MacLeod-Industries

Over 400 hours in KSP... and apparently I have never orbited correctly.

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I am approaching 450 hours in KSP. I have accomplished many achievments...

I have:

landed on the moon... once (I never returned because I can't dock a lander to an orbiter... I was going to land again, but my new heavy lifter rocket was super glitchy for some reason. Testing the stages seperate it would have had enough delta V to go there and back... Possible even to minmus.)

Made a plane that goes suborbital with only jet engines

recreated Apollo 11

Made a rocket to carry my Saturn V rocket into orbit (WHILE it is thrusting down!)

And I have never once orbited correctly...

Apparently there is such thing as a "gravity turn..."

Normally I would just rocket until my apogee is above 70 km, wait until I am near the apogee, and then thrust prograde to orbit.

It worked, but turning the rocket 90 degrees was a little irritating. (Usually I needed vernier engines or a LOT of RCS for heavy rockets)

I don't know how I learned to orbit this way, but today marks the day I will do my first (correct) orbit...

Edited by MacLeod-Industries

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Well, back in the day before proper aero, that was how it was usually done.

You're going to discover you have a lot more dV than you thought you did.

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Just now, Gojira1000 said:

Well, back in the day before proper aero, that was how it was usually done.

You're going to discover you have a lot more dV than you thought you did.

Yeah...

but I started in 1.0.5

xD
 

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Your approach certainly isn't efficient but if it worked for you that's all that matters.

What you were doing was basically like walking two sides of a square to go corner to corner instead of just walking across it diagonally.

If it makes you feel any better I played for a year or two before I realized you could EVA, collect all your science data, then decouple the science parts so you didn't have to take them down through re-entry with you.

Just now, MacLeod-Industries said:

When is a good time to do the gravity turn? I have started doing it when the atmosphere marker drops to the darkest blue.

Right off the pad, do it slowly and gradually...basically just tilt the nose and let the rocket fall to 45 degrees as you climb. You should definitely complete it by 10km up.

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4 minutes ago, Rocket In My Pocket said:

Your approach certainly isn't efficient but if it worked for you that's all that matters.

What you were doing was basically like walking two sides of a square to go corner to corner instead of just walking across it diagonally.

If it makes you feel any better I played for a year or two before I realized you could EVA, collect all your science data, then decouple the science parts so you didn't have to take them down through re-entry with you.

Right off the pad, do it slowly and gradually...basically just tilt the nose and let the rocket fall to 45 degrees as you climb. You should definitely complete it by 10km up.

Wait... you can collect you science data?

-_-

I don't play career mode often enough so I don't use science too much, but still...

 

WAIT! No wonder I can't get the stock space shuttle in orbit...

That makes a lot of sense now. xD

Edited by MacLeod-Industries

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Just now, MacLeod-Industries said:

Wait... you can collect you science data?

-_-

I don't play career mode often enough so I don't use science too much, but sitll.

Yeah it wasn't obvious to me at first either but it really saves you weight in your return vehicle.

Especially when going to the Mun for example, you can just leave the science parts on the surface and take the data with your Kerbal back into space, and back home to Kerbin.

Another example of something the game should really tell you in a tutorial or something.

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1 minute ago, Rocket In My Pocket said:

Yeah it wasn't obvious to me at first either but it really saves you weight in your return vehicle.

Especially when going to the Mun for example, you can just leave the science parts on the surface and take the data with your Kerbal back into space, and back home to Kerbin.

Another example of something the game should really tell you in a tutorial or something.

The tutorials are certainly better in 1.1

I would probably take half of my science equipment back anyways, as I am that type of guy. Even if it is super cheap...

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14 minutes ago, MacLeod-Industries said:

When is a good time to do the gravity turn? I have started doing it when the atmosphere marker drops to the darkest blue.

I do mine at around 18km, any lower and my craft seems to flip, I also throttle down more as I go higher up in the atmosphere to be more efficient but when you leave the atmosphere you can throttle to full again

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Don't be too hard on yourself, it happens to the best of us.

Some of the most popular KSP streamers are... not so good... with orbital mechanics, and I cringe everytime I watch them try to set up a maneuver node...
Meanwhile, I myself just can't build good and useful planes. I know all the theory, but everytime I go into the SPH and start sticking parts together, the result turns out both ugly, and only moderately airworthy at best...

We all have our areas where we excel, and our areas where we must admit our shortcomings :P

Edited by Streetwind

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1 minute ago, Streetwind said:

Don't be too hard on yourself, it happens to the best of us.

Some of the most popular KSP streamers are... not so good... with orbital mechanics, and I cringe everytime I watch them try to set up a maneuver node...
Meanwhile, I myself just can't build good and useful planes. I know all the theory, but everytime I go into the SPH and start sticking parts together, the result turns out both ugly, and only moderately airworthy at best...

We all have our areas where we excel, and our areas where we must admit our shortcomings :P

Wasn't trying to make it look like I was hard on myself...

I was putting this up in a humorous tone...

