Atmosphere Decay of "low" orbit vessels - non-focused thrust?

[dorin6565]

I have changed the cfg's of Paul's 64K fork of RSS 6.4x config to use the atmosphere of regular RSS, in others words restored the 130km atmosphere to Kerbin replacing the 91km atmosphere. I wanted a higher (realistic) atmosphere that I could still use stock parts and 64K. Did the same for Eve (venus) and Duna (Mars) giving them the RSS atmospheres.

It got me to thinking about atmospheric drag for vessels like the ISS space station and other sats that decay over time due to drag and have to be re-boosted when in a "low" orbit above the 130km cut-off. It would require flights to deliver fuel or boost tugs to go to them.

I know craft are on rails when not focused in KSP. A tiny drag force couldn't be always applied to simulate atmospheric drag to spiral ships to lower orbits and finally causing them to reenter.

I have been searching forums to see if anyone has been able to apply "thrust" to a ship not under focus to see how they did it. So my question is does anyone know if this has been done?

[hab136]

Orbit Manipulator Series has an atmospheric decay that works on rails; it could be adapted to work above the atmosphere line too.

It also has "Warpable engines" - on-rails thrust!

[dorin6565]

Thank you!!

That is what I am looking for!!

I will see if I can mod it to do what I want.

EDIT: I have changed the mod to give drag outside the edge of the atmosphere up to 3x the top of the atmosphere. Used a scale height extension of pressure/density beyond where HoneyFox stopped (top of the atmosphere) as a first model. Having issues getting the density beyond the top of the atmosphere to align without a step function. Works fine though as it is, will deorbit everything below 210km given long enough.

Will open a thread in add-on development when I get it stable and after asking HoneyFox if they mind if I start a fork of this mod.

Going to use this very interesting article on satellite orbital decay calculations as the basis for the mod in both normal kerbin atmosphere and RSS atmosphere models.

http://www.ips.gov.au/Category/Educational/Space%20Weather/Space%20Weather%20Effects/SatelliteOrbitalDecayCalculations.pdf

Edited January 17, 2015 by dorin6565
added article about satellite orbital decay