Higgs

How do YOU launch?

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Okay, this is for fun to see how we all do things. It is a simple question: Do you just throttle up THEN fire the motors, then, decouple clamps? Do you Fire the motors, throttle up and release clamps all at once? Or do you do some combo other than what I listed?

I myself, tend to slam on the gas, light the candle and blow my clamps lose in ONE step. Im like Jeb, impatient XD. Now, how do YOU do it?

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For most craft:

0) Press Z (or previously hold down shift until 100% throttle is reached)

1) Press space to fire engines (and launch clamps if relevant)

If you're not spending most of your ascent at full throttle, you either have too much engine, or are doing something silly.

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I press space.

On serious side, clamps in same stage as engines. Full throttle, go.

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1) throttle up

2) press space

3a) Watch the rocket drop onto the pad as the clamps release but no engines fire because the editor gave the clamps an exclusive first stage. Revert to assembly to fix

3b) alternatively stage 1 fired but clamps were spread across 3 other stages by the editor and the torque of only half releasing just ripped the rocket apart, revert to assembly

4) Ship explodes on the launchpad as soon as physics kicks in. revert once agian.

5) Ship loads fine but Jeb snuck into the pod agian. Send it back to the VAB to pry him out of the seat.

6) Jeb is safely tied up in the lounge.... BOOM! sigh stupid physics.

7) Right pilot? check? No boom? check. Staging good? check. Liftoff and its a smooth ride to orbit.

Prety much I fire engiens and detach clamps at the same time. If that does not happen something probably went wrong. Normaly have enough TWR on that first stage that even at half throttle it will still hover or drop slow enough I can throttle up if I forgot. I might throttle back once up to speed till the solids burn out depending on design but liquids normaly can go full out all the way up.

Edited by merendel

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Revert to assembly to fix

In case you weren't aware, you can actually edit the staging while in-flight. No need to revert to the editor! :)

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If you're not spending most of your ascent at full throttle, you either have too much engine, or are doing something silly.

Only with multiple stages. With a single-stage rocket design, it's not that simple. You need max throttle to get up to terminal velocity as fast as possible, but then you want to steadily tweak the throttle downward to follow the optimal ascent curve (see the wiki) as you expend fuel. Once you get to about 15000m, it's back to max again as air resistance drops off quickly. If you were to reduce the engine power to decrease the amount of time you're reducing throttle in the middle period, you'll have a harder time getting up to speed at the start, wasting even more mass from the extra fuel.

(With a spaceplane it's a lot easier to keep throttle at 100% the whole way, since you can easily adjust your ascent angle to compensate for these differences.)

As to the original question, it's generally a single keypress as 1.25m and 2.5m engines throttle up rapidly enough that you can trigger them at the same time you release the clamps without risking a damaging collision with the ground. If you're using larger rockets (3.75m or higher) that won't work any more; you have to activate them, wait for them to build thrust, and THEN release clamps. A really huge rocket can't even sit on landing struts on the launch pad without breaking it, making this even more important now that they've added repair costs to career mode.

Regardless of size, you should be setting throttle to 100% before launch unless you're using solid boosters for an initial kick, or a really complex asparagus setup.

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In case you weren't aware, you can actually edit the staging while in-flight. No need to revert to the editor! :)

ya but normaly something just broke badly when a stageing misshap involving the launch clamps happens. Might as well go back and fix it on the save'd ship while I'm thinking about it or it will just happen agian if I ever send up another copy of that ship. That and the post was ment to be humorous :P

Edited by merendel

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Only with multiple stages. With a single-stage rocket design, it's not that simple. You need max throttle to get up to terminal velocity as fast as possible, but then you want to steadily tweak the throttle downward to follow the optimal ascent curve (see the wiki) as you expend fuel. Once you get to about 15000m, it's back to max again as air resistance drops off quickly. If you were to reduce the engine power to decrease the amount of time you're reducing throttle in the middle period, you'll have a harder time getting up to speed at the start, wasting even more mass from the extra fuel.

I still stand by my argument with SSTOs in the lower end of on-pad TWR (<1.5), and that anything with a TWR above 2 on the pad is under-burdened. Sure, you can spend less ÃŽâ€V to get to orbit, but in my experience, the large mass of the engine gives you a lower overall payload fraction. (Less true with the changes in 0.23.5 and 0.24, but still...)

edit: I also used a weasel word ("most"), so I can justify brief throttling down for something in the 1.5-2.0 on-pad TWR range. >_>

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In case of stock:

Press Z

Press Spacebar, it detaches both clamps, and ignites all first stage engines

bam.

In case of KW

Z,

Spacebar, activate liquid engines (particuarily the 5M ones, they take a few seconds to spool and sound awesome), I use FASA so it decouples a few clamps

Spacebar again, activate any boosters, release all clamps and liftoff!

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Sure, you can spend less ÃŽâ€V to get to orbit, but in my experience, the large mass of the engine gives you a lower overall payload fraction.

Obviously an SSTO rocket will have a lower payload fraction than a multi-stage setup, but even if you're only talking SSTOs then engine mass is hardly a significant impediment when you're building boosters massing 10,000 tons or more, given the sheer mass of fuel involved. Large SSTO rockets are superior to multiple stages for many reasons: easier to make fully recoverable, less risk of catastrophes (since you're not separating stages mid-flight), lower part counts, no debris, and better geometry for attachment of awkward payloads (like a space station). Unfortunately, that means you can't tweak the ascent in the design stage to mostly remove the need for throttle control, like you can for multi-stage setups.