I was just surprised that I only have learned about it yesterday.

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1 minute ago, MacLeod-Industries said:

I was just surprised that I only have learned about it yesterday.

I once had a guy tell me the entire space program was fake because get this;

The shuttle's don't go straight up, they turn...so they couldn't possibly be going to space.

I was just like... :rolleyes:

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2 minutes ago, Rocket In My Pocket said:

I once had a guy tell me the entire space program was fake because get this;

The shuttle's don't go straight up, they turn...so they couldn't possibly be going to space.

I was just like... :rolleyes:

I purposely look up "NASA is fake" websites to see their arguments...

One guy just said "We went to the moon in the 1969. But not the space shuttle only goes to low earth orbit and we are in the 2000's. Why is NASA's technology going backwards? It isn't. It is all a lie!"

Uh... the budget is the thing that is going backwards...

Another guy also kept calling apollo 11 apollo 13.

How am I supposed to take you seriously if you can't even say the right name?

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On manual, I run vertical until I get to the last 1/3 of atmosphere, turn 45 until my apo is well above 70 (about 100), then I go flat or slightly down until I complete the orbit.

I don't like MechJeb's ascent, it burns too much drag/heat in the atmosphere, the only time I let it take over is the final orbital speed and circularization burn.

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1 minute ago, MacLeod-Industries said:

I purposely look up "NASA is fake" websites to see their arguments...

Yeah, me too! Conspiracy theory videos on Youtube are a guilty pleasure of mine. Lol.

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59 minutes ago, MacLeod-Industries said:

Normally I would just rocket until my apogee is above 70 km, wait until I am near the apogee, and then thrust prograde to orbit.

Ouch.  Yes, that will be really inefficient and expensive in terms of dV.

55 minutes ago, Gojira1000 said:

Well, back in the day before proper aero, that was how it was usually done.

Even in the old pre-1.0 aero days, that still would have been really inefficient.  The classic path to orbit, pre-1.0, was:  "go straight up to 10 km, then crank it over 45 degrees."

(I hasten to add, for the benefit of anyone new to KSP, in case it's not clear already, that's not how you do it now.)  :wink:

36 minutes ago, MacLeod-Industries said:

When is a good time to do the gravity turn? I have started doing it when the atmosphere marker drops to the darkest blue.

34 minutes ago, Rocket In My Pocket said:

Right off the pad, do it slowly and gradually

^ This.  What R.i.m.P. said.  I generally wait until I've reached around 20 m/s, just so I have a reasonably stable prograde marker, but yeah, practically right off the pad.  Just a gentle eastward nudge, and then you can pretty much hands-off the controls (except for staging) and let it fly itself.

The tricky part is not when to do it, but estimating how much of a nudge to give it.  That's because the initial eastward nudge needs to be really small, and it's very sensitive.  Not enough, and you're still going too steep when you get up high.  Too much, and you pitch over too fast and end up going horizontally when you're still low in the atmospheric soup.

The good news is that you can tell fairly early whether you've nailed it:  just look at what your rocket is doing when you're at 10 km altitude.  If you're going over 300 m/s and are at about 45 degrees, then you're good.  If you're a lot steeper or shallower than 45 degrees when you're at 10 km, then your nudge was off-- revert to launch and try it again.

You can make your life easier by designing your rockets so that they always have the same launchpad TWR.  Just pick a number that works for you (I like to use 1.5, myself), and religiously keep your designs to that launchpad TWR.  That way, they all have a similarly shaped gravity curve and the piloting for that critical, initial eastward nudge will be similar.  (You may want to adjust that for extreme discrepancies of scale:  really big ships are less affected by aero drag, so you may want to run them at higher TWR, which in turn would be a different shape to the curve.)

20 minutes ago, AeroAviation said:

I do mine at around 18km, any lower and my craft seems to flip

2 minutes ago, sdrevik said:

On manual, I run vertical until I get to the last 1/3 of atmosphere, turn 45 until my apo is well above 70 (about 100), then I go flat or slightly down until I complete the orbit.

That's way too high (at least, for the sake of dV efficiency)-- if you're having flipping problems, that's a rocket design issue with aero stability.  It's readily addressed by tweaking your design; they'll fly themselves and won't ever flip.  Hard to give really specific advice without seeing a screenshot of the ship, but the general maxims are "heavy and pointy in the front, light and draggy on the back."

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At this moment I am slowly descending from my first "Good" orbit...

yay?

Bill Bob and Valentina are pretty toasty...

I used minimal delta V to deorbit so re-entry is not fun.

Edited by MacLeod-Industries

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1 minute ago, MacLeod-Industries said:

I used minimal delta V to deorbit so re-entry is not fun.

Why not?  Minimal dV is a good thing.  Reentry is supposed to be warm.  :)

If it gets warm to the point of being explody, then yeah, that would be a problem... but that's a problem easily addressed by rocket design and/or piloting.

Screenshot of your rocket?  Also, what altitude did you set your Pe to for your reentry burn?  20-30 km is typically the sweet spot for reentry; much higher or lower than that and you tend to get toasted.

