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Hi guys i launched with the z throttlen up but i know if i press the space i will sepearete the booster s and i did not touch nothing to speedu up as the temptation to press wasd or arrows is big. ok now i reached much after the atmosphere how can i get to any space station, moon or mars?? or turn the vehicle, left, right ? i got rid off the boosters. I did mistake i reckon with pressing space and getting rid of boosters as after i pressed space again and the plane started to burn , how can i get to any space station ? or launch space station ?

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The ideal launch method is to start at between 5 degrees and 15 degrees from vertical (depending on launch thrust to weight ratio) then keep your nose at prograde as prograde slowly lowers.   To deepen the curve lower throttle, to heighten the curve, raise throttle. 

This drastically reduces drag and wasted fuel.

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On 12/18/2019 at 3:18 PM, michaelbezos1 said:

Hi guys i launched with the z throttlen up but i know if i press the space i will sepearete the booster s and i did not touch nothing to speedu up as the temptation to press wasd or arrows is big. ok now i reached much after the atmosphere how can i get to any space station, moon or mars?? or turn the vehicle, left, right ? i got rid off the boosters. I did mistake i reckon with pressing space and getting rid of boosters as after i pressed space again and the plane started to burn , how can i get to any space station ? or launch space station ?

What I normally do is pack in tons of SRBs, launch up to roughly 120km, and circularize with maneuverable engines. Inefficient as heck, and hard to use with rendezvous, but it works.

To do this, the first stage has to be a ton of SRBs that have fins and maybe some ASAS units. The next stage is ideally either the Skipper, or the Poodle.

As for launching heavy things like stations, just build your launcher with bigger stages and more boosters.

If you hate SRBs, try asparagus staging. 

As for lining up launches for rendezvous... I can't do that, I'm just not good enough for that. As for rendezvous itself, that's an entirely different question from launching.

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On 12/20/2019 at 2:26 AM, Ruedii said:

The ideal launch method is to start at between 5 degrees and 15 degrees from vertical (depending on launch thrust to weight ratio) then keep your nose at prograde as prograde slowly lowers.   To deepen the curve lower throttle, to heighten the curve, raise throttle. 

This drastically reduces drag and wasted fuel.

I always doubt this to be true, I never saw any real proof.

 

Yet I can easily give proof of the opposite, actual delta-v for a launch vehicle is:

 

DV = Isp * 9.81 * ln(m0/mf) - integral(g(t) dt) - integral( d(t) dt) - otherlosses

 

with integral(g(t) dt) being the integral over time for the gravity at time t, between start of the burn and end of the burn. (and d(t) for drag between start and end of *maneuver*). Since gravity is near constant during launch, we can simplify to:

 

DV = Isp * 9.81 * ln(m0/mf) - g0 * t_burn -  integral( d(t) dt) - otherlosses

Now the question is chiefly: is the drag loss due to increased velocity by burning more fuel faster offset by the gravity losses. Given Kerbin's very thin atmosphere above 13ish km I can easily argue "yes", at least above the very first few km. So the longer you burn the more fuel you "waste" (t_burn increases).

 

Now that I have this statement, you ought to bring back a counter argument. And "experience" or "others say so" is not a valid argument, that's not what science is based upon, I need something I can repeat and that shows it.

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I was expelled from the night shelter today due to possessing splashed can of beer in the room as it is against the rules so I must postpone the kerbal space program as I do not have now computer which use the steam.I

I published new photos and the movie may be same available at www.rocketlaunches.webnode.com if I was more ambitious I would find the link for particular photo of movie and try to put in

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20 minutes ago, paul23 said:

Now the question is chiefly: is the drag loss due to increased velocity by burning more fuel faster offset by the gravity losses. Given Kerbin's very thin atmosphere above 13ish km I can easily argue "yes", at least above the very first few km. So the longer you burn the more fuel you "waste" (t_burn increases).

 

Now that I have this statement, you ought to bring back a counter argument. And "experience" or "others say so" is not a valid argument, that's not what science is based upon, I need something I can repeat and that shows it.

You are correct, there is plenty of evidence on this forum that full throttle launches are the most efficient. If you're having to ease off, pitch over more (subject to not burning up).

