The Grand KSP 1.1 Discussion Thread

[Majorjim!]

Just now, JeanHavoc said:

So, I've played KSP a bit since 1.1 was released.  I haven't got any of the (newer) updates but I do have a question.  It would appear that nowadays the most difficult mission profile possible is a simple suborbital launch from KSC itself.  I'm find it easier to get to Eeloo than to go up to 70 Km and come back down without exploding on impact.  I'm -not- going straight up and coming down again either; in fact I'm finding even an apoapsis of 50 Km to be too much.   Although it seems to be more dependent upon the velocity I reach - anything over 1,000 m/s prior to decent is a guaranteed death sentence.  This occurs even if I'm just coming down with a one-kerbal capsule, heat shield and parachute.  This isn't a huge problem but I like to progress in a natural way to orbit and I'm finding myself stumped by this problem.  Any advice, and is this how things are supposed to be?  Somehow I have a hard time imaging Freedom 7 being way more difficult than Apollo 8, but maybe I'm wrong there.

Sploding on ascent or burning up on descent or hitting the surface?

[JeanHavoc]

49 minutes ago, Majorjim said:

Sploding on ascent or burning up on descent or hitting the surface?

I'm early in Career mode.  I'm wanting to do a simple suborbital flight wherein I reach the atmosphere and come right back down.  The ascent and reentry go fine; heat shield works properly, rocket exhibits no peculiar instability.  The problem is on the way down; namely I'm going too fast and by the time it's safe to deploy my Mk16 parachute, I'm too close to the ground and I end up making my own crater in the surface.  Now, I follow a launch profile that's similar to what I'd do going to orbit - and my path is a wide arc covering a fair bit of distance between KSC and, in this case, the northern areas of the continent.  I've attempted to slow my rocket's speed, I've changed the apoapsis from 70 Km to 50 Km to 40 Km all with the same end result; and again I apply plenty of horizontal thrust, but obviously not enough.  The common factor is that I exceed 1,000 m/s of velocity on the way up, which puts me "over budget" if you will coming down.  All I can think to do is to build a rocket capable of reaching orbit and then simply fail to do so, in order to fudge what should otherwise be an intermediate step between atmospheric flight and orbiting the planet.  My vessel is just a Mk1 Pod, a Mk16 parachute and a 1.25 meter heat shield.  That's all.

Update: Well the solution, obviously, is to use drogue parachutes.  I tried everything else and no re-entry profile works without them.  That's fine, lesson learned.  I'm still curious though if this is really working as designed, particularly when considering the constraints of early career mode. 

Edited May 2, 2016 by JeanHavoc
Addendum.

[XrayLima]

This has to be the definition of a first kebin problem but after a couple of weeks without playing I got a chance to update and have a play again last night.  And my thoughts:  It's too slick!!  It's too fast!!

My test vehicle, a saturn IB sized, lunar orbiter launched into the black with the clock staying green the entire way.  No stutter, graphics panned and rotated smoothly but before In knew it, there was I in orbit smooth as silk.  It was too quick, it all happened too easily.  Where was the tension?  Where was the minutes of drama? Where was that tiny freeze just before something gave way? Where was the hard work!?!

 

Oh well, guess I need to go design something bigger.  I mean, if a launch doesn't take the time needed to boil the kettle for a cuppa it's going too quick!

 

Ooft, this release is slick.

Edited May 2, 2016 by XrayLima
Felt like it. Basically.

[basic.syntax]

2 hours ago, JeanHavoc said:

I'm early in Career mode. [...]The common factor is that I exceed 1,000 m/s of velocity on the way up,

What you describe sounds about right. A pod re-entering practically straight down from orbital height (if you have cancelled out a lot of horizontal velocity) may need some extra drag to help slow it down, and you found one good method in drogue chutes. Next time, (without drogue) try not cancelling out so much of the horizontal velocity, and let the air do it. Re-entering at a shallower angle (and higher speed) exposes you to more linear distance travelled through air, more heating (what the head shield is for), time suffering under drag effects, and hopefully a lower velocity closer to the ground than you saw before.

[Superfluous J]

4 hours ago, JeanHavoc said:

It would appear that nowadays the most difficult mission profile possible is a simple suborbital launch from KSC itself. ... I'm -not- going straight up and coming down again either; in fact I'm finding even an apoapsis of 50 Km to be too much. ... Any advice, and is this how things are supposed to be?

 

3 hours ago, JeanHavoc said:

I'm going too fast and by the time it's safe to deploy my Mk16 parachute, I'm too close to the ground and I end up making my own crater in the surface.  Now, I follow a launch profile that's similar to what I'd do going to orbit - and my path is a wide arc covering a fair bit of distance between KSC and, in this case, the northern areas of the continent.