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I never said it was recommended, Snark :) 

As a rule of thumb, on a balanced rocket with TWR 1.5 or so, I gently tilt 10 degrees east at @75 m/s, 20 at @150 ms, then smoothly to hit 45 degrees at 15K altitude, then flat to the horizon at 40km. Every launcher is different, though. Your Mileage May Vary

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5 minutes ago, Snark said:

Why not?  Minimal dV is a good thing.  Reentry is supposed to be warm.  :)

If it gets warm to the point of being explody, then yeah, that would be a problem... but that's a problem easily addressed by rocket design and/or piloting.

Screenshot of your rocket?  Also, what altitude did you set your Pe to for your reentry burn?  20-30 km is typically the sweet spot for reentry; much higher or lower than that and you tend to get toasted.

50K was my pe.

Splashdown as I am writing this.

I had a heat shield though. I meant it wasn't fun as in it ate through ablator. About 200-ish.

My rocket wasn't really good, it was just to test the concept. But I will still screen shot it.

 

That reminds me...

When I first did KSP... and I returned from orbit I used extra fuel to burn and slow myself down...

I never realized that you could pod the command pod off and that would be fine...

All those hours struggling to get it work that way... lol

 

Edited by MacLeod-Industries

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Before I let mechjeb do it I used to burn up to 10km then start turning, with the nav-ball scale as such:

15-20km: 15degrees east from vertical

20-30: 30 degrees east

30-50km 45 degrees east

50-60: 80 degrees east

60+: at prograde until desired orbit altitude.

 

As for the rocket flipping:  First add Winglets to the bottom.  If that doesn't fix the flip do a fairing over the payload.  If both of that doesn't work, drag the payload into orbit behind a lift structure, making sure your thrust origin is ahead of the payload.  It will naturally fix itself this way (but could be hard to gravity turn).  This is especially needed if you launch biospheres from the civilian population mod.

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8 minutes ago, MacLeod-Industries said:

50K was my pe.

That's fine if it works for you, but be advised that you're going to suffer a lot more heating that way.  It's too high.  Lower it to 25-30 km and you'll do better.

I know this seems really counterintuitive.  You're probably thinking of the atmosphere along the same lines as a bathtub of really scalding water, and you figure it's better to just gently dip your toe in it as gradually as possible, so you "spread the heat out" rather than getting it in a rush.

The problem is that that's not how it works.  Reentry heat in KSP is not simply a matter of, "I have X amount of kinetic and potential energy, and it's all going to turn to heat in my ship, and the total amount of heat I get will be the same regardless of how I enter, so I should enter more slowly so the heat is spread out more over time."

That would make intuitive sense, on a certain level... but it's not how it works.  If you're zipping along at high speed in the extreme upper atmosphere, it generates a whole lot of heat but doesn't actually slow your ship down by a corresponding amount.  You end up generating a huge amount of heat.  You actually get less total heating if you enter more steeply.

So, just rip that band-aid right off.  :)

4 minutes ago, michaelhester07 said:

15-20km: 15degrees east from vertical

20-30: 30 degrees east

30-50km 45 degrees east

50-60: 80 degrees east

60+: at prograde until desired orbit altitude.

That's far too high and too gentle a turn, for efficiency.  The rocket should be about 45 degrees from vertical by the time it's at 10 km... and it should be prograde all the way.

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Just now, Snark said:

That's fine if it works for you, but be advised that you're going to suffer a lot more heating that way.  It's too high.  Lower it to 25-30 km and you'll do better.

I know this seems really counterintuitive.  You're probably thinking of the atmosphere along the same lines as a bathtub of really scalding water, and you figure it's better to just gently dip your toe in it as gradually as possible, so you "spread the heat out" rather than getting it in a rush.

The problem is that that's not how it works.  Reentry heat in KSP is not simply a matter of, "I have X amount of kinetic and potential energy, and it's all going to turn to heat in my ship, and the total amount of heat I get will be the same regardless of how I enter, so I should enter more slowly so the heat is spread out more over time."

That would make intuitive sense, on a certain level... but it's not how it works.  If you're zipping along at high speed in the extreme upper atmosphere, it generates a whole lot of heat but doesn't actually slow your ship down by a corresponding amount.  You end up generating a huge amount of heat.  You actually get less total heating if you enter more steeply.

Oh I know, I just didn't have the right altitude offhand...

and I accidentally jettisoned the retro-rocket before I could change it -_-

Here is the rocket:

 

 

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If using an engine with a lot of gimbal I do it right off the pad. If using fins to turn I wait until my speed is about 50m/s. Early as possible.

Both times I start slow but I am 45 degrees or less above the horizon by around 10km. I end up very nearly horizontal around the 40-50km mark depending on TWR.

The air is so thin by about 40km that you can fly as though you are out of the atmosphere, concentrating on increasing your orbital speed instead of thrusting upwards. Make sure you have a decent vertical speed though, don`t let that drop too much.

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