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On 12/22/2019 at 9:19 AM, paul23 said:

I always doubt this to be true, I never saw any real proof.

 

Yet I can easily give proof of the opposite, actual delta-v for a launch vehicle is:

 

DV = Isp * 9.81 * ln(m0/mf) - integral(g(t) dt) - integral( d(t) dt) - otherlosses

 

with integral(g(t) dt) being the integral over time for the gravity at time t, between start of the burn and end of the burn. (and d(t) for drag between start and end of *maneuver*). Since gravity is near constant during launch, we can simplify to:

 

DV = Isp * 9.81 * ln(m0/mf) - g0 * t_burn -  integral( d(t) dt) - otherlosses

Now the question is chiefly: is the drag loss due to increased velocity by burning more fuel faster offset by the gravity losses. Given Kerbin's very thin atmosphere above 13ish km I can easily argue "yes", at least above the very first few km. So the longer you burn the more fuel you "waste" (t_burn increases).

 

Now that I have this statement, you ought to bring back a counter argument. And "experience" or "others say so" is not a valid argument, that's not what science is based upon, I need something I can repeat and that shows it.

Except you are failing to account that more powerful engines add more dead weight and are less efficient.  Also, engines burn less efficient at low altitudes. 

Additionally, fuel burnt at a lower angle, at an altitude of 24Km is much more efficient, than fuel burnt at 80 degrees. at an altitude of 0km.

Finally, you are presuming the flight is a straight line, not a curve.

When you can launch to full orbit with less than 2800 Delta-V  expended, and less than 1500 ground equivilant Delta-V expended, come back, as that is what I get with my technique.

 

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On 12/23/2019 at 6:57 PM, Ruedii said:

Except you are failing to account that more powerful engines add more dead weight and are less efficient.

That's captured by the `M0/Mf`, starting mass over the final mass component: heavier engines will give a smaller fuel fraction. If fuel burns "less efficient at low altitude" is the driving force the best solution would be to go perfectly vertical and then once you are at sufficient altitude do a turn. however this is not a gravity turn at which you minimize offset between prograde and gravity. It would be a much sharper turn, and unless you come up with some form of calculation or test I cannot verify such statements.

 

On 12/23/2019 at 6:57 PM, Ruedii said:

Additionally, fuel burnt at a lower angle, at an altitude of 24Km is much more efficient, than fuel burnt at 80 degrees. at an altitude of 0km.

What? This is just repurposed bovine waste, the direction has no (in ksp, and very very very minimal in real life) influence on the way a fuel burns, or even how a nozzle works.

 

On 12/23/2019 at 6:57 PM, Ruedii said:

When you can launch to full orbit with less than 2800 Delta-V  expended, and less than 1500 ground equivilant Delta-V expended, come back, as that is what I get with my technique.

I'm out, this is exactly why I said: "verifiable proof", not "I can do x, you need to get good". This is not scientific and reeks of claims that are just false, [snip] claims.

Edited by Vanamonde
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hi guys i did not read all of your posts but i postponed playing the kerbal space program as i do not have computer to install the steam now but i plan to change asap and use it as the prioritaire.

I am working or searching for work and i was refused from the night shelter with the good computer but i already prepared good appeal to the law clinic, frontline solicitors , council and other huamn rights organisation .

 

I need also postponing the launch of proper rocket but i am going for work so this may change soon.

 

Much love :>

 

Keep the things together.

 

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13 hours ago, paul23 said:

That's captured by the `M0/Mf`, starting mass over the final mass component: heavier engines will give a smaller fuel fraction. If fuel burns "less efficient at low altitude" is the driving force the best solution would be to go perfectly vertical and then once you are at sufficient altitude do a turn. however this is not a gravity turn at which you minimize offset between prograde and gravity. It would be a much sharper turn, and unless you come up with some form of calculation or test I cannot verify such statements.

 

What? This is just repurposed bovine waste, the direction has no (in ksp, and very very very minimal in real life) influence on the way a fuel burns, or even how a nozzle works.

 

I'm out, this is exactly why I said: "verifiable proof", not "I can do x, you need to get good". This is not scientific and reeks of claims that are just false, trumplike claims.

Do you need a video?

Do you need a craft file?

