OpenRocket sims- on Mars?

[kjohnson]

I had a brief discussion with a friend of mine who wondered how she could simulate a rocket launched on Mars. Are there any changes that could be made in parameters to try this out, or would it need a fork to update constants in use by the program?

thanks,
kj

 

[Aeva]

You will probably have to modify all of the instances referring to the Earth's gravity, and the atmospheric density calculations. My intuition is that the gradient of density in Mars' atmosphere doesn't follow the same trend as Earth's given it has a different atmospheric composition. Temperature and dryness might factor in, but you can set the humidity to nothing and temperature based off known data using the gui.

I would also guess you would need to increase the stability margin if you're depending on fins to keep it upright/balancing CD+CG. IE, larger fins, longer rocket, or weighted nose. I know open rocket allows you to set the air pressure at launch, but I don't know if that's used in the CD calculations... so bear that in mind.

 

[NTP2]

My intuition is that the gradient of density in Mars' atmosphere doesn't follow the same trend as Earth's

On the large scale your right it’s a much thinner atmosphere and it lacks a ozone layer or anything like that but on the scale of a model rocket it’ll be fine as long as the pressure is correct.

Ps also @neil_w