General Question what is the acceleration units for hover thrusters??

[mathyou9]

The 2009 Orbiter manual states that the acceleration unit for the hover thrusters is m/s^2. This is obviously the case for Orbiter 2006 (i.e., when I hover at a held altitude on the Moon using Orbiter 2006, the hover thrusters fluctuate between "1.6" and "1.7" matching the force of the Moon's gravity in m/s^2.) But not for Orbiter 2009. When using Orbiter 2009, the unit is indicated as "k." And so when I'm hovering on the Moon, it shows to fluctuate anywhere between "39k" and "40k" (give or take a few tenths.)

I'm new to all this; I don't have a clue what acceleration unit is "k." Thanks.

 

[Lucy]

You can get the same value in m/s^2 from the "Surface" MFD, if I remember rightly.
I can't remember exactly what it is Orbiter 2009/2010 measures engine output in but it's closer to dV IIRC.

 

[EtherDragon]

In new orbiter, all acceleration readouts are in Newtons.

 

[the.punk]

The k could be for kilo( thousand). So 39000N

 

[Hielor]

In new orbiter, all acceleration readouts are in Newtons.

...

Really?

Newtons measure force, not acceleration...I can see that being useful for engine readouts, but m/s^2 is a whole lot more usable...

 

[Enjo]

precisely what was acceleration is now thrust and that's it.

But yeah. I also liked acceleration more, because it's a ship-neutral value.

 

[EtherDragon]

precisely what was acceleration is now thrust and that's it.

But yeah. I also liked acceleration more, because it's a ship-neutral value.

I agree, I could quickly relate the fact that a 1.5m/s/s readout meant that I was thrusting at roughly 0.15g.

Oh well, guess we'll just have to know our ship specs a little better to do some estimations in our head.

 

[Hielor]

I don't understand the reason for this change. Thrust seems like it has value only in the context of an engine simulation (ie, "is the engine developing as much thrust as I expect?") which Orbiter doesn't really have.

Now, if I want to do some napkin calculations of what I should be burning at in order to arrive at 0 velocity in a given amount of time, I need to take into account the mass of the vessel and fuel (which isn't shown anywhere easily accessible, I believe), whereas previously, if my velocity was currently 500m/s and I want to stop in 100s, I just apply 5m/s^2 of engine power.

 

[EtherDragon]

I agree - the napkin math is much harder to do now because we don't have that information at our finger-tips.

But there are tons of MFDs that do deliver that info pretty nicely.