Recent content by Ed

A lot of astronautics engineers started out with aeronautics. I started out with physics. A friend of mine is a nuclear engineer, who originally did maths. My advice would be to study the one that engages you the most - not what you suspect will pay you more in 20 years time.

If you'd like a formula in Microsoft Excel to this for you... =IF(A1<=6000,0,IF(A1<=25000,(A1-6000)*0.15,IF(A1<=75000,3750+(A1-25000)*0.3,IF(A1<=150000,18750+(A1-75000)*0.4,48750+(A1-150000)*0.45)))) where A1 is the cell which contains the Net salarý.

Hi folks, I have a little problem which seems to be melting my brain. I have a (software) model which I wish to rotate based on the topography of the ground. I'm using two angles to represent the terrain - a "North" and "East" elevation (hopefully that's self explanatory). Once I have the...

You're quite right, by assuming it's on an axis it makes it possible to reduce the problem to a couple of 2D basic trig problems. Thanks for the reply.

presumably because there's a higher density there - perhaps due to a large quantity of heavy metals.

Hi folks, I'm hoping for a little help with something which I'm sure should be pretty easy... but I don't have access to any kind of maths textbooks to look anything up, sadly, so I'm hoping you guys might help? Let's consider a point P on the surface of a sphere, and define Vo as the unit...

For the satellite, this gives: xsat = r.cos(n+Wsat.cos i).cos(Wsat.sin i) ysat = r.sin(n+Wsat.cos i).cos(Wsat.sin i) zsat = r.sin(Wsat.sin i) which seems to make sense - if you consider the simplified cases when i=0 or 90° if i=0 xsat = r.cos(n+Wsat) ysat = r.sin(n+Wsat) zsat = 0...

I'm calculating a,d for the perigee, which isn't time dependent. I realized this after a little while. Hence my edit of the post to add theta later on... it was still a work-in-progress when I initially posted, sorry. That'll teach me not to check stuff. I was staring blankly at my diagram...

OK, thanks again, I'm getting there slowly one step at a time! I'd find this impossible without your help to be sure. just a quick confirmation of my maths really.. please let me know if I've gone wrong.. I have the orbit in terms of the arguments of ascending node and perigee (n and w)which...

Hi folks, thanks for those replies, that's very useful. Any ideas to the original problem? I'm currently working with assuming I have a fully defined elliptical orbit about a central body with a groundstation at a given lat & long. At a given time, I can calculate the eccentric anomaly, and...

On a (related) side note, if I have x - A sin(x) = B where A, B are known constants, how do I solve for x?

Hi folks, If I have the elements of a spacecraft 's (eliptical) orbit (a,e,i,etc) and the lat/long of a ground station, how can I calculate the times at which the spacecraft will be visibile from the groundstation (preferably in terms of time since perifocal passage)? I've been googling for...