Update: Well the solution, obviously, is to use drogue parachutes.  I tried everything else and no re-entry profile works without them.  That's fine, lesson learned.  I'm still curious though if this is really working as designed, particularly when considering the constraints of early career mode. 

I've not had any of these problems in early career. Sure, I hit the ground too fast sometimes but I've always attributed that to:

1. Not being shallow enough, which is what my gut is saying for you.
2. Having too much mass for my cross-sectional area, which could be your problem as well.

For 1, the solution is to be even moar orbital with your suborbital. With just 10 science points (first 2 nodes) you can reach orbit with some work, so getting an extremely elongated (half the planet wide with an 80-100km apoapsis is what I'm talking) suborbital trajectory should be doable as well.

For 2, I see you're using *almost* the bare minimum parts, but I suggest you also jettison the heat shield (right click it). Once you get below 1000m/s you don't need it. You probably don't even need it at all, really. I don't even bring them to Mun and reserve them only for interplanetary travel. Mass is momentum. Momentum is death.

Edited May 2, 2016 by 5thHorseman
I missed that the OP stated he was only descending with 3 parts, not an entire ship.

[Curveball Anders]

3 hours ago, JeanHavoc said:

My vessel is just a Mk1 Pod, a Mk16 parachute and a 1.25 meter heat shield.  That's all.

It sounds like only a very steep trajectory could crash that.

What's your Pe at Ap?

[JeanHavoc]

3 hours ago, Curveball Anders said:

It sounds like only a very steep trajectory could crash that.

What's your Pe at Ap?

I don't have the numbers in front of me, but I can tell you the trajectory was not covering (as mentioned above) half the planet.  I think my definition of "very steep" and what others have presented here may be rather different.  But in any case, the point I was getting at - more broadly - was in the difficulty of replicating a truly intermediate mission profile between atmospheric and orbital flight.  When I return from orbit I aim for about a 25 Km periapsis which has never given me any complications  For very simplistic designs that barely hit 40 Km of altitude I'm not going fast enough to encounter these problems.  I feel like KSP is rather nudging me to go from atmospheric directly to orbital flight without any in-between, which is certainly doable at early tech levels.  I think perhaps the rocket I was using was simultaneously too powerful and not powerful enough, including as it did an LV-T45 engine and around ~ 2,500 m/s of D/v (per KER).  It could get me to 70 Km, and give me some horizontal velocity but not nearly enough as it turned out.  I felt like it was a perfectly fine incremental design, I think the game might disagree.

[Curveball Anders]

18 minutes ago, JeanHavoc said:

But in any case, the point I was getting at - more broadly - was in the difficulty of replicating a truly intermediate mission profile between atmospheric and orbital flight.

As you go higher, you need to travel further to establish a survivable ballistic trajectory.

The basic principle of "more power to get me higher" simple doesn't work, you need to get the trajectory right.

About twice as far as high if I remember my Mercury suborbital flights correctly.

[JeanHavoc]

4 minutes ago, Curveball Anders said:

The basic principle of "more power to get me higher" simple doesn't work, you need to get the trajectory right.

I never really suggested "more power" was the solution.  I tried trajectories that peaked at 40 Km and covered more than a fourth of the circumference of Kerbin and still blew up on impact without the extra parachutes.  That must have been something like 900 Km or more and the result was the same as if I had gone up to 70 Km and only covered say half that distance.  I consider the matter solved as the drogues work perfectly well; it just wasn't an intuitive solution for me.  Orbital rendezvous and rescue, easy - this, very hard.  Strange how that works out sometimes.

[HvP]

Well, Freedom 7 did use a drogue chute before the main chute so that's realistic. It also traveled three times farther downrange than its vertical height with a 25-35 degree reentry angle. Of course, the atmosphere in Kerbal is significantly different than real life so you just have to work with what you've got.

Also consider saving weight wherever you can. Drain the monoprop from your capsule before launch as you won't need it. You can also reduce the ablator on the heat shield to around 60 or less units for suborbital flights. If you can rotate your capsule sideways after the shock heating stops you can induce a great deal more drag and eject your heat shield as well.

[FullMetalMachinist]

13 hours ago, JeanHavoc said:

and my path is a wide arc covering a fair bit of distance between KSC and, in this case, the northern areas of the continent.

I know that you said you solved the problem with drougues, but I'm just curious. Any particular reason that you launched to the north instead of the east? You know that you get a few hundred m/s Dv boost by launching with Kerbin's rotation (to the east), right? 

