How can I Tell How Much DeltaV I have left?

[Jak]

How can I tell how much DeltaV I have left? You know, that m/s thing? That's DeltaV, right?

[JoeDaTomato]

If you have KER, use the widget.

If you don't have KER:

ISP*9.81*ln(total mass left/mass when all fuel is used) = Delta-V.

After doing that, get KER.

[Toastie Buns]

Press F5
Check speed
Burn prograde until empty
Subtract original speed
Theres your absolute d/v
Press F9
Now start thinking how to use that wisely :D

[JoeDaTomato]

Originally posted by Toastie Buns:

Press F5
Check speed
Burn prograde until empty
Subtract original speed
Theres your absolute d/v
Press F9
Now start thinking how to use that wisely :D

That won't give you your Delta-V. It'll give you a value slightly less or slightly more than your Delta-V.

[maculator]

Well and your DeltaV readout or the one you calculated is something else?
There is steering loss, drag loss and what not else loss....
Just burning for it sounds stupid but will give you a push in the right direction.

[JoeDaTomato]

Originally posted by maculator:

Well and your DeltaV readout or the one you calculated is something else?
There is steering loss, drag loss and what not else loss....
Just burning for it sounds stupid but will give you a push in the right direction.

No drag loss in space (in KSP). No steering loss if you disable gimbal.

[maculator]

SAS and wobble will cost you some. Fact is just burning for it and reloading can be a legit way to see what you got left.

[GeneralVeers]

Originally posted by JoeDaTomato:

Originally posted by Toastie Buns:

Press F5
Check speed
Burn prograde until empty
Subtract original speed
Theres your absolute d/v
Press F9
Now start thinking how to use that wisely :D

That won't give you your Delta-V. It'll give you a value slightly less or slightly more than your Delta-V.

So what?? A "Toastie burn" will show you what amount of delta-V you'll ACTUALLY get. Calculating the amount of delta-V you're "supposed to" have is useless if the actual burn comes out different.

[Toastie Buns]

Originally posted by GeneralVeers:

Originally posted by JoeDaTomato:

That won't give you your Delta-V. It'll give you a value slightly less or slightly more than your Delta-V.

So what?? A "Toastie burn" will show you what amount of delta-V you'll ACTUALLY get. Calculating the amount of delta-V you're "supposed to" have is useless if the actual burn comes out different.

They're envious of my happy go lucky space program.
(thanks for the giggle btw)

[JoeDaTomato]

Originally posted by maculator:

SAS and wobble will cost you some. Fact is just burning for it and reloading can be a legit way to see what you got left.

SAS won't make you lose any. Wobble is negligible on a well-designed craft.

Originally posted by GeneralVeers:

Originally posted by JoeDaTomato:

That won't give you your Delta-V. It'll give you a value slightly less or slightly more than your Delta-V.

So what?? A "Toastie burn" will show you what amount of delta-V you'll ACTUALLY get. Calculating the amount of delta-V you're "supposed to" have is useless if the actual burn comes out different.

It's not just what you're "supposed to" get. It's what you WILL get. It's a mathamatical fact. Using your method, you'll get different values for how much Delta-V you have left at any other body/orbit, and, as I'm sure you know, you can't change how much Delta-V you have just by being in a different place in empty space. If you could, then we'd have to look at and seriously change the principles of physics.

[maculator]

You're defending a unholdable position here...
First you take "no drag losses in space" as your argument and then, when it doesn't suit your cause anymore, you switch to " you'll get different values for how much Delta-V you have left at any other body/orbit"

[JoeDaTomato]

Originally posted by maculator:

You're defending a unholdable position here...
First you take "no drag losses in space" as your argument and then, when it doesn't suit your cause anymore, you switch to " you'll get different values for how much Delta-V you have left at any other body/orbit"

That's because you're not losing it from drag? Drag is an areodynamic (or hydrodynamic, etc) force. You'd get different values based on the the strength of gravity at your current orbit. I can write out the calculus that proves you'd get different values, if you want.

[JoeDaTomato]

Originally posted by JoeDaTomato:

Originally posted by maculator:

You're defending a unholdable position here...
First you take "no drag losses in space" as your argument and then, when it doesn't suit your cause anymore, you switch to " you'll get different values for how much Delta-V you have left at any other body/orbit"

That's because you're not losing it from drag? Drag is an areodynamic (or hydrodynamic, etc) force. You'd get different values based on the the strength of gravity at your current orbit. I can write out the calculus that proves you'd get different values, if you want.

Just to make that clear, I'm saying that both things I said are true. Using the "Toasty Burn" (a term I've come to like), you'll wind up with different values for your remaining Delta-V depending on your current body and current orbit.

I'm also saying that drag doesn't exist in this game in space. There are no particles in space (in KSP) to slow you down.

[maculator]

It will vary, thats what I said, but its a good enough estimate.

[Toastie Buns]

A toastie burn will not not lie to you, nor threaten to stab you.

...Even in an atmosphere.

[JoeDaTomato]

Originally posted by maculator:

It will vary, thats what I said, but its a good enough estimate.

Maybe for most people. I like precise values, though. If it's good enough for you, use it, but I don't want something so... vague.

Originally posted by Toastie Buns:

A toastie burn will not not lie to you, nor threaten to stab you.

...Even in an atmosphere.

If this is a joke, I find it really funny. If not, I'm very confused.