Is it ever desirable to start a mission with engines at half throttle?

[nigelvn]

Mostly I leave it on half power als my boosters can carry the craft, only when I dump the boosters I use z to max out.

[Admac]

There is no risk or aerodynamic weirdness before about 200m/s, so I always sprint to get to that speed then control throttle to keep me at 14-22 M/S^2 depending on how aerodynamic my rocket is that launch. so starting with anything less than 100% seems like a bit of a waste in every situation. For rockets at least, planes make some sense I suppose.

[worir4]

More TWR than is needed.

This is not possible.

NEVER ENOUGH BOOOSTERS!!!!

[Aragosnat]

Are there really people who play a game without browsing thorough the controls page?

Shockingly enough. People don't read such as most games hold their hands telling them what keys to press and when. Kind of like why no one reads the game manuels anymore. Outside of it is a pain to find them when they do have them.

But, to the OP's question. Depends on the craft and the mode you are in. In career with the 30 part limit. I found I had to use more powerful SRB's set to a reduced thrust just to increase the part count so I could it places like Mün and Minmus. Otherwise I would be building fat craft that would need 100% just for lift off.

[Luckless]

I'll often use a ring of SRBs and a central gimballed liquid engine that is throttled way back as my first stage, then drop the spent SRBs and power the main engine up in the second stage. I just want the liquid engine to vector thrust a little and help keep everything in line rather than using fins and increase drag, but let the SRBs carry the bulk of the weight off the pad.

I've also had a few landers that come down full thrust, leave the bulk of the mass as a ground station, and only need partial throttle on takeoff.

The default position doesn't really bother me, as I always (try to) check that stuff before launch anyway.

The game really needs in-game checklists.

[FlowerChild]

IMO, the 50% thing is just a faulty solution to a game design problem that further obfuscates what's going wrong:

Zero throttle, new players quickly learn they need to throttle up or their engines don't work. Experienced players quickly identify what they did wrong when they occasionally forget, and it winds up feeling like the player made the mistake, not Squad. It's a clearly identifiable problem for which an in-game solution is provided.

50% throttle delays new players learning that they need to throttle up and causes their otherwise valid designs to underperform or crash back into the launchpad. Meanwhile, flames are shooting out of their engines, indicating that they are indeed working, and thus that must not be the source of the problem (which it actually is). Experienced players may not identify if they have forgotten until mid-flight, usually resulting in a revert, largely wasted time, and a bit of swearing at Squad.

100% throttle, I doubt this thread would even exist or anyone would be complaining. The odd fringe design where it's not appropriate, players would likely know to throttle down before launch, and if they didn't, would receive ample feedback to know what went wrong (like stuff exploding).

IMO, the worst case of those three was selected for some strange reason, like some kind of mathematical compromise that doesn't actually make any sense in practice was chosen. I guess 25% would be even worse, but not much else would be

Edited May 7, 2015 by FlowerChild

[tntristan12]

I vote they set the default to 42%, because at least that would solve everything!

[SaturnV]

Squad should add a new overlay shows basic controlls on screen, just like that in space engineer. The last tip is “You can turn this off in the option menu“

Throttle problem solved, newbie knows something called “options“

Win win.

[Red Iron Crown]

0% or 100% would be better IMO but it is a very small thing, especially now that the z key snaps the throttle to 100%. T, Z, Space for almost every launch.

Regarding the OP's question: About the only situation that I can think of in which 50% might be desirable is a liquid fueled core stage assisted by SRBs for the initial ascent, it might be preferable to have the LFO engine at part throttle when the SRBs are at their lowest TWR, easing it back as the solids burn through their fuel, then back to 100% once they are staged away. That's a really edge case, though.

[Varsi]

In real life the Delta IV heavy core goes to partial thrust mode soon after lift off, and then ramps up to full again at booster sep. It also looks like it's made by Rockomax.

First time I made a rocket with orange tanks with mainsails as core and boosters I had to next go and check what Delta IV Heavy looked like...

I've been wondering about the 50% thing too. Usually my rockets will explode a lot faster at 50% than at 100%. Needless to say 0% would be even faster way to get fireworks.

[Zamolxes77]

Wow, I guess just me and another guy that posted earlier (sorry if I missed your name) are really fans of checklists.

Mine isn't as involved as his, but generally I turn on the resource button, check the missions ones, move Engineer window so it doesn't obstruct anything, check staging, turn on SAS and lately RCS (found it it helps a lot with stability at low speeds off the pad), press Z to max throttle then launch.

If my mission is somewhat different, like testing a component, or survey something on Kerbin, anything else than a launch to orbit, then I press M, target the objective, or check the direction and identify which way I have to turn towards it (sometimes they are hidden on NavBall even when targeted)

Also I like to do flights just to test the design. I rectify many, many flaws before my design actually gets to fly in a mission.

Does it fly right? Does it turn? Can it survive the heat? How about a hard landing? Water and land? Does it wobble? Is it difficult to steer? Loses charge or monoprop too fast? Is it stable at low speeds? How about high speeds?

I like to fly easy, maneuverable crafts, that sometimes leads to over-engineering, but I have ... never ... lost ... a single craft due to design failure. Plenty of test crashes though. I might crash a design 10-20 times before it gets to fly a mission.