If you have a reason, like because you wanted to land in a different biome to get new science when you landed that's totally cool, like I said, just curious. 

[JeanHavoc]

There are certain science benefits to heading north, including landing at the pole.  Since, in this case I wasn't planning to go to orbit anyway I felt there wasn't a need to go the usual eastern route.  It's just an expedient way to keep things moving forward in the early going.

[Jacke]

1 hour ago, JeanHavoc said:

There are certain science benefits to heading north, including landing at the pole.  Since, in this case I wasn't planning to go to orbit anyway I felt there wasn't a need to go the usual eastern route.  It's just an expedient way to keep things moving forward in the early going.

Still have to get a career going to test out Mk1 reentries in KSP 1.1.2, but I'm familiar with reentry as it is on Earth, as well as back in KSP 1.0.

Reentries from 90deg polar orbits face an extra 175m/s velocity increase compared to Kerbin equatorial prograde reentries, as Kerbin is turning at 175m/s to the east, which helps the prograde reentries.  At least it's not as bad as a retrograde reentry; coming back from a retrograde orbit, the reentry will be at 350m/s greater speed.

[TBryson2]

Well, I looked for it, but could not find it,  HOW do I know what revision KSP I have?  When I launch, it says 1.1.1250.   I cannot find any reference to this on the forum, or Wiki.  I do see references in the forum and Wiki to 1.1.1, and 1.1.2... but not what is actually displayed on KSP when I launch it.

Thanks!!!

TB2

Edited May 3, 2016 by TBryson2

[Wragie]

Just start the program and when it gets to the first menu screen ie three floaty kerbals in space, then look inthe lower right corner of the screen to see the version.

[Andem]

Ok, so going to the editor is fine, but after about 30 seconds the game will crash to desktop. God dammit, I just want to play a game that relieves stress rather than induces it!

[EwingKang]

People argues and debates around 1.1, which I find perfectly normal as long as we can respect others opinion, considering how large the KSP fan base have.
Me I'm simply amazed how SMOOTHLY my computer can run the simulation. Happily sending my massive 100t Air-Launch-Rocket-To-Orbit vehicle to orbit (wat~).

Its definately not somthing spectacular craft among KSP community, but it's already like a dream for my little laptop.
Yes, it does CTD a little bit more often (along with that  bug in VAB) then 1.0.5, but considering the time it saved by simulating in normal speed it definately worth it. I've never had any problem regarding those large landing gear.
Take some rest and keep up the good work SQUAD.

Edited May 3, 2016 by EwingKang
numbers, grammar, and typo

[Jacke]

4 hours ago, TBryson2 said:

Well, I looked for it, but could not find it,  HOW do I know what revision KSP I have?  When I launch, it says 1.1.1250.   I cannot find any reference to this on the forum, or Wiki.  I do see references in the forum and Wiki to 1.1.1, and 1.1.2... but not what is actually displayed on KSP when I launch it.

When you launch KSP you should see the 4-part release number in the lower right, as well as an indicator whether you are running in 64-bit mod.  There is an option in the settings to turn it off, but you shouldn't see a partial one.  Although it could be some sort of graphics issue, I've never heard of one in the menu splash screens.

Here are the recent KSP releases:

1.1.0.1230

1.1.1.1250

1.1.2.1260

You probably have 1.1.1.1250.

Edited May 3, 2016 by Jacke

[JeanHavoc]

9 hours ago, Jacke said:

Still have to get a career going to test out Mk1 reentries in KSP 1.1.2, but I'm familiar with reentry as it is on Earth, as well as back in KSP 1.0.

Reentries from 90deg polar orbits face an extra 175m/s velocity increase compared to Kerbin equatorial prograde reentries, as Kerbin is turning at 175m/s to the east, which helps the prograde reentries.  At least it's not as bad as a retrograde reentry; coming back from a retrograde orbit, the reentry will be at 350m/s greater speed.

I feel I should clarify here that I've tried suborbital reentry going East, North and Retrograde - the result (without drogue parachutes) is always the same - explosive death.  At least, that is, when I don't have a rocket powerful enough to give me a very long arc, like say half way across the planet's surface.

[StrandedonEarth]

2 hours ago, JeanHavoc said:

I feel I should clarify here that I've tried suborbital reentry going East, North and Retrograde - the result (without drogue parachutes) is always the same - explosive death.  At least, that is, when I don't have a rocket powerful enough to give me a very long arc, like say half way across the planet's surface.

