Tweaking Ascension

[lajoswinkler]

I hope some of you will remember @Kragrathea's Planet Factory mod which has been resurrected as Sentar Expansion that still works (yes, I've checked).

Most of its planetary body addons were experiments before Kopernicus existed and are not really interesting, but a handful deserves to be mentioned such as Ablate (the overbaked sungrazer), Ascension (the comet) and Inaccessable (dwarf planet rotating so fast that most of its surface is under upward acceleration, downright goofy and unrealistic but lots of fun).

 

I've been working around Ascension. The idea around it is very good and I agree we need such body in stock solar system. If combined with Outer Planets Mod, you can see its periapsis is inside Moho's orbit, and apoapsis between Sarnus and Urlum.

However, Ascension is too dense and too big for a comet even when translated into regular world's values. It's larger than Gilly which makes no sense. Thus, its surface gravity is 0.66 g which is completely silly for a comet. Comets in KSP should be a lot smaller than Gilly which is a pretty big asteroid (remember, everything is smaller in KSP by an average factor of 10) having a diameter of 26 km.

After tweaking Ascension's CFG file to 0.001 g what seems very realistic (similar to average comets, used for simulations with 67P/Churyumov–Gerasimenko and being convenient for Kerbals), its mass, standard gravitational parameter (GM), escape velocity and sphere of influence have changed, too. However, the radius is still the same as it's independent, so I did some calculations to make it reflect the nature of comets more properly.

 

If we assume Gilly is an asteroid, and that average densities of asteroids and comets are 2 and 0.6 g/cm³, respectively, we could set up this ratio equation.

ρ_Gilly : ρ_asteroid = ρ_Ascension : ρ_comet

13.496328 g/cm³ : 2 = x : 0.6

x ≈ 4 g/cm³

It makes sense for KSP universe, doesn't it?

 

If we plug this value into:

g = 4/3 π G ρ r

while using 0.001 for g, radius of Ascension turns out to be almost 900 m so we can approximate and set its diameter as 1800 m. Seems neat to me.

 

I've yet to try all of these tweaks combined. Honestly, I have no idea what such reduction in size will do to the surface, but Ascension is very spherical so even if it gets all wrinkled, there won't be any harm as comets aren't spherical.

I won't change its orbital parameters as it's unique to Ascension and Kragrathea made it like that. I'm just somewhat annoyed SOI is a constant. In case of highly eccentrical orbits, SOI should differ greatly.

 

Please comment on this, I'd like to know what you think of the tweaks.

Edited February 19, 2017 by lajoswinkler

[lajoswinkler]

Here's what I got. It seems to work.

 

The body is visible in the tracking station and it looks unchanged. I've got a probe going towards it and will report on how that goes. Stay tuned.

[lajoswinkler]

Forked Ascension works like a charm. Mission successful. It looks wonderful.