Can you orbit an asteroid?

[StupidAndy]

so i have a mission to an asteroid, currently very VERY fast, and i want to ask, can KSP simulate you orbiting an asteroid, or is the game simply not detailed enough to simulate that, because that would be a cool mission, you could do stuff like Rosseta and Osiris REx!

[Snark]

30 minutes ago, StupidAndy said:

can KSP simulate you orbiting an asteroid

Nope.

Asteroids in KSP aren't celestial bodies; they have no gravity, you can't orbit them.

(Which is kind of a pity, given that the Project Scientist for OSIRIS-REx is a KSP forum member...)

The closest thing to having an asteroid-orbiting experience in KSP is to go to Gilly.

[NSEP]

You cant, but i wish you could. It would be great for some space missions for that extra science.

[Gianni1122]

Is there a mod that allows it? If not, you could suggest it in the add-on thread. That might actually be one a mod author would be interested in.

[Corw]

11 minutes ago, Gianni1122 said:

Is there a mod that allows it? If not, you could suggest it in the add-on thread. That might actually be one a mod author would be interested in.

I'm not sure, but I think gravity on asteroid would be too low for anything meaningful.

[Matuchkin]

Can't you just enter into a close quasi-orbit and call it a day?

[MitchS]

I once saw an example about Hill Spheres (SOIs, to the KSPer) in an astro textbook that said something like, "If you brought a basketball-sized sphere of heavy metal with you into space, you could easily toss grains of rice into orbit around it.

I've been fascinated with that idea ever since. You can orbit around anything as long as its hill sphere is larger than the space it occupies.

I really, REALLY want to put a little science probe into a 0.1m/s orbit around an asteroid on KSP.

Edited December 20, 2016 by MitchS

[Guest]

5 hours ago, Gianni1122 said:

Is there a mod that allows it? If not, you could suggest it in the add-on thread. That might actually be one a mod author would be interested in.

Possibly this, but asteroids are coded as ship parts so even with this mod I'm not sure they can have gravity applied to them. Feel free to ask in the thread though.

 

Edited December 20, 2016 by Guest

[StupidAndy]

well one thing you could do is have it have such a low relative velocity that it just seems like your orbiting it...tidally locked...

[MarvinKitFox]

On 2016/12/20 at 3:51 PM, Corw said:

I'm not sure, but I think gravity on asteroid would be too low for anything meaningful.

Assuming KSP implemented gravity around asteroids...

If you locate the largest possible asteroid (3828 tons), and enter a 1km orbit around it, your orbital period will be 3450 hours..

Around a normal class-A asteroid of about 6 tons, this orbit would take 90 000 hours.

 

This is a teensy bit....impractical.

 

 

 

p.s. orbital velocity around that class-a is 0.02 millimetres per second.

 

Edited December 23, 2016 by MarvinKitFox

[Ultimate Steve]

4 minutes ago, MarvinKitFox said:

Assuming KSP implemented gravity around asteroids...

If you locate the largest possible asteroid (3828 tons), and enter a 1km orbit around it, your orbital period will be 3450 hours..

Around a normal class-A asteroid of about 6 tons, this orbit would take 90 000 hours.

 

This is a teensy bit....impractical.

Also, don't forget that unless you're really far out from the sun, their SOI's probably won't be that big. Some probably have SOI's smaller than the actual asteroid.

[Sharpy]

On 20.12.2016 at 7:39 PM, MitchS said:

I once saw an example about Hill Spheres (SOIs, to the KSPer) in an astro textbook that said something like, "If you brought a basketball-sized sphere of heavy metal with you into space, you could easily toss grains of rice into orbit around it.

I've been fascinated with that idea ever since. You can orbit around anything as long as its hill sphere is larger than the space it occupies.

I really, REALLY want to put a little science probe into a 0.1m/s orbit around an asteroid on KSP.

You can bring anything into something that appears exactly like orbit around the asteroid though.

Have the asteroid in an orbit that is near-circle, with, say, 200m difference between periapsis and apoapsis. Write down the orbital period (read it using KER).

When the asteroid is about to reach its apoapsis, place your 'orbiter' "below" the asteroid (between the planet and the asteroid), 200m from the asteroid. Perform a maneuver that puts your new periapsis there, and apoapsis about 200m above the asteroid's periapsis. Perform minuscule corrections to get your orbital period match that of the asteroid to within a second.

There. You're in 200m orbit around the asteroid; your orbital period around the asteroid is the same as the period around the planet.

It's not real orbit around the asteroid - it's not caused by its gravity. But the eccentricity of your two orbits is such, that the two objects move in a circular trajectory relative to each other - from the craft, or from the asteroid, it looks exactly like orbiting.

You may try other orientations, like shifting Pe/Ap relative to each other, or starting at an angle and not directly below, or making the whole thing asymmetric, for different "orbits" - what matters is to retain *some* eccentricity of at least one body in the vertical plane (if you start just "sideways" you'll bump into the asteroid, and if you start "behind" you'll just keep the distance) and to keep the orbital period matching very precisely.