!

Edited August 3, 2016 by Rune

[zdkroot]

On 8/3/2016 at 6:07 AM, Rune said:

Good to see you are discovering the wonderful world of drag. Yes, it's weird, and yes, it's poorly explained. The best way of learning it is with the debug options, especially the right-click info. It helps to know what things to look for and yes, open nodes are always the first worst thing. Ditto for unmatched nodes (a 1.25 node connecting to a 2.5m one, for example). Also, note that the shielded volumes of the cargo bays are modeled as ovoids, so you will likely have problems if you place stuff in the corners.

The drag bug (so far) is confirmed to affect all kinds of landing gear and legs, and kerbals sitting on chairs BTW. But only those kinds of parts, as far as I know. And I've studied it quite a bit...

 

Rune. Keep on sciencing!

Yeah the right click info is the best. Good to know about the oval shape. What about struts inside a cargo bay, attaching to the frame at the corners? Their drag is applied to the root part not the connecting part right? I think I saw a post about that somewhere. Thanks for your input! I've seen your ships, they're pretty awesome.

And I never replied to @Cupcake... ... your ship is awesome man! I love the look of the clipped cooler/rapier and the fuel pods on the side. Basically no control surfaces at all haha. How does it fly? Great work.