One of my latest designs, a first flyby mission to Minmus, with 2 passengers, didn't test it enough, I put monoprop tanks on it ... but forgot the RCS jets lol, so I just went to Minmus and back with nearly half a ton of useless cargo.

Anyway, to answer to OP: I only use full throttle off the pad. As soon as my craft reaches 600 m/s, I start to throttle back, once you jump to orbital speed(25 km?), its a game, chasing the apoapsis. My procedure involves playing with the throttle, to maintain a 10-20 second time to apoapsis. It almost never goes to zero throttle during that process, always maintaining a speed increase at lowest setting possible to save fuel and only goes to max in an emergency.

The only situation I can think of, that would require such use, is if you use a very light craft with a very powerful engine and questionable aerodynamic control, like a test bed for engines/chutes: those are almost always launched at 50%.

Edited May 8, 2015 by Zamolxes77

[MalfunctionM1Ke]

Throttle should always be 100% when you go to launch.

Also the Navball should always be visible when you enter Mapview.

Two simple tweaks, that would make life a little easier

[adinfinitum]

I really don't get how you could forget to throttle up to 100% at the beginning of launch. Launch sequence is almost always CAPSLOCK, T, Z, and then space.

Also the Navball should always be visible when you enter Mapview.

And definitely seconding this, idk why the navball is closed by default in map view.

[Raptor98k]

I think having the throttle at 0% by default is a bit more intuitive than the current, random 50%. I never saw a good reason for them to make that change, but when they did I assumed it was to shorten the amount of time you had to hold Shift to get to 100% (as the Z key hadn't been implemented yet). While I consider it to mostly be a general annoyance (though not as annoying as not having a navball in map view, or having crew assignment in the VAB rather than just before launch), I did have a few mishaps in 0.90 while playing around with RemoteTech and kOS.

For fun, I wrote some kOS scripts to put a rocket into orbit, reenter and land, and a third to tie those together for a fully autonomous flight. At the end on my launch script, it sets the throttle to 0%, then unlocks the throttle so it is under user control again. Problem is, when the throttle is unlocked, it reverts back to the position it was in before the script was initialized. If I forgot to hit X before starting the script, the engine would start again, and rocket would spin out of control as I was out of range of any comms satellites.

I think the throttle should default to 0% which an option to change it.

[Dunbaratu]

For fun, I wrote some kOS scripts to put a rocket into orbit, reenter and land, and a third to tie those together for a fully autonomous flight. At the end on my launch script, it sets the throttle to 0%, then unlocks the throttle so it is under user control again. Problem is, when the throttle is unlocked, it reverts back to the position it was in before the script was initialized.

Yes. This.

We on the kOS dev team *HATED* this change when it first came out. The design of kOS was not to hardcode the value of the throttle to zero when you exit the program, but rather to return you to the state it was in when you first started the program - that way you can turn an autopilot on and off while flying a plane and not have the plane's engines cut out when you kill the autopilot. But this stupid change really broke people's scripts (you have a perfect launching script - get it to a nice circular orbit, and then the script ends and your engines fire up to 50% again and distort your orbit right away because that's the silly default the game chose for them on the launchpad before you ran the auto-loaded booted launch script. We had to give them the ability to query and set the initial throttle, or the "exit" throttle that it will return to when you quit.)

And you can't actually change it. If you put a vessel on the launchpad, hit 'x' to kill throttle, then leave the launchpad and come back (or save the game and come back later), the act of coming back to the launchpad again resets the throttle to 50%. The game sets the throttle to 50% every time you enter the "launchpad" scene again, clobbering whatever value it had been saved as before for that vessel.

There is no reason at all for defaulting it to 50%. None. I have no idea why Squad did it.

Hey Squad, I strongly suspect there are zero, (count them, zero) players who find the the 50% throttle feature superior. Can't you please just fix that? Nobody wanted it. Everyone hates it.

[Guest]

http://forum.kerbalspaceprogram.com/threads/114527-Revert-default-throttle-to-0

I wonder, why current thread looks so familiar.

[Grumman]

I start my launches at 0% - when the SRBs separate from the rocket, I give them a second to get clear at a less destructive relative velocity before starting up the main engines, just in case there's a collision.

[Tex_NL]

...

Also the Navball should always be visible when you enter Mapview.

...

And that too has been modded: http://forum.kerbalspaceprogram.com/threads/80683-0-23-5-MapShowNavBall-show-navball-by-default

It's made for 0.23.5 but still works perfect in 1.0.X

[Friend Bear]

To answer the primary question:

Press "z" - it will throw you to max throttle.

To answer the caption:

You want to just pay attention to your thrust TWR (get engineer redux to help). The higher the TWR, the faster the acceleration, realistically.

If you have a high output for your weight, you won't need so much initial thrust. But there is a balance you have to find.

Too much thrust with all that aero resistance is an overburn and you needlessly lose Deltav.

Too little thrust forces you to use more fuel over a longer period, because your speed is not as high as it should be to get you out of the atmosphere sooner so there is little to no resistence when you decide to burn a little hotter.

So really...it depends on the rocket.

---

This is why solid fuel boosters are so worth it.. They get you to a faster speed sooner so you can later sustain that speed with the liquid fuel, all at little cost (since solid fuel is so cheap)

Edited May 9, 2015 by Friend Bear