The angle is more efficient because of oberth effect.   Simply put, fuel burnt facing the horizon has more of it's energy go into orbital energy, and less into steering waste.

Your math is not scientific.  It's fuzzy math making false predictions.  Specifically, it presumes a linear trajectory.  Do you launch with a linear trajectory?   Do you launch with your nose pointing any direction other than prograde?  If so, that's your problem.

You are applying 8th grade algebra to a math problem that requires calculus.   THAT is why you are getting a wrong answer.  You are specifically using formulas made for model rockets and low altitude sounding rockets, where the curvature of the earth becomes moot.  You are failing to account for orbital mechanics, and the oberth effect of how energy spent towards the horizon will raise both your apoapsis and periapsis, and energy spent burning straight up will lower your periapsis, while raising your apoapsis, and do so at a lower efficiency because it's spending energy doing both.

Here is a list of ALL your presumptions:

You are presuming Kerbin is flat.  (The curvature of kerbin means that flying in a straight line towards the horizon is actually upwards.)
You are presuming the only option is to fly the rocket in a straight line. (A gravity turn is curved through the full flight, not straight.  You are on a suborbital arch instead of a vertical climb)
You are presuming your rocket has the same ASLISP as Vacume ISP
You are presuming your rocket has the same start and end TWR
You are presuming your rockets has the same ASL Thrust as Vaccume Thrust.
You are presuming the start weight and end weight of the rocket are the same.

Claiming all this stuff is moot is a Trumpian claim, not saying what my experience has proven, as well as what EVERY SPACE AGENCY ON EARTH DOES!

BTW, if you want proof, there is a Stock craft I built while working with the experimental testing team that is in the game.  All of Squad has tested it.

It's called "Comsat LX"

I actually added substantial additional fuel to that design from what I could launch with, because I wanted to make it reasonably easy to use, and wanted it to deliver the satelite to orbit without relying on the satalite's fuel too much.

Here is a test craft to steam with the minimum to get into orbit. 
https://steamcommunity.com/sharedfiles/filedetails/?id=1945768347
A rather haphazard, imperfect launch got me 400 Delta V left in the satelite after achieving full orbit. 

As a note, this later one is one of my designs Squad considered "too difficult for a beginner to fly."  In order to make it flyable it also needs a higher tier probe core than Squad wanted in the stock crafts they were adding, because it requires the SAS  Prograde Lock feature to be able to fly straight.  I also had made a jet with similar issues, but that one was more a demonstration of pushing the limits of aerodynamics.  (It had a unique ability of being able to recover stability, after losing it.)

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You are presuming Kerbin is flat.  (The curvature of kerbin means that flying in a straight line towards the horizon is actually upwards.)

Where did I do that? I am not talking about the trajectory at all, I'm just outlining a baseline for calculations. You are the one making a statement, so the burden of proof falls upon you.

17 hours ago, Ruedii said:

You are presuming the only option is to fly the rocket in a straight line.

Again I'm not talking about a straight line. Though I'm considering a simple trajectory where you always fire prograde, but instead of lowering thrust to make a "gravity turn" you turn just like doing a hohman transfer. 

17 hours ago, Ruedii said:

You are presuming your rocket has the same ASLISP as Vacume ISP

...

You are presuming your rockets has the same ASL Thrust as Vaccume Thrust.

Indeed I am. However as the vacuum specific impulse is not that much higher than the sea level impulse. Combined with the fact that the more simple proposal, of just firing much more straight/with full thrust, and "firing again during apoapsis", means a larger proportion is fired in vacuum.

 

17 hours ago, Ruedii said:

You are presuming your rocket has the same start and end TWR

Not at all, I'm not talking about thrust to weight ratio. The gravity loss I do consider to be equal, since the distance traveled (70km) is small compared to the total radii (600 and 670 km).

 

17 hours ago, Ruedii said:

You are presuming the start weight and end weight of the rocket are the same.

Again not at all, where do you get his impression?

 

 

17 hours ago, Ruedii said:

Do you need a video?

Do you need a craft file?

What we need is something that can easily be repeated by anyone. Something that can be verified, a craft with instructions how to fly. Either a video talk about the control input and design or something else. So long as anyone can repeat your results. I'll test out the design later once I got time away from the family.

