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[1.5.1] Realistic Ascension (2018-10-26)

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Ascension is a short period inactive comet with aphelion inside Urlum's (OPM) orbit. Kerbal Astronomical Society thinks landing on it would be a great idea, but certain members fear any thrusters would knock it into Kerbin one day. Despite those fears, majority of Kerbal scientific community doesn't care about it and even looks forward seeing such dreadful development as it would be a valid reason to visit it again and shove it around some more.


This is a modified part of Sentar Expansion mod made by Borisbee, which itself is a modernized Planet Factory by Kragrathea. Both of them did a massive great job.


My longstanding opinion is that KSP should get a body like Ascension (and Ablate, for that matter) for its unique qualities and mission opportunities, but years have passed and no development regarding the solar system was observed. For those reasons I've decided to do make this modification so that a stockalike comet reaches wider audience.


Some crucial parameters of the original comet have been tweaked after calculations and experimenting in order to make it behave more realistically for stock KSP solar system. All the original orbital parameters have been preserved as Kragrathea made them. Only the comet itself has been reduced in size and mass and its surface has been darkened. Sadly, there is no tail because I really don't know how to make one, but if/when circumstances allow it, it will get both coma and a tail full of poisonous goodies, preferably variable in size.


fuel requirements - Missions require loads of Δv and careful planning. This is way worse than trying to catch an asteroid about to hit Kerbin. Speed differences are enormous.

thermal protection - Be careful with timing your mission. If you stay on the comet during perihelion, whatever you landed there might cook.

surface mobility - I recommend Kerbal Attachment System mod to anchor your vessels firmly against the surface. Kerbals should use jetpacks as they can't walk. "Orbital mode" for the view could be used without any issues as "down" is barely applicable here. Rovers can't use wheels, but tiny landers with reaction wheels can happily hop around.

One must observe care when orbiting Ascension or moving on its surface. KSP experiences floating point errors at extreme values, being large or small . For example, gravitational constant gets wonky. Also, Ascension rotates at 66.6% of maximum (superfast rotator) speed, so if a Kerbal jumps from the equator, it's possible there is no coming back if the cliff is high enough. It's entirely safe to jump on poles, but make sure you pack propellant unless your Kerbal doesn't mind spending hours falling back.

Even though surface gravity is enough to keep them on the ground, the floating point problem gets even worse in the case of Kerbals just standing on the equator. They aren't held by the ground properly. That's KSP's problem, not something that I can solve.

home signal - Mind the aphelion distance because even the strongest stock relay antenna will lose signal near comet's aphelion.




  • tiny inactive comet, a crumpled rubble pile
  • problems catching it and staying on it
  • periapsis below Moho and apoapsis above Eeloo (or, if you use Outer Planets Mod, between Sarnus and Urlum)
  • "biomes"
  • gravity so low Gilly feels like your mom



  • coma and tail(s)
  • active surface (gas jets)
  • surface scatter





Recommended mods

- Kerbal Attachment System

- Probes Plus

- Antenna Helper


Download links

https://spacedock.info/mod/1409/Realistic Ascension




  1. if you have "Sentar Expansion" mod installed, delete the Ascension folder from it, for obvious reasons
  2. extract the "Realistic Ascension" folder into your GameData folder like this: Kerbal Space Program\GameData\RealisticAscension
  3. install latest Kopernicus fitted for your version of KSP




Edited by lajoswinkler
verifying v1.5.1 compatibility, texture darkening
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18 minutes ago, Nightside said:

Good job! But what do you mean by inactive comet?

No tail, no coma. One day I'd like to see Scatterer coma+tail around it, but I'm way too dumb to make it happen.

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On 2017-6-9 at 9:22 AM, lajoswinkler said:

No tail, no coma. One day I'd like to see Scatterer coma+tail around it, but I'm way too dumb to make it happen.

I think you need the KopernicusExpansion to make comet tails, but unfortunately it seems that mod has been inactive in development.

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4 hours ago, Z3R0_0NL1N3 said:

I think you need the KopernicusExpansion to make comet tails, but unfortunately it seems that mod has been inactive in development.

I see what you mean.

This is amazing, I had no idea it existed. It's one of the best coma and tail renderings I've ever seen. I'm sure it could be even better with tweaked settings to make it fade around the edges and to make it much larger. Thanks for mentioning this.

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On 11/06/2017 at 7:45 AM, Z3R0_0NL1N3 said:

I think you need the KopernicusExpansion to make comet tails, but unfortunately it seems that mod has been inactive in development.

Not completely inactive:


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I've noticed an issue when I've placed a Kerbal on the equatorial surface. They stand there for some short time and then their floating mode (arms spread, feet angled) turns on, as if gravity is no longer present.

I've never touched the original Kragrathea's kinematic variables so it made me think if the comet is now a superfast rotator which would be unrealistic and therefore against the point of this mod.


If we assume it's spinning at the exact speed where surface gravity on the equator gets to zero, we can set up an equation for this frame of reference:

Fcentrifugal = Fcentripetal = Fg

m ω2 r = m g

ω2 r = g


= √(9.81 x10-3 m s-2 / 1800 m)

= 2.33 x10-3 rad s-1

Then we can get the period of rotation at which this is the case:

ω = /T


= 2691.42 s


Ascension's rotational period is 4040 s which means it's rotating at 66.6 % of its limiting speed at which it would break apart, therefore it's not a superfast rotator but it's somewhat close.

This means the problems encountered are due to game's internal issues with extremely low values and I can't do anything about it.

(If someone thinks the calculation is incorrect, I'd be happy to correct it.)


Funny thing with Kerbals on Ascension is that if they jump while being on the pole, they'll reach an average of 2 km height, compared to Gilly's average of 200 m. However, jumping from the equator is a completely different thing. Jump from a low area and you're in for a half day journey, reaching 16 km. Jump from a very high point and you'll reach some 64 km, with the trip back lasting more than two days.

There are equatorial cliffs that are so high that Kerbal's jump, combined with the angular speed of the cliff, exceeds the second cosmic speed of Ascension and the poor Kerbal never falls back, being left on a hyperbolic trajectory away from the comet. It's up to you to find those spots.

At least the view is amazing, with the comet rotating below.


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On 11/2/2017 at 5:04 PM, Bej Kerman said:

Cool, immediately downloading on CKAN! :D

Edit: The kraken always slings me to space when attempting to land.

It's possible kraken will attack when your terrain rendering is not at maximum settings. I haven't tried it myself (I play on highest settings) but it's a plausible explanation.

Landing on this comet is not really landing. It's more like rendezvous with a specific point on the ground. KAS hooks work wonderfully with this, making Rosetta-style missions doable in a realistic way.


On 11/4/2017 at 8:43 PM, Interplanet Janet said:

Why not add some more comets with this pack? One or two short-period comets could be a nice touch.

There are such mods, although they aren't realistic and add procedurally generated small lumps. This mod just made an existing body appear realistic against stock planetary bodies.

I will consider it in the future, thanks.

Edited by lajoswinkler
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I Think With Work This Might Just Be One Of The Best Mods Out There I Saw You Plan For The Tails And Jets And Thats The Reason.                                                                                                                                 Good Luck With The Development And Keep Up The Good Work

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