And really, the delta-V is the entire point of the whole exercise, so you can't discount it like that. The logarithmic nature of the rocket equation means there's a HUGE difference in mass between a rocket that reaches a circular orbit on an optimal profile versus one that uses a less efficient ascent. If you're not adjusting your throttle for an ideal ascent, then you're forcing yourself to build rockets much bigger than they need to be to make up the difference, and that'll kill your payload fraction more than anything else. It's hardly a coincidence that the ISPs of the larger stock rockets in the game give them just about enough delta-V to reach a decent orbit in a single stage...

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Two ways, throttle up, press space this is also done for spaceplanes, optional set up mechjeb and press space.

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All launch clamps and first stage engines set to a single stage. I use the instant power response configs for KW because MechJeb doesn't like managing the throttle if engines have a spool up / spool down constant.

I use MechJeb for everything except docking, because it's better than me at everything except docking. More precise, more accurate, and it uses more efficient trajectories than I would. It uses more monopropellant than I do when docking, so I still handle that part myself. It's not a big deal, I had plenty of docking practice in Orbiter before KSP even had docking ports, so docking is easy for me.

I still make sure I can fly without it every time a new version of KSP comes out, and I'm ready to override it if it has problems.

Edited by SciMan

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Oh, I guess I'll be the one to admit to the ultimate in lazyness... I just let MJ do it. Bring up the ascent autopilot, enter desired altitude and engage autopilot. I do my own staging however, that got to be good for something - right? Right?

With spaceplanes it's all manual however. Mainly because MJ is a lousy spaceplane pilot. Engage brakes, get SAS going, start jets at 50%, wait a bit for them to spool up and then release brakes. Then go 100% thrust. Get to about 20km pretty fast at 30-40 degree climb, then build speed at 5-10 degrees or less until jets are about to flame out or I reach 30km with plenty of speed. Engage rocket or switch mode on Rapier, nose up and reach orbit altitude and circularize.

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SRBs only, fire engines and clamps at once. For turbojets and larger KW rockets, fire engines, let power up, release clamps.

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I actually have some sort of prelaunch procedure, especially for large rockets and important/expensive payloads.

1. If multiple probe parts exist, select the one pointing straight up and "Control from here"

2. Disable or Enable Torque on Payload SAS units, as required

3. Check staging from the bottom to the top

4. Prepare MechJeb Windows: Orbit info, Delta-V Info (for staging times) and something with "atmospheric drag"

5. Check that my joystick is functional

6. Turn on SAS, Full throttle

7. LAUNCH! With releasing launch clamps and engaging boosters all at once.

Edited by Kobymaru

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Depends if i have a replica of a real rocket with it's launch pad or not :P

For soyuz style, i release the stock clamps + decouple the launch arms (which 'holds' the whole counterweight system for physics load), so the rocket 'holds' herself. then, from throttle at zero, stage the engines and increase throttle (which makes a nice cinematic launch as the rocket's boosters weight leaves the arms, which are pulled away by their counterweights)

For ariane V style, i first start the main engine (and throttle up to full thrust), then activate the SRBs and release the clamps

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Depends on how much I'm throwing out of the atmosphere. Generally though initial staging looks like the following:

0: throttle up to 1.1 - 1.3 TWR

1: Fire liquid fuel engine(s)

2: SRBs and/or clamps.

3: Adjust throttle as neccessary to avoid a stupidly high/dangerous maxQ.

4: Realise that the rocket isn't rolling for orbit, cry as the AP of the trajectory climbs higher and higher.

5: Revert to VAB \o/

Edited by Crashy_McSplodey

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I press space, go up about 20 meters, explode....

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With FAR

1: Throttle up to max

2: Spacebar for engine ignition and launch clamp release

3: Roll program if necessary

4. Pitching slowly over, throttling down to keep thrust from going too high

5. After booster seperation, throttle back to maximum and continue climb into orbit

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Engine ignition and launch clamps go in different stages. Ignition usually at 50% throttle, then throttle up to 100%, followed by release of the clamps.

Gravity turn starts when velocity exceeds 100 m/s with a 2 degree pitch. Then i slowly pitch the rocket further over, reaching a 45 degree ascend angle at around 10.000m of altitude. The rocket continues at 45 degrees until the apoapsis is about 40 seconds in front. By pitching the rocket further towards the horizon and starting to throttle down i keep that 40 second distance as long as possible. When passing an apoapsis of about 60 km, the periapsis starts to rise above zero.

Usually this gives you a perfect circular 85 km orbit (or higher if desired) without the need of cutting engines. As you gain horizontal velocity early with the constant thrust preventing the rocket to loose speed to gravity and drag, this way of launching seems to be very efficient.

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Select the right probe core if applicable. When I have a flexible payload I often put a probe on the launcher itself, it helps the control.

Set appropriate throttle. Usually full, the most obvious exception being rockets that use SRBs and liquid engines to launch.

EVA any unwanted Kerbals that have snuck in. Walk the little blighters to a hopefully safe spot.

Space ignites engines and releases launch clamps if applicable. We have liftoff.

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I use a Fueled Launch Clamp on most of my launches. It's a FL-T800, fuel line, probe core, and lights, all attached to a standard launch clamp and saved as a subassembly. So before launch my craft can sit on the pad all pretty and illuminated until its launch window.

Then for the actual launch procedure:

1. Cut throttle.

2. Engage SAS.

3. Ignite stage 1 liquid fuel engines.

4. Gradually over about 5 seconds raise throttle to 100%.

5. Ignite any SRBs, disengage launch clamps.

6. Once clear of pad and stably ascending, engage MJ ascent autopilot, if applicable.

So yeah, a little wasteful, but I like the somewhat real-world feel of it. If anything's wrong with the staging or something snaps off, I can abort the launch right up until the SRBs are lit.

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