 

17 hours ago, Ruedii said:

Your math is not scientific.  It's fuzzy math making false predictions.  Specifically, it presumes a linear trajectory.  Do you launch with a linear trajectory?   Do you launch with your nose pointing any direction other than prograde?  If so, that's your problem.

This I get a chuckle with "fuzzy math". If there's one field you simply cannot be fuzzy in it's math. I come back to my earlier statement which is that the burden of proof lies with the claimer, the "simple" formulas show otherwise. As for why you see such low thrust to weight ratios in real life applications: this is due to (a) payload restrictions, and (b) it's hard to make rockets with more thrust, and more thrust means often much less thermal efficiency.

17 hours ago, Ruedii said:

You are applying 8th grade algebra to a math problem that requires calculus.   THAT is why you are getting a wrong answer.  You are specifically using formulas made for model rockets and low altitude sounding rockets, where the curvature of the earth becomes moot.  You are failing to account for orbital mechanics, and the oberth effect of how energy spent towards the horizon will raise both your apoapsis and periapsis, and energy spent burning straight up will lower your periapsis, while raising your apoapsis, and do so at a lower efficiency because it's spending energy doing both.

No what I propose is just firing enough power to get a short burn to get the apoapsis up, the direction I am not even talking about, I'm just talking about doing a very short burn. Doing a short burn will mean you will fly "straight" as you call it for the latter part/coasting to the end of the atmosphere. After which you complete the circulation near the  apoapsis.

 

I am advocating always burning at full thrust, or at least after reaching a minimum altitude, and not lowering thrust to "keep doing a gravity turn". The direction I have not made any statements about.

 

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I gave you two crafts, the instructions to fly are in the KSP manual.

Now where all your presumptions are;
They are all in your formula which does not account for any of those things.

You provided the formula, the burden of proof is on YOU to show they account for these things.

This includes, the curvature of the top of the atmosphere.

I provided you with TWO crafts, and the instructions to fly it I already provided.

The stock craft "Comsat LX", and the craft I linked on Steam.  Comsat LX was verified by the entire team at squad, so you KNOW it can make orbit.  If you can't make orbit your method doesn't work.

As a note, Comsat LX has 25% more fuel than my original design, specifically so beginners can get to orbit with it.  I can get to orbit with it removing the extra upper fuel tank. 

The Steam craft demonstrates WHY you need to lower throttle.   Simply put a gimbal-only launcher cannot operate with zero thrust or an angle above   Try it, it will flip.  However, if you lower thrust you can maintain your control while still assending to the target 71km.

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Hi guys yesterday 26/12/2019 i did not play game .today straight from the morning i turned the computer but still postponing the game which is not the best idea when i again listen to jeff bezos speeches and the importance of the space program which should for every wise person be drive to concentrate on the space researches.

quotation now : in many years and with time i get more and more conviction of my words the blue origin is the most important job i am doing. -Jeff bezos words the richest person in the world should clearly indicates what to do:

Play kerbal space program and other space researches. 

Still exploring this beautiful game at youtubue and admiring this beautiful youtube tuitions : munar pancake rover, ksp: Massive orbital colony to laythe and other landing on the space station but i am still not on this stage. 

 

Hi guys did not play kerbal space program today but did designing of the first moon rover.

 

It is so basic, simple and  ugly

 

but at least it makes me keep going and feel that i am on the top of the things and do right development in the good direction (according to the elon musks and blue origin space race). 

https://rocketlaunches.webnode.com/siemensnx-elonmusksoftware/#&gid=1&pid=22

 

Much love: >

Keep going. 

 

Edited by michaelbezos1
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@michaelbezos1 Hey, how's it going mate? I spent some time reading through that website you linked. Is it yours? You've got some really good notes there, are you trying to build a liquid fueld rocket?

I saw the Estes one you're putting together. I've launched those a few times before and they're really fun. Let me know how the launch goes!

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Yes i bought from ebay estes rocket and tried to fold in the library as one person he steal the fin from it but i can overcome this as i have still materials for making another fin, . Generally the estes which i bought does not have launch pad as i overlook it . I can refund it or but improved one. 