As others have said, try without the heat shield as you really don't need it. More mass within the same cross-section means you don't slow down as fast. Also, if you're landing on land instead of water that means you have less airspace to slow down, especially if you come down over mountains 

[Kramer]

3 hours ago, JeanHavoc said:

I feel I should clarify here that I've tried suborbital reentry going East, North and Retrograde - the result (without drogue parachutes) is always the same - explosive death.  At least, that is, when I don't have a rocket powerful enough to give me a very long arc, like say half way across the planet's surface.

I also noticed trouble slowing down with a simple capsule like yours. I have a good bit of experience with 1.0.5 with the identical capsule (parachute, Mk 1, heat shield) and never had trouble slowing down with all kinds of different trajectories. The ship seemed to have tons of drag once it got down to 20000m or so. In 1.1.2 I just barely am able to get the chute deployed in time--speed drops to safe deploy speed about 4000m or less and with chute deploy time, it does not start braking seriously until 400m from sea level.

This is very different from 1.0.5. So my question is, I have seen in previous posts that it is claimed that there were no changes to the atmosphere and its effects. But some ships are less draggy. So is the heatshield less draggy? Or is it just not true--that the atmo effects have changed?

-Kramer

[Terwin]

Not sure which parts specifically are less draggy, but it sounded like some(all?) Mk1 parts are less draggy, probably including the mk1 capsule.

[Violent Jeb]

Many the MK1 parts had drag reduced. They move faster through the atmosphere. I also found the sub-orbital mission difficult, mainly for not taking these things into account. 

In order to pass the mission you need to reach 70km up. even if you just scrape that point you need a serious amount of horizontal thrust to make up for it. If you can get to orbit with ~3600 dv, then a ship will need ~3300 to reach 70km and return safetly.

Ofc, there's always the possibility of launching [almost] straight up, touching 70, and burning retrograde to survive the return trip. No idea how much more or less dv that would require, but you might be able to do away with drogues if that's your thing.

It's more complicated than before, but I suppose it's good because it gives you an opportunity to play with flight patterns and get a hands on feel for the atmosphere and how it reacts.

I also particularly like that re-entry is not easy and keeps you on your toes now. As i mentioned elsewhere, drogue chutes and a heatshield should be mandatory for re-entry as is.

Edited May 3, 2016 by Violent Jeb

[herbal space program]

I just spent a little time playing 1.1.2 after rather a long KSP hiatus. I must say that I am quite impressed by the improvement in frame rate with the combined upgrades to Unity 5 and 64 bit, but even after the two patches there still seems to be a host of weird little bugs. Toggling back and forth between the orbital and staging views has been a particularly consistent cause of problems for me (playing 64-bit Windows 10, unmodded, flying a fairly simple LOR-type Mun landing mission). Sometimes it just won't let me go back to the staging view, sometimes it only lets me go back after I click on the orbital view button a second time, and sometimes going to the orbital view (so far always while under acceleration in the 40-70km range above Kerbin) seems to cause a brief but strong phantom rotational impulse, resulting in the end that should not point towards space suddenly pointing towards space. I'd be interested to know if anyone else is seeing that behavior, as I did not note anyone talking about it in the bug forum. The game also seems to fully crash significantly more often, but I haven't been able to discern yet if there's a consistent gameplay circumstance involved. Overall, I think this upgrade was much needed to make the game more playable, but I also think it's going to be a long haul to iron out all these glitches. Anyway, based on comments above I'm eager to see if my Mk1 spaceplanes can once again get the same level of performance they had before the nerfing of 1.0.5!

15 minutes ago, Violent Jeb said:

Ofc, there's always the possibility of launching [almost] straight up, touching 70, and burning retrograde to survive the return trip. No idea how much more or less dv that would require, but you might be able to do away with drogues if that's your thing.

 

I haven't tried that in this version yet, but I'm guessing that if you hit 70km close to the apex of your trajectory, it won't take much of a retro burn to make re-entry pretty trivial.

[NikkyD]

Those straight up and back down trips early on can be tricky as most crafts will have a good streamline. Just a capsule and 2 staged boosters gets you to 150km but you never survive the reentry, you fall through the atmosphere like a rock and when u hit about 20 km you start slowing down a little but still not enough and you hit the ground with 1 km/s. Not even heat is the issue here.

Edit:

If you just need "some science from space around Kerbin", take an MK1 capsule, a chute and a RT10 set to about 60% thrust. This will get you to above 80 km where you can crew-report and EVA. On the way back down, set the whole thing horizontal and hold it there with SAS. Somewhere in the lower atmosphere it will start pointing the capsule to the ground as it is the heaviest object. Then you need to move left and right (like a pendulum) to stay as much sideways as possible, this should slow you down to chute speeds and thats it.

Edited May 4, 2016 by NikkyD