I always walk with the notebook but always postpone developing kerbal space program or space engineer as i make excuses for myself in type like: It is so noisy in the library or it is so annoying i nthe mcdonals which shows i am just lazy. 

Before i had routine in the night shelter to use the computer from 19:15 till 23 and after i got wifi but i got expelled from nightshelter due to their find the can of beer in it even though i did not bring the beer. I will try to appeal tommorrow 04.01.2020 due to having sold cans of aluminum to the recycling point and right to appeal the case. 

I have notebook with me but instead of playing the games i look for work. 

 

Much love:> 

 

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hi guys turned on the notebook without the cable https://www.youtube.com/watch?v=nGid0zIf_Fk and open this scenarios and switched to toggle map so ices is breaked and motivation boosted. 

 

Hi guys playing this beautiful game but the multitasking delays the foucs but fortunately if i live the computer on looks like i can play it even without the wifi network i could play last night but it is much easier to play training than scenarios i stucked now and randezvous approach at the click the velocity meter stage. Great game but not easy to master 

 

looking for inspiration to use again siemens nx i found this https://www.dezeen.com/tag/space/ website good ideas but i still think it is much more to d odesigning according to the rocket and spacecraft engineering beside do it at kerbal space program elon musks spend 80 percent of his time designing and engineering my designs are much worst than musks and i did not do any estimations according to the staging which i can do it according to the equations from the rocket and spacecraft engineering .

All engineering proccess of putting the rocket into the space is much built and there are lots of equations dividing for : specific impulse , 3 stages, foruth and payload . 

If you add the reusable rockets which i thinkt are the most difficult in engineering as they must land into the ground and go through the atmosphere and face the loss of the gravity and all journey above the atmosphere. Next work i will concentrate on designing as they are totally not advanced like from the page above 

Much love:> 

Keep going. 

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On ‎12‎/‎22‎/‎2019 at 3:19 PM, paul23 said:

I always doubt this to be true, I never saw any real proof.

I always doubted it until I did some experimentation, throttling back to maintain a fixed time to Ap

 

Nmp2iBm.jpg

While I completely agree that if you're throttling back then it means you could have used a less powerful, and therefore lighter engine, for a given vessel throttling back can achieve pretty much the same dV as starting at a steeper initial turn angle (15 degrees at full power didn't make it to orbit but I didn't get as far as working out the exact maximum angle).

I now try to design with a first stage that will get to around 60 seconds lead, and a second stage with a TWR of around 1.5 to maintain the lead.  A shorter lead time is more efficient but 60s gives me a decent safety margin for not that much extra fuel.

On ‎12‎/‎22‎/‎2019 at 3:19 PM, paul23 said:

DV = Isp * 9.81 * ln(m0/mf) - g0 * t_burn -  integral( d(t) dt) - otherlosses

Doesn't that assume the entire burn is vertical?  By throttling back you decrease the amount of thrust delivered vertically and increase the amount delivered horizontally.

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  • 1 month later...
On 1/6/2020 at 11:37 AM, RizzoTheRat said:

I always doubted it until I did some experimentation, throttling back to maintain a fixed time to Ap

 

Nmp2iBm.jpg

While I completely agree that if you're throttling back then it means you could have used a less powerful, and therefore lighter engine, for a given vessel throttling back can achieve pretty much the same dV as starting at a steeper initial turn angle (15 degrees at full power didn't make it to orbit but I didn't get as far as working out the exact maximum angle).

I now try to design with a first stage that will get to around 60 seconds lead, and a second stage with a TWR of around 1.5 to maintain the lead.  A shorter lead time is more efficient but 60s gives me a decent safety margin for not that much extra fuel.

Doesn't that assume the entire burn is vertical?  By throttling back you decrease the amount of thrust delivered vertically and increase the amount delivered horizontally.

Yes, running a less powerful stage at full throttle IS more efficient than a throttling back.

My point was that getting that angle lower and staying closer to the apoapsis will provide you with better TWR.

Thanks for describing it in more scientifically verifiable terms. 

Also, that assuming all the burn is either vertical or horizontal WAS the fuzzy math I was talking about.  Thanks for point that out.
Additionally, the fact that he just gave his finished formula WITHOUT